The excisable trait of the LAC12 marker allows the introduction of many different heterologous genes, and makes it possible to introduce a complete heterologous metabolic pathway.
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Heterologous expression refers to the expression of a gene or part of a gene in a host organism, which does not naturally have this gene or gene fragment. Insertion of the gene in the heterologous host is performed by recombinant DNA technology. After being inserted in the host, the gene may be integrated into the host DNA, causing permanent expression, or not integrated, causing transient expression. Heterologous expression can be done in many type of host organisms.
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Industrially- focused engineering efforts are centered on improving MIOX activity in order to produce glucaric acid in heterologous hosts.
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Extracting stem cells from amniotic fluid is possible for both autologous and heterologous uses at the time of childbirth.
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Microbial heterologous expression of key tobacco enzymatic genes may be used to identify their function and to generate solanesol derivatives of medicinal value.
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E. coli, yeast (S. cerevisiae, P. pastoris), immortalized mammalian cells, and amphibian oocytes (i.e. unfertilized eggs) are commonly for studies that require heterologous expression.
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Endogenous antigens include xenogenic (heterologous), autologous and idiotypic or allogenic (homologous) antigens. Sometimes antigens are part of the host itself in an autoimmune disease.
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Some of these helices have been shown to mediate the encapsulation of native enzymes into BMCs, as well as heterologous proteins (such as GFP).
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Strains of S. coelicolor produce various antibiotics, including actinorhodin, methylenomycin, undecylprodigiosin, and perimycin. Certain strains of S. coelicolor can be used for heterologous protein expression.
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It is well known from animal studies that infections, apart from inducing pathogen-specific T-cells, also induce cross-reactive T-cells through epitope sharing, so-called heterologous immunity. Heterologous T-cell immunity can lead to improved clearance of a subsequent cross-reactive challenge, but it may also lead to increased morbidity. This mechanism may explain why DTP could have negative effects. It would, however, not explain effects occurring shortly after vaccination, as for instance the rapidly occurring beneficial effects of BCG vaccine, as the heterologous effect would only be expected to be present after some weeks, as the adaptive immune response need time to develop.
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Podduturi, V., & Pinto, K. R. (2016, January). Mullerian adenosarcoma of the cervix with heterologous elements and sarcomatous overgrowth. In Baylor University Medical Center Proceedings (Vol. 29, No. 1, pp. 65-67).
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The conversion of myo-inositol to glucaric acid--a top value-added chemical from biomass--can be achieved with a combination of MIOX and UDH enabling heterologous production of glucaric acid.
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The formation of simple alpha-carboxysomes in heterologous systems has been shown to require just Rubisco large and small subunits, the internal anchoring protein CsoS2 and the major shell protein CsoS1A.
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Kv3.2 currents in heterologous systems are highly sensitive to external tetraethylammonium (TEA) or 4-aminopyridine (4-AP) (IC50 values are 0.1 mM for both of the drugs). This can be useful in identifying native channels.
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An example of a bacterial expression vector is the pGEX-3x plasmid The expression host of choice for the expression of many proteins is Escherichia coli as the production of heterologous protein in E. coli is relatively simple and convenient, as well as being rapid and cheap. A large number of E. coli expression plasmids are also available for a wide variety of needs. Other bacteria used for protein production include Bacillus subtilis. Most heterologous proteins are expressed in the cytoplasm of E. coli.
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Using this heterologous prime-boost dosing regimen, the immune system becomes focused on inducing PSA-specific T cell responses, designed to kill tumor cells expressing PSA. There is some evidence that Prostvac is more effective with blood types B and C.
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The complete fosfomycin biosynthetic gene cluster from Streptomyces fradiae has been cloned and sequenced and the heterologous production of fosfomycin in S. lividans has been achieved by Ryan Woodyer of the Huimin Zhao and Wilfred van der Donk research groups.
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The combined resistance to novobiocin and oxacillin is hypothesized to have originated from a simultaneous introduction of genes controlling the resistance to the two. These genes were believed to have been acquired originally through heterologous DNA from a methicillin-resistant strain of one of the novobiocin-resistant species belonging to the S. sciuri or the S. saprophyticus groups. The larger genome size of the SHN compared to that of S. hominis hominis may be the result of the acquiring of heterologous DNA. This new, divergent strain was first described in 1998, and was first implicated in causing bacteremia in 2002.
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Streptomyces coelicolor, Streptomyces avermitilis, Streptomyces griseus, and Saccharopolyspora erythraea, are capable of secondary metabolite production. Streptomyces coelicolor has shown useful for the heterologous expression of proteins. Methods like "ribosome engineering" have been used to achieve 180-fold higher yields with S. coelicolor.
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Vaccines containing trophozoites inactivated with formalin and prepared in oil adjuvants have been developed and have shown good protection against the homologous serotype. Several P. dicentrarchi serotypes have been described. However, the protection induced against heterologous isolates appears to be very low or non-existent.
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Another method of heterologous protein fusion is fusion with fimbriae/flagella, which are filamentous protrusions on the cell surface. There are many fimbriae on mainly Gram-negative bacteria, so displaying proteins on fimbriae is advantageous over some other surface proteins which are less numerous. A disadvantage of using fimbriae is that there is a relatively small insert size limit of 10-30 amino acids. Flow Cytometer Instrument Once the heterologous protein has been fused with the bacterial cell surface protein, it is exposed to either an enzyme, a cell (expressing a target protein) or an antibody (usually fluorescently tagged), depending on the application of the experiment.
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Additionally, sg mRNA can also be synthesized from the IBV D-RNA, although the mechanism of that process is still largely unknown. IBV D-RNA is often used in the reverse genetics approach to experimentally induce heterologous gene expression and site- specific mutagenesis of the coronavirus genome. However, a translation associated sequence (TAS), which is normally used to transcribe sg mRNA and is derived from gene 5 of the Beaudette strain of IBV, is needed as a promoter to regulate heterologous gene expression. It is also thought that TAS may program some IBV D-RNA to synthesize sg mRNA, which are necessary for homologous gene protein synthesis.
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This commonly occurs with G protein coupled receptors (see Protein kinase C#Function); cytokine and other non-G protein couple receptor types may also become heterologously desensitized by agents that activate protein kinase C but, perhaps more commonly, by agents that activate other protein kinases such as mitogen-activated protein kinase (p38 MAP kinase). Heterologous desensitization may occur in cells that are grossly overstimulated for prolonged times by a certain agents. Receptor desensitization, whether heterologous or homologous, may contribute to human pathology. For example, excessive desensitization due to the overexpression of GRK2 leads to the loss of β-adrenergic receptor signaling in hearts (see Adrenergic receptor#β receptors].
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Distinct protein subunits interact in hetero-oligomers, which are essential to control several cellular functions. The importance of the communication between heterologous proteins is even more evident during cell signaling events and such interactions are only possible due to structural domains within the proteins (as described below).
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Heterologous polyclonal antibodies are obtained from the serum of animals (e.g., rabbit, horse), and injected with the patient's thymocytes or lymphocytes. The antilymphocyte (ALG) and antithymocyte antigens (ATG) are being used. They are part of the steroid-resistant acute rejection reaction and grave aplastic anemia treatment.
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Following its activation, EP4 undergoes homologous desensitization. That is, EP4 becomes insensitive to further activation and internalizes. This effect limits the duration and extent to which EP4 can stimulate cells. Agents which activate certain isoforms of protein kinase C can also desensitize EP4 by a process termed heterologous desensitization.
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Scaffolds are used to display the heterologous protein on the bacterial cell surface. There are various scaffolds which have been used such as outer membrane proteins, fimbriae/flagella proteins and CPX (circularly permuted OmpX). The CPX scaffold allows peptide fusion at both termini of the scaffold. OMPs are common scaffolds for bacterial display.
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Proteins can also be displayed on the bacterial cell surface through the use of autotransporters. Autotransporters form part of the type V secretion system. They usually have three domains: leader sequence at the N-terminal; central passenger domain; autotransporter domain at the C-terminal. The heterologous protein is inserted at the passenger domain.
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The host organism can be a bacterium, yeast, mammalian cell, or plant cell. This host is called the "expression system". Homologous expression, on the other hand, refers to the overexpression of a gene in a system from where it originates. Genes are subjected to heterologous expression often to study specific protein interactions.
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Patrelli, T. S., Gizzo, S., Di Gangi, S., Guidi, G., Rondinelli, M., & Nardelli, G. B. (2011). Cervical Mullerian adenosarcoma with heterologous sarcomatous overgrowth: a fourth case and review of literature. BMC cancer, 11(1), 236. Sarcomatous overgrowth is diagnosed when the sarcomatous portion of the adenosarcoma makes up more than 25% of the tumor.
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As restoring motility of pomA mutants by heterologous expression of MotA does not change the ion used to power the flagellum of the transgenic Vibrio alginolyticus, MotA is not in itself an essential specificity factor in ion selectivity, though that does not exclude it being partially involved in determining ion specificity of the flagellar complex.
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G-protein-coupled receptor oligomerisation is a widespread phenomenon. One of the best-studied examples is the metabotropic GABAB receptor. This so-called constitutive receptor is formed by heterodimerization of GABABR1 and GABABR2 subunits. Expression of the GABABR1 without the GABABR2 in heterologous systems leads to retention of the subunit in the endoplasmic reticulum.
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Past and ongoing research continues to elucidate the many biological functions of sulfatide and their many implications as well as the pathology that has been associated with sulfatide. Most research utilizes mice models, but heterologous expression systems are utilized as well, including, but not limited to, Madin-Darby canine kidney cells and COS-7 Cells.
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Biosynthesis and regulation of 3-deoxyanthocyanidin phytoalexins induced during Sorghum-Colletotrichum interaction: Heterologous expression in maize. Chopra, Surinder Gaffoor, Iffa Ibraheem, Farag 6-Methoxymellein is a dihydroisocoumarin and a phytoalexin induced in carrot slices by UV-C, that allows resistance to Botrytis cinerea and other microorganisms. Danielone is a phytoalexin found in the papaya fruit.
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This feature is compatible with heterologous protein expression, giving higher yields of production. 4: The technology required for genetic manipulation of P. pastoris is similar to that of Saccharomyces cerevisiae, which is one of the most well-studied yeast model organisms. As a result, the experiment protocol and materials are easy to build for P. pastoris.
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Kv3.1 currents in heterologous systems are highly sensitive to external tetraethylammonium (TEA) or 4-aminopyridine (4-AP) (IC50 values are 0.2 mM and 29 μM respectively). This can be useful in identifying native channels. The overlapping sensitivity of potassium current to both 0.5 mM TEA and 30 μM 4-AP strongly suggest an action on Kv3.1 subunits.
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Ribostamycin, along with other aminoglycosides with the DOS subunit, is an important broad-spectrum antibiotic with important use against human immunodeficiency virus and is considered a critically important antimicrobial by the World Health Organization.,Kurumbang N.P.; Liou, K.; Sohng, J.K.; Biosynthesis of Ribostamycin Derivatives by Reconstitution and Heterologous Expression of Required Gene Sets. Applied Biochemistry and Biotechnology.
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GamEvac-Combi () is a heterologous VSV- and Ad5-vectored Ebola vaccine. There is also a version called GamEvac which is a homologous Ad5-vectored vaccine. GamEvac-Combi was developed by Gamaleya Research Institute of Epidemiology and Microbiology. the vaccine has been licensed in Russia for emergency use, on the basis of Phase 1 and Phase 2 clinical trials.
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The α-subunits are also able to form functional homopentamers in heterologous expression systems in African clawed frog oocytes or mammalian cell lines, which are useful for studies of channel pharmacokinetics and pharmacodynamics. The β subunit is unable to form functional channels without α subunits but determines the synaptic localization of GlyRs and the pharmacological profile of glycinergic currents.
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GALT29A, a member of GT29 family was identified as being co-expressed with GALT31A and act co- operatively and form complexes. Three members of GT14 named GlcAT14A, GlcAT14B, and GlcAT14C were reported to add GlcA to both β-1,6- and β-1,3-Gal chains in an in vitro enzyme assay following heterologous expression in Pichia pastoris.
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Screening is used to find the apparent affinities of heterologous proteins displayed on the bacterial cell surface for target proteins. This method is usually combined with FACS, and the addition of a non-fluorescent target protein competitor is beneficial to obtaining more accurate binding affinities. Adding a competitor reduces the chance of target proteins rebinding, which would render the binding affinity less accurate.
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Generally, cell lines from multicellular organisms require complex and expensive types of media, including amino acids, vitamins, as well as other growth factors. These types of media significantly increase the cost of producing heterologous proteins. Additionally, since Pichia can grow in media containing only one carbon source and one nitrogen source, which is suitable for isotopic labelling applications, like protein NMR.
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Expression of flavoHb within xenografted tumors led to depletion of NO generated by iNOS/NOS2. The phenotypic result was loss of tumorigenicity of the CSCs and improved mouse survival. These experiments demonstrate that flavoHb can be employed for in vivo studies of nitric oxide biology and suggest that therapeutic NO-depletion may be achieved via heterologous expression of bacterial flavoHbs.
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Also known as heterologous or "Jennerian" vaccines, these are vaccines that are pathogens of other animals that either do not cause disease or cause mild disease in the organism being treated. The classic example is Jenner's use of cowpox to protect against smallpox. A current example is the use of BCG vaccine made from Mycobacterium bovis to protect against human tuberculosis.
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The study of these channels has been slow because they do not traffic to the cell membrane in many heterologous systems. There are several factors that can activate the CatSper calcium channel, depending on species. In the human, channel is activated by progesterone released by the oocyte. The human CatSper channel is pH-sensitive, and requires a high-pH environment.
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GPCRs become desensitized when exposed to their ligand for a long period of time. There are two recognized forms of desensitization: 1) homologous desensitization, in which the activated GPCR is downregulated; and 2) heterologous desensitization, wherein the activated GPCR causes downregulation of a different GPCR. The key reaction of this downregulation is the phosphorylation of the intracellular (or cytoplasmic) receptor domain by protein kinases.
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The Transmissible Gastroenteritis Virus has been engineered as an expression vector. The vector was constructed by replacing the nonessential 3a and 3b ORF, which is driven by the transcription-regulating sequences (TRS) with green fluorescent protein. The resulting construct was still enteropathogenic, but with reduced growth. The infection of cells with this altered virus elicits a specific lactogenic immune response against the heterologous protein.
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The mechanism of conformational proofreading is utilized in the system of homologous recombination to discern between similar DNA sequences. Homologous recombination facilitates the exchange of genetic material between homologous DNA molecules. This crucial process requires detecting a specific homologous DNA sequence within a huge variety of heterologous sequences. The detection is mediated by RecA in E. coli, or members of its superfamily in other organisms.
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The trial with Okairos vaccine candidate on naïve patients is in progress. The study started in November 2009. To date 23 patients have been enrolled. The primary objective of the trial is to test the safety, tolerability and immunogenicity of the heterologous prime-boost HCV vaccine candidate, when administered alone or in combination with the SOC therapy (pegylated-interferon and ribavirin – PEG-IFN/RBV).
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The yeast cell maintains a heterogeneous distribution of Mg2+ suggesting that multiple systems inside the yeast are transporting Mg2+ into storage compartments. This internal transport will very likely mask the uptake process. The expression of ALR1 in S. typhimurium without Mg2+ uptake genes may be an alternative, but, as stated earlier, the effects of a heterologous expression system would need to be taken into account.
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They wondered specifically about the regulation of period mRNA level fluctuations, and found that per mRNA levels were transcriptionally regulated. This was supported by the evidence that per precursor RNA cycles with the same phase as mature transcripts, and oscillate with respect to Zeitgeber Time (ZT). Other evidence for transcriptional regulation is that per gene promoter is sufficient to confer cycling to heterologous mRNA.
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Cosmid cloning experiments from the Blasticidin S producer Streptomyces griseochromogenes, followed by evaluation of the putative biosynthetic gene cluster via heterologous reconstitution of Blasticidin S production in Streptomyces lividans, indicated that a 20 Kbp gene cluster with 19 genes, plus possibly a peptidase outside the gene cluster that acts on the final leucylblasticidin S (LBS) intermediate, was sufficient for reconstitution of Blasticidin S biosynthesis.
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As myeloma cells, NSo cells are naturally antibody-producing suspension cells with a lymphoblast morphology. Gene amplification is typically performed using GS-transfected NS0 cells to select for producing cell lines. The GS-NS0 is a heterologous mammalian expression system that allows for the rapid expression of recombinant proteins. Several therapeutic antibody products are produced using the NS0 cell line including daclizumab and eculizumab.
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This transgenic plant can survive in the presence of 1.7% sodium chloride (half seawater salinity concentration), while the non transgenic line and wild type plants cannot.ZHIGANG LI, Christian M. Baldwin, Qian Hu, Haibo Liu, Hong Luo (2010). Heterologous Expression of Arabidopsis H+-PPase Enhances Salt Tolerance in Transgenic Creeping Bentgrass (Agrostis stolonifera L.). Plant, Cell and Environ, Volume 33 Issue 2, P. 272–289.
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The sample is then passed through a beam of light during FACS, in a very narrow stream of fluid so that only one cell can pass at a time, and the fluorescence emitted is detected. Information on the size of the cell can be obtained by the scattering of light and if binding of the heterologous protein with the target protein/cell has occurred, there will be more fluorescence emitted.
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P. pastoris is frequently used as an expression system for the production of heterologous proteins. Several properties make P. pastoris suited for this task. Currently, several strains of P. pastoris are used for biotechnical purposes, with significant differences among them in growth and protein production. Some common variants possess a mutation in the HIS4 gene, leading to the selection of cells which are transformed successfully with expression vectors.
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There are both attenuated vaccines and inactivated vaccines available. Their effectiveness is diminished by poor cross-protection. The nature of the protective immune response to IBV is poorly understood, but the surface spike protein, the amino-terminal S1 half, is sufficient to induce good protective immunity. Experimental vector IB vaccines and genetically manipulated IBVs—with heterologous spike protein genes—have produced promising results, including in the context of in ovo vaccination.
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T cell depletion methods can be broadly categorized into either physical or immunological. Examples of physical separation include using counterflow centrifugal elutriation, fractionation on density gradients, or the differential agglutination with lectins followed by rosetting with sheep red blood cells. Immunological methods utilize antibodies, either alone, in conjunction with homologous, heterologous, or rabbit complement factors which are directed against the T cells. In addition, these techniques can be used in combinations.
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Specific characteristics of M. flagellatus such as its high coefficient of conversion of oxidizers (methanol) to its own biomassMarchenko GN, Marchenko ND, Tsygankov YD, Chistoserdov AY. “Organization of threonine biosynthesis genes from the obligate methylotroph Methylobacillus flagellatus” Microbiology. 1999. Vol 145, No.11. p. 3273-3282. allows for practical applications such as inexpensive industrial productions of commercially needed compounds. These compounds can range from heterologous proteins and amino- acids to vitamins.
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Later in 1995, Georg Nagel et al. and Ernst Bamberg tried the heterologous expression of microbial rhodopsins (also bacteriorhodopsin and also in a non-neural system, Xenopus oocytes) (Nagel et al., 1995, FEBS Lett.) and showed light-induced current. An earlier use of light to activate neurons was carried out by Richard Fork, who demonstrated laser activation of neurons within intact tissue, although not in a genetically-targeted manner.
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Assembly of a highly ordered coherent monomolecular S-layer array on a growing cell surface requires a continuous synthesis of a surplus of S-layer proteins and their translocation to sites of lattice growth. Moreover, information concerning this dynamic process were obtained from reconstitution experiments with isolated S-layer subunits on cell surfaces from which they had been removed (homologous reattachment) or on those of other organisms (heterologous reattachment).
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Gene transformation occurs mainly by homologous recombination in the chloroplast and heterologous recombination in the nucleus. The C. reinhardtii chloroplast genome can be transformed using microprojectile particle bombardment or glass bead agitation, however this last method is far less efficient. The nuclear genome has been transformed with both glass bead agitation and electroporation. The biolistic procedure appears to be the most efficient way of introducing DNA into the chloroplast genome.
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In recent years, biotechnology researchers have begun using Streptomyces species for heterologous expression of proteins. Traditionally, Escherichia coli was the species of choice to express eukaryotic genes, since it was well understood and easy to work with. Expression of eukaryotic proteins in E. coli may be problematic. Sometimes, proteins do not fold properly, which may lead to insolubility, deposition in inclusion bodies, and loss of bioactivity of the product.
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The authors suggested that the original results might have been affected by low ATPase signals, few experimental repeats and large standard deviations. The lack of artemisinin inhibition of E255L mammalian SERCA matched results from heterologous expression in mammalian and yeast cells. PfATP6 mutations clearly play no role in the reduced artemisinin susceptibility observed in southeast Asia. The consensus is that PfATP6 is not directly involved in artemisinin action or resistance.
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These phosphorylations are often sufficient to impair G-protein coupling on their own as well. # PKC/PKA may, instead, phosphorylate GRKs, which can also lead to GPCR phosphorylation and β-arrestin binding in an occupation- independent manner. These latter two mechanisms allow for desensitization of one GPCR due to the activities of others, or heterologous desensitization. GRKs may also have GAP domains and so may contribute to inactivation through non-kinase mechanisms as well.
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The trial with Okairos vaccine candidate started in October 2008 and was completed on 31 January 2011. The primary objective of the trial is to assess the safety and the immunogenicity of the heterologous prime-boost of vaccine candidate. The vaccine showed excellent safety and immunogenicity. In the last year of the project the vaccine will be tested in healthy individuals for safety and dose optimization and in chronically infected patients (therapeutic trial).
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Shors pp. 809 When they are infected, plants often produce natural disinfectants that kill viruses, such as salicylic acid, nitric oxide, and reactive oxygen molecules. Plant virus particles or virus-like particles (VLPs) have applications in both biotechnology and nanotechnology. The capsids of most plant viruses are simple and robust structures and can be produced in large quantities either by the infection of plants or by expression in a variety of heterologous systems.
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Some prokaryotes express proton pumps called bacteriorhodopsins, archaerhodopsins, proteorhodopsins, heliorhodopsins and xanthorhodopsins to carry out phototrophy. Like animal visual pigments, these contain a retinal chromophore (although it is an all- trans, rather than 11-cis form) and have seven transmembrane alpha helices; however, they are not coupled to a G protein. Prokaryotic halorhodopsins are light-activated chloride pumps. Unicellular flagellate algae contain channelrhodopsins that act as light-gated cation channels when expressed in heterologous systems.
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In the presence of dirigent protein from Forsythia intermedia, production of (+)-pinoresinol is greatly enriched while production of other products of dimerization is inhibited. The activity of dirigent protein from Forsythia intermedia is specific to coniferyl alcohol. When other monolignols, such as p-coumaryl alcohol and sinapyl alcohol, are reacted in vitro with oxidative enzymes in the presence of dirigent protein, they produce a heterologous mixture of products indistinguishable from identical experiments in the absence of dirigent protein.
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Obtained data are also used to calibrate mathematical models of intracellular systems and to estimate rates of gene expression. Similarly, GFP can be used as an indicator of protein expression in heterologous systems. In this scenario, fusion proteins containing GFP are introduced indirectly, using RNA of the construct, or directly, with the tagged protein itself. This method is useful for studying structural and functional characteristics of the tagged protein on a macromolecular or single-molecule scale with fluorescence microscopy.
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The potentially unlimited source of cell and tissues may have direct application for tissue engineering, cell replacement and transplantation following acute injuries and reconstructive surgery. These applications are limited to the cell types that can be differentiated efficiently and safely from human PSCs with the proper organogenesis. Decellularized organs are also being used as tissue scaffold for organogenesis. Source material can be normal healthy cells from another donor (heterologous transplantation) or genetically corrected from the same patient (autologous).
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The discovery of KLB represents an example of a “genome mining” approach. Cluster of genes encoding KLB biosynthetic pathway was found in genome database using low-level homology of one of the proteins to microcin B17 synthetase. Cloning and expression of cluster in a heterologous host (Escherichia coli) yielded the active compound. The name given to the compound reflects the original bacterium where the biosynthetic cluster was found (Klebs-) and the presence of azole cycles (-azolicin).
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That year he won a stage in the 2005 Tour de l'Avenir. In 2007 De Kort joined the team. Following the positive tests for heterologous blood doping by team members Alexander Vinokourov and Andrey Kashechkin, Astana did not have much chance to compete in 2007 and was limited in 2008. Speaking to Dutch media, De Kort expressed his frustrations at not having the chance to compete after being in a similar situation in 2006 with the Liberty Serguros team.
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While heterologous desensitization occurs rapidly at low agonist concentrations, homologous desensitization shows a dose dependent response and usually begins at significantly higher concentrations. Homologous desensitization serves as a mechanism for tachyphylaxis and helps organisms to maintain homeostasis. The process of homologous desensitization has been extensively studied utilizing G protein–coupled receptors (GPCRs). While the different mechanisms for desensitization are still being characterized, there are currently four known mechanisms: uncoupling of receptors from associated G proteins, endocytosis, degradation, and downregulation.
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A subgenomic promoter is a promoter added to a virus for a specific heterologous gene, resulting in the formation of mRNA for that gene alone. Many positive-sense RNA viruses produce these subgenomic mRNAs (sgRNA) as one of the common infection techniques used by these viruses and generally transcribe late viral genes. Subgenomic promoters range from 24 nucleotide (Sindbis virus) to over 100 nucleotides (Beet necrotic yellow vein virus) and are usually found upstream of the transcription start.
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As with many other GPCRs, there is still a lack of experimental structures at atomic level for olfactory receptors and structural information is based on homology modeling methods. The limited functional expression of olfactory receptors in heterologous systems, however, has greatly hampered attempts to deorphanize them (analyze the response profiles of single olfactory receptors). This was first completed by genetically engineered receptor, OR-I7 to characterize the “odor space” of a population of native aldehyde receptors.
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In mammalian cells, these protein aggregates are termed "aggresomes" and they are formed when the cell is diseased. This is because aggregates tend to form when there are heterologous proteins present in the cell, which can arise when the cell is mutated. The E3 ubiquitin ligase is able to recognize misfolded proteins and ubiquinate them. HDAC6 can then bind to the ubiquitin and the motor protein dynein to bring the marked aggregates to the microtubule organizing center (MTOC).
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The researchers in the field had turned their interest to heterologous expression of the same enzymes due to difficulties in obtaining these enzymes in the native form. Only have recently a few recombinant reductive dehalogenases been functionally expressed, bringing the dehalogenase research into next levels. Those successful efforts facilitate further investigations on their biochemical and structural properties. The first membrane-associated respiratory reductive dehalogenase was heterologously expressed in a soluble and active form and purified using Bacillus megaterium.
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Lactobacillus plantarum is the most common bacterium used in silage inoculants. During the anaerobic conditions of ensilage, these organisms quickly dominate the microbial population, and, within 48 hours, they begin to produce lactic and acetic acids via the Embden-Meyerhof Pathway, further diminishing their competition. Under these conditions, L. plantarum strains producing high levels of heterologous proteins have been found to remain highly competitive. This quality could allow this species to be utilized as an effective biological pretreatment for lignocellulosic biomass.
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F. tularensis was highly virulent in the mice and cavies (guinea pigs) used in studies. It only took one to 10 cells of F. tularensis to kill the animal of either species, although F. novicida took 10 to 100 cells in cavies and up to a 1,000 cells in mice. The immunological differences, though, are the strongest evidence used to support the idea that F. novicida and F. tularensis are separate species. Nonliving vaccines provided no protection against the heterologous organism.
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The name nepenthesin was coined in 1968 by Shigeru Nakayama and Shizuko Amagase. Alternative names for this enzyme include Nepenthes acid proteinase and Nepenthes aspartic proteinase. Two isozymes have been identified in Nepenthes: nepenthesin I and nepenthesin II. The production of large quantities of nepenthesin-1 through heterologous expression in Escherichia coli was described in 2014. The names cephalotusin, dionaeasin and droserasin have been proposed for similar aspartic endopeptidases originating from the carnivorous plant genera Cephalotus, Dionaea and Drosera, respectively.
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EsV-1 encodes a 124 codon ORF that has significant amino acid similarity to PBCV-1 Kcv (41% amino acid identity). However, the EsV-1 protein has a longer N-terminus (35 amino acids) containing two consensus protein kinase C sites and it has three transmembrane domains. It is unknown whether the EsV-1 protein can form a functional channel in heterologous cells. The EsV-1 genome also encodes several proteins with hydrophobic amino acid rich regions that resemble helical transmembrane domains.
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The essential role of the PAS complex in PtdIns(3,5)P2 synthesis and turnover is supported by data from siRNA-mediated protein silencing and heterologous expression of the PAS complex components in various cell types as well as by data from genetic knockout of the PAS complex proteins. Ikonomov OC, Sbrissa D, Dondapati R, Shisheva A. ArPIKfyve-PIKfyve interaction and role in insulin-regulated GLUT4 translocation and glucose transport in 3T3-L1 adipocytes. Exp Cell Res. 2007 Jul 1;313(11):2404-16.
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Small Blue Round Cell Tumor under a microscope Malignant ectomesenchymomas may form in the head and neck, abdomen, perineum, scrotum, or limbs. The tumor is defined by its heterologous rhabdomyoblastic components. MEM histology is that of an elongated cell with an embryonic morphology Holland, James F.; Frei III, Emil; Weichselbaum, Ralph R.; Bast, Robert C.; Gansler, Ted S.; Kufe, Donald W.; Pollock, Raphael E., eds. (2003), "Resemblance to embryonal tissue", Holland-Frei Cancer Medicine (6th ed.), Hamilton, Ontario, Canada: BC Decker, , OCLC 53895425, retrieved 3 Dec 2011.
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The funding for this project had run out, so Prasher sent cDNA samples to several labs. The lab of Martin Chalfie expressed the coding sequence of wtGFP, with the first few amino acids deleted, in heterologous cells of E. coli and C. elegans, publishing the results in Science in 1994. Frederick Tsuji's lab independently reported the expression of the recombinant protein one month later. Remarkably, the GFP molecule folded and was fluorescent at room temperature, without the need for exogenous cofactors specific to the jellyfish.
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Shapiro, Roger L. MD; Charles Hatheway, PhD; and David L. Swerdlow, MD Botulism in the United States: A Clinical and Epidemiologic Review Annals of Internal Medicine. 1 August 1998 Volume 129 Issue 3 Pages 221-228 Antitoxin also known as heterologous hyperimmune serum is often also given prophylactically to individuals known to have ingested contaminated food. IVIG treatment was also used successfully to treat several victims of toxic shock syndrome, during the 1970s tampon scare. Antibody therapy is also used to treat viral infections.
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Global replacement of all hydrogens in muscone was achieved by heating muscone with Rh/C in D2O at 150 °C. It was found that the human musk-recognizing receptor, OR5AN1, identified using a heterologous olfactory receptor expression system and robustly responding to muscone, fails to distinguish between muscone and the so-prepared isotopologue in vitro. OR5AN1 is reported to bind to muscone and related musks such as civetone through hydrogen-bond formation from tyrosine-258 along with hydrophobic interactions with surrounding aromatic residues in the receptor.
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The feasibility of using Lactic acid bacteria (LAB) as functional protein delivery vectors has been widely investigated. Lactococcus lactis has been demonstrated to be a promising candidate for the delivery of functional proteins because of its noninvasive and nonpathogenic characters. Many different expression systems of L. lactis have been developed and used for heterologous protein expression. Lactose fermentation In Shuichi Nakamura’s, Yusuke V. Marimoto, and Seishi Kudo’s study, they seek to prove that some fermentation produced by L. lactis can hinder motility in pathogenic bacteria.
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There is one problem with connecting heterologous modules though; there is recent evidence that the amino acid sequence between the ACP domain and the subsequent KS domain of downstream modules plays an important role in the transfer of the growing polyketide from one module to another. These regions have been labeled as “linkers” and although they have no direct catalytic role, any substitution of a linker region that is not structurally compatible with the wild-type PKS may cause poor yields of the expected product.
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AIRE is composed of a multidomain structure that is able to bind to chromatin and act as a regulator of gene transcription. The specific makeup of AIRE includes a caspase activation and recruitment domain (CARD), nuclear localization signal (NLS), SAND domain, and two plant-homeodomain (PHD) fingers. The SAND domain is located in the middle of the amino-acid chain (aa 180-280) and mediates the binding of AIRE to phosphate groups of DNA. Another potential role for this domain is to anchor AIRE to heterologous proteins.
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RNA-dependent RNA polymerases (RdRPs) are critical components in the life cycle of double-stranded RNA (dsRNA) viruses. However, it is not fully understood how these important enzymes function during viral replication. Expression and characterization of the purified recombinant RdRP of Φ6 is the first direct demonstration of RdRP activity catalyzed by a single protein from a dsRNA virus. The recombinant Φ6 RdRP is highly active in vitro, possesses RNA replication and transcription activities, and is capable of using both homologous and heterologous RNA molecules as templates.
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They published their models of intron folding in Biochimie in 1982 and this article quickly became a reference for researchers in the field. But the precise function of the omega-encoded protein was still unknown. Bernard Dujon decided to adapt the mitochondrial gene to the universal genetic code in order to be able to express it in a heterologous system. At that time, it was a real tour de force, since oligonucleotide synthesis and in vitro mutagenesis were uncommon and not available in Gif-sur-Yvette.
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Earlier, REMI (restriction enzyme-mediated integration) could be used to insert exogenous DNA into the chromosome to produce mutant strains. This relies on inserting exogenous DNA and restriction enzymes into the protoplast cell, allowing for the enzymes to cut the chromosome at specific sites which match those sites used to produce linearized plasmid DNA with the gene of interest; subsequently, host enzymes ligate the cut sites and thus produce integrated heterologous, exogenous DNA. Although successful, undesirable mutations are likely. Chemical mutagenesis (also random) can also be done.
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Because this enrichment is so pronounced, the enzyme is hypothesized to produce (+)-pinoresinol exclusively, and to compete with the non-protein-mediated coupling reaction, which produces a heterologous mix of products. This has been confirmed by analyzing the various mixtures produced with different concentrations of dirigent proteins present. The mechanism by which this stereoselectivity is achieved is not well understood at this time. However, since no reaction proceeds in the absence of oxidative enzymes, dirigent protein does not itself appear to catalyze the oxidation of coniferyl alcohol to form radicals.
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Heterologous expression of gas vesicles in bacterial and mammalian cells enabled their use as the first family of acoustic reporter genes. While fluorescent reporter genes like green fluorescent protein (GFP) had widespread use in biology, their in vivo applications are limited by the penetration depth of light in tissue, typically a few mm. Luminescence can be detected deeper within the tissue, but have a low spatial resolution. Acoustic reporter genes provide sub-millimeter spatial resolution and a penetration depth of several centimeters, enabling the in vivo study of biological processes deep within the tissue.
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This might also explain some of the results from studies on teleost using heterologous mammalian Lep. E.g. treatment with the mammalian hormone caused an anorexic effect in goldfish (Carassius auratus) and green sunfish (Lepomis cyanellus), but not in Coho salmon (Oncorhynchus kisutch), channel catfish (Ictalurus punctatus) and green sunfish. These contradicting results have been explained by the relatively large differences in amino acid sequences observed between mammals and fish. Rønnestad and colleagues recently detected five isoforms of the leptin receptor (lepr) that have differences in 3'-end of the mRNA sequence.
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A NOG (NOD/Shi-scid/IL-2Rγnull) mouse is a new generation of severely immunodeficient mouse, developed by Central Institute for Experimental Animals (CIEA) in 2000. The NOG mouse accepts heterologous cells much more easily compared with any other type of immunodeficient rodent models, such as nude mouse and NOD/scid mouse. Thus, the mouse can be the best model as a highly efficient recipient of human cells to engraft, proliferate and differentiate. This unique feature offers a great opportunity for enhancing therapy researches of cancer, leukemia, visceral diseases, AIDS, and other human diseases.
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Once again this modified network can be modeled to calculate the new product yield. The ultimate goal of metabolic engineering is to be able to use these organisms to produce valuable substances on an industrial scale in a cost-effective manner. Current examples include producing beer, wine, cheese, pharmaceuticals, and other biotechnology products. Some of the common strategies used for metabolic engineering are (1) overexpressing the gene encoding the rate-limiting enzyme of the biosynthetic pathway, (2) blocking the competing metabolic pathways, (3) heterologous gene expression, and (4) enzyme engineering.
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3807–3809, In Sorghum, the SbF3'H2 gene, encoding a flavonoid 3'-hydroxylase, seems to be expressed in pathogen-specific 3-deoxyanthocyanidin phytoalexins synthesis, for example in Sorghum-Colletotrichum interactions."Biosynthesis and regulation of 3-deoxyanthocyanidin phytoalexins induced during Sorghum- Colletotrichum interaction: Heterologous expression in maize". Chopra Surinder, Gaffoor Iffa, Ibraheem Farag, Poster at the American Society of Plant Biologists (abstract ) 6-Methoxymellein is a dihydroisocoumarin and a phytoalexin induced in carrot slices by UV-C, that allows resistance to Botrytis cinerea and other microorganisms. Danielone is a phytoalexin found in the papaya fruit.
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Expression of single isoforms in heterologous systems such as human embryonic kidney (HEK) cells, Chinese hamster ovary (CHO) cells and Xenopus oocytes yield homotetrameric channels able to generate ion currents with properties similar to those of the native If/Ih current, but with quantitative differences in the voltage-dependence, activation/deactivation kinetics and sensitivity to the nucleotide cyclic AMP (cAMP): HCN1 channels have a more positive threshold for activation, faster activation kinetics, and a lower sensitivity to cAMP, while HCN4 channels are slowly gating and strongly sensitive to cAMP. HCN2 and HCN3 have intermediate properties.
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Eastern European scientists have used phage therapy as an alternative to antibiotics for some time, and interest in this approach is increasing, because of the high level of antibiotic resistance now found in some pathogenic bacteria. The expression of heterologous proteins by viruses is the basis of several manufacturing processes that are currently being used for the production of various proteins such as vaccine antigens and antibodies. Industrial processes have been recently developed using viral vectors and a number of pharmaceutical proteins are currently in pre-clinical and clinical trials.
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A transient transformation involves a plasmid/vector system using Agrobacterium tumefaciens which integrates the exogenous genes into the T-DNA, then infects the vegetable tissue. Agrobacterium is the common technique used currently because it’s a soil pathogenic bacterium that naturally infects plants and transfers their genes (T-DNA) to the nucleus of the plant. A. tumefaciens is the most preferred strain because it carries tumour-inducing plasmids. The genes will be made into a neutralized Ti-plasmid and the heterologous gene is inserted to form a recombinant plasmid vector.
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A Cav3.2 T-Type Calcium Channel Point Mutation Has Splice-Variant-Specific Effects on Function and Segregates with Seizure Expression in a Polygenic Rat Model of Absence Epilepsy. Journal of Neuroscience 29, 371–380. In addition, the effect is due to a gain-of-function splice variant mutation, and is semi-dominant, explaining about 20% of the phenotypic variance in the cross. In heterologous expression studies, it was shown that the GAERS splice variant allele on Cav3.2 conferred faster recovery from channel inactivation and greater charge transference during high- frequency bursts.
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The functional mammalian sAC consist of two heterologous catalytic domains (C1 and C2), forming the 50 kDa amino terminus of the protein. The additional ~140 kDa C terminus of the enzyme includes an autoinhibitory region, canonical P-loop, potential heme-binding domain, and leucine zipper-like sequence, which are a form of putative regulatory domains. A truncated form of the enzyme only includes the C1 and C2 domains and it is refers to as the minimal functional sAC variant. This sAC-truncated form has cAMP-forming activity much higher than its full-length type.
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The idea that there must be specific transport proteins associated with the uptake of monoamines and acetylcholine into vesicles developed due to the discovery of specific inhibitors which interfered with monoamine neurotransmission and also depleted monoamines in neuroendocrine tissues. VMAT1 and VMAT2 were first identified in rats upon cloning CDNAs for proteins which gave non-amine accumulating recipient cells the ability to sequester monoamines. Subsequently, human VMATs were cloned using human cDNA libraries with the rat homologs as probes, and heterologous-cell amine uptake assays were performed to verify transport properties.
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Survival is influenced by the presence of myometrial invasion, sarcomatous overgrowth, lymphovascular invasion, necrosis, and the presence of heterologous elements, which are features in the tumor not native to the tissue of origin such as rhabdomyoblastic differentiation Post-operative recurrence is common in uterine adenosarcomas. Recurrence usually occurs in the vagina, pelvis, and abdomen, and is seen in up to 30% of cases resulting in a poor prognosis. The presence and depth of the sarcoma’s myometrial invasion determines early staging diagnosis. The FIGO (International Federation of Gynecology and Obstetrics) staging is IA: no myometrial invasion, IB: inner myometrial half, IC: outer myometrial half.
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It would require construction of another cDNA library during the following (non-funded) year for Prasher to isolate a full-length cDNA clone, although it must be noted that this partial cDNA clone was subsequently used and found to be sufficient for successful heterologous expression in E. coli, C. elegans and A. thaliana. By this time Prasher could not afford to devote limited resources to expression studies in E. coli. It wasn't until the Nobel Prize announcement that it became clear how unfortunate this had been. Chalfie and Tsien went on to their successful expression studies.
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Because of its long history of laboratory culture and ease of manipulation, E. coli also plays an important role in modern biological engineering and industrial microbiology. The work of Stanley Norman Cohen and Herbert Boyer in E. coli, using plasmids and restriction enzymes to create recombinant DNA, became a foundation of biotechnology. Considered a very versatile host for the production of heterologous proteins, researchers can introduce genes into the microbes using plasmids, allowing for the mass production of proteins in industrial fermentation processes. Genetic systems have also been developed which allow the production of recombinant proteins using E. coli.
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As DNA printing and DNA assembly methods have allowed commercial gene synthesis to become progressively and exponentially cheaper over the past years, artificial gene synthesis represents a powerful and flexible engineering tool for creating and designing new DNA sequences and protein functions. Besides synthetic biology, various research areas like those involving heterologous gene expression, vaccine development, gene therapy and molecular engineering, would benefit greatly from having fast and cheap methods to synthesise DNA to code for proteins and peptides. The methods used for DNA printing and assembly have even enabled the use of DNA as an information storage medium.
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The AOX promoters are induced by methanol, and repressed by glucose. Usually, the gene for the desired protein is introduced under the control of the Aox1 promoter, which means that protein production can be induced by the addition of methanol on medium. After several researches, scientists found that the promotor derived from AOX1 gene in P. pastoris is extremely suitable to control the expression of foreign genes, which had been transformed into the P. pastoris genome, producing heterologous proteins. 3: With a key trait, P. pastoris can grow with extremely high cell density on the culture.
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Bilsborough J and Viney JL. (2015). GPR15: a tale of two species. Nat Immunol 16:137-9.3084.pdf Ligands There are at least two endogenous ligand found recently. One ligand encoded by the human gene C10orf99 was identified as a robust marker for psoriasis whose abundance decreased after therapeutic treatment with anti-interleukin-17 antibody. Transcripts of C10orf99 are abundant in cervix and colon. It is currently unknown whether C10orf99 causes disease symptoms or is the consequence of a disturbed epithelial barrier. It does not act as a chemotactic agent but rather decrease T cell migration suggesting a mechanism of heterologous receptor desensitization.
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Therefore, a fundamental difference appears to exist in the antigenic composition of the two organisms, which was also demonstrated by cross-absorption in passive cutaneous anaphylaxis test (PCAs). The ability of the given antigen to remove all reactivity from its homologous antiserum while leaving the heterologous antiserum intact indicates the lack of antigen identity. To many scientists, this is enough proof to consider F. novicida and F. tularensis as separate species. Much debate still occurs over how to classify the two organisms, and it is important for scientists to establish a species concept for this organism due to its medical relevance.
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Due to the commercial value of carotenoids, their biosynthesis has been studied extensively in both natural producers, and non-natural (heterologous) systems such as the bacteria Escherichia coli and yeast Saccharomyces cerevisiae. Canthanaxanthin biosynthesis proceeds from beta-carotene via the action of a single protein, known as a beta-carotene ketolase, that is able to add a carbonyl group to carbon 4 and 4' of the beta carotene molecule. Although functionally identical, several distinct beta-carotene ketolase proteins are known. That is to say they differ from an evolutionary perspective in their primary amino acid/protein sequence.
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Classical mutation and (or) selection techniques, together with advanced cloning and protein engineering strategies, have been exploited to develop these products. Efforts to produce and secrete high yields of foreign recombinant proteins in Bacillus hosts initially appeared to be hampered by the degradation of the products by the host proteases. Recent studies have revealed that the slow folding of heterologous proteins at the membrane-cell wall interface of Gram-positive bacteria renders them vulnerable to attack by wall-associated proteases. In addition, the presence of thiol-disulphide oxidoreductases in B. subtilis may be beneficial in the secretion of disulphide-bond-containing proteins.
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Such developments from our understanding of the complex protein translocation machinery of Gram-positive bacteria should allow the resolution of current secretion challenges and make Bacillus species preeminent hosts for heterologous protein production. Bacillus strains have also been developed and engineered as industrial producers of nucleotides, the vitamin riboflavin, the flavor agent ribose, and the supplement poly-gamma-glutamic acid. With the recent characterization of the genome of B. subtilis 168 and of some related strains, Bacillus species are poised to become the preferred hosts for the production of many new and improved products as we move through the genomic and proteomic era.
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Competition for iron also serves as a strong selective force determining the microbial population in the rhizosphere. Several studies show that PGPR exert their plant growth-promoting activity by depriving native microflora of iron. Although iron is abundant in nature, the extremely low solubility of Fe at pH 7 means that most organisms face the problem of obtaining enough iron from their environments. To fulfill their requirements for iron, bacteria have developed several strategies, including the reduction of ferric to ferrous ions, the secretion of high-affinity iron-chelating compounds, called siderophores, and the uptake of heterologous siderophores.
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General pathways for GPCR homologous desensitization Homologous desensitization occurs when a receptor decreases its response to an agonist at high concentration. It is a process through which, after prolonged agonist exposure, the receptor is uncoupled from its signaling cascade and thus the cellular effect of receptor activation is attenuated. Homologous desensitization is distinguished from heterologous desensitization, a process in which repeated stimulation of a receptor by an agonist results in desensitization of the stimulated receptor as well as other, usually inactive, receptors on the same cell. They are sometimes denoted as agonist-dependent and agonist-independent desensitization respectively.
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Apart from its original function in bacterial immunity, the Cas9 protein has been heavily utilized as a genome engineering tool to induce site-directed double-strand breaks in DNA. These breaks can lead to gene inactivation or the introduction of heterologous genes through non-homologous end joining and homologous recombination respectively in many laboratory model organisms. Alongside zinc finger nucleases and Transcription activator-like effector nuclease (Talen) proteins, Cas9 is becoming a prominent tool in the field of genome editing. Cas9 has gained traction in recent years because it can cleave nearly any sequence complementary to the guide RNA.
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In 1979, Francis Crick suggested that controlling all cells from one type in the brain while leaving the others more or less unaltered is a real challenge for neuroscience. Francis Crick speculated that a technology using light might be useful to control neuronal activity with temporal and spatial precision but at the time there was no technique to make neurons responsive to light. By early 1990s LC Katz and E Callaway had shown that light could uncage glutamate. Heberle and Büldt in 1994 had already shown functional heterologous expression of a bacteriorhodopsin for light-activated ion flow in yeast.
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The presence of a promoter is necessary when screening techniques such as blue-white selection are used. Cloning vectors without promoter and RBS for the cloned DNA sequence are sometimes used, for example when cloning genes whose products are toxic to E. coli cells. Promoter and RBS for the cloned DNA sequence are also unnecessary when first making a genomic or cDNA library of clones since the cloned genes are normally subcloned into a more appropriate expression vector if their expression is required. Some vectors are designed for transcription only with no heterologous protein expressed, for example for in vitro mRNA production.
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The responsibility for national production of immunobiologicals is entrusted to public laboratories; which have a long-standing tradition of producing vaccines and sera for use in official programs. The Ministry of Public Health invested some US$120 million in the development of the capacity of these laboratories. In 2000, the supply of products was sufficient to meet the need for heterologous sera, such as those used in the vaccines against tuberculosis, measles, diphtheria, tetanus, whooping cough, yellow fever, and rabies. In 1999, quality control of the transfused blood consisted of 26 coordinating centers and by 44 regional centers.
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Of the cAMP targets, protein kinase A (PKA) has been associated with ethanol use. While acute ethanol use increases the activity of AC, chronic use tends to desensitize AC such that more simulation, increased ethanol consumption, is required to elicit the same response.Mochly-Rosen, D., Chang, F.H., Cheever, L., Kim, M., Diamond, I., Gordon, A.S. (1988) Chronic ethanol causes heterologous desensitization of receptors by reducing as messenger RNA. Nature, 333, 848–850Tabakoff, B., Whelan, J.P., Ovchinnikova, L., Nhamburo, P., Yoshimura, M., Hoffman, P.L. (1995) Quantitative changes in G proteins do not mediate ethanol-induced downregulation of adenylyl cyclase in mouse cerebral cortex.
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This gene encodes a nuclear protein that has three zinc fingers at the end of its C-terminal domain, a serine/threonine-rich central region, and an acidic domain lying within the N-terminal region. The zinc fingers of this protein are responsible for the specific DNA binding with the guanine-rich core promoter elements. The central region might be involved in activation or posttranslational regulatory pathways, and the acidic N-terminal domain might play an important role in the process of transcriptional activation. It is capable of activating transcription approximately 4-fold either on homologous or heterologous promoters.
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Interactions between T cells and specific microbiota components may represent evolutionary outcome by which the skin immune system and the microbiota provide heterologous protection against invasive pathogens and calibrate barrier immunity through the use of chemical signals. This shows that the skin immune system is a highly dynamic environment that can be rapidly and specifically remodeled by certain commensals. Finally, studying microbiota interactions and skin T cells can help to detect the cause of various diseases and possible cures for these. The increasing development of tools for personalized medicine will undoubtedly help to this goal, because each person has a different microbiota.
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Ulocladium botrytis is an anamorphic fungus, thus it undergoes asexual reproduction. Although it is an asexual fungus, U. botrytis possesses the mating type locus, which consists of two dissimilar DNA sequences termed MAT1-1-1 and MAT1-2-1. These U. botrytis MAT genes are essential for controlling colony size and asexual traits such as conidial size and number in U.botrytis. The U. botrytis MAT genes have lost the ability to regulate sexual reproduction in U. botrytis; however, they have the ability to partially induce sexual reproduction in Cochliobolus heterostrophus, a heterothallic species, upon heterologous complementation.
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Recently, it was proposed to be an intrinsically disordered protein with an essential role in alpha-carboxysome assembly. CsoSCA is a shell-associated beta-carbonic anhydrase. Studies in Halothiobacillus neapolitanus have shown that empty shells of normal shape and composition are assembled in carboxysomal RuBisCO-lacking mutants, suggesting that alpha-carboxysome shell biogenesis and enzyme sequestration are two independent, but functionally linked processes. Intriguingly, carboxysomes of Halothiobacillus neapolitanus have been found to accommodate chimeric and heterologous species of RuBisCO and it is the large subunit of RuBisCO which determines whether the enzyme is sequestered into carboxysomes or not.
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Xenotransplantation (xenos- from the Greek meaning "foreign" or strange), or heterologous transplant is the transplantation of living cells, tissues or organs from one species to another.Xenotransplantation. Definition by the World Health Organization Such cells, tissues or organs are called xenografts or xenotransplants. It is contrasted with allotransplantation (from other individual of same species), syngeneic transplantation or isotransplantation (grafts transplanted between two genetically identical individuals of the same species) and autotransplantation (from one part of the body to another in the same person). Xenotransplantation of human tumor cells into immunocompromised mice is a research technique frequently used in pre-clinical oncology research.
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Evidence exists that a specific zeaxanthin-binding protein recruits circulating zeaxanthin and lutein for uptake within the macula. Due to the commercial value of carotenoids, their biosynthesis has been studied extensively in both natural products and non-natural (heterologous) systems such as the bacteria Escherichia coli and yeast Saccharomyces cerevisiae. Zeaxanthin biosynthesis proceeds from beta-carotene via the action of a single protein, known as a beta-carotene hydroxylase, that is able to add a hydroxyl group (-OH) to carbon 3 and 3′ of the beta-carotene molecule. Zeaxanthin biosynthesis therefore proceeds from beta-carotene to zeaxanthin (a di-hydroxylated product) via beta-cryptoxanthin (the mono hydroxylated intermediate).
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The antigen Thy-1 was the first T cell marker to be identified. Thy-1 was discovered by Reif and Allen in 1964 during a search for heterologous antisera against mouse leukemia cells, and was demonstrated by them to be present on murine thymocytes, on T lymphocytes, and on neuronal cells. It was originally named theta (θ) antigen, then Thy-1 (THYmocyte differentiation antigen 1) due to its prior identification in thymocytes (precursors of T cells in the thymus). The human homolog was isolated in 1980 as a 25kDa protein (p25) of T-lymphoblastoid cell line MOLT-3 binding with anti-monkey-thymocyte antisera.
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NdeI is a specific Type II restriction enzyme that cuts open specific target sequences, unlike exonucleases. This enzyme is used in gene cloning to cut open reading frames in the plasmid of certain bacteria such as E. coli and insert a foreign gene, such as the gfpuv gene that codes for bio fluorescence of the jelly fish Aequorea victoria. NdeI is useful in generating heterologous DNA construct because it contains the start codon ATG. It therefore can be in used in some expression vectors, such as those in the pET series of vectors, for the ligation of the start of a gene when making an expression construct.
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Specifically, Block et al. report that the human musk-recognizing receptor, OR5AN1, identified using a heterologous olfactory receptor expression system and robustly responding to cyclopentadecanone and muscone, fails to distinguish isotopomers of these compounds in vitro. Furthermore, the mouse (methylthio)methanethiol-recognizing receptor, MOR244-3, as well as other selected human and mouse olfactory receptors, responded similarly to normal, deuterated, and carbon-13 isotopomers of their respective ligands, paralleling results found with the musk receptor OR5AN1. Based on these findings, the authors conclude that the proposed vibration theory does not apply to the human musk receptor OR5AN1, mouse thiol receptor MOR244-3, or other olfactory receptors examined.
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In particular, IBV D-RNA CD-61 is used to experimentally produce recombinant IBV vaccines. D-RNA CD-61 was created from the naturally occurring IBV D-RNA CD-91, which is produced by multiple passage of high concentration IBV in chick kidney (CK) cells. The IBV D-RNA CD-61 resulted from deletion mutagenesis of CD-91 and lacks much of the genome but retains the sequences necessary for replication and packaging of viral particles in the presence of a helper virus. One particularly promising method of IBV D-RNA-mediated heterologous gene expression uses the helper virus dependent system to promote IBV immunity.
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They often almost exclusively contain the over-expressed protein and aggregation and has been reported to be reversible. It has been suggested that inclusion bodies are dynamic structures formed by an unbalanced equilibrium between aggregated and soluble proteins of Escherichia coli. There is a growing body of information indicating that formation of inclusion bodies occurs as a result of intracellular accumulation of partially folded expressed proteins which aggregate through non-covalent hydrophobic or ionic interactions or a combination of both. Inclusion bodies are dense electron-refractile particles of aggregated protein found in both the cytoplasmic and periplasmic spaces of E. coli during high-level expression of heterologous protein.
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Although FS cells do not secrete hormones, they influence the functionality of hormone- secreting endocrine cells via gap junctions. FS cells form homologous gap junctions with their adjacent counterparts, but also heterologous gap junctions with hormone-secreting endocrine cells. The gap junctions that exist between adjacent FS cells are used to propagate calcium-mediated signals throughout the pituitary to coordinate the function of excitable endocrine cells distributed throughout the gland. The endocrine-FS cell gap junctions, alongside the FS-FS gap junctions form a cell network that allows information about the physiological environment to be transferred around the pituitary to coordinate its secretory function.
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PtdIns(3,5)P2 regulates endosomal operations (fission and fusion) that maintain endomembrane homeostasis and proper performance of the trafficking pathways emanating from or traversing endosomes. Decrease of PtdIns(3,5)P2 levels upon perturbations of cellular PIKfyve by heterologous expression of enzymatically inactive PIKfyve point mutants, Ikonomov OC, Sbrissa D, Shisheva A. Mammalian cell morphology and endocytic membrane homeostasis require enzymatically active phosphoinositide 5-kinase PIKfyve. J Biol Chem. 2001 Jul 13;276(28):26141-7. Epub 2001 Apr 2. siRNA-medicated silencing, Rutherford AC, Traer C, Wassmer T, Pattni K, Bujny MV, Carlton JG, Stenmark H, Cullen PJ. The mammalian phosphatidylinositol 3-phosphate 5-kinase (PIKfyve) regulates endosome-to-TGN retrograde transport.
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Because of its long history of laboratory culture and ease of manipulation, E. coli plays an important role in modern biological engineering and industrial microbiology. The work of Stanley Norman Cohen and Herbert Boyer in E. coli, using plasmids and restriction enzymes to create recombinant DNA, became a foundation of biotechnology. E. coli is a very versatile host for the production of heterologous proteins, and various protein expression systems have been developed which allow the production of recombinant proteins in E. coli. Researchers can introduce genes into the microbes using plasmids which permit high level expression of protein, and such protein may be mass-produced in industrial fermentation processes.
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Mortierella alpina typically only produces ETA in trace amounts at low temperatures, making it difficult to isolate and examine. This developed mutant strain is capable of producing larger amounts of ETA due to the expression of an ω-3-desaturase gene, typically responsible for the significant production of the more abundant PUFAs.The development of a mutant strain was considered in the context of the over-expression of the endogenous ω-3-desaturase gene versus the heterologous Saprolegnia diclina Δ17 (sdd17m) desaturase gene. The endogenous ω-3-desaturase gene transformed fungi had ETA at 42.1% in total lipid concentration, 84.2-fold and 3.2-fold more than two wild-type strain fungi when contrasted at a temperature of 12 degrees Celsius.
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Aside from the harmful impact these organisms can have, Phytomonas species can also be useful as parallel models for the study of dangerous diseases caused by organisms in other infections trypanosomatid genera. Trypanosoma cruzi is the causative agent of Chagas' disease, and as a member of the family Trypanosomatidae, is related to organisms of the genus Phytomonas. In a 2015 study, Phytomonas Jma was tested as a model for the expression of heterologous proteins in the dangerous T. cruzi. It was found that Phytomonas was able to express GFP levels similar to that of T. cruzi, and it was concluded that organisms in the genus could be used as human-safe models for functional expression of trypanosomatid proteins.
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This is the first (and so far, only) example of the reconstitution of a circadian clock in vitro. The output of this oscillator to rhythms of gene expression may be mediated by one or both of the following mechanisms: (1) the Biochemical Cascade Model that implicates the globally acting transcription factors, RpaA and B. RpaA seems to be coupled to the central KaiABC oscillator by histidine kinase SasA through a two-component signaling pathway, and/or the (2) Chromosome/Nucleoid Hypothesis, in which the circadian clock orchestrates dramatic circadian changes in DNA topology, which causes a change in the transcription rates. The behavior of heterologous promoters from other bacteria when expressed in cyanobacteria support the latter hypothesis.
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T. Whary, S. J. Danon, Y. Feng, Z. Ge, N. Sundina, V. Ng, N. S. Taylor, A. B. Rogers and J. G. Fox. Rapid onset of ulcerative typhlocolitis in B6.129P2-IL10tm1Cgn (IL-10-/-) mice infected with Helicobacter trogontum is associated with decreased colonization by altered Schaedler’s flora. 2006. Infect. Immun. 74(12):6615.] In another summary, Fox examined the relationship between microbiome of the gut and the onset of inflammatory bowel disease (IBD) with the infection of H. bilis. H. bilis is noted to elicit heterologous immune response to lower gut flora, in both activating pro-inflammatory cytokine and dendritic cell activity and probiotic anti-inflammatory activity due to the presentation of commensal antigens.
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Moreover, many are the examples regarding functionalization of plant virus-based nanoparticles by means of modification of their external surface and by loading cargo molecules into their internal cavity. This plasticity in terms of nanoparticles engineering is the ground on which multivalency, payload containment and targeted delivery can be fully exploited. George P. Lomonossoff writing in "Recent Advances in Plant Virology", The capsids of most plant viruses are simple and robust structures consisting of multiple copies of one or a few types of protein subunit arranged with either icosahedral or helical symmetry. The capsids can be produced in large quantities either by the infection of plants or by the expression of the subunit(s) in a variety of heterologous systems.
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Because it was known that EFF-1 mutants successfully fused the anchor cell and (uterine seam) utse syncytium to produce a continuous uterine-vulval tube, where these connections failed, AFF-1 mutants were discovered. AFF-1 was deemed necessary for this process in addition to the fusion of heterologous cells in C. elegans. The transmembrane forms of these proteins, like most viral fusogens, possess an N-terminal signal sequence followed by a long extracellular portion, a predicted transmembrane domain, and a short intracellular tail. " A striking conservation in the position and number of all 16 cysteines in the extracellular portion" of EFF-AFF proteins from different nematode species suggests that these proteins are folded in a similar 3D structure that is essential for their fusogenic activity.
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Autodisplay is based on the autotransporter proteins of gram-negative bacteria, which were first discovered in the late 1980s, when the IgA1 protease of Neisseria gonorrhoeae was described. By the early 1990s, several groups had attempted to attach heterologous proteins to IgA1 protease and express the product in Escherichia coli, however the N. gonorrhoeae IgA1 protease was not expressed well in E. coli, limiting the usefulness of this system. Subsequently, the IgA1 protease was replaced by an autotransporter native to E. coli, namely the AIDA-1 protein from Enteropathogenic E. coli. This was expressed to much higher levels in E. coli than the previously used N. gonorrhoeae protein had been, allowing this system to be used for larger- scale biotechnological applications.
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As a result, imidazole engineering has been suggested as a means to specifically inhibit NO dioxygenases. In addition, genetically modified plants with heterologous flavohemoglobin-NODs are being developed to limit NO toxicity created by metabolism of nitrogen fertilizers by soil microbes and as a means towards plant self-fertilization through absorption of environmental NO. Recently a lentiviral vector that allows for expression of E. coli flavoHb in mammalian cells has been described. This approach demonstrated that flavoHb is indeed enzymatically active within human and murine cells and potently blocks exogenous and endogenous sources of nitrosative stress. This technology was then extended to interrogate the role of NO synthesis in the highly tumorigenic cancer stem cells (CSCs) from human glioblastoma (brain tumor) samples.
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When initially bound to PGE2 or other stimulating ligand, EP1 mobilizes G proteins containing the Gq alpha subunit (Gαq/11)-G beta-gamma complex. These two subunits in turn stimulate the Phosphoinositide 3-kinase pathway that raises cellular cytosolic Ca2+ levels thereby regulating Ca2+-sensitive cell signal pathways which include, among several others, those that promote the activation of certain protein kinase C isoforms. Since, this rise in cytosolic Ca2+ can also contract muscle cells, EP1 has been classified as a contractile type of prostanoid receptor. The activation of protein kinases C feeds back to phosphorylate and thereby desensitizes the activated EP1 receptor (see homologous desensitization but may also desensitize other types of prostanoid and non-prostanoid receptors (see heterologous desensitization).
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Dual oxidases are characterized by a defining N-terminal, extracellular domain exhibiting considerable sequence identity with the mammalian peroxidases, a transmembrane (TM) segment appended to an EF-hand calcium-binding cytosolic region and a NOX2 homologous structure (six TMs tethered to NADPH oxidase). Topological studies place this peroxidase domain on the opposite side of the membrane from the NADPH oxidase domain. hDUOX1 and hDUOX2 are 83% homologous, ~190 kDa in size (after extensive glycosylation contributing ~30 kDa in mass), and require maturation factors (DUOXA1 and DUOXA2) to achieve heterologous expression in full-length, active form. Mature DUOX enzymes produce H2O2; this activity is regulated by Ca2+ concentration through triggered dissociation of NOXA1 and possibly other as yet unidentified interacting proteins.
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In response to Turin's 2013 paper, involving deuterated and undeuterated isotopomers of the musk cyclopentadecanone, Block et al. in a 2015 paper in PNAS report that the human musk-recognizing receptor, OR5AN1, identified using a heterologous olfactory receptor expression system and robustly responding to cyclopentadecanone and muscone (which has 30 hydrogens), fails to distinguish isotopomers of these compounds in vitro. Furthermore, the mouse (methylthio)methanethiol-recognizing receptor, MOR244-3, as well as other selected human and mouse olfactory receptors, responded similarly to normal, deuterated, and carbon-13 isotopomers of their respective ligands, paralleling results found with the musk receptor OR5AN1. Based on these findings, the authors conclude that the proposed vibration theory of olfaction does not apply to the human musk receptor OR5AN1, mouse thiol receptor MOR244-3, or other olfactory receptors examined.
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In standard molecular biology research, the bacterium Escherichia coli is the most frequently used organism for expression system, to produce heterologous proteins, due to its features of fast growth rate, high protein production rate, as well as undemanding growth conditions. Protein production in E. coli is usually faster than that in P. pastoris, with reasons: Competent E. coli cells can be stored frozen, and thawed before use, whereas Pichia cells have to be produced immediately before use.Expression yields in Pichia vary between different clones, so that a large number of clones has to be screened for protein production, to find the best producer. The biggest advantage of Pichia over E. coli is that Pichia is capable of forming disulfide bonds and glycosylations in proteins, but E. coli cannot.
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He is best known for his work on heterologous down-regulation of EGF receptor by NGF, which would appear to be an efficient mean of desensitizing the neurons to proliferative signals. Lazarovici pursued neuroscience as a visiting associate in the Section on Growth Factors at National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA. After completion of his research, he joined as Lecturer in The School of Pharmacy, The Hebrew University of Jerusalem and later he became the full Professor. He is an active member of the Israel Societies for Physiology and Pharmacology (ISPP), and Neuroscience (ISN), American Societies for Neuroscience (ASN), and Pharmacology and Experimental Therapeutics (ASPET). Lazarovici was part of the Israeli group developing with TEVA Co. the drug for Parkinson’s named Rasagiline (Azilect).
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Transcriptional repression by corepressors is in many ways conceptually comparable to the mediation of receptor transcriptional activation by coactivators, but has an opposite outcome. Recruitment of corepressors, generally occurring in the absence of ligand, depends on a critical conformation of the receptor AF-2 domain, as well as upon nuclear receptor box-like helical motifs in the corepressor. Moreover, corepressors themselves recruit ancillary enzyme activities which help to establish or maintain the repressive state at their target promoters. Early cell transfection experiments had shown that discrete regions of certain receptors, such as thyroid hormone receptor, were sufficient to repress, or silence, reporter genes when fused to DNA-binding domains of heterologous transcription factors, suggesting that specific cellular factors – or corepressors - might bind to these regions and silence receptors in cells.
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The instability of fushi tarazu mRNA may contribute to the localization of this pattern of expression, but this is unlikely to be a dominant effect since the 744 base-pair ftz zebra stripe element can drive the ectopic expression of a reporter construct (with mRNA structure entirely unrelated to the ftz transcript) in a qualitatively highly similar pattern. Experiments provide evidence for at least two destabilizing elements in the fushi tarazu mRNA, one located within the 5′ one-third of the mRNA and the other near the 3′ end (termed FIE3 for ftz instability element 3′). The FIE3 lies within a 201-nucleotide sequence just upstream of the polyadenylation signal and can act autonomously to destabilize a heterologous mRNA. Further deletion constructs identified an essential 68-nucleotide element within the FIE3.
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Heterologous desensitization (also known as cross-desensitization) is the term for the unresponsiveness of cells to one or more agonists to which they are normally responsive. Typically, desensitization is a receptor (biochemistry)-based phenomenon in which one receptor type, when bound to its ligand, becomes unable to further influence the signalling pathways by which it regulates cells and, in the case of cell surface membrane receptors, may thereafter be internalized. The desensitized receptor is degraded or freed of its activating ligand and re-cycled to a state where it is again able to respond to cognate ligands by activating its signalling pathways. This type of desensitization, termed homologous desensitization, leaves a cell transiently unresponsive to agents that activate the desensitized receptor but not to agents that activate other receptors.
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While no ETA accumulation is documented at 28 degrees Celsius, the mutant strain of the fungus transformed with the heterologous sdd17mgene exhibited 24.9% of the total lipid content at the same temperature, indicating success in the genetic alteration and abundance of ETA provided for the study, at a variety of different temperatures and conditions. This allows for a more inclusive analysis of the effects of ETA on the human body and provides new insight for medical treatments to inflammatory conditions, given the newfound methods for producing and collecting these molecules for isolation and analysis. This study provides insight as to how many molecules may have multiple functions, some of which are unknown and are still being determined by scientists. The duality of molecules like eicosatetraenoic acid and other eicosanoids, both as inflammatory and anti-inflammatory molecules, is a point of compelling research.
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An additional study involves the use of genetically engineered CD34+ hematopoietic stem and progenitor cells. Experimental long-term in vivo HIV gene therapy have had huge issues due to both transduction ending in multiple copies of heterologous DNA in target cells as well as low efficacy of cell transduction at the time of transplantation. This study demonstrated the efficacy of a transplantation approach that ultimately allows for an enriched population of HSPCs expressing a single copy of a CCR5 miRNA. Since positive selection of modified cells is likely to be insufficient below the threshold they found of at least 70% of the HIV target cells resulting in gene modification from efficient maintenance of CD34+ T cell and a low viral titer, the findings show evidence that clinical protocols of HIV gene therapy require a selective enrichment of genetically targeted cells.
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A malignant mixed Müllerian tumor, also known as malignant mixed mesodermal tumor (MMMT) is a cancer found in the uterus, the ovaries, the fallopian tubes and other parts of the body that contains both carcinomatous (epithelial tissue) and sarcomatous (connective tissue) components. It is divided into two types, homologous (in which the sarcomatous component is made of tissues found in the uterus such as endometrial, fibrous and/or smooth muscle tissues) and a heterologous type (made up of tissues not found in the uterus, such as cartilage, skeletal muscle and/or bone). MMMT account for between two and five percent of all tumors derived from the body of the uterus, and are found predominantly in postmenopausal women with an average age of 66 years. Risk factors are similar to those of adenocarcinomas and include obesity, exogenous estrogen therapies, and nulliparity.
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NSP1, the product of rotavirus gene 5, is a nonstructural RNA-binding protein that contains a cysteine-rich region and is a component of early replication intermediates. RNA-folding predictions suggest that this region of the NSP1 mRNA can interact with itself, producing a stem-loop structure similar to that found near the 5'-terminus of the NSP1 mRNA. The carboxyl-half of the rotavirus nonstructural protein NSP1 is not required for virus replication. NSP1 could play a role in host range restriction. The cysteine-rich region of NSP1 is not considered essential for genome segment reassortment with heterologous virus. NSP1 interacts with IRF3 in the infected cell. NSP1 is an antagonist of the IFN-signaling pathway. Interferon regulatory factor 3 (IRF3) is a key transcription factor involved in the induction of interferon (IFN) in response to viral infection.
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Polyubiquitination is the formation of a ubiquitin chain on a single lysine residue on the substrate protein. Following addition of a single ubiquitin moiety to a protein substrate, further ubiquitin molecules can be added to the first, yielding a polyubiquitin chain. These chains are made by linking the glycine residue of a ubiquitin molecule to a lysine of ubiquitin bound to a substrate. Ubiquitin has seven lysine residues and an N-terminus that serves as points of ubiquitination; they are K6, K11, K27, K29, K33, K48, K63 and M1, respectively. Lysine 48-linked chains were the first identified and are the best-characterised type of ubiquitin chain. K63 chains have also been well- characterised, whereas the function of other lysine chains, mixed chains, branched chains, M1-linked linear chains, and heterologous chains (mixtures of ubiquitin and other ubiquitin-like proteins) remains more unclear.
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In all of these instances, an aberrant form of the protein itself appears to be the pathogenic agent. In some cases, the deposition of one type of protein can be experimentally induced by aggregated assemblies of other proteins that are rich in β-sheet structure, possibly because of structural complementarity of the protein molecules. For example, AA amyloidosis can be stimulated in mice by such diverse macromolecules as silk, the yeast amyloid Sup35, and curli fibrils from the bacterium Escherichia coli. In addition, apolipoprotein AII amyloid can be induced in mice by a variety of β-sheet rich amyloid fibrils, and cerebral tauopathy can be induced by brain extracts that are rich in aggregated Aβ. There is also experimental evidence for cross-seeding between prion protein and Aβ. In general, such heterologous seeding is less efficient than is seeding by a corrupted form of the same protein.
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It was believed that one way to obtain the protein structure of a potassium channel was to identify a gene encoding the channel protein in a genetically tractable organism, and then combine newly developed tools in biophysics, molecular genetics, DNA sequencing in eukaryotes, and molecular cloning, to clone and sequence the gene and functionally express the encoded channel in a heterologous expression system. To this end, as a postdoctoral researcher, Salkoff adapted the voltage clamp technique to the fruit fly Drosophila which had been used by Alan Lloyd Hodgkin and Andrew Huxley to reveal the ionic basis of the nerve action potential. This enabled the direct observation of ion currents in a genetically tractable organism. This technique was then used to show that the Drosophila Shaker gene was the structural gene for a potassium channel, a claim which was based on several genetic criteria and confirmed by biophysical analysis of the expected ion channel current phenotype.
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The closely related simian immunodeficiency virus (SIV) has evolved into many strains, classified by the natural host species. SIV strains of the African green monkey (SIVagm) and sooty mangabey (SIVsmm) are thought to have a long evolutionary history with their hosts. These hosts have adapted to the presence of the virus, which is present at high levels in the host's blood, but evokes only a mild immune response, does not cause the development of simian AIDS, and does not undergo the extensive mutation and recombination typical of HIV infection in humans. In contrast, when these strains infect species that have not adapted to SIV ("heterologous" or similar hosts such as rhesus or cynomologus macaques), the animals develop AIDS and the virus generates genetic diversity similar to what is seen in human HIV infection. Chimpanzee SIV (SIVcpz), the closest genetic relative of HIV-1, is associated with increased mortality and AIDS-like symptoms in its natural host.
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See in review During a sabbatical year in 1998-99 at the Institute for Theoretical Physics in UC Santa Barbara and at the Curie Institute in Paris, Gelbart became deeply intrigued by viruses and over the course of the next several years, with his UCLA colleague Charles Knobler, established a laboratory to investigate simple viruses outside their hosts and isolated in test tubes. Early results included: the first measurement of pressure inside DNA viruses, establishing that it is as high as tens of atmospheres depending on genome length and ambient salt concentrations; and the demonstration that capsid proteins from certain viruses are capable of complete in vitro packaging of a broad range of lengths of heterologous RNA.See review: This work, along with that of several other groups in the United States and Europe, helped launch the field of "physical virology". Most recently he moved his viruses from test tubes to host cells, and from wildtype viruses to artificial viruses and virus-like particles, engineered for purposes of delivering self- replicating RNA genes, RNA vaccines, and therapeutic microRNA to targeted mammalian cells.
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There is debate over the naming of MMMT; the term carcinosarcoma was formerly used to describe lesions with homologous tumors, and "malignant mixed Müllerian tumor" or "mixed mesodermal tumor" was used to describe heterologous tumors. While "carcinosarcoma" now considered standard, "malignant mixed Müllerian tumor" has a lengthy history within gynecological literature and is expected to continue to be used. The naming issue to a certain extent reflects histological characteristics and development of the tumors, in which the different types of tissues are believed to either develop separately and join into a single mass (the "collision" theory), that an adenocarcinoma stimulates the stroma to create a tumor (the "composition" theory), or that the tumor is the result of a stem cell that differentiates into different cell types (the "combination" theory). "Collision" tumors are normally easily recognized and not considered true MMMTs; the "combination" theory is most widely held, and is due to evidence that the tumors develop from a single line of cells, developing in a fashion similar to the fundus of the uterus from the Müllerian duct - first from a stem cell into a population of cells, that then differentiates into epithelial and stromal components.
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5:424–434, 1962 In 1962, Fiers moved to Madison, Wisconsin, to work in the laboratory of future Nobel laureate, Gobind Khorana. At the end of 1962, Fiers returned to Belgium and set up the Laboratory of Molecular Biology at the University of Ghent. His research involved Bacteriophage MS2; he was the first to establish the complete nucleotide sequence of a gene (1972) and of a viral genome (bacteriophage MS2)(1976).Min Jou W, Haegeman G, Ysebaert M, Fiers W., Nucleotide sequence of the gene coding for the bacteriophage MS2 coat protein, Nature. 1972 May 12;237(5350):82–8Fiers W, Contreras R, Duerinck F, Haegeman G, Iserentant D, Merregaert J, Min Jou W, Molemans F, Raeymaekers A, Van den Berghe A, Volckaert G, Ysebaert M., Complete nucleotide-sequence of bacteriophage MS2-RNA - primary and secondary structure of replicase gene, Nature, 260, 500–507, 1976 In 1978 Fiers and his team were the first to reveal the complete nucleotide-sequence of SV40.Fiers W, Contreras R, Haegemann G, Rogiers R, Van de Voorde A, Van Heuverswyn H, Van Herreweghe J, Volckaert G, Ysebaert M., Complete nucleotide-sequence of SV40 DNA, Nature, 273, 113–120, 1978 The development of totally new procedures and knowledge led to the ability to clone almost any gene and to replicate these efficiently into bacteria or in other heterologous hosts.
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