Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038362 (stomatitis)
 8,852 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Low light level video microscopy of the fusion of DiI- (1,1'-dihexadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate) labeled rabbit erythrocyte ghosts with unlabeled rabbit erythrocyte ghosts, held in stable apposition by dielectrophoresis in sodium phosphate buffers, showed reproducible time intervals (delays) between the application of a single fusogenic electric pulse and the earliest detection of fluorescence in the unlabeled adjacent membranes. The delay increased over the range 0.3-4 s with a decrease in (i) the electric field strength of the fusion-inducing pulse from 1000 to 250 V/mm, (ii) the decay half-time of the fusogenic pulse in the range 1.8-0.073 ms, and (iii) the dielectrophoretic force which brings the membranes into close apposition. A change in the buffer viscosity from 1.8 to 10 mP.s caused the delay to increase from 0.36 to 3.7 s (in glycerol solutions) or to 5.2 s (in sucrose solutions). The delay decreased 2-3 times with an increase in temperature from 21 to 37 degrees C. It did not differ significantly for "white" ghosts [0.013 mM hemoglobin (Hb)] or "red" ghosts (0.15 mM Hb) or buffer strength over the range 5-60 mM (sodium phosphate, pH 8.5). The calculated activation energy, 17 kcal/mol, does not depend on the field strength. The yield of fused cells was high when the delay was short. The delay in electrofusion resembles the delays in pH-dependent fusion of vesicular stomatitis viruses with erythrocyte ghosts [Clague, M. J., Schoch, C., Zech, L., & Blumenthal, R. (1990) Biochemistry 29, 1303-1308] and of fibroblasts expressing influenza hemagglutinin and red blood cells [Morris, S. J., Sarkar, D.P., White, J. M., & Blumenthal, R. (1989) J. Biol. Chem. 264, 3972-3978].(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A delay in membrane fusion: lag times observed by fluorescence microscopy of individual fusion events induced by an electric field pulse. 217 98

We have used cell fusion to address the question of whether macromolecules are rapidly exchanged between lysosomes. Donor cell lysosomes were labeled by the long-term internalization of the fluid-phase pinocytic markers, invertase (sucrase), Lucifer Yellow, FITC-conjugated dextran, or Texas red-conjugated dextran. Recipient cells contained lysosomes swollen by long-term internalization of dilute sucrose or marked by an overnight FITC-dextran uptake. Cells were incubated for 1 or 2 h in marker-free media before cell fusion to clear any marker from an endosomal compartment. Recipient cells were infected with vesicular stomatitis virus as a fusogen. Donor and recipient cells were co-cultured for 1 or 2 h and then fused by a brief exposure to pH 5. In all cases, extensive exchange of content between donor and recipient cell lysosomes was observed at 37 degrees C. Incubation of cell syncytia at 17 degrees C blocked lysosome/lysosome exchange, although a "priming" process(es) appeared to occur at 17 degrees C. The kinetics of lysosome/lysosome exchange in fusions between cells containing invertase-positive lysosomes and sucrose-positive lysosomes indicated that lysosome/lysosome exchange was as rapid, if not more rapid, than endosome/lysosome exchange. These experiments suggest that in vivo the lysosome is a rapidly intermixing organellar compartment.
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PMID:Chinese hamster ovary cell lysosomes rapidly exchange contents. 244 96

We carried out experiments designed to generate a novel cell-surface protein from a small glycosylated secretory protein. DNA encoding the entire precursor of human chorionic gonadotropin (hCG, alpha subunit) was fused precisely to DNA encoding the transmembrane and cytoplasmic domains of the vesicular stomatitis virus glycoprotein. When expressed in animal cells this DNA encoded the 92-amino acid hCG-alpha subunit anchored in cellular membranes by an extension composed of the 49 carboxyl-terminal amino acids of vesicular stomatitis virus glycoprotein. This hybrid protein was transported efficiently to the plasma membrane of animal cells. The two asparagine-linked glycans on the anchored form of hCG-alpha were large and heterogeneous when compared to those on the secretory form. Experiments employing in vitro mutagenesis and the glycosylation inhibitor tunicamycin established that the presence of at least one of the two asparagine-linked glycans was required for expression of the anchored molecule on the cell surface. However, as reported previously, secretion of hCG-alpha occurred in the absence of glycosylation. Also, mutations eliminating the second glycosylation site (at amino acid 78) in both the anchored or secreted forms apparently led to partial denaturation or a conformational change interfering with transport of the protein.
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PMID:Cell-surface expression of a membrane-anchored form of the human chorionic gonadotropin alpha subunit. 245 67

Two integral membrane proteins, influenza virus hemagglutinin (HA) and vesicular stomatitis virus G protein, are transported to and accumulated on the apical and basolateral surfaces, respectively, of the plasma membrane of polarized epithelial cells. We have used chimeric constructions to identify the domains of HA and G proteins which contain the signals for polarized transport. Previously, we have shown that a chimeric protein containing the cleavable leader and the ectodomain of HA fused to the anchoring and cytoplasmic domains of G is transported to the apical surface of polarized MDCK cells (McQueen, N.L., Nayak, D.P., Stephens, E.B., and Compans, R.W. (1986) Proc. Natl. Acad. Sci. U.S.A. 83, 9318-9322). In this report we show that a chimera containing the cleavable leader and ectodomain of G fused to the anchoring and cytoplasmic domains of HA is transported to the basolateral surface of polarized cells. Another chimera which contains the leader sequence of G fused to leader minus HA is transported to the apical surface of polarized cells. These results taken together suggest that the signals for the polarized transport of HA and G proteins may reside in their ectodomains.
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PMID:Basolateral expression of a chimeric protein in which the transmembrane and cytoplasmic domains of vesicular stomatitis virus G protein have been replaced by those of the influenza virus hemagglutinin. 282 83

Recently, we fused a matrix-targeting signal to a large fragment of vesicular stomatitis virus G protein, which contains near its COOH-terminus a well-characterized endoplasmic reticulum (ER) stop-transfer sequence; the hybrid G protein was sorted to the inner mitochondrial membrane (Nguyen, M., and G. C. Shore. 1987. J. Biol. Chem. 262:3929-3931). Here, we show that the 19 amino acid G stop-transfer domain functions in an identical fashion when inserted toward the COOH-terminus of an otherwise normal matrix precursor protein, pre-ornithine carbamyl transferase; after import, the mutant protein was found anchored in the inner membrane via the stop-transfer sequence, with its NH2 terminus facing the matrix and its short COOH-terminal tail located in the intermembrane space. However, when the G stop-transfer sequence was placed near the NH2 terminus, the protein was inserted into the outer membrane, in the reverse orientation (NH2 terminus facing out, with a large COOH-terminal fragment located in the intermembrane space). These observations for mitochondrial topogenesis can be explained by a simple extension of existing models for ER sorting.
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PMID:Protein sorting between mitochondrial membranes specified by position of the stop-transfer domain. 283 33

In this study, we present a new general approach for immuno-isolation: a foreign integral membrane protein, the G-protein of vesicular stomatitis virus (VSV), is implanted into the plasma membrane for subsequent immuno-isolation. A quantitative analysis was accomplished using the erythrocyte plasma membrane as a model system. The virus was artificially bound to the membrane via a lectin and subsequently fused at low pH. Vesicles of two opposite orientations were prepared from erythrocytes with fused G-protein. Right-side-out and inside-out vesicles expose the exoplasmic and the cytoplasmic domains of the G-protein on their surfaces respectively. In immuno-isolation experiments antibodies against each of the domains of the G-protein were used. Vesicles were presented to an immunoadsorbent (ImAd) consisting of a solid support with appropriate antibodies bound to its surface. Two commonly used immunoadsorbents prepared from either polyacrylamide beads or fixed Staphylococcus aureus cells were compared and found to have identical immuno-isolation efficiencies. It was possible to control and quantitate the amount of implanted antigen. Therefore, we were able to show that the critical antigen density required for immuno-isolation is 50 G molecules/micron2 plasma membrane surface area for both types of vesicle/antibody couples. This analysis showed that vesicles presenting either the cytoplasmic or the exoplasmic domain of the G-protein are immuno-isolated with the same efficiency.
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PMID:Immuno-isolation of vesicles using antigenic sites either located on the cytoplasmic or the exoplasmic domain of an implanted viral protein. A quantitative analysis. 299 34

cDNAs encoding either the structural proteins (capsid and glycoproteins E1 and E2) of Sindbis virus or the glycoprotein of vesicular stomatitis virus (VSV) were fused to the Saccharomyces cerevisiae galactokinase gene (GAL1) promoter and inserted into a yeast shuttle vector. After addition of galactose to yeast transformed with this vector, 2.5-3% of total yeast protein synthesis was detected as virus proteins by specific anti-virus protein antibodies. In cells containing the Sindbis virus structural genes, the virus capsid protein was effectively released from the nascent polypeptide and two endoglycosidase H-sensitive glycoproteins were produced. One of these was identical in its gel mobility to E1 and the other appeared to be p62, a precursor to E2. A low level of E1 protein was detected on the cell's surface membranes. A single molecular weight species of glycosylated VSV glycoprotein was produced and half of the total protein could be detected at the surface membranes of yeast. Addition of long mannose chains and acylation of the virus proteins with fatty acids were not observed. Formation of virus proteins was also examined in yeast secretory mutants; one of these (sec53) failed to glycosylate the virus proteins.
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PMID:Regulated expression of Sindbis and vesicular stomatitis virus glycoproteins in Saccharomyces cerevisiae. 301 23

We have attempted to rescue presumptive human endogenous retrovirus(es) by using a competent animal oncovirus as a helper. Human melanoma cells (line HMB2) were fused, using polyethylene glycol, with mouse NIH-3T3 cells which had been infected and transformed by the Harvey murine leukaemia and sarcoma virus complex (MLV and MSV). The heteropolykaryons obtained were co-cultivated with fresh NIH-3T3 cells; filtered (Millipore 0.22 micron) medium from these was used to infect further NIH-3T3 cells. In these cells after several passages, vesicular stomatitis virus (VSV) pseudotypes could be produced. These were infectious not only for mouse cells (manifesting the helper MLV), but also for human cells (HeLa, HEC human embryo fibroblasts, HMB2); they were not infectious for CCL64 (mink) or for Vero (African green monkey) cells. The presence of such VSV pseudotypes infectious for human cells indicated that a human ecotropic virus [provisionally named rescued human virus (RHV)] had been rescued by the fusion of human melanoma cells with MLV-infected mouse cells. This was supported by the following evidence. The human-specific pseudotype was neutralized by sheep antisera raised to antigens selected by VSV from human tumour cell lines HMB2, T47D and HeLa. These antisera also aggregated NIH cells infected with MLV and RHV. Mouse antisera raised to antigens present in HIH cells infected with MLV and RHV, in contrast to sera raised to NIH cells infected with MLV only, immunoprecipitated an 85,000 mol. wt. protein band from human cells (HEC, HMB2 and HeLa) surface-labelled with 125I.
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PMID:Rescue of presumptive viral information from human cells by a helper oncovirus. 301 51

The nucleocapsid of vesicular stomatitis virus (VSV) was introduced into the cytoplasm of Saccharomyces cerevisiae by low pH-dependent fusion of the viral envelope with the spheroplast plasma membrane. This led to de novo synthesis of the three major structural proteins of the virus--the G, N, and M proteins--as shown by immunoprecipitation of [35S]methionine-labeled spheroplast lysates. In NaDodSO4/polyacrylamide gel electrophoresis, M and N proteins comigrated with those of the virion, whereas the yeast-made G protein migrated as two bands with apparent molecular sizes of 60 and 70 kDa. Both polypeptides appeared to be N-glycosylated, since only one polypeptide with the apparent molecular mass of approximately equal to 55 kDa was produced in the presence of tunicamycin. Phase separation into Triton X-114 suggested that the unglycosylated G protein was membrane bound. According to immunofluorescent surface staining of live spheroplasts, at least part of the G protein was transported to the plasma membrane. Spheroplasts expressing the VSV genes could be fused together by low pH to form polykaryons, indicating that G protein synthetized by yeast was fusogenic--i.e., biologically active.
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PMID:Expression of the RNA genome of an animal virus in Saccharomyces cerevisiae. 302 81

cDNA fusions were employed to construct a 35-kDa hybrid protein bearing the amino-terminal signal sequence of pre-ornithine carbamoyltransferase (pOCT), a mitochondrial matrix enzyme, fused to the carboxyl-terminal half of vesicular stomatitis virus G protein (VSV G). Following transcription-translation in vitro, the hybrid protein was imported by purified mitochondria and processed at its amino terminus by the matrix processing enzyme. The protein, however, remained anchored in the mitochondrial inner membrane, apparently in a transmembrane configuration, via the hydrophobic VSV G stop-transfer domain; a small portion (approximately 2 kDa) of the G protein fragment was accessible to protease digestion only after selective permeabilization of the mitochondrial outer membrane with digitonin, a finding consistent with localization of the extreme carboxyl-terminal cytoplasmic tail of G in the intermembrane space. The results demonstrate that the membrane-anchor domain of VSV G can function in a post-translational manner and can operate in membranes other than those derived from the endoplasmic reticulum. However, it appears to be selectively recognized as a stop-transfer signal by the translocation machinery of the mitochondrial inner, rather than outer, membrane.
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PMID:Import of hybrid vesicular stomatitis G protein to the mitochondrial inner membrane. 303 Oct 55


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