Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Translation in vitro of the mRNA coding for the vesicular stomatitis virus membrane glycoprotein G in a membrane-free ribosomal extract from HeLa cells allowed the synthesis of only the unglycosylated protein G1 (molecular weight, 63,000). Addition of stripped crude microsomal membranes from HeLa cells resulted in the conversion of G1 to the glycosylated protein G2 (molecular weight, 67,000). The G2 protein synthesized by the reconstructed microsomal membrane/ribosome system was found to be segregated inside the microsomal membrane vesicles and was thus protected from the proteolytic action of trypsin and chymotrypsin. Stripped membranes were required at an early stage of protein synthesis for the synthesized protein to be inserted into the membrane vesicles and to be glycosilated. The segregated protein G2, however, was not completely protected from proteolytic digestion, showing that a portion of the polypeptide chain of about 3000 daltons was present on the cytoplasmic side of the membrane vesicle. Our data thus suggest that, unlike the secretory proteins, the membrane glycoproteins are not completely discharged across the microsomal membranes.
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PMID:In vitro synthesis of vesicular stomatitis virus membrane glycoprotein and insertion into membranes. 20 29

The synthesis of the complex-type oligosaccharide unit of the vesicular stomatitis virus G protein is initiated by the en bloc transfer of a high molecular weight oligosaccharide from a lipid carrier to the nascent polypeptide. Following transfer the oligosaccharide is "processed" by removal of glucose and mannose residues and the sugars that constitute the outer branches of the complex-type oligosaccharide are added. The structure of the oligosaccharide moiety of the lipid-linked precursor has been elucidated in order to further define the steps involved in processing. Since it was not feasible to obtain adequate amounts of material for standard structural studies, most of the structural studies were performed on radiolabeled material, with radioactivity incorporated differentially into glucose, mannose, and N-acetylglucosamine. Based on endo-beta-N-acetylglucosaminidase CII digestion, alpha-mannosidase digestion, acetolysis, Smith periodate degradation, methylation analysis, and periodate oxidation, we propose the following structure for the oligosaccharide moiety of the lipid-linked oligosaccharide.
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PMID:The synthesis of complex-type oligosaccharides. I. Structure of the lipid-linked oligosaccharide precursor of the complex-type oligosaccharides of the vesicular stomatitis virus G protein. 21 34

Previous work has shown that the mRNA encoding the vesicular stomatitis virus (VSV) glycoprotein (G) is bound to the rough endoplasmic reticulum (RER) and that newly made G protein is localized to the RER. In this paper, we have investigated the topology and processing of the newly synthesized G protein in microsomal vesicles. G was labeled with [35S]methionine ([35S]met), either by pulse-labeling infected cells or by allowing membrane-bound polysomes containing nascent G polipeptides to complete G synthesis in vitro. In either case, digestion of microsomal vesicles with any of several proteases removes approximately 5% (30 amino acids) from each G molecule. These proteases will digest the entire G protein if detergents are present during digestion. Using the method of Dintzis (1961, Proc. Natl. Acad. Sci. U. S. A. 47:247--261) to order tryptic peptides (8), we show that peptides lost from G protein by protease treatment of closed vesicles are derived from the carboxyterminus of the molecule. The newly made VSV G in microsomal membranes is glycosylated. If carbohydrate is removed by glycosidases, the resultant peptide migrates more rapidly on polyacrylamide gels than the unglycosylated, G0, form synthesized in cell-free systems in the absence of membranes. We infer that some proteolytic cleavage of the polypeptide backbone is associated with membrane insertion of G. Further, our findings demonstrate that, soon after synthesis, G is found in a transmembrane, asymmetric orientation in microsomal membranes, with its carboxyterminus exposed to the extracisternal, or cytoplasmic, face of the vesicles, and with most or all of its amino-terminal peptides and its carbohydrate sequestered within the bilayer and lumen of the microsomes.
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PMID:Transmembrane biogenesis of the vesicular stomatitis virus glycoprotein. 22 71

The virion-associated RNA transcriptase activity of vesicular stomatitis virus New Jersey temperature-sensitive (ts) mutants was assayed in vitro at the permissive (31 degrees C) and restrictive (39 degrees C) temperatures. RNA synthesis at 39 degrees C by the RNA-negative ts A1 and the RNA-positive ts C1 and ts D1 mutants was similar to that of wild-type virus. The RNA-negative ts B1 synthesized only small amounts of RNA in vitro at 39 degrees C. The three mutants of complementation group E were dissimilar in the amounts of RNA they synthesized at 39 degrees C: ts E1 synthesized very little RNA, ts E2 synthesized moderate amounts, and RNA synthesis by ts E3 was not inhibited. The two mutants of group F were also dissimilar, since ts F1 synthesized very little RNA at 39 degrees C, whereas ts F2 synthesized as much RNA as wild-type virus. The revertant clones ts B1/R1, ts E1/R1, and ts F1/R1 synthesized RNA at 39 degrees C in amounts comparable to wild-type virus, indicating that the heat sensitivity of the transcriptase activity of the mutants ts B1, ts E1, and ts F1 was associated with temperature sensitivity. Similar heat sensitivities were observed when transcribing nucleoprotein complexes were used in the assays, showing that the mutated polypeptides were part of the viral core. The heat stability of the mutant ts B1 was similar to that of wild-type virus, and in vitro RNA synthesis was fully restored when the temperature was lowered to 31 degrees C after 30 min of preincubation at 39 degrees C, showing that the inhibition was due to reversible configurational change of the mutated polypeptide. When virions of the mutant ts E1 were heated for 5 h at 39 degrees C, their infectivity and transcriptase activity were as stable as those of the wild-type virus, whereas transcriptase activity became very heat labile after disruption of the viral coat with a neutral detergent. This suggests an interaction between the mutated polypeptide and a coat polypeptide which stabilizes the activity of the transcriptase. The RNA transcriptase activity of the mutant ts F1 was also heat labile, although to a lesser extent than that of ts E1. Thus, the defects in transcriptase activity of groups B, E, and F suggest that all three polypeptides of the virus core, polypeptides L, N, and NS, are involved in the transcription. In addition, we postulate that the mutated gene products of groups E and F are multifunctional, being required both in transcription and replication, and that the gene product of group E may also be involved in some late stage of virus development.
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PMID:Effect of temperature-sensitive mutation on activity of the RNA transcriptase of vesicular stomatitis virus New Jersey. 22 38

In vesicular stomatitis virus New Jersey serotype polyacrylamide gel electrophoresis was unable to distinguish the polypeptides of the temperature-sensitive (ts) mutants of complementation groups A, B, C, and F from those of the wild-type virus. However, the NS polypeptide of the representative mutant of group E, ts E1, had a significantly greater electrophoretic mobility than that of the wild-type virus NS polypeptide. The electrophoretic mobilities of the NS polypeptides of the three mutants of complementation group E varied, being greatest in the case of ts E1, slightly less for ts E2, and only a little greater than that of wild-type virus NS polypeptide in the case of ts E3. Since the NS polypeptides of the revertant clones ts E1/R1 and ts E3/R1 have mobilities identical to that of wild-type NS polypeptide, the observed altered mobilities of the group E mutants are almost certainly the direct result of the ts mutations in the E locus. The electrophoretic mobilities of the intracellular NS polypeptides of the group E mutants were indistinguishable from those of their virion NS polypeptides. The electrophoretic mobilities of the NS polypeptides of the group E mutants synthesized in vitro using mRNA synthesized in vitro by TNP were identical to those of the NS polypeptides of their purified virions. The NS polypeptides of all three mutants were labeled with (32)P(i) to approximately the same extent as wild-type virus NS polypeptide, indicating that gross differences in phosphorylation of this polypeptide are unlikely to account for the altered mobilities. We propose a model in which the NS polypeptide consists of at least three loops held in this configuration by hydrophobic or ionic forces or both and stabilized by phosphodiester bridges. If a mutation affects one of the amino acids to which the phosphate is covalently linked, the phosphodiester bridge cannot be formed, and, as a result, in the presence of sodium dodecyl sulfate the affected loop opens and thus the NS polypeptide migrates further into the gel. Such a configuration may also explain the multifunctional nature of the NS polypeptide.
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PMID:Temperature-sensitive mutants of complementation group E of vesicular stomatitis virus New Jersey serotype possess altered NS polypeptides. 22 57

Pulse-chase labeling and cell fractionation were used to examine the pathways taken by the three nucleocapsid polypeptide species of vesicular stomatitis virus into nucleocapsids and then into virions. An improved method of polyacrylamide gel electrophoresis resolved nucleocapsid polypeptides N and NS from cellular actin, facilitating accurate quantitation of the viral polypeptides. Contrary to previous belief, the rate of NS synthesis was found to be a constant fraction of total virus protein synthesis throughout infection, indicating a consistent mechanism of virus protein synthesis regulation. In the kinetic studies, each polypeptide species displayed the following characteristic behavior. (i) Structural polypeptide N was the only species that entered a metabolically active soluble pool before assembly into nucleocapsids. The size of this pool increased with time after infection, causing an increasing delay in the appearance of pulse-labeled N molecules in nucleocapsids. (ii) Throughout infection, the entire complement of L molecules entered nucleocapsids immediately after their synthesis, without diversion through a soluble pool. (iii) Although 75% of newly synthesized molecules of the transcriptase-associated protein NS entered a soluble pool, they never emerged from the compartment. At all times after infection, about 25% of the NS molecules bypassed the soluble pool and entered nucleocapsids directly after their synthesis, as if in concert with L. These results indicate that VSV nucleocapsid assembly in vivo is a stepwise process, comprising an initial condensation of N with the viral RNA, followed by attachment of L and NS, analogous to the stepwise assembly of Sendai virus nucleocapsids. (D. W. Kingsbury, C.-H. Hsu, and K. G. Murti. Virology 91:86-94, 1978). About half of the intracellular nucleocapsids were recovered in a form that sedimented at anomalously low centrifugal forces, reflecting an association with large cellular organelles. This attachment was mediated mainly by electrostatic forces, since these "bound" nucleocapsids were released by elevated salt concentrations. The kinetic behavior of nucleocapsid polypeptides was the same in both fractions, providing no evidence for a division of nucleocapsid functions between cellular compartments.
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PMID:Assembly of vesicular stomatitis virus nucleocapsids in vivo: a kinetic analysis. 23 81

The components of biological membranes are asymmetrically distributed between the membrane surfaces. Proteins are absolutely asymmetrical in that every copy of a polypeptide chain has the same orientation in the membrane, and lipids are nonabsolutely asymmetrical in that almost every type of lipid is present on both sides of the bilayer, but in different and highly variable amounts. Asymmetry is maintained by lack of transmembrane diffusion. Two types of membrane proteins, called ectoproteins and endoproteins, are distinguished. Biosynthetic pathways for both types of proteins and for membrane lipids are inferred from their topography and distribution in the formed cells. Note added in proof. A cell-free system has now been developed which permits the mechanisms of membrane protein assembly to be studied (108). The membrane glycoprotein of vesicular stomatitis virus has been synthesized by wheat germ ribosomes in the presence of rough endoplasmic reticulum from pancreas. The resulting polypeptide is incorporated into the membrane, spans the lipid bilayer asymmetrically, and is glycosylated (108). The amino terminal portion of this transmembrane protein is found inside the endoplasmic reticulum vesicle, while the carboxyl terminal portion is exposed on the outer surface of the vesicle. Furthermore, addition of the glycoprotein to membranes after protein synthesis does not result in incorporation of the protein into the membrane in the manner described above (108). Consequently, protein synthesis and incorporation into the membrane must be closely coupled. Indeed, using techniques to synchronize the growth of nascent polypeptides, it has been shown (109) that no more than one-fourth of the glycoprotein chain can be made in the absence of membranes and still cross the lipid bilayer when chains are subsequently completed in the presence of membranes. These findings demonstrate directly that the extracytoplasmic portion of an ectoprotein can cross the membrane only during biosynthesis, and not after.
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PMID:Membrane asymmetry. 40 30

Purified reticulocyte initiation factors were assayed for their ability to stimulate the translation of uncapped vesicular stomatitis virus (VSV) mRNA relative to capped VSV mRNA in reticulocyte lysates. Both eIF-3 and eIF-4B preparations contained such an activity. However, at least some of the activity was due to the presence of an as yet unidentified factor that contaminated the eIF-3 and eIF-4B preparations. A polypeptide of apparent molecular weight 24,000 that can be specifically cross-linked to the oxidized 5'-terminal cap structures of reovirus and other viral mRNAs co-purifies with this new factor, and may be a component of it. This stimulatory activity present in our eIF-4B preparations was found to be greater when lower concentrations of KCl were present in the reaction mixture, possibly explaining why uncapped VSV mRNA is translated relatively more efficiently at low K+ concentrations.
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PMID:Characterization of rabbit reticulocyte factor(s) that stimulates the translation of mRNAs lacking 5'-terminal 7-methylguanosine. 76 41

Viruses isolated from fish with viral haemorrhagic septicaemia (VHS), infectious haematopoietic necrosis (IHN), spring viraemia of carp (SVC), swim-bladder inflammation (SBI) and pike fry disease (PFD) have been grown to high titre in fathead minnow cells. While our preparations of the IHN, SVC, SBI and PFD viruses showed typical rhabdovirus morphology with bullet-shaped particles and distinct surface projections, the VHS virus preparations had a less typical rhabdovirus morphology but were pleomorphic with a preponderance of flexuous rods. Using virus labelled with [-3H]-uridine, it was shown that each virus contained RNA which sedimented at 38 to 40 S and was hydrolysed by very low concentrations of ribonuclease. The viruses of SVC, PFD and SBI had a polypeptide composition similar to that of vesicular stomatitis virus, the prototype rhabdovirus, but the IHN and VHS viruses gave a pattern similar to that of rabies virus. In serum neutralization tests the SVC and SBI viruses were indistinguishable. VHS virus showed no serological relationship with the other four viruses but there was a low level of cross-reaction between the PFD, IHN and SVC-SBI viruses.
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PMID:Physico-chemical and serological characterization of five rhabdoviruses infecting fish. 117 Feb 78

We investigated a 73-kDa polypeptide (p73), a minor component of the rabies virion (HEP-Flury and ERA strains), accounting for as much as 1% of total virion proteins. Two-dimensional gel electrophoresis and immunoblotting with the antiserum against the heat shock protein 70 (hsp70) demonstrated that p73 was identical to a constitutive type of cellular hsp70. The antiserum also detected p73/hsp70 in the purified virions of other negative-stranded RNA viruses, such as vesicular stomatitis virus (New Jersey serotype), Newcastle disease virus (Miyadera strain), and influenza A virus (PR8 strain), among which, however, the contents were variable.
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PMID:Identification of heat shock protein 70 in the rabies virion. 132 9


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