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)

Palmitylation of vesicular stomatitis virus G and Sindbis virus E1 glycoproteins has been studied in relation to the transport from the endoplasmic reticulum (ER) to the Golgi complex. Incubation of infected cells at 15 degrees C prevents the transport of newly synthesized membrane proteins from the ER to the Golgi (Saraste, J., and Kuismanen, E. (1984) Cell 38, 535-549). In these conditions, also palmitylation of G protein and of E1 glycoprotein is blocked. When the transport is restored by increasing the temperature, palmitylation occurs quickly and is followed by the complete trimming of peripheral mannose residues due to mannosidase I (a putative cis-Golgi function). Immunofluorescence analysis showed that the G glycoprotein accumulated at 15 degrees C in structures distinct from both ER and Golgi. These studies suggest that transport from the ER to the cis-Golgi involves intermediate compartments.
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PMID:Palmitylation of viral membrane glycoproteins takes place after exit from the endoplasmic reticulum. 254 12

The vesicular stomatitis virus glycoprotein forms noncovalently linked trimers in the endoplasmic reticulum before being transported to the Golgi apparatus. The experiments reported here were designed to determine if the extracellular domain of the glycoprotein contains structural information sufficient to direct trimer formation. To accomplish this, we generated a construct encoding G protein with the normal transmembrane and anchor sequences replaced with the sequence encoding 53 C-terminal amino acids from the Thy-1.1 glycoprotein. We show here that these sequences were able to specify glycolipid addition to the truncated G protein, probably after cleavage of 31 amino acids derived from Thy-1.1. The glycolipid-anchored G protein formed trimers and was expressed on the cell surface in a form that could be cleaved by phosphoinositol-specific phospholipase C. However, the rate of transport was reduced, compared with that of wild-type G protein. A second form of the G protein was generated by deletion of only the transmembrane and cytoplasmic domains. This mutant protein also formed trimers with relatively high efficiency and was secreted slowly from cells.
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PMID:Oligomerization of glycolipid-anchored and soluble forms of the vesicular stomatitis virus glycoprotein. 255 57

The appearance of newly synthesized glycoprotein (G) of vesicular stomatitis virus at the surface of infected BHK cells is inhibited reversibly by treatment with carbonylcyanide m-chlorophenylhydrazone (CCCP). Under the conditions used, CCCP treatment depleted the cellular ATP levels by 40-60%, consistent with inhibition of transport at energy-requiring stages. The G protein that accumulates in cells treated with CCCP is heterogeneous. Most of it is larger than the newly synthesized G protein, is acylated with palmitic acid, and is resistant to endoglycosidase H (Endo H). Most of the arrested G protein is also sensitive to digestion with neuraminidase, indicating that it has undergone at least partial sialylation. A minority of G protein accumulates under these conditions in a less-mature form, suggesting its inability to reach the mid-Golgi compartment. The oligosaccharides of this G protein are Endo-H-sensitive and seem to be partly trimmed. Whereas sialylated G protein was arrested intracellularly, fucose-labelled G protein was able to complete its transport to the cell surface, indicating that a late CCCP-sensitive step separates sialylation from fucosylation. These post-translational modifications indicate that G protein can be transported as far as the trans-Golgi in the presence of CCCP and is not merely arrested in the endoplasmic reticulum.
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PMID:Intracellular transport of the glycoprotein of VSV is inhibited by CCCP at a late stage of post-translational processing. 255 59

The post-translational modifications of the G protein of vesicular stomatitis virus, described in the preceding paper, indicate that its transport is arrested by carbonylcyanide m-chlorophenylhydrazone (CCCP) in or near the trans-Golgi. Immunofluorescence microscopy of BHK-21 cells infected with vesicular stomatitis virus and treated with CCCP shows an accumulation of G protein in the Golgi area. In the same cells, the morphology of wheat germ agglutinin (WGA)-staining structures in the perinuclear region is aberrant. Using anti-BiP antibody, there is no obvious change in the structure of the endoplasmic reticulum. Electron microscopy reveals that the aberrant structures in the perinuclear region result from dilation of Golgi cisternae and accumulation of large vacuoles near the Golgi stack. The appearance of these aberrant structures is dose-dependent and they disappear after the protonophore is removed. The vast majority of the vacuoles accumulate on the trans side of the Golgi stack. A small fraction of them contain the marker enzyme thiamine pyrophosphatase (TPPase). By immunoelectron microscopy, most of the vacuoles contain G protein. We conclude that most of the Golgi-associated vacuoles are derived from a distal Golgi transport compartment, possibly the trans-Golgi reticulum, and that CCCP reversibly inhibits the transport of newly synthesized G protein through this distal compartment.
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PMID:The glycoprotein of VSV accumulates in a distal Golgi compartment in the presence of CCCP. 255 60

The generation and transport of the soluble glycoprotein (Gs) of wild-type vesicular stomatitis virus (VSV) were studied using cell fractionation and transport inhibitors. Gs was found in the rough endoplasmic reticulum (RER) and the Golgi-enriched membrane fractions of infected Chinese hamster ovary cells. The identity of intracellular Gs was confirmed by its precipitation with a monoclonal antibody to the ectodomain but not with a anti-peptide antibody directed against the first 15 amino acids at the carboxy terminus of the VSV transmembrane glycoprotein G. Their extracellular appearance was affected in a concentration-dependent manner by monensin and carbonyl cyanide m-chlorophenylhydrazone (CCCP) and was completely inhibited by incubation at 20 degrees. Inhibitors failed to dissociate the transport of Gs from G. These experiments indicate that in fibroblast cells Gs can be generated intracellularly, probably in the RER, and that Gs, like G, is transported from there to the Golgi complex and then presumably to the extracellular environment.
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PMID:Effects of transport inhibitors on the generation and transport of a soluble viral glycoprotein. 282 86

We have characterized the process by which the vesicular stomatitis virus (VSV) G protein acquires its final oligomeric structure using density-gradient centrifugation in mildly acidic sucrose gradients. The mature wild-type VSV G protein is a noncovalently associated trimer. Trimers are assembled from newly synthesized G monomers with a t1/2 of 6-8 min. To localize the site of trimerization and to correlate trimer formation with steps in transport between the endoplasmic reticulum (ER) and Golgi complex, we examined the kinetics of assembly of the temperature-sensitive mutant VSV strain, ts045. At the nonpermissive temperature (39 degrees C), ts045 G protein is not transported from the ER. The phenotypic defect that inhibited export from the ER at the nonpermissive temperature was found to be the accumulation of ts045 G protein in an aggregate. After being shifted to the permissive temperature (32 degrees C), the ts045 G protein aggregate rapidly dissociated (t1/2 less than 1 min) to monomeric G protein which subsequently trimerized with the same kinetics as the wild-type G protein. Only trimers were transported to the Golgi complex. Kinetic studies, as well as the finding that trimerization occurred under conditions which block ER to Golgi transport (at both 15 and 4 degrees C), showed that trimers were formed in the ER. Depletion of cellular ATP inhibited both the dissociation of the aggregated intermediate of ts045 G protein as well as the formation of stable trimers. The results indicate that oligomerization of G protein occurs in several steps, is sensitive to cellular ATP, and is required for transport from the ER.
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PMID:Role for adenosine triphosphate in regulating the assembly and transport of vesicular stomatitis virus G protein trimers. 282 24

In this report we have extended our studies on a panel of vesicular stomatitis virus G proteins with altered glycosylation sites. These mutant proteins were generated by oligonucleotide-directed mutagenesis of the coding sequence to create new consensus sites for asparagine-linked oligosaccharide addition. We report that the intracellular transport of most of the mutant proteins is temperature-sensitive, implying a polypeptide folding step is affected. In addition, we find that the nonglycosylated G protein and those mutant proteins which lack oligosaccharides at the normal positions are subject to aberrant intermolecular disulfide bonding, leading to the accumulation of large complexes in the endoplasmic reticulum. These results imply that carbohydrate plays an indirect role in the intracellular transport of G protein.
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PMID:Vesicular stomatitis virus G proteins with altered glycosylation sites display temperature-sensitive intracellular transport and are subject to aberrant intermolecular disulfide bonding. 283 24

Incubation of cultured cells at 20 degrees C blocks the transport of newly synthesized plasma membrane proteins, and the proteins accumulate intracellularly in a terminally glycosylated form. When baby hamster kidney cells are infected with the ts O45 mutant of vesicular stomatitis virus, and incubated at 20 degrees C, the terminally glycosylated spike glycoprotein G of the virus accumulates in the membranes of a tubular network localized on the trans side of the Golgi cisternae, the trans-Golgi network (TGN). We have used the G protein of ts O45 as a marker for the TGN and isolated a TGN fraction using a combination of conventional cell fractionation techniques and immunoisolation. The TGN was separated from the bulk of the endoplasmic reticulum, mitochondria, lysosomes, plasma membrane, and endosomes, while the activity of trans-Golgi marker galactosyltransferase copurified with the G protein. Using G protein as the TGN marker we have determined that the TGN was enriched 25-fold in the final fraction relative to the total homogenate. Several polypeptides (Mr 75,000, 87,000, 92,000, and 120,000) copurified with the G protein in the isolated TGN fraction and most likely represent resident markers of the compartment.
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PMID:Isolation of a fraction enriched in the trans-Golgi network from baby hamster kidney cells. 283 10

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

We have examined the requirement for ribonucleotides and ribonucleotide triphosphate hydrolysis during early events in the membrane integration of two membrane proteins: the G protein of vesicular stomatitis virus and the hemagglutinin-neuraminidase (HN) glycoprotein of Newcastle disease virus. Both proteins contain a single transmembrane-spanning segment but are integrated in the membrane with opposite orientations. The G protein has an amino-terminal signal sequence and a stop-transfer sequence located near the carboxy terminus. The HN glycoprotein has a single sequence near the amino terminus that functions as both a signal-sequence and a transmembrane-spanning segment. Membrane insertion was explored using a cell-free system directed by transcribed mRNAs encoding amino-terminal segments of the two proteins. Ribosome-bound nascent polypeptides were assembled, ribonucleotides were removed by gel filtration chromatography, and the ribosomes were incubated with microsomal membranes under conditions of defined ribonucleotide content. Nascent chain insertion into the membrane required the presence of both the signal recognition particle and a functional signal recognition particle receptor. In the absence of ribonucleotides, insertion of nascent membrane proteins was not detected. GTP or nonhydrolyzable GTP analogues promoted efficient insertion, while ATP was comparatively ineffective. Surprisingly, the majority of the HN nascent chain remained ribosome associated after puromycin treatment. Ribosome-associated HN nascent chains remained competent for membrane insertion, while free HN chains were not competent. We conclude that a GTP binding protein performs an essential function during ribosome-dependent insertion of membrane proteins into the endoplasmic reticulum that is unrelated to protein synthesis.
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PMID:Integration of membrane proteins into the endoplasmic reticulum requires GTP. 283 21


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