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)

In this report, we have investigated the contribution of primary sequence to the carbohydrate requirement for intracellular transport of two closely related glycoproteins, the G proteins of the San Juan and Orsay strains of vesicular stomatitis virus. We used site-directed mutagenesis of the coding sequence to eliminate the two consensus sites for glycosylation in the Orsay G protein. Whereas the nonglycosylated San Juan G protein required at least one of its two asparagine-linked oligosaccharides for transport to the plasma membrane at 37 degrees C, a fraction of the Orsay G protein was transported without carbohydrate. Of the 10 amino acid differences between these two proteins, residue 172 (tyrosine in San Juan, aspartic acid in Orsay) played the major role in determining the stringency for the carbohydrate requirement. The rates at which the glycosylated and nonglycosylated Orsay G proteins were transported to the cell surface were the same, although a smaller fraction of the nonglycosylated protein was transported. These results suggest that the carbohydrate does not promote intracellular transport directly but influences a polypeptide folding or oligomerization step which is critical for transport.
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PMID:A single-amino-acid substitution eliminates the stringent carbohydrate requirement for intracellular transport of a viral glycoprotein. 276 Sep 84

Sequences were determined of the coding regions of the M-protein genes of the Glasgow and Orsay strains of vesicular stomatitis virus (Indiana serotype) and of two group III (M-protein) mutants derived from each wild type. Synthetic primers were annealed with viral genomic RNA and extended with reverse transcriptase. The resulting high-molecular-weight cDNA was sequenced directly. Both Glasgow and Orsay wild types differed in 13 bases from a clone of the San Juan strain sequenced by J. K. Rose and C. J. Gallione (J. Virol. 39:519-528, 1981). Six of these base changes caused amino acid changes in each wild type, whereas seven were degenerate. The Orsay and Glasgow sequences resembled each other more closely than either resembled that of Rose and Gallione, differing in eight nucleotides and four amino acids. Each of the four mutants, however, differed from its parent wild type in only one or two point mutations. Every mutation caused a change either from or to a charged amino acid; the change for tsG31 was Lys (position 215) to Glu, the change for tsO23 was Gly (position 21) to Glu, the change for tsO89 was Ala (position 133) to Asp, the changes for tsG33 were Lys (position 204) to Thr and Glu (position 214) to Lys. The charge differences predicted from these amino acid changes was confirmed by nonequilibrium pH gradient electrophoresis for tsG31, tsG33, tsO23, and the two wild types. These mutations affect residues spanning nearly 85% of the linear sequence, although the mutants possess nearly identical phenotypic properties.
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PMID:Sequence alterations in temperature-sensitive M-protein mutants (complementation group III) of vesicular stomatitis virus. 299 21

Cyclic administration of methotrexate (MTX) and L-Asparaginase (L-Asp) was utilized either as induction and maintenance chemotherapy or as maintenance chemotherapy alone following induction with other medications in treating 36 children with multiple relapses of acute leukemia. A complete remission rate (CR) of 67% was obtained in children with null-cell acute lymphocytic leukemia (ALL). The average length of remission was greater than four months. One of three patients with T-cell ALL and one of two patients with B-cell ALL achieved CR. In six cases of acute nonlymphocytic leukemia (ANLL), two patients achieved CR. One of two patients with terminal deoxynucleotidyl transferase (TdT) negative myeloblastic transformation of Ph'-positive chronic myelogenous leukemia (CML) obtained a CR lasting 20 weeks. Toxicity secondary to the chemotherapy included bone marrow suppression, hepatic injury, nausea, diarrhea, stomatitis, and allergic reactions to L-Asp. One case of subacute necrotizing leukoencephalopathy was seen.
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PMID:Methotrexate/L-asparaginase combination chemotherapy for patients with acute leukemia in relapse: a study of 36 children. 696 21

The carboxyl-terminal Lys-Asp-Glu-Leu (KDEL), or a closely-related sequence, is important for ER localization of both lumenal as well as type II membrane proteins. This sequence functions as a retrieval signal at post-ER compartment(s), but the exact compartment(s) where the retrieval occurs remains unresolved. With an affinity-purified antibody against the carboxyl-terminal sequence of the mammalian KDEL receptor, we have investigated its subcellular localization using immunogold labeling on thawed cryosections of different tissues, such as mouse spermatids and rat pancreas, as well as HeLa, Vero, NRK, and mouse L cells. We show that rab1 is an excellent marker of the intermediate compartment, and we use this marker, as well as budding profiles of the mouse hepatitis virus (MHV) in cells infected with this virus, to identify this compartment. Our results demonstrate that the KDEL receptor is concentrated in the intermediate compartment, as well as in the Golgi stack. Lower but significant labeling was detected in the rough ER. In general, only small amounts of the receptor were detected on the trans side of the Golgi stack, including the trans-Golgi network (TGN) of normal cells and tissues. However, some stress conditions, such as infection with vaccinia virus or vesicular stomatitis virus, as well as 20 degrees C or 43 degrees C treatment, resulted in a significant shift of the distribution towards the trans-TGN side of the Golgi stack. This shift could be quantified in HeLa cells stably expressing a TGN marker. No significant labeling was detected in structures distal to the TGN under all conditions tested. After GTP gamma S treatment of permeabilized cells, the receptor was detected in the beta-COP-containing buds/vesicles that accumulate after this treatment, suggesting that these vesicles may transport the receptor between compartments. We propose that retrieval of KDEL-containing proteins occurs at multiple post-ER compartments up to the TGN along the exocytotic pathway, and that within this pathway, the amounts of the receptor in different compartments varies according to physiological conditions.
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PMID:Localization of the Lys, Asp, Glu, Leu tetrapeptide receptor to the Golgi complex and the intermediate compartment in mammalian cells. 779 12

Many soluble resident proteins of the endoplasmic reticulum share a COOH-terminal Lys-Asp-Glu-Leu (KDEL) sequence. Current opinion favours a model in which these proteins can escape from the endoplasmic reticulum (ER) by bulk flow and are recognized and sorted in the Golgi apparatus by binding to a specific KDEL-receptor, which returns them to the ER. Through biochemical, morphological and mutational analysis we have studied the mechanisms that determine the localization of calreticulin, a soluble 60 kDa KDEL-protein of the ER. Immunogold labelling established the ER localization of calreticulin in transfected and nontransfected COS cells. Although the ER cisternae in transfected cells were enormously dilated and heavily labelled by gold particles we found no significant label in any other compartment. In vivo pulse chase experiments with [35S]methionine followed by biochemical fractionation of calreticulin overexpressing COS cells (50- to 100-fold) revealed that only a minor part of labelled calreticulin leaves the ER. Retrieval from the Golgi was confirmed by a partial redistribution of the endogenous KDEL-receptor as shown by double immunofluorescence. These data suggest a KDEL-independent retention of calreticulin in the ER. Further supporting evidence has come from morphological in vivo studies using calreticulin-transfected and vesicular stomatitis virus (ts045)-infected COS cells. Stimulation of vesicular transport from the ER by releasing the temperature-dependent transport block for the viral G-protein resulted in a small but significant appearance of calreticulin in a post-ER compartment. In contrast a calreticulin mutant, which lacked the Ca(2+)-binding domain but included the KDEL sequence, could escape from the ER to a much higher extent. Secretion of the nonmutated calreticulin was very low (1-2% of total calreticulin in 3 hours) compared to the mutated form (18% in 3 hours). Deletion of the KDEL sequence led to an increase in secretion to 29% over a 3 hour period, which is much less than expected for a secretory protein. Taken together these results strongly support the hypothesis of two independently operating retention/retrieval mechanisms for calreticulin: one providing for direct retention in the ER with a very high capacity and having Ca(2+)-dependent properties; the other a KDEL-based retrieval system for escaped calreticulin present in the Golgi apparatus.
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PMID:Retention and retrieval: both mechanisms cooperate to maintain calreticulin in the endoplasmic reticulum. 787 39

The envelope glycoprotein G of vesicular stomatitis virus induces membrane fusion at low pH. Site-directed mutagenesis of specific amino acids within a segment spanning amino acids 123 to 137 of G protein, which is highly conserved in vesiculoviruses and was previously shown by us to be involved in fusogenic activity (Y. Li, C. Drone, E. Sat, and H. P. Ghosh, J. Virol. 67:4070-4077, 1993), was used to determine the role of this region in low-pH-induced membrane fusion. The mutant glycoproteins expressed in COS cells were assayed for acid-pH-induced cell-cell fusion. Substitution of the variant Pro-123 with Leu had no effect on the fusogenic activity, while substitution of conserved Phe-125 and Asp-137 with Tyr and Asn, respectively, shifted the pH optimum of membrane fusion to a more acidic pH value and decreased the fusion efficiency. The deletion of amino acid residues 124 to 127, 131 to 137, or 124 to 137 produced mutants defective in transport. Mutation of the conserved residues Gly-124 and Pro-127 to Ala and to Gly or Leu, respectively, inhibited cell-cell fusion activity by about 90% without affecting transport of the mutant proteins to the cell surface, suggesting that these two residues may be present within the fusion peptide and thus may be directly involved in fusion. This highly conserved domain containing neutral amino acids of G protein may therefore represent the putative fusion domain of vesicular stomatitis virus G protein.
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PMID:Characterization of the putative fusogenic domain in vesicular stomatitis virus glycoprotein G. 813 3

Specific interaction between the nucleocapsid protein (N) and the phosphoprotein (P) of vesicular stomatitis virus (VSV), an important step in the life-cycle of the virus, was studied by using a two-hybrid system. Plasmids encoding P fused with the yeast GAL4 DNA-binding domain (pGALP) and N fused with the herpes simplex virus VP16 transactivating region (pVPN) were transfected into CHO cells along with a reporter plasmid encoding chloramphenicol acetyltransferase (CAT). The ability of N and P to associate in vivo was measured by activation of the CAT gene by the VP16 transactivating region. Transfection of plasmids pGALP and pVPN resulted in a high level of CAT activity, indicating that the N and P portions of the fusion proteins associated very strongly with each other. Progressive C-terminal deletions of the P protein revealed two regions that are important for association with the N protein: the N-terminal acidic domain and the C-terminal basic domain. Phosphorylation of P protein was not required for N-P association. Various deletions and mutations of the N protein revealed the C-terminal 5 amino acids (Val-Glu-Phe-Asp-Lys), in particular the amino acids Val-Glu-Phe, to be critical for N association with P. This two-hybrid system can be used in other viral systems to study the interaction between proteins involved in transcription and replication.
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PMID:Mapping of interacting domains between the nucleocapsid protein and the phosphoprotein of vesicular stomatitis virus by using a two-hybrid system. 823 1

A transgenic mouse has been made that expresses a mutant MHC class I H-2Kb molecule with glutamic acid at position 65 (E65) in place of glutamine. The side chain at position 65, on the outward face of the alpha-helix of the alpha 1 domain of the class I molecule, interacts with the TCR, and not with the peptide binding groove. The transgenic mouse, on a DBA/2 background, mounts Kb,E65-restricted Ag-specific responses to conventional Kb-restricted Ag such as OVA and vesicular stomatitis virus, and shows strong alloreactivity to wild-type Kb. The transgenic mouse also mounts a primary in vitro alloreactive response directed to a mutant molecule with aspartic acid at position 65 (D65). This response is relatively weak, probably because of the structural similarities between aspartic and glutamic acid side chains; both have carboxylic termini, and the aspartic acid side chain is shorter by a single secondary carbon. The alloreactive CTL lines elicited by this conservative change are cross-reactive among several position-65 variants of H-2Kb. Individual CTL clones are specific for self peptides that can be extracted from cells expressing Kb,E65, and from purified wild-type Kb molecules, and that are recognized in the context of the D65 residue. Thus, the smallest variance from self in a class I molecule, even outside the peptide binding groove, can be antigenic.
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PMID:A conservative mutation in a class I MHC molecule outside the peptide binding groove stimulates responses to self peptides. 840 80

IFN-gamma is a pleiotropic cytokine that plays a major role in anti-infectious immune responses. The physiologic effects of IFN-gamma are thought to be mediated by the binding of extracellular IFN-gamma to its receptor at the cell surface, thereby triggering an intracellular signaling cascade. In this work, we present evidence for a completely intracellular mechanism for IFN-gamma to induce virus protection. Murine fibroblasts were transfected with the cDNA for murine IFN-gamma, and although no detectable amounts of IFN-gamma were released, these cells were resistant to lysis by the cytolytic vesicular stomatitis virus. In contrast to exogenously added IFN-gamma, the effect of the endogenously produced IFN-gamma was not abolished by treatment with neutralizing Abs. To test whether intracellular signal transduction occurs, an IFN-gamma variant was constructed with the carboxyl-terminal endoplasmic reticulum retention signal Lys-Asp-Glu-Leu (KDEL). Transfection of fibroblasts with this mutant IFN-gamma, anchored in the endoplasmic reticulum, led to virus resistance, thus demonstrating that biologic effects of this protein do not necessarily require binding to the receptor at the cell surface. However, the antiviral state induced by transfection with IFN-gamma-KDEL was strictly dependent on the presence of the IFN-gammaR, since fibroblasts derived from IFN-gammaR-deficient mice (IFN-gammaR -/-) were not rendered virus resistant. The virus resistance induced was accompanied by enhanced expression of 2'-5' oligoadenylate synthetase and constitutive activation of STAT1 (signal transducers and activators of transcription). Hence, autocrinous effects of IFN-gamma in cells naturally producing this cytokine might occur even in the absence of its secretion. The mechanisms involved in signaling appear to be identical with or closely related to those occurring after binding of IFN-gamma to its receptor at the cell surface.
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PMID:Intracellular murine IFN-gamma mediates virus resistance, expression of oligoadenylate synthetase, and activation of STAT transcription factors. 890 36

Transport of membrane proteins between intracellular compartments requires specific sequences in the protein cytoplasmic domain to direct packaging into vesicle shuttles. A sequence that mediates export from the endoplasmic reticulum (ER) has proved elusive. A di-acidic signal (Asp-X-Glu, where X represents any amino acid) on the cytoplasmic tail of vesicular stomatitis virus glycoprotein (VSV-G) and other cargo molecules was required for efficient recruitment to vesicles mediating export from the ER in baby hamster kidney cells. The existence of such a signal provides evidence that export from the ER occurs through a selective mechanism.
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PMID:A di-acidic signal required for selective export from the endoplasmic reticulum. 922 4


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