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)

The biosynthesis of a secretory protein and a transmembrane viral glycoprotein are compared by two different experimental approaches. (a) NH2-terminal sequence analysis has been performed on various forms of the transmembrane glycoprotein of vesicular stomatitis virus synthesized in cell-free systems. The sequence data presented demonstrate that the nascent precursor of the glycoprotein contains a "signal sequence" of 16 amino acids at the NH2 terminus, whose sequence is Met-Lys-Cys-Leu-Leu-Tyr-Leu-Ala-Phe-Leu-Phe-Ile-(His-Val-Asn)-Cys. This signal sequence is proteolytically cleaved during the process of insertion into microsomal membranes prior to chain completion. The new NH2 terminus of the inserted, cleaved, and glycosylated membrane protein is located within the lumen of the microsomal vesicles and is identical to that of the authentic glycoprotein from virions. (b) Nascent chain competition experiments were performed between this glycoprotein, bovine pituitary prolactin (a secretory protein), and rabbit globin (a cytosolic protein). It was found that the nascent membrane glycoprotein, but not nascent globin, competed with nascent prolactin for membrane sites involved in the early biosynthetic event of transfer across membranes. These data suggest that an initially common pathway is involved in the biogenesis of secretory proteins and at least one class of integral membrane proteins.
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PMID:A signal sequence for the insertion of a transmembrane glycoprotein. Similarities to the signals of secretory proteins in primary structure and function. 21 27

Protein secretion is blocked in Xenopus oocytes arrested at second meiotic metaphase. In this report, we show that secretion becomes blocked coincident with germinal vesicle breakdown (GVBD). Transport through the metaphase-arrested oocyte's secretory pathway continues unimpeded until proteins reach the trans-Golgi. These conclusions are drawn from experiments using exogenous prolactin and vesicular stomatitis virus G protein (VSV G) encoded by SP6 transcripts and endogenous glycosaminoglycan (GAG) chains initiated on beta-D-4-methylumbelliferyl-xyloside. From the initiation of maturation with progesterone until GVBD, secretion of prolactin synthesized before the start of maturation is comparable to secretion in immature oocytes, but after GVBD secretion of prolactin declines approximately 63% in the first hour. Not all steps in the secretory pathway are blocked when oocytes mature. Since VSV G protein acquires resistance to endo H digestion with equal efficiency in immature oocytes (arrested in first meiotic prophase) and matured oocytes (arrested in second meiotic metaphase), we conclude that transport of this protein from the ER to the Golgi is not inhibited at meiotic metaphase. Using [35S]sulfate to label xyloside-initiated GAG chains we find that transport of GAG chains from the trans-Golgi to the cell surface is 15-fold lower in matured oocytes than in immature oocytes. Examination of the size of GAG chains by SDS-PAGE and HPLC indicates that matured oocytes produce GAG chains significantly larger than GAG chains from immature oocytes. This increase in size suggests that GAG chains from matured oocytes have a longer residence time in the trans-Golgi than GAG chains from immature oocytes. Hence, part of the block to secretion in metaphase-arrested oocytes could be an inhibition of vesicle budding from the trans-Golgi.
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PMID:The secretory pathway is blocked between the trans-Golgi and the plasma membrane during meiotic maturation in Xenopus oocytes. 239 Sep 97

Current model propose that in nonpolarized cells, transport of plasma membrane proteins to the surface occurs by default. In contrast, compelling evidence indicates that in polarized epithelial cells, plasma membrane proteins are sorted in the TGN into at least two vectorial routes to apical and basolateral surface domains. Since both apical and basolateral proteins are also normally expressed by both polarized and nonpolarized cells, we explored here whether recently described basolateral sorting signals in the cytoplasmic domain of basolateral proteins are recognized and used for post TGN transport by nonpolarized cells. To this end, we compared the inhibitory effect of basolateral signal peptides on the cytosol-stimulated release of two basolateral and one apical marker in semi-intact fibroblasts (3T3), pituitary (GH3), and epithelial (MDCK) cells. A basolateral signal peptide (VSVGp) corresponding to the 29-amino acid cytoplasmic tail of vesicular stomatitis virus G protein (VSVG) inhibited with identical potency the vesicular release of VSVG from the TGN of all three cell lines. On the other hand, the VSVG peptide did not inhibit the vesicular release of HA in MDCK cells not of two polypeptide hormones (growth hormone and prolactin) in GH3 cells, whereas in 3T3 cells (influenza) hemagglutinin was inhibited, albeit with a 3x lower potency than VSVG. The results support the existence of a basolateral-like, signal-mediated constitutive pathway from TGN to plasma membrane in all three cell types, and suggest that an apical-like pathway may be present in fibroblast. The data support cargo protein involvement, not bulk flow, in the formation of post-TGN vesicles and predict the involvement of distinct cytosolic factors in the assembly of apical and basolateral transport vesicles.
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PMID:Transport of vesicular stomatitis virus G protein to the cell surface is signal mediated in polarized and nonpolarized cells. 863 30

Nordihydroguaiaretic acid (NDGA) blocks intra-Golgi protein transport in a cell-free system and prolactin secretion from GH3 cells [Tagaya, M., Henomatsu, N., Yoshimori, T., Yamamoto, A., Tashiro, Y., and Fukui, T. (1993) FEBS Lett. 324, 201-204]. To determine which intracellular secretory pathway(s) is inhibited by NDGA, we investigated its effect on the transport of the vesicular stomatitis virus-encoded glycoprotein in BHK-21 cells. NDGA blocked protein transport from the endoplasmic reticulum to the Golgi apparatus, and from the trans-Golgi network to the plasma membrane. In addition, it retarded the brefeldin A-induced retrograde transport of mannosidase II to the endoplasmic reticulum. Although NDGA had an inhibitory effect on protein synthesis, it induced the expression of BiP, a chaperone located in the endoplasmic reticulum. The induction of BiP may be a consequence of the inhibition of protein transport by NDGA.
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PMID:Inhibition of vesicle-mediated protein transport by nordihydroguaiaretic acid. 879 85