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)

We have used monospecific antisera to two lysosomal membrane glycoproteins, lgp120 and a similar protein, lgp110, to compare the biosynthesis and intracellular transport of lysosomal membrane components, plasma membrane proteins, and lysosomal enzymes. In J774 cells and NRK cells, newly synthesized lysosomal membrane and plasma membrane proteins (the IgG1/IgG2b Fc receptor or influenza virus hemagglutinin) were transported through the Golgi apparatus (defined by acquisition of resistance to endo-beta-N-acetylglucosaminidase H) with the same kinetics (t1/2 = 11-14 min). In addition, immunoelectron microscopy of normal rat kidney cells showed that lgp120 and vesicular stomatitis virus G-protein were present in the same Golgi cisternae demonstrating that lysosomal and plasma membrane proteins were not sorted either before or during transport through the Golgi apparatus. To define the site at which sorting occurred, we compared the kinetics of transport of lysosomal and plasma membrane proteins and a lysosomal enzyme to their respective destinations. Newly synthesized proteins were detected in dense lysosomes (lgp's and beta-glucuronidase) or on the cell surface (Fc receptor or hemagglutinin) after the same lag period (20-25 min), and accumulated at their final destinations with similar kinetics (t1/2 = 30-45 min), suggesting that these two lgp's are not transported to the plasma membrane before reaching lysosomes. This was further supported by measurements of the transport of membrane-bound endocytic markers from the cell surface to lysosomes, which exhibited additional lag periods of 5-15 min and half-times of 1.5-2 h. The time required for transport of newly synthesized plasma membrane proteins to the cell surface, and for the transport of plasma membrane markers from the cell surface to lysosomes would appear too long to account for the rapid transport of lgp's from the Golgi apparatus to lysosomes. Thus, the observed kinetics suggest that lysosomal membrane proteins are sorted from plasma membrane proteins at a post-Golgi intracellular site, possibly the trans Golgi network, before their delivery to lysosomes.
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PMID:Kinetics of intracellular transport and sorting of lysosomal membrane and plasma membrane proteins. 282 Oct 12

To examine the requirements of the human respiratory syncytial virus (HRSV) SH (small hydrophobic), G (attachment), and F (fusion) proteins for virus infectivity and morphology, we used the prototype A2 strain of HRSV to generate a series of cDNAs from which (i) the SH open reading frame (ORF), (ii) the SH and G ORFs, or (iii) the SH, G, and F ORFs were deleted. Each deleted ORF was replaced as follows: the SH ORF was replaced with that of green fluorescent protein; the G ORF was replaced with that of G(vsv), a chimeric glycoprotein consisting of the vesicular stomatitis Indiana virus (VSIV) G protein ecto- and transmembrane domains coupled to the HRSV F cytoplasmic tail; and the F ORF was replaced with that of marker protein beta-glucuronidase. The number of genes and the intergenic junctions in the constructs were kept as found in A2 virus in order to maintain authentic levels of transcription. Infectious viruses were recovered from all three engineered cDNAs and designated RSdeltash, RSdeltash,g/G(vsv), and RSdeltash,g,f/G(vsv), respectively. Low-pH-induced syncytium formation was observed in cells infected with viruses RSdeltaSH,G/G(vsv) and RSdeltaSH,G,F/G(vsv), indicating that G(vsv) was expressed and functional. Neutralization of infectivity by anti-VSIV G antibodies and inhibition of entry by ammonium chloride showed that RSdeltaSH,G,F/G(vsv) infectivity was mediated by G(vsv) and that an acidification step was required for entry into the host cell, similar to VSIV virions. All three engineered viruses displayed growth kinetics and virus yields similar to a wild-type A2 virus, both in Vero and HEp-2 cells. Abundant virus-induced filaments were observed at the surface of cells infected with each of the three engineered viruses or with virus A2, indicating that neither the SH and G proteins nor the F protein ecto- and transmembrane domains were required for the formation of these structures. This is the first report of the recovery of an infectious HRSV lacking a fusion protein of the Paramyxoviridae family and of manipulation of the HRSV entry pathway via incorporation of a nonparamyxoviral transmembrane glycoprotein.
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PMID:Infectivity of a human respiratory syncytial virus lacking the SH, G, and F proteins is efficiently mediated by the vesicular stomatitis virus G protein. 1261 Jan 53