Role of oligosaccharides in the processing and maturation of envelope glycoproteins of human immunodeficiency virus type 1.
AUTOR(ES)
Pal, R
RESUMO
The processing and maturation of envelope glycoproteins of human immunodeficiency virus type 1 (HIV-1) were studied in infected cells treated with inhibitors of oligosaccharide processing. In MOLT-3 cells chronically infected with HIV-1 (strain HTLV-IIIB), tunicamycin severely inhibited the glycosylation of envelope proteins. Deoxynojirimycin, an inhibitor of glucosidase I in the rough endoplasmic reticulum, inhibited the proteolytic processing of gp160, whereas no such effect was noted with either deoxymannojirimycin or swainsonine, inhibitors of mannosidase I and II, respectively, in the Golgi complex. The processed gp120 and gp41 synthesized in the presence of deoxymannojirimycin were found to contain mannose-rich oligosaccharide cores as evidenced by their susceptibility to endoglycosidase H digestion. The formation of syncytia normally observed when CEM cells are cocultured with HIV-1-infected cells was markedly inhibited in the presence of deoxynojirimycin, but such inhibition was not observed in cells treated with deoxymannojirimycin or swainsonine. The infectivity of virions released from MOLT-3/HTLV-IIIB cells treated with deoxynojirimycin or deoxymannojirimycin was significantly lower than the infectivity of virions released from untreated cells. On the other hand, treatment with swainsonine did not affect the infectivity of the progeny virus. These results suggest that the proteolytic processing of gp160 takes place in infected cells when the glycoprotein has mannose-rich oligosaccharide structures. Trimming of glucose residues and the primary trimming of mannose residues are necessary for the release of infectious virus.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=287137Documentos Relacionados
- Enhancing the Proteolytic Maturation of Human Immunodeficiency Virus Type 1 Envelope Glycoproteins
- Role of N-linked glycans of envelope glycoproteins in infectivity of human immunodeficiency virus type 1.
- Biosynthesis and processing of human immunodeficiency virus type 1 envelope glycoproteins: effects of monensin on glycosylation and transport.
- Role of capsid precursor processing and myristoylation in morphogenesis and infectivity of human immunodeficiency virus type 1.
- Immunoprecipitation of human immunodeficiency virus type 2 glycoproteins by sera positive for human immunodeficiency virus type 1.