Self-association of truncated forms of HIV-1 gp120.
HIV-1 gp120 and truncated forms were expressed in HeLa T4 cells by vaccinia recombinant viruses. The truncated gp120 molecules consisted of N-terminal overlapping envelope proteins of 204, 287 and 393 amino acids respectively. Immunoprecipitation with specific monoclonal antibodies and SDS-PAGE analyses of HIV-1 gp120 revealed bands corresponding to low amounts of secreted and cell-bound stable dimers. In contrast, the truncated forms of gp120 expressed larger amounts of SDS-stable putative dimers and the amounts observed were inversely proportional to their size. The shortest gp120 mutant (204 aa) was found to be secreted almost exclusively as a dimer. The processing of gp120 and its truncated forms was further investigated in the presence of inhibitors of N-glycosylation. Monomers and dimers migrated on gels with the same relative changes, confirming that the protein with the higher molecular weight is a multimer of the smaller one. The putative dimeric form of the truncated gp120s could be stabilized by chemical cross-linking. Finally, the possible existence of an association domain in the N-terminal 204 amino acids (aa) of gp120 is discussed.
Malvoisin
E
E
INSERM Unit 404, Institut Pasteur de Lyon, France.
Kiény
M P
MP
Wild
F
F
D019281:Dimerization; D005822:Genetic Vectors; D015699:HIV Envelope Protein gp120 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D011134:Polysaccharides / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000378:metabolism*; D014616:Vaccinia virus / Q000235:genetics
D015699:HIV Envelope Protein gp120; D011134:Polysaccharides; D011994:Recombinant Proteins