The assembly of the HIV-1 env glycoprotein into dimers and tetramers.
The envelope (env) glycoprotein of human immunodeficiency virus 1 (HIV-1), initially synthesized as a precursor molecule termed gp160, is cleaved into two noncovalently associated subunits prior to delivery to the plasma membrane. We have studied the oligomeric structure of this protein using chemical cross-linking, velocity gradient sedimentation, and SDS-resistance. We find that gp160 forms stable homodimers after synthesis. After cleavage to gp120/gp41 the molecule becomes less stable to detergent solubilization and centrifugation but remains dimeric. Interactions between the 129 amino terminal residues in the ectodomains of adjoining gp41 subunits are both sufficient and necessary for assembly. In addition, tetramers composed of two dimers were also formed. Larger structures were not observed. The tetrameric paramyxovirus F protein, which has structural and functional similarities to the HIV-1 env protein, also forms a dimer of dimers.
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Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892.
Earl
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Moss
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B
D015686:Gene Products, env / Q000378:metabolism*; D006678:HIV / Q000378:metabolism*; D015699:HIV Envelope Protein gp120 / Q000378:metabolism; D019302:HIV Envelope Protein gp160; D015700:HIV Envelope Protein gp41 / Q000378:metabolism; D006801:Humans; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins / Q000378:metabolism*; D011487:Protein Conformation; D011489:Protein Denaturation; D011498:Protein Precursors / Q000378:metabolism*; D011499:Protein Processing, Post-Translational
D015686:Gene Products, env; D015699:HIV Envelope Protein gp120; D019302:HIV Envelope Protein gp160; D015700:HIV Envelope Protein gp41; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins; D011498:Protein Precursors