Biochemical and genetic definition of the cellular protease required for HIV-1 gp160 processing.
The surface glycoproteins of enveloped viruses bind to target cell receptors and trigger membrane fusion for infection. The human immunodeficiency virus 1 (HIV-1) envelope glycoprotein gp120 (CD4 binding protein) and gp41 (transmembrane fusion protein) are initially synthesized as a gp160 precursor. The intracellular cleavage of gp160 by a host cell protease during transit through the secretory pathway is essential for viral activities such as infectivity, membrane fusion, and T-cell syncytium formation. We report that gp160 biogenesis, protein processing, and cell-surface expression have been successfully reproduced in the yeast Saccharomyces cerevisiae. Genetic and biochemical approaches are used for defining that the unique cellular protease, Kex2p, is directly responsible for HIV-gp160 processing in yeast, in vivo and in vitro. The yeast system described in this report represents a powerful strategy for identifying, characterizing and inhibiting the host T-cell protease essential for HIV infectivity and AIDS.
Franzusoff
A
A
Department of Cellular and Structural Biology, University of Colorado Medical School, Denver 80262.
Volpe
A M
AM
Josse
D
D
Pichuantes
S
S
Wolf
J R
JR
D002462:Cell Membrane / Q000378:metabolism; D003001:Cloning, Molecular; D015870:Gene Expression; D015686:Gene Products, env / Q000096:biosynthesis* / Q000302:isolation & purification; D019302:HIV Envelope Protein gp160; D015497:HIV-1 / Q000378:metabolism*; D010957:Plasmids; D016133:Polymerase Chain Reaction; D043484:Proprotein Convertases; D011498:Protein Precursors / Q000096:biosynthesis* / Q000302:isolation & purification; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000302:isolation & purification; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins; D013381:Subtilisins / Q000378:metabolism*; D014759:Viral Envelope Proteins / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism
D015686:Gene Products, env; D019302:HIV Envelope Protein gp160; D011498:Protein Precursors; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D014759:Viral Envelope Proteins; D043484:Proprotein Convertases; D013381:Subtilisins; C058751:KEX2 protein, S cerevisiae