Characterization of a myristoylated, monomeric HIV Gag protein.
The process of HIV assembly requires extensive homomultimerization of the Gag polyprotein on cellular membranes to generate the nascent particle bud. Here we generated a full-length, monomeric Gag polyprotein bearing mutations that eliminated multimerization in living cells as indicated by fluorescence resonance energy transfer (FRET). Monomeric Gag resembled non-myristoylated Gag in its weak membrane binding characteristics and lack of association with detergent-resistant membranes (DRMs or lipid rafts). Monomeric Gag failed to assemble virus-like particles, but was inefficiently rescued into particles by wildtype Gag through the influence of the matrix domain. The subcellular distribution of monomeric Gag was remarkably different than either non-myristoylated Gag or wildtype Gag. Monomeric Gag was found on intracellular membranes and at the plasma membrane, where it highlighted plasma membrane extensions and ruffles. This study indicates that monomeric Gag can traffic to assembly sites in the cell, where it interacts weakly with membranes.
Dou
Jun
J
Emory University School of Medicine, Department of Pediatrics, Atlanta, GA 30322, USA.
Wang
Jaang-Jiun
JJ
Chen
Xuemin
X
Li
Hua
H
Ding
Lingmei
L
Spearman
Paul
P
D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D019814:Myristic Acid / Q000378:metabolism*; D055503:Protein Multimerization; D021381:Protein Transport; D013329:Structure-Activity Relationship; D019065:Virus Assembly; D014779:Virus Replication; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000378:metabolism*
D054301:gag Gene Products, Human Immunodeficiency Virus; D019814:Myristic Acid