Dou Jun, Wang Jaang-Jiun, Chen Xuemin, Li Hua, Ding Lingmei, Spearman Paul
Emory University School of Medicine, Department of Pediatrics, Atlanta, GA 30322, USA.
Virology. 2009 May 10;387(2):341-52. doi: 10.1016/j.virol.2009.02.037. Epub 2009 Mar 12.
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.
HIV组装过程需要Gag多聚蛋白在细胞膜上广泛地同源多聚化，以产生新生的病毒颗粒芽。在这里，我们构建了一个全长单体Gag多聚蛋白，该蛋白带有一些突变，这些突变消除了活细胞中的多聚化，荧光共振能量转移（FRET）结果表明了这一点。单体Gag在其弱膜结合特性以及缺乏与抗去污剂膜（DRMs或脂筏）的结合方面类似于非肉豆蔻酰化的Gag。单体Gag无法组装病毒样颗粒，但通过基质结构域的影响，野生型Gag能低效地将其挽救到颗粒中。单体Gag的亚细胞分布与非肉豆蔻酰化Gag或野生型Gag明显不同。在细胞内膜和质膜上发现了单体Gag，它突出了质膜的延伸和褶皱。这项研究表明，单体Gag可以运输到细胞中的组装位点，在那里它与膜的相互作用较弱。
