Weldon R A, Parker W B, Sakalian M, Hunter E
Department of Microbiology, University of Alabama at Birmingham, 35294, USA.
J Virol. 1998 Apr;72(4):3098-106. doi: 10.1128/JVI.72.4.3098-3106.1998.
Mason-Pfizer monkey virus (M-PMV), the prototype type D retrovirus, differs from most other retroviruses by assembling its Gag polyproteins into procapsids in the cytoplasm of infected cells. Once assembled, the procapsids migrate to the plasma membrane, where they acquire their envelope during budding. Because the processes of M-PMV protein transport, procapsid assembly, and budding are temporally and spatially unlinked, we have been able to determine whether cellular proteins play an active role during the different stages of procapsid morphogenesis. We report here that at least two stages of morphogenesis require ATP. Both procapsid assembly and procapsid transport to the plasma membrane were reversibly blocked by treating infected cells with sodium azide and 2-deoxy-D-glucose, which we show rapidly and reversibly depletes cellular ATP pools. Assembly of procapsids in vitro in a cell-free translation/assembly system was inhibited by the addition of nonhydrolyzable ATP analogs, suggesting that ATP hydrolysis and not just ATP binding is required. Since retrovirus Gag polyproteins do not bind or hydrolyze ATP, these results demonstrate that cellular components must play an active role during retrovirus morphogenesis.
梅森- Pfizer猴病毒（M-PMV）是D型逆转录病毒的原型，它与大多数其他逆转录病毒的不同之处在于，其Gag多聚蛋白在受感染细胞的细胞质中组装成原衣壳。一旦组装完成，原衣壳就会迁移到质膜，在出芽过程中获得包膜。由于M-PMV蛋白运输、原衣壳组装和出芽过程在时间和空间上是不相关联的，我们得以确定细胞蛋白在原衣壳形态发生的不同阶段是否发挥积极作用。我们在此报告，形态发生的至少两个阶段需要ATP。用叠氮化钠和2-脱氧-D-葡萄糖处理受感染细胞，可使原衣壳组装和原衣壳向质膜的运输可逆性受阻，我们发现这会迅速且可逆地耗尽细胞ATP池。在无细胞翻译/组装系统中体外组装原衣壳时，加入不可水解的ATP类似物会抑制组装，这表明需要ATP水解而不仅仅是ATP结合。由于逆转录病毒Gag多聚蛋白不结合或水解ATP，这些结果表明细胞成分在逆转录病毒形态发生过程中必须发挥积极作用。
