Rayne F, Bouamr F, Lalanne J, Mamoun R Z
INSERM U443, Equipe Rétrovirus et Transfert Génique, Université Victor Segalen Bordeaux 2, F-33076 Bordeaux Cedex, France.
J Virol. 2001 Jun;75(11):5277-87. doi: 10.1128/JVI.75.11.5277-5287.2001.
The human immunodeficiency virus type 1 (HIV-1) and human T-cell leukemia virus type 1 (HTLV-1) capsid proteins (CA) display similar structures formed by two independently folded N-terminal (NTD) and C-terminal (CTD) domains. To characterize the functions harbored by the HTLV-1 CA domains in particle formation, 12 sites scattered throughout the protein were mutated. The effects of the mutations on Gag membrane binding, proteolytic processing, and virus-like particle secretion were analyzed. It appears that the NTD is the major partner of indirect or direct Gag-Gag interactions. In particular, most of the NTD mutations impaired virion morphogenesis, and no mutation located in the NTD could be fully rescued by coexpression of wild-type Gag. In contrast, the CTD seems not to be involved in Gag-Gag interactions. Nevertheless, an unknown function required for particle formation is located in the CTD. Thus, despite an overall structural similarity between the HIV-1 and HTLV-1 CA proteins, their NTDs and CTDs exhibit different functions.
1型人类免疫缺陷病毒（HIV-1）和1型人类T细胞白血病病毒（HTLV-1）的衣壳蛋白（CA）呈现出由两个独立折叠的N端（NTD）和C端（CTD）结构域形成的相似结构。为了表征HTLV-1 CA结构域在病毒颗粒形成中所具有的功能，对遍布该蛋白的12个位点进行了突变。分析了这些突变对Gag膜结合、蛋白水解加工以及病毒样颗粒分泌的影响。似乎NTD是间接或直接的Gag-Gag相互作用的主要参与者。特别是，大多数NTD突变损害了病毒体形态发生，并且位于NTD的突变没有一个能通过共表达野生型Gag而被完全挽救。相比之下，CTD似乎不参与Gag-Gag相互作用。然而，病毒颗粒形成所需的一个未知功能位于CTD中。因此，尽管HIV-1和HTLV-1 CA蛋白在整体结构上相似，但它们的NTD和CTD表现出不同的功能。
