Aaron Diamond AIDS Research Center, The Rockefeller University, New York, New York, United States of America.
PLoS Pathog. 2011 May;7(5):e1002039. doi: 10.1371/journal.ppat.1002039. Epub 2011 May 19.
Lentiviral Nef proteins have multiple functions and are important for viral pathogenesis. Recently, Nef proteins from many simian immunodefiency viruses were shown to antagonize a cellular antiviral protein, named Tetherin, that blocks release of viral particles from the cell surface. However, the mechanism by which Nef antagonizes Tetherin is unknown. Here, using related Nef proteins that differ in their ability to antagonize Tetherin, we identify three amino-acids in the C-terminal domain of Nef that are critical specifically for its ability to antagonize Tetherin. Additionally, divergent Nef proteins bind to the AP-2 clathrin adaptor complex, and we show that residues important for this interaction are required for Tetherin antagonism, downregulation of Tetherin from the cell surface and removal of Tetherin from sites of particle assembly. Accordingly, depletion of AP-2 using RNA interference impairs the ability of Nef to antagonize Tetherin, demonstrating that AP-2 recruitment is required for Nef proteins to counteract this antiviral protein.
慢病毒 Nef 蛋白具有多种功能，对病毒发病机制很重要。最近，许多猴免疫缺陷病毒的 Nef 蛋白被证明可以拮抗一种名为 tetherin 的细胞抗病毒蛋白，该蛋白阻止病毒颗粒从细胞表面释放。然而，Nef 拮抗 tetherin 的机制尚不清楚。在这里，我们使用在拮抗 tetherin 能力上存在差异的相关 Nef 蛋白，鉴定出 Nef 的 C 末端结构域中的三个氨基酸残基对其拮抗 tetherin 的能力至关重要。此外，不同的 Nef 蛋白与 AP-2 网格蛋白衔接子复合物结合，我们表明，该相互作用的重要残基对于 tetherin 的拮抗、从细胞表面下调 tetherin 和从颗粒组装部位去除 tetherin 都是必需的。因此，使用 RNA 干扰耗尽 AP-2 会损害 Nef 拮抗 tetherin 的能力，表明 AP-2 的募集对于 Nef 蛋白拮抗这种抗病毒蛋白是必需的。
