The host cell MAP kinase ERK-2 regulates viral assembly and release by phosphorylating the p6gag protein of HIV-1
The host cell MAP kinase ERK-2 regulates viral assembly and release by phosphorylating the p6gag protein of HIV-1
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DOI：
10.1074/jbc.m313137200
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发表时间：
2004-07-30
影响因子：
4.8
通讯作者：
Briant, L
中科院分区：
文献类型：
--
作者：
Hemonnot, B;Cartier, C;Briant, L
整合在人类免疫缺陷病毒1型颗粒内的宿主细胞MAP激酶ERK-2通过磷酸化病毒蛋白在病毒感染性中起关键作用。最近，据报道，掺入病毒的含有晚期（L）结构域的p6（gag）蛋白的一部分被未知的病毒相关细胞蛋白激酶磷酸化（Muller，B.，Patschinsky，T.，Krausslich，H. G.等人（2002）J. Virol. 76，1015 - 1024）。本研究证实了MAP激酶ERK-2在p6（gag）磷酸化中的作用。根据突变分析，一个单一的ERK-2-磷酸化的苏氨酸残基，属于一个高度保守的磷酸化MAP激酶的共识网站，被确定在位置23内的p6（gag）。发现pNL4.3分子克隆内Thr（23）可磷酸化残基被丙氨酸取代可减少各种细胞类型的病毒释放。如从电子显微镜实验观察到的，从该分子克隆产生的大多数病毒体保持与宿主细胞膜不完全分离，具有不成熟的形态，并且在单轮感染实验中显示出降低的感染性。通过蛋白质印迹实验分析蛋白质加工揭示了不完全的Pr55（gag）成熟和病毒体相关逆转录酶蛋白的减少，观察到这与细胞内病毒蛋白表达的差异无关。总之，这些数据表明，p6（gag）蛋白磷酸化的病毒相关的ERK-2参与了HIV-1生命周期的萌芽阶段。
The host cell MAP kinase ERK-2 incorporated within human immunodeficiency virus type 1 particles plays a critical role in virus infectivity by phosphorylating viral proteins. Recently, a fraction of the virus incorporated late (L) domain-containing p6(gag) protein, which has an essential function in the release of viral particles from the cell surface, was reported to be phosphorylated by an unknown virus-associated cellular protein kinase (Muller, B., Patschinsky, T., and Krausslich, H. G. (2002) J. Virol. 76, 1015-1024). The present study demonstrates the contribution of the MAP kinase ERK-2 in p6(gag) phosphorylation. According to mutational analysis, a single ERK-2-phosphorylated threonine residue, belonging to a highly conserved phosphorylation MAP kinase consensus site, was identified at position 23 within p6(gag). Substitution by an alanine of the Thr(23) phosphorylable residue within the pNL4.3 molecular clone was found to decrease viral release from various cell types. As observed from electron microscopy experiments, most virions produced from this molecular clone remained incompletely separated from the host cell membrane with an immature morphology and displayed a reduced infectivity in single round infection experiments. Analysis of protein processing by Western blotting experiments revealed an incomplete Pr55(gag) maturation and a reduction in the virion-associated reverse transcriptase proteins was observed that was not related to differences in intracellular viral protein expression. Altogether, these data suggest that phosphorylation of p6(gag) protein by virus-associated ERK-2 is involved in the budding stage of HIV-1 life cycle.