Chan Woan-Eng, Chen Steve S-L
Institute of Biomedical Sciences, Academia Sinica, Nankang, Taipei, Taiwan, Republic of China.
Virology. 2006 May 10;348(2):418-29. doi: 10.1016/j.virol.2006.01.010. Epub 2006 Feb 9.
The cytoplasmic domain of human immunodeficiency virus type 1 (HIV-1) envelope (Env) transmembrane protein gp41 interacts with the viral matrix MA protein, which facilitates incorporation of the trimeric Env complex into the virus. It is thus feasible to design an anti-HIV strategy targeting this interaction. We herein describe that Gag expression can be downregulated by a cytoplasmic domain fusion protein of the Env transmembrane protein, beta-galactosidase (beta-gal)/706-856, which contains the cytoplasmic tail of gp41 fused at the C terminus of Escherichia coli beta-gal. This mediator depleted intracellular Gag molecules in a dose-dependent manner. Sucrose gradient ultracentrifugation and confocal microscopy revealed that Gag and beta-gal/706-856 had stable interactions and formed aggregated complexes in perinuclear, intracellular sites. Pulse-chase and cycloheximide chase analyses demonstrated that this mediator enhanced unmyristylated Gag degradation. The results demonstrate a novel mode of HIV-1 Gag downregulation by directing Gag to an intracellular site via the interaction of Gag with a gp41 cytoplasmic domain fusion protein.
人类免疫缺陷病毒1型（HIV-1）包膜（Env）跨膜蛋白gp41的胞质结构域与病毒基质MA蛋白相互作用，这有助于三聚体Env复合物掺入病毒中。因此，设计一种针对这种相互作用的抗HIV策略是可行的。我们在此描述，Env跨膜蛋白β-半乳糖苷酶（β-gal）/706-856的胞质结构域融合蛋白可下调Gag表达，该融合蛋白包含在大肠杆菌β-半乳糖苷酶C末端融合的gp41胞质尾巴。这种介质以剂量依赖的方式消耗细胞内的Gag分子。蔗糖梯度超速离心和共聚焦显微镜显示，Gag与β-gal/706-856有稳定的相互作用，并在核周的细胞内位点形成聚集复合物。脉冲追踪和放线菌酮追踪分析表明，这种介质增强了未豆蔻酰化Gag的降解。结果表明，通过Gag与gp41胞质结构域融合蛋白的相互作用将Gag引导至细胞内位点，这是一种新的HIV-1 Gag下调模式。
