Two distinct CCR5 domains can mediate coreceptor usage by human immunodeficiency virus type 1
Two distinct CCR5 domains can mediate coreceptor usage by human immunodeficiency virus type 1
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DOI：
10.1128/jvi.71.9.6305-6314.1997
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发表时间：
1997-09-01
影响因子：
5.4
通讯作者：
Peiper, SC
中科院分区：
文献类型：
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作者：
Doranz, BJ;Lu, ZH;Peiper, SC
趋化因子受体CCR 5是人类免疫缺陷病毒1型（HIV-1）嗜巨噬细胞株的主要融合辅助受体。为了确定CCR 5的结构，可以支持包膜（Env）介导的膜融合，我们分析了同源物，嵌合体，和突变体的人CCR 5的活性在一个敏感的基因报告细胞-细胞融合试验。猴，但不是鼠，同源的CCR 5是完全活跃的HIV-1融合共受体。CCR 5和趋化因子受体之间的嵌合体证明了CCR 5的两个不同区域的存在，其可用于Env介导的融合，氨基末端结构域和细胞外环。双嗜性Env蛋白对CCR 5氨基端结构域的改变特别敏感，这表明该结构域可能在体内辅助受体使用的演变中发挥关键作用。我们确定了两个功能区，天冬氨酸-11，赖氨酸-197，和天冬氨酸-276，有助于辅助受体功能的个别残基。删除一个高度保守的细胞质基序CCR 5不能信号，但没有废除其作为辅助受体的功能，这意味着融合和G蛋白介导的趋化因子受体信号的独立性。最后，我们开发了一种新的CCR 5单克隆抗体，以协助未来的研究CCR 5的表达。
The chemokine receptor CCR5 is the major fusion coreceptor for macrophage-tropic strains of human immunodeficiency virus type 1 (HIV-1). To define the structures of CCR5 that can support envelope (Env)mediated membrane fusion, we analyzed the activity of homologs, chimeras, and mutants of human CCR5 in a sensitive gene reporter cell-cell fusion assay. Simian, but not murine, homologs of CCR5 were fully active as HIV-1 fusion coreceptors. Chimeras between CCR5 and divergent chemokine receptors demonstrated the existence of two distinct regions of CCR5 that could be utilized for Env-mediated fusion, the amino-terminal domain and the extracellular loops. Dual-tropic Env proteins were particularly sensitive to alterations in the CCR5 amino-terminal domain, suggesting that this domain may play a pivotal role in the evolution of coreceptor usage in vivo. We identified individual residues in both functional regions, Asp-11, Lys-197, and Asp-276, that contribute to coreceptor function. Deletion of a highly conserved cytoplasmic motif rendered CCR5 incapable of signaling but did not abrogate its ability to function as a coreceptor, implying the independence of fusion and G-protein-mediated chemokine receptor signaling. Finally, we developed a novel monoclonal antibody to CCR5 to assist in future studies of CCR5 expression.