CCR5基因的多态性非洲绿猴和老鼠暗示特定的氨基酸在猿和人类免疫缺陷病毒感染。
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科扎克Kuhmann SE,普拉特EJ, SL,卡巴特D
CCR5基因的多态性非洲绿猴和老鼠暗示特定的氨基酸在猿和人类免疫缺陷病毒感染。
J微生物学报。1997年11月,71 (11):8642 - 56。
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9343222 (在PubMed]
- 文摘
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为CC趋化因子受体CCR5,咆哮,Mip1alpha, Mip1beta,已被确定为一个coreceptor macrophage-tropic隔离感染的人类免疫缺陷病毒1型(hiv - 1)。研究其结构和功能,我们孤立cDNA克隆人类,非洲绿猴(AGM)和NIH /瑞士鼠标CCR5,我们定量分析后由macrophage-tropic hiv - 1感染和SIVmac251使转染人类HeLa-CD4细胞与CCR5表达向量。年度股东大会和NIH /瑞士鼠标CCR5蛋白质是相同的人类蛋白质97.7到98.3%和79.8%,分别。此外,我们分析了定点突变体和这些ccr5的嵌合体。CCR5蛋白质的细胞表面表达监测通过使用特定的兔抗血清和趋化因子[125 i] Mip1beta绑定。我们的主要结果如下。(我)两种不同的AGM CCR5在会阴细胞的DNA序列可再生产地发现。年度股东大会克隆1 CCR5蛋白质的不同克隆2两个替换,Y14N伴细胞外地区和L352F羧基末端。有趣的是,AGM克隆1 CCR5是不活跃的所有测试macrophage-tropic coreceptor hiv - 1的分离,而AGM克隆2 CCR5是活跃的。如图所示嵌合体研究和定点诱变,AGM克隆1中的Y14N替换CCR5是单独负责阻断hiv - 1感染。 In contrast, both AGM CCR5 clones were active coreceptors for SIVmac251. Studies of DNA samples from other AGMs indicated frequent additional CCR5 polymorphisms, and we cloned an AGM clone 2 variant with a Q93R substitution in the extracellular loop 1 from one heterozygote. This variant CCR5 was active as a coreceptor for SIVmac251 but was only weakly active for macrophage-tropic isolates of HIV-1. In addition, SIVmac251 appeared to be dependent on the extracellular amino terminus and loop 2 regions of human CCR5 for maximal infection. Our results suggest major differences in the interactions of SIVmac251 and macrophage-tropic HIV-1 isolates with 19, N13, and Y14 in the amino terminus; with Q93 in extracellular loop 1; and with extracellular loop 2 of human CCR5. (ii) The NIH/Swiss mouse CCR5 protein differs at multiple positions from sequences recently reported for other inbred strains of mice. This CCR5 was inactive as a coreceptor for HIV-1 and SIVmac251. Studies of chimeras that contained different portions of NIH/Swiss mouse CCR5 substituted into human CCR5, as well as the reciprocal chimeras, indicated that the amino-terminal region and extracellular loops 1 and 2 of human CCR5 contribute to its coreceptor activity for macrophage-tropic isolates of HIV-1. Specific differences with previous CCR5 chimera results occurred because the NIH/Swiss mouse CCR5 contains a unique substitution corresponding to P183L in extracellular loop 2 that is nonpermissive for coreceptor activity. We conclude that diverse CCR5 sequences occur in AGMs and mice, that SIVmac251 and macrophage-tropic HIV-1 isolates interact differently with specific CCR5 amino acids, and that multiple regions of human CCR5 contribute to its coreceptor functions. In addition, we have identified naturally occurring amino acid polymorphisms in three extracellular regions of CCR5 (Y14N, Q93R, and P183L) that do not interfere with cell surface expression or Mip1beta binding but prevent infections by macrophage-tropic isolates of HIV-1. In contrast to previous evidence, these results suggest that CCR5 contains critical sites that are essential for HIV-1 infections.