Rapid expansion of killer cell immunoglobulin-like receptor genes in primates and their coevolution with MHC Class I genes
Rapid expansion of killer cell immunoglobulin-like receptor genes in primates and their coevolution with MHC Class I genes
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DOI：
10.1016/j.gene.2004.12.012
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发表时间：
2005-03-14
期刊：
影响因子：
3.5
通讯作者：
Nei, M
中科院分区：
文献类型：
--
作者：
Hao, L;Nei, M
灵长类中的杀伤细胞免疫球蛋白样受体（KIR）基因家族提供了抵抗病毒感染和肿瘤转化的第一道防线。KIRs与MHC I类分子相互作用，可以调节自然杀伤（NK）细胞的细胞毒活性，并将肿瘤和病毒感染的细胞与正常体细胞区分开来。系统发育分析和结构域结构的比较确定了三个主要组的KIR基因（组I，II和III基因）。这些组的KIR基因，产生了一系列的基因复制，获得了不同的MHG结合特异性。祖先的KIR序列的推断表明，从第II组基因的功能分歧发生在重复后的MHC结合位点的正选择。我们的进化研究表明，I组基因在大约1700万年前（Mya）从II组基因中分离出来，显然是在人科动物从旧大陆（OW）猴子中分离出来之后。大约在同一时间，产生I类MHC-C位点的基因复制似乎已经发生。这些发现表明，KIR和MHC I类基因作为一个相互作用的系统共同进化。KIR基因家族在灵长类物种中经历了快速扩展。这个基因家族的扩展速度似乎是所有类人猿基因家族中最高的。KIR基因家族也经历了出生和死亡的进化。(c)2004爱思唯尔RV保留所有权利。
The gene family of killer cell immunoglobulin-like receptors (KIRs) in primates provides the first line of defense against virus infection and tumor transformation. Interacting with MHC class I molecules, KIRs can regulate the cytotoxic activity of natural killer (NK) cells and distinguish the tumor and virus infected cells from normal body cells. Phylogenetic analysis and comparison of domain structures identified three major groups of KIR genes (group I, II, and III genes). These groups of KIR genes, generated by a series of gene duplications, have acquired different MHG-binding specificity. Inference of ancestral KIR sequences suggested that the functional divergence of group I genes from group II genes occurred by positive selection at the MHC-binding sites after duplication. Our evolutionary study has shown that group I Genes diverged from group II genes about 17 million years ago (Mya) apparently after separation of hominoids from Old World (OW) monkeys. Around the same time, gene duplication generating the class I MHC-C locus appears to have occurred. These findings suggest that KIR and MHC class I genes have coevolved as an interacting system. The KIR gene family has experienced a rapid expansion in primate species. The rate of expansion of this gene family seems to be one of the highest among all hominoid gene families. The KIR gene family is also subject to birth-and-death evolution. (c) 2004 Elsevier RV All rights reserved.