Characterization of the G protein-coupled receptor kinase GRK4 - Identification of four splice variants
Characterization of the G protein-coupled receptor kinase GRK4 - Identification of four splice variants
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DOI：
10.1074/jbc.271.11.6403
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发表时间：
1996-03-15
影响因子：
4.8
通讯作者：
Lefkowitz, RJ
中科院分区：
文献类型：
--
作者：
Premont, RT;Macrae, AD;Lefkowitz, RJ
一种新的人类G蛋白偶联受体激酶是最近通过定位克隆在寻找亨廷顿病基因座(Ambrose，C.，James，M.，Barnes，G.，Lin，C.，Bates，G.，Altherr，M.，Duyao，M.，Groot，N.，Church，D.，Wasmuth，J.，Lehrach，H.，Housman，D.，Buckler，A.，Gusella，J.F.和MacDonald，M.E.(1993)Hum)中鉴定出来的。梅尔。吉内。1,697-703)。比较GRK4与GRK5和GRK6的氨基酸序列，发现GRK4的氨基末端有32个密码子缺失，羧基末端有46个密码子缺失。这两个区域在GRK4mRNA中经历了选择性剪接，这是由于存在或不存在填补其中一个或两个明显缺口的外显子造成的。每个插入的序列维持开放阅读框架，推导的氨基酸序列与GRK5和GRK6的相应区域相似。因此，GRK4mRNA和GRK4蛋白可以以四种不同的变体形式存在。人类GRK4基因由16个外显子组成，延伸超过75kb的DNA对。两个选择性剪接的外显子对应于外显子II和XV。GRK4基因的基因组组织与人类的GRK2基因完全不同，突显了自这两个基因分化以来的进化距离。人GRK4基因只在睾丸中高表达，两个外显子在睾丸中都有丰富的表达，四种GRK4蛋白均已表达，均含有[H-3]棕榈酸。GRK4能够增强大鼠促黄体激素/绒毛膜促性腺激素受体在HEK293细胞中共表达时的脱敏作用，并能磷酸化激动剂占据的、纯化的β(3)-肾上腺素能受体，表明GRK4是一种功能性蛋白激酶。
A novel human G protein-coupled receptor kinase was recently identified by positional cloning in the search for the Huntington's disease locus (Ambrose, C., James, M., Barnes, G., Lin, C., Bates, G., Altherr, M., Duyao, M., Groot, N., Church, D., Wasmuth, J. J., Lehrach, H., Housman, D., Buckler, A., Gusella, J. F., and MacDonald, M. E. (1993) Hum. Mel. Genet. 1, 697-703). Comparison off the deduced amino acid sequence of GRK4 with those of the closely related GRK5 and GRK6 suggested the apparent loss of 32 codons in the amino-terminal domain and 46 codons in the carboxyl terminal domain of GRK4. These two regions undergo alternative splicing in the GRK4 mRNA, resulting from the presence or absence of exons filling one or both of these apparent gaps. Each inserted sequence maintains the open reading frame, and the deduced amino acid sequences are similar to corresponding regions of GRK5 and GRK6. Thus, the GRK4 mRNA and the GRK4 protein can exist as four distinct variant forms.The human GRK4 gene is composed of 16 exons extending over 75 kilobase pairs of DNA. The two alternatively spliced exons correspond to exons II and XV. The genomic organization of the GRK4 gene is completely distinct from that of the human GRK2 gene, highlighting the evolutionary distance since the divergence of these two genes. Human GRK4 mRNA is expressed highly only in testis, and both alternative exons are abundant in testis mRNA.The four GRK4 proteins have been expressed, and all incorporate [H-3]palmitate. GRK4 is capable of augmenting the desensitization of the rat luteinizing hormone/chorionic gonadotropin receptor upon coexpression in HEK293 cells and of phosphorylating the agonist-occupied, purified beta(3)-adrenergic receptor, indicating that GRK4 is a functional protein kinase.