Bobak D A, Nightingale M S, Murtagh J J, Price S R, Moss J, Vaughan M
Laboratory of Cellular Metabolism, National Heart, Lung, and Blood Institute, Bethesda, MD 20892.
Proc Natl Acad Sci U S A. 1989 Aug;86(16):6101-5. doi: 10.1073/pnas.86.16.6101.
ADP-ribosylation factors (ARFs) are small guanine nucleotide-binding proteins that enhance the enzymatic activities of cholera toxin. Two ARF cDNAs, ARF1 and ARF3, were cloned from a human cerebellum library. Based on deduced amino acid sequences and patterns of hybridization of cDNA and oligonucleotide probes with mammalian brain poly(A)+ RNA, human ARF1 is the homologue of bovine ARF1. Human ARF3, which differs from bovine ARF1 and bovine ARF2, appears to represent a newly identified third type of ARF. Hybridization patterns of human ARF cDNA and clone-specific oligonucleotides with poly(A)+ RNA are consistent with the presence of at least two, and perhaps four, separate ARF messages in human brain. In vitro translation of ARF1, ARF2, and ARF3 produced proteins that behaved, by SDS/PAGE, similar to a purified soluble brain ARF. Deduced amino acid sequences of human ARF1 and ARF3 contain regions, similar to those in other G proteins, that are believed to be involved in GTP binding and hydrolysis. ARFs also exhibit a modest degree of homology with a bovine phospholipase C. The observations reported here support the conclusion that the ARFs are members of a multigene family of small guanine nucleotide-binding proteins. Definition of the regulation of ARF mRNAs and of function(s) of recombinant ARF proteins will aid in the elucidation of the physiologic role(s) of ARFs.
ADP-核糖基化因子（ARFs）是一类小的鸟嘌呤核苷酸结合蛋白，可增强霍乱毒素的酶活性。从人小脑文库中克隆出了两个ARF cDNA，即ARF1和ARF3。根据推导的氨基酸序列以及cDNA和寡核苷酸探针与哺乳动物脑多聚腺苷酸加尾RNA（poly(A)+ RNA）的杂交模式，人ARF1是牛ARF1的同源物。人ARF3与牛ARF1和牛ARF2不同，似乎代表一种新鉴定出的第三种类型的ARF。人ARF cDNA和克隆特异性寡核苷酸与poly(A)+ RNA的杂交模式与人类大脑中至少存在两种、也许四种不同的ARF信使核糖核酸（mRNA）相一致。ARF1、ARF2和ARF3的体外翻译产生的蛋白质，通过十二烷基硫酸钠/聚丙烯酰胺凝胶电泳（SDS/PAGE）显示，其行为与纯化的可溶性脑ARF相似。人ARF1和ARF3推导的氨基酸序列包含与其他G蛋白中相似的区域，据信这些区域参与鸟苷三磷酸（GTP）结合和水解。ARFs与一种牛磷脂酶C也表现出一定程度的同源性。此处报道的观察结果支持以下结论：ARFs是小的鸟嘌呤核苷酸结合蛋白多基因家族的成员。对ARF mRNA调控以及重组ARF蛋白功能的定义将有助于阐明ARFs的生理作用。
