小GTP酶Arf家族在哺乳动物中的功能研究进展

The functions of the small Arf GTPase family in mammals

ADP-核糖基化因子(Arf)属于小GTP酶的Ras超家族,与其他Ras相关的GTP结合蛋白一样,Arf蛋白在其活性GTP结合和非活性GDP结合构象之间循环。在酵母中其参与高尔基体和核内体的结构并发挥功能。在哺乳动物中Arf家族共包含了六个成员,基于大小和氨基酸序列同一性,这六种Arf蛋白可分为三类,Ⅰ类包括Arf1、Arf2和Arf3,Ⅱ类包括Arf4和Arf5,Ⅲ类包括Arf6。Arf蛋白在生物体内普遍表达,通过膜蛋白、细胞骨架调节因子的膜募集等协调细胞中的囊泡运输。同时,Arf蛋白还参与脂质信号传导和脂质代谢调节脂质介导的非囊泡运输。因此,Arf蛋白在有丝分裂、减数分裂、肌动蛋白细胞骨架、纤毛运输中均发挥重要功能。文章阐述了Arf蛋白家族成员在哺乳动物中的作用机制与功能,并对其未来研究进行了展望。

The ADP-ribosylation factor(Arf)belongs to the Ras superfamily of small GTPases.Like other Ras-associa-ted GTP-binding proteins,Arf proteins circulate between their active GTP-binding and inactive GDP-bound conformations,and participate reportedly in the construction and function of the Golgi body and endosomes in yeast.In mammals,Arf family contains six members which can be classified into three categories:ClassⅠincluding Arf1,Arf2 and Arf3,Class Ⅱ including Arf4 and Arf5,and Class Ⅲ including Arf6,respectively,based on size and amino acid sequence identity.The Arf proteins were found to be widely expressed in cells through membrane recruitment of membrane proteins and cytoskeletal regulatory factors to facilitate the vesicle trafficking in the cells.Meanwhile,Arfs are also involved in lipid signaling and lipid metabolism regulating lipid-mediated non-vesicular trafficking.In addition,recent studies have found that Arfs play important roles in mitosis,meiosis,actin cytoskeleton and ciliary transport.This article reviews the mechanisms and functions of Arf family members in mammals and looks into the future of Arf research.