植物小G蛋白功能的最新研究进展

Recent Progress on the Small GTPase Gene Superfamily in Plants

小G蛋白超家族包括Ras、Rab、Rho、Arf和Ran亚家族,不同成员间在结构和功能方面又呈现明显的多样性。小G蛋白作为重要的分子开关,其结构域主要包括4个鸟苷酸(GTP/GDP)结合域、1个效应区,其鸟苷酸结合域起着关键作用且保守性最高,在植物、动物和酵母中均有较高的保守性。小G蛋白成员凭借其多样性和不同鸟苷酸结合态的功能调控(结合GTP时为活性状态,而结合GDP时为非活性状态),参与多种细胞生命活动,履行不同的生物学功能,例如基因表达调控,细胞骨架重组,囊泡运输的调节,出芽过程,核-质运输及微管形成。本文主要阐述植物中研究小G蛋白各个家族功能的最新进展。

The small G-protein superfamily includes Ras, Rho, Rab, Arf and Ran homologs, and has structural and functional diversity. These proteins function as important molecular switches, which contain four guanine nucleotide （GTP/GDP） binding （GNB） domains and an effector domain. Their GNB domains play a key role in molecular regulation, and are highly conserved both structurally and functionally across the kingdoms of plants, animals and yeasts. These small GTPases participate in various cellular life activities by its diverse and functional regulation of four guanine nucleotide binding states （being active by binding GTP, and inactive by binding GDP）. Small GTPases perform various biological functions, such as cytoskeletal reorganization, vesicle traffic, budding process, nucleocytoplasmic transport and microtubules formation. Our review is focused on the recent progress in functions of individual members of small GTPases in plants.