摘要
液泡型H+-ATPase(vacuolar H+-ATPase,V-ATPase)是一类特殊的膜转运结合蛋白,其由8-12个亚基组成,包括V0和V1两个结构域。V-ATPase可利用水解ATP产生的能量将质子泵入细胞区室内,通过调节细胞和细胞器的pH值,产生跨膜质子电化学势梯度,从而驱动离子与代谢物质的转运、调节细胞膨压、生长以及气孔的开闭。同时,V-ATPase在植物处于干旱、盐碱、低温等非生物胁迫条件下,起到重要而积极的作用。拟南芥V-ATPase的c亚基是V0域的重要组成部分之一,现已明确其由五个同源基因编码,以6拷贝的形式组成V-ATPase离子进出的通道,是植物响应逆境胁迫中最为敏感的亚基。但其在植物抗非生物胁迫中的作用机理上不清楚,仍有待于进一步研究。
The plant vacuolar H+-ATPase(V-ATPase)is a membrane-bound transporter protein and it contains 8-12 distinct subunits organized into two large sub-complexes:the cytosolic V1 and membrane V0.It uses the energy released during cleavage of the γ-phosphate of cytosolic ATP to pump protons into the vacuolar lumen and acidify the vacuole,thereby creating an electrochemical H+-gradient which is the driving force for a variety of transport events of ions and metabolites and so influences turgor,cell expansion and guard cell movement.On the other hand,under stress conditions such as drought,salinity or cold,the V-ATPase plays a key role.Subunit c of V-ATPase in Arabidopsis coded by five genes is a major component of V0 sector and forms the proton conductance pathway.In addition,subunit c is also the most sensitive component when plants are under stress conditions.However,the related mechanisms are unknown.
出处
《河套学院论坛》
2007年第2期36-41,共6页
HETAO COLLEGE FORUM
