作　　者： (邱全胜）;

机构地区： 兰州大学生命科学学院,兰州730000

出　　处： 《中国科学：生命科学》 2017年第8期839-846,共8页

摘　　要： 拟南芥(Arabidopsis thaliana)AtNHX5和AtNHX6离子转运特性和生物功能的研究取得了重要进展.AtNHX5和AtNHX6属于内膜Na^+,K^+/H^+反向交换体(NHX),定位于高尔基(Golgi),反面高尔基网(TGN)和多胞体/液胞前体(MVB/PVC).研究表明,AtNHX5和AtNHX6在调控细胞Na^+,K^+和pH平衡以及耐盐胁迫和钾营养等方面起着重要的作用.AtNHX5和AtNHX6跨膜结构域存在保守的酸性氨基酸残基;这些保守的酸性氨基酸残基调控着AtNHX5和AtNHX6的离子转运活性,从而调节植物的生长发育.最近研究发现,AtNHX5和AtNHX6调控着蛋白质向液胞的运输过程.并且发现,AtNHX5和AtNHX6在许多环节上调控着蛋白质的运输过程:AtNHX5和AtNHX6可能调控着液胞分选受体(VSR)与运输物的结合、VSR的循环运输过程以及SNARE复合物的亚细胞定位3个不同的细胞过程.本文将结合本研究组近年的研究工作,综述目前关于AtNHX5和AtNHX6的离子转运特性和生物功能方面的研究进展. Great progress has been made in understanding the transport properties and function of AtNHX5 and AtNHX6,the endosomal Na~＋,K~＋/H~＋ antiporters（endosomal NHX） in Arabidopsis.Studies have shown that AtNHX5 and AtNHX6 are localized in the endosomal compartments,including the Golgi,TGN and MVB/PVC.AtNHX5 and AtNHX6 are critical for the homeostasis of cellular Na~＋,K~＋ and pH.They play important roles in salt tolerance and potassium nutrition in plants.Three conserved acidic amino acid residues in the transmembrane domains of AtNHX5 and AtNHX6 are essential for their ion exchange activity and seedling growth.Recent studies have found that AtNHX5 and AtNHX6 regulate the transport of seed storage proteins into the vacuole in Arabidopsis seeds.AtNHX5 and AtNHX6 may control multiple steps of the protein transport;they may control the binding of VSR to its cargoes,the recycling of VSRs,and the subcellular localization of the SNARE complex.Recent progress in characterizing ion transport and physiological functions of AtNHX5 and AtNHX6 is summarized in this article.

关 键 词： 反向交换体 离子平衡 蛋白质运输 保守酸性氨基酸残基