拟南芥内膜Na+,K+/H+反向转运体研究进展

Progress in endosomal Na+,K+/H+ antiporter in Arabidopsis thaliana

摘要:

拟南芥内膜Na,K+/H+反向转运体 (Endosomal NHX) 的亚细胞定位、离子转运特性及生物学功能阐释取得了重要进展。拟南芥内膜Na+,K+/H+反向转运体包含AtNHX5和AtNHX6两个成员，它们的氨基酸序列相似性为78.7%。研究表明，AtNHX5和AtNHX6具有功能冗余，它们都定位在高尔基体 (Golgi)、反面高尔基体管网状结构 (TGN)、内质网 (ER) 和液胞前体 (PVC)，参与调控耐盐胁迫、pH平衡和K+平衡等。有报道显示内膜NHXs跨膜结构域存在能够调控自身离子活性的酸性保守氨基酸残基，对其自身功能具有决定性作用。最新研究结果表明，拟南芥内膜NHXs影响囊泡运输和蛋白存贮，并参与生长素介导的植物生长和发育。文中主要对拟南芥内膜NHXs的亚细胞定位、离子转运、功能及应用进展进行了概述。

Abstract:

Important progress has been made in the interpretation of subcellular location, ion transport characteristics and biological functions of endosomal Na+,K+/H+ antiporter in Arabidopsis thaliana. The endosomal Na+,K+/H+ antiporter contain two members, AtNHX5 and AtNHX6, whose amino acid sequence similarity is 78.7%. Studies have shown that AtNHX5 and AtNHX6 are functionally redundant, and they are all located in Golgi, trans-Golgi network (TGN), endoplasmic reticulum (ER) and prevacuolar compartment (PVC). AtNHX5 and AtNHX6 are critical for salt tolerance stress and the homeostasis of pH and K+. It has been reported that there are conservative acidic amino acid residues that can regulate their ion activity in the endosomal NHXs transmembrane domain, which plays a decisive role in their own functions. The results of the latest research indicate that endosomal NHXs affect vacuolar transport and protein storage, and participate in the growth of auxin-mediated development in A. thaliana. In this paper, the progress of subcellular localization, ion transport, function and application of endosomal NHXs in A. thaliana was summarized.