7种植物K~＋/H~＋逆向转运蛋白的生物信息学分析  

Bioinformatics Analysis of 7 Plants' K^+/H^+ Antiporters

作　　者：韩蕾[1,2] 宋志忠[1,2] 王莉[1,2] 苏彦华[1] 

机构地区：[1]土壤与农业可持续发展国家重点实验室,中国科学院南京土壤研究所,南京210008 [2]中国科学院研究生院,北京100049

出　　处：《基因组学与应用生物学》2011年第3期372-378,共7页Genomics and Applied Biology

基　　金：国家973项目(2007CB109303);国家转基因重大专项课题(2009ZX08009-129B)共同资助

摘　　要：K+/H+逆向转运是普遍存在于几乎所有生物体内的重要离子平衡机制之一。该机制主要由多基因家族KEA(K efflux antiporter)介导。然而,长期以来对KEA的功能特征和生理意义的认识,除了在大肠杆菌中有零星的报道之外,绝大部分尚为空白。本文通过生物信息学分析,比较了7个植物物种KEA的同源和进化关系,发现KEA家族中的部分成员在物种进化过程中具有极高的保守性。以模式植物拟南芥为例,进一步研究了KEA的蛋白质跨膜结构、关键结构域和亚细胞定位预测等。结果表明,AtKEA大多具有10～12个跨膜结构,是典型的膜蛋白,在跨膜区的N端有多个丝氨酸磷酸化调控位点;都含有K+/H+交换结构域和相应的调控域,推测其能够介导K+/H+交换。基因芯片研究表明,AtKEA在根、茎、叶、花和荚果等不同组织器官的表达丰度不同,表明KEA基因家族各成员的生理功能具有时空分异性。上述结果可为进一步深入研究植物K+/H+逆向转运系统的功能提供借鉴。K＋/H＋ antiporting is employed by almost all living organisms as an important mechanism of ion homeostasis.This machinery is composed of a multi-gene family known as KEA（K efflux antiporter）.However,except a couple of reports from E.coli,the functionalities of most KEAs and their physiological significances remain largely unclear.In this report,homologous comparison of KEAs from seven plant species which had been accomplished in full genome sequencing had revealed members of the KEA family were highly conserved along evolution.Further analyses engaged the KEAs of the model plant Arabidopsis thaliana in regard of their transmembrane structure,putative functional hallmarks as well as predicted subcellular localizations.The results indicated that AtKEAs were membrane proteins and contained 10 to 12 transmembrane domains（TM）,on which locating multiple serine phosphorylation sites to the N-termini of the TMs.Morever,KEAs harbor structurally,a putative K＋/H＋ exchange motif as well as related regulation components,which was in support of a functional deduction as K＋/H＋ antiporters.Results from microarrays indicated that expression of AtKEA genes varied in tissues/organs and developmental stages,suggesting a temporal and spatial pattern of their physiological roles.This report would be expected to provide useful inspiration toward discovery of the functionality of plant K＋/H＋ antiport system.

关 键 词：植物K+/H+逆向转运蛋白 进化保守性 结构特征 基因表达 

分 类 号：Q946[生物学—植物学]