拟南芥液泡型H^(+)-ATP酶E1亚基编码基因AtTUF的研究进展

Research Progress on AtTUF Gene of Vacuolar H^(+)-ATPase E1 Subunit in Arabidopsis thaliana

液泡型H^(+)-ATP酶(Vacuolar-H+-ATPase,V-ATP酶,VHA)是存在于所有真核生物中的一类质子泵,主要存在于植物液泡膜、高尔基体及胞内体等内膜系统上,在维持真核细胞内膜区室的pH稳态过程中发挥着重要作用.V-ATP酶是一种多亚基蛋白复合体,由亲水的头部V_(1)和疏水的基部V_(0)两个区域组成,V_(1)位于膜外胞质区,呈球茎状,由A~H 8个亚基组成,主要负责ATP的水解;V_(0)整合于膜中,由a、c、c''、d、e 5个亚基组成,主要负责质子易位.在拟南芥中,V-ATP酶的大多数亚基由包含2~5个成员的小基因家族编码,其中VHA的E亚基由3个具有差异表达的同工型基因编码,在种子发育期间,VHA-E1是胚胎发生过程中的主要同工型,VHA-E2具有花粉特异性,而VHA-E3主要在胚乳和周围的母体组织中表达.VHA-E1亚基由AtTUF基因(又被称为TUFF,EMB2448,VHA-E1,VHAE1,基因号AT4G11150)编码,与跨液泡膜的物质运输密切相关,在体细胞发育过程中对维持功能性分泌系统及植物对各种非生物胁迫的响应过程中均起着重要作用.论文综述了拟南芥中AtTUF的研究进展,以期为相关领域的研究提供参考.

Vacuolar type-H^(+)-ATPase(V-ATPase,VHA)is a major type of proton pump present in all eukaryotes,mainly in the inner membrane systems of plant vacuoles,Golgi apparatus,and endosomes,which plays an important role in maintaining the pH homeostasis in the inner compartment of eukaryotes.V-ATPase is a protein complex composed of multi subunits,and it is devided into two major domains:the cytosolic-located hydrophilic V_(1) domain,which is comprising of eight different subunits(A~H),responsible for ATP hydrolysis,and a membrane-embedded hydrophobic V0 domain comprising of five subunits(a,c,c'',d and e),is mainly responsible for proton tanslocation.In Arabidopsis thaliana,most subunits of V-ATPase are encoded by small gene families containing 2~5 members.Among them,VHA-E is encoded by three isotype genes with differential expression patterns.During the period of seed development,VHA-E1 is the major isotype during embryogenesis,which is necessary in the process of embryogenesis;VHA-E2 is pollen specific,and VHA-E3 mainly expresses in endosperm and the surrounding maternal tissues.The Arabidopsis V-ATPase subunit E1(VHA-E1)is encoded by AtTUF,which is closely related to the transport of substances across the vacuole membrane,plays an essential role in maintaining functional secretion system during the somatic development and in response to various abiotic stresses in plants.In this paper,the research progress of AtTUF gene in Arabidopsis thaliana was summarized,which may provide some reference for the research in related fields in the future.