Na^+/K^+-ATPase α-subunit in swimming crab Portunus trituberculatus: molecular cloning, characterization, and expression under low salinity stress  

作　　者：韩晓琳 刘萍 高保全 王好锋 段亚飞 徐文斐 陈萍 

机构地区：[1]Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences [2]Dalian Ocean University

出　　处：《Chinese Journal of Oceanology and Limnology》2015年第4期828-837,共10页中国海洋湖沼学报（英文版）

基　　金：Supported by the National High Technology Research and Development Program of China(863 Program)(No.2012AA10A409);the National Natural Science Foundation of China(No.41306177);the Special Scientific Research Funds for Central Non-Profit Institutes,Yellow Sea Fisheries Research Institutes(No.20603022013027)

摘　　要：Na^＋/K^＋-ATPases are membrane-associated enzymes responsible for the active transport of Na^＋ and K^＋ ions across cell membranes, generating chemical and electrical gradients. These enzymes＇ α-subunit provides catalytic function, binding and hydrolyzing ATP, and itself becoming phosphorylated during the transport cycle. In this study, Na^＋/K^＋-ATPase α-subunit eDNA was cloned from gill tissue of the swimming crab Portunus trituberculatus by reverse-transcription polymerase chain reaction （RT-PCR） and rapid amplification of eDNA end methods. Analysis of the nucleotide sequence revealed that the eDNA had a full-length of 3 833 base pairs （bp）, with an open reading frame of 3 120 bp, 5＇ untranslated region （UTR） of 317 bp, and 3＇ UTR of 396 bp. The sequence encoded a 1 039 amino acid protein with a predicted molecular weight of 115.57 kDa and with estimated pI of 5.21. It was predicted here to possess all expected features of Na^＋/K^＋-ATPase members, including eight transmembrane domains, putative ATP-binding site, and phosphorylation site. Comparison of arnino acid sequences showed that the P. tritubereulatus α-subunit possessed an overall identity of 75%-99% to that of other organisms. Phylogenetic analysis revealed that this α-subunit was in the same category as those of crustaceans. Quantitative real-time RT-PCR analysis indicated that this α-subunit＇s transcript were most highly expressed in gill and lowest in muscle. RT-PCR analysis also revealed that α-subunit expression in crab gill decreased after 2 and 6 h, but increased after 12, 24, 48, and 72 h. In addition, α-subunit expression in hepatopancreas of crab decreased after 2-72 h. These facts indicated that the crab＇s Na^＋/K^＋-ATPase α-subunit was potentially involved in the observed acute response to low salinity stress.A bstract Na + /K +-ATPases are membrane-associated enzymes responsible for the active transport of Na + and K + ions across cell membranes, generating chemical and electrical gradients. These enzymes' α-subunit provides catalytic function, binding and hydrolyzing ATP, and itself becoming phosphorylated during the transport cycle. In this study, Na+ /K +-ATPase α-subunit c DNA was cloned from gill tissue of the swimming crab P ortunus trituberculatus by reverse-transcription polymerase chain reaction(RT-PCR) and rapid amplification of c DNA end methods. Analysis of the nucleotide sequence revealed that the c DNA had a full-length of 3 833 base pairs(bp), with an open reading frame of 3 120 bp, 5' untranslated region(UTR) of 317 bp, and 3' UTR of 396 bp. The sequence encoded a 1 039 amino acid protein with a predicted molecular weight of 115.57 k Da and with estimated p I of 5.21. It was predicted here to possess all expected features of Na+ /K +-ATPase members, including eight transmembrane domains, putative ATP-binding site, and phosphorylation site. Comparison of amino acid sequences showed that the P. trituberculatus α-subunit possessed an overall identity of 75%–99% to that of other organisms. Phylogenetic analysis revealed that this α-subunit was in the same category as those of crustaceans. Quantitative real-time RT-PCR analysis indicated that this α-subunit's transcript were most highly expressed in gill and lowest in muscle. RT-PCR analysis also revealed that α-subunit expression in crab gill decreased after 2 and 6 h, but increased after 12, 24, 48, and 72 h. In addition, α-subunit expression in hepatopancreas of crab decreased after 2–72 h. These facts indicated that the crab's Na+ /K +-ATPase α-subunit was potentially involved in the observed acute response to low salinity stress.

关 键 词：cloning EXPRESSION Na^＋/K^＋-ATPase α-subunit Portunus trituberculatus SALINITY 

分 类 号：S917.4[农业科学—水产科学]