大叶补血草Na+/H+ 逆向转运蛋白基因( SOS1)的克隆与序列分析

 用RT-PCR及RACE方法从盐生植物大叶补血草Limonium gmelinii (Willd. ) Kuntze中分离出Na⁺/H⁺ 逆向转运蛋白基因的cDNA (LgSOS1, GenBank登录号EU780458) , LgSOS1的cDNA全长为3 910bp, 5′非翻译区为79 bp, 3′非翻译区为376 bp, 开放阅读框为3 455 bp, 编码1 151个氨基酸, 推测分子量为126 kD。氨基酸同源性分析表明, LgSOS1与冰叶午时花、沙拐枣、番茄、盐芥和拟南芥质膜型Na⁺/H⁺ 逆向转运蛋白的一致性分别为69.02%, 64.42% , 61.96% , 60.12%和59.62%。预测分析表明, LgSOS1有12个跨膜结构区域。系统发育分析表明该蛋白与质膜型的Na⁺/H⁺ 逆向转运蛋白的亲缘关系较近, 与液泡型的Na⁺/H⁺ 逆向转运蛋白亲缘关系较远。

Cloning and Sequence Analysis of a Na+/H+ Antiporter Gene in Halophyte Limonium gmelinii

A plasma membrane Na⁺/H⁺ antiporter gene ( LgSOS1, GenBank accession No.EU780458) has been separated from halophyte Limonium gmelinii by RT-PCR and RACE. The LgSOS1 cDNA is 3 910 bp long including 5′untranslated region of 79 bp, 3′untranslated region of 376 bp with PolyA, and an open reading frame of 3 455 bp encoding a protein of 1 151 amino acids with a predicted molecular mass of 126 kD. Bymultiple sequence alignment analysis of amino acids, it has been shown that the identities n amino acids to plasma membrane Na⁺/H⁺ antiporters gene of LgSOS1 is 69.02% , and 64.42% ,61.96% , 60.12% , and 59.62% of Mesembryanthemum crystallinum, Populus euphratica, Lycopersicon esculentum, Thellungiella halophila and Arabidopsis thaliana, respectively. TM pred prediction showed LgSOS1 has 12 transmembrane domains. Phylogenetic analysis indicates that LgSOS1 is more related to plasma membrane-type Na⁺/H⁺ antiporter, compared with vacuolar-type Na⁺/H⁺ antiporter, to which it is less related