鲈鱼 ZnT 基因的 cDNA 克隆及生物信息学分析

摘要

Zinc transporters family plays important roles in cellular zinc storage , release and distribution .This study described the clo-ning and sequence analysis of the zinc transporters (ZnT) in the seabass (Lateolabrax japonicus) using RT-PCR and SMART RACE. The acquired ZnT was 1747 bp in length , including a 84 bp 5′-UTR, a 490 bp 3′-UTR and a 1173 bp coding sequence which could code 390 amino acid .The obtained sequence was postulated to have six transmenbrane domains , an intracellular N-terminus and C-ter-minus and a His-rich loop between transmembrane domains IV and V .The sequence alignment analysis indicated that the obtained ami-no acid sequence of ZnT shared high identity with ZnT 7s of other species: Danio rerio, 85.6%;Salmo salar, 85.4%; Takifugu ru-bripes, 84.3%;Homo sapiens, 75.1%;Mus musculus 73.8%.Phylogenetic analysis indicated that the acquired ZnT was first clus-tered with ZnT7 of teleost and human, then clusterd with other type ZnT of teleost , which showed that the obtained ZnT was type ZnT 7.%锌转运蛋白（ zinc transporters ， ZnT）在细胞锌的储藏，释放和分布中起了重要的作用。运用RT－PCR和SMART RACE方法从鲈鱼肝脏克隆得到了鲈鱼ZnT基因全长cDNA序列。结果显示，鲈鱼ZnT全长为1747 bp，包括5′非翻译区84 bp，3′非翻译区490 bp，开放阅读框1173 bp，可编码390个氨基酸。生物信息学分析表明该蛋白有6次跨膜结构，N端和C端均位于细胞膜内侧，第IV和第V跨膜区之间的环富含组氨酸。鲈鱼ZnT的氨基酸序列与其他生物的ZnT7序列有高度的相似性：斑马鱼，85．6％；大西洋鲑，85．4％；红鳍东方鲀，84．3％；人，75．1％；小鼠，73．8％。聚类分析显示鲈鱼ZnT首先与其它鱼类和人ZnT7成一簇，再与鱼的其他类别ZnT聚合，说明分离到的鲈鱼ZnT为ZnT7。