大黄鱼CD53基因克隆和分子特征分析

白细胞表面抗原CD53属于四跨膜蛋白超家族,在免疫反应中起着重要作用。在构建大黄鱼（Larim ichthyscrocea）肌肉组织cDNA文库的基础上,克隆了CD53基因。克隆到的CD53基因全长1210bp,其中5-′UTR 113bp,3′-UTR 422bp,CDS 675bp,编码224个氨基酸。生物信息学分析显示大黄鱼CD53存在4次跨膜结构,N端和C端都位于细胞膜内,膜外有两个亲水环,跨膜区域为疏水区域,两个N-糖基化位点都位于靠近C端的亲水环上。大黄鱼CD53氨基酸序列具非常高的保守性,与三刺鱼、斑马鱼、虹鳟等多种鱼类的相似性在70%以上。在检测的10种组织中,CD53只在大黄鱼的脾、骨骼肌、肾、肝、肠组织中表达,其中在肠组织中表达最强。

Cloning and characterization analysis of CD53 gene in Larimichthys crocea

Leukocyte surface antigen CD53,a member of the transmembrane 4 superfamily（TM4SF）,has an important role in immune reaction.On the basis of constructing the full length cDNA library from the skeletal muscle of Larimichthys crocea,CD53 gene was cloned and sequenced.The aquired CD53 gene was 1,210bp in length,including a 113bp 5′-UTR,a 422bp 3′-UTR,and a 675bp coding sequence which encodes 224 amino acids.The bioinformatics analysis showed that CD53 of Larimichthys crocea had four hydrophobic transmembrane spanning domains.Both its N-and C-termini were located in the interior of cell membrance,and two hydrophilic loops were located outside the membrance.Two N-glycosylated sites were located in the hydrophilic loop near the C-terminus.CD53 amino acid sequence was highly conserved,and the similarity among Gasterosteus aculeatus,Danio rerio,Oncorhynchus mykiss and Larimichthys crocea was over 70%.In the examined ten tissues,CD53 gene was expressed in spleen,skeletal muscle,kidney,liver,and intestine,with the highest expression in intestine.