Londou Adamantia, Mikrou Angeliki, Zarkadis Ioannis K
Department of Biology, School of Medicine, University of Patras, Rion 26500, Patras, Greece.
Mol Immunol. 2008 Jan;45(2):470-8. doi: 10.1016/j.molimm.2007.05.027. Epub 2007 Jul 31.
Clusterin is a broadly distributed glycoprotein constitutively expressed by various tissues and cell types and has been shown to be associated with several physiological and pathological functions. In order to study the molecular evolution of clusterin, here we report the cloning and characterization of two clusterin genes in rainbow trout (Oncorhynchus mykiss). The deduced amino acid sequences of clusterin-1 and a partial clusterin-2 clone are 89% identical to each other, showing 45, 42 and 38% identity with chicken, frog and human orthologs, respectively. Most of the putative N-glycosylation sites, as well as all 10 cysteine residues which are involved in disulfide bond formation in the mature trout clusterin-1 protein, are fully conserved when aligned with its orthologs from various species. Although trout clusterin genes exhibit the same exon-intron organization, in line with that of human clusterin, they show a totally different mRNA expression profile among various trout tissues. Phylogenetic analysis indicates an early segregation of the clusterin ancestral gene within the taxon of fish leading to the formation of a separate subgroup.
聚集素是一种广泛分布的糖蛋白，由各种组织和细胞类型组成性表达，并已被证明与多种生理和病理功能相关。为了研究聚集素的分子进化，我们在此报告虹鳟（Oncorhynchus mykiss）中两个聚集素基因的克隆和特征。聚集素-1和部分聚集素-2克隆的推导氨基酸序列彼此具有89%的同一性，分别与鸡、青蛙和人类直系同源物具有45%、42%和38%的同一性。当与其来自不同物种的直系同源物比对时，大多数推定的N-糖基化位点以及成熟虹鳟聚集素-1蛋白中参与二硫键形成的所有10个半胱氨酸残基都是完全保守的。尽管虹鳟聚集素基因表现出与人聚集素相同的外显子-内含子组织，但它们在虹鳟的各种组织中显示出完全不同的mRNA表达谱。系统发育分析表明，聚集素祖先基因在鱼类分类群中早期分离，导致形成一个单独的亚组。
