大菱鲆热休克蛋白90基因cDNA的克隆及其表达特征

Molecular cloning and expression of heat shock protein 90 gene cDNA from turbot Psetta maxima

中文关键词: HSP90  大菱鲆  cDNA  感染

英文关键词: HSP90  Turbot Psetta maxima  cDNA  Infection

中文摘要:

      从大菱鲆脾脏cDNA文库中筛选到HSP90，采用基因克隆方法获得含有1个97bp的5’UTR、2190bp的开放阅读框和501bp的3’UTR的全长cDNA序列。整个开放阅读框编码729个氨基酸，包含HSP90家族5个保守信号区。与其他物种已知序列同源比对的结果显示，此编码氨基酸更接近于热休克蛋白90β亚型（HSP90β），与牙鲆HSP90β的同源性高达96.6%。RT-PCR分析表明，在胚胎发育初期就能检测到HSP90，其表达量伴随着胚胎发育，先增加后减少，在尾芽期达到最高。HSP90在健康大菱鲆各供试组织中均有表达。经鳗弧菌感染处理后，在胚胎细胞中也有HSP90的强烈表达。结果显示，大菱鲆HSP90 cDNA序列为HSP90β，是一种组成型表达的基因，其在维持正常生理机能、胚胎发育和应激中发挥重要的作用。

英文摘要:

      Heat shock protein 90 (HSP90), functioning as a molecular chaperone in protein biosynthesis, plays an important role in signal transduction, immune response and embryogenesis. We have recently isolated the cDNA encoding HSP90 from turbot Psetta maxima spleen cDNA library. The full length cDNA of the HSP90 contains 97bp 5’terminal UTR, 501bp 3’terminal UTR and 2,190bp open reading frame for a protein of 729 amino acid residues. Comparison of amino acid sequence revealed the presence of five classical HSP90 signature sequences in turbot HSP90. The deduced amino acid sequence of turbot HSP90 exhibited higher homology with HSP90β isoform. HSP90 transcripts were found to be expressed in all tested normal physiological tissues (intestine, kidney, gill, skin, liver, spleen, head kidney, gonad, brain, muscle and heart) and could also be detected in the earlier embryonic stage. The level of HSP90 mRNA in embryos gradually increased during embryogenesis and reached the maximum at tail bud stage. Challenge of turbot embryonic cell line (TEC) with pathogenic bacteria, Vibrio anguillarum, elevated HSP90 mRNA levels dramatically. These results demonstrated that this turbot HSP90 cDNA sequence was the constitutive expressed HSP90β isoform, and it may be involved in embryogenesis and cellular protection events under normal and stress condition.