菲律宾蛤仔(Venerupis philippinarum)Rho型GST和微粒体型GST的序列分析及表达特征研究

摘要

Glutathione S-transferase (GST) is a family of versatile enzymes playing significant roles in cellular defense against oxidative stress.In this study,the full-length cDNAs of two glutathione S-transferases (GSTs) (named VpGSTR and VpGSTMi) were cloned from Venerupis philippinarum using RACE technique.Sequence analysis showed that VpGSTR comprised an open reading frame (ORF) of 705bp,encoding a polypeptide of 234 amino acids,and VpGSTMi possessed an ORF of 450bp,encoding a polypeptide of 149 amino acids.Phylogenetic analysis showed that VpGSTR and VpGSTMi were linked in evolution with other Rho and microsomal homologues.The VpGSTR and VpGSTMi transcript were detected in all tissues but in the highest level in hepatopancreas.After challenged with Vibrio anguillarum,the expression of both VpGSTR and VpGSTMi transcripts was up-regulated in 24h.These findings suggest that VpGSTR and VpGSTMi may play an important role in cellular defense against oxidative stress caused by bacterial challenge.%谷胱甘肽硫转移酶是一类在细胞解毒和抗氧化过程中发挥重要作用的超家族酶系.采用cDNA末端快速扩增技术,从菲律宾蛤仔中克隆获得Rho型GST和微粒体型GST基因的全长序列(分别命名为VpGSTR和VpGSTMi).序列分析显示,VpGSTR和VpGSTMi的cDNA全长分别为942bp和661bp,编码234和149个氨基酸.系统分析结果表明,菲律宾蛤仔GSTR与GSTMi在进化树上的位置与其分类所处的位置一致.荧光定量PCR结果发现,VpGSTR和VpGSTMi广泛分布于所检测组织中,且在肝胰腺组织中表达量最高.在鳗弧菌侵染后,VpGSTR和VpGSTMi基因表达量在24h内均表现出明显的上升趋势.上述结果表明,VpGSTR和VpGSTMi可能在菲律宾蛤仔抵御细菌侵染导致的氧化应激中发挥重要功能.