花生AhXTH32蛋白的生物信息学分析、亚细胞定位与原核表达

Bioinformatics Analysis,Subcellular Localization and Prokaryotic Expression of AhXTH32 Protein in Peanut

木葡聚糖内糖基转移酶/水解酶(XTH)在植物的生长发育和逆境应答中发挥重要作用。本研究运用生物信息学技术对花生AhXTH32蛋白的理化性质、结构等进行分析,利用水稻原生质体瞬时表达法对Ah XTH32进行亚细胞定位,通过原核表达初步研究其表达情况。结果表明:AhXTH32蛋白的N端含有信号肽,没有跨膜结构,属于典型的分泌蛋白;含有GH16、XET-C两个保守结构域,属于XTH蛋白家族;定位在细胞质、细胞膜、质外体,缺失信号肽时,蛋白不能分泌到胞外;在大肠杆菌中成功表达可溶性重组AhXTH32蛋白。推测该蛋白可能与质膜结合后分泌到胞外水解细胞壁半纤维素,参与花生的防御机制。

Xyloglucan endotransglycosylase/hydrolase(XTH)plays an important role in plant growth,development and stress responses.In this study,the physicochemical properties and structures of peanut AhXTH32 protein were analyzed by bioinformatics technology,and the function of AhXTH32 was studied by transient expression methods of rice protoplasts,and the expression of AhXTH32 was preliminary investigated through prokaryotic expression.The results showed that the N-terminal of AhXTH32 protein contained a signal peptide but not transmembrane structure,suggesting that it was a typically secreted protein.Moreover,it contained two conserved domains of GH16 and XET-C,belonging to the XTH protein family.The protein was localized in cytoplasm,cell membrane and apoplast when with signal peptide,but could not be secreted outside the cell when without signal peptide.Soluble recombinant AhXTH32 protein was successfully expressed in Escherichia coli.It is speculated that AhXTH32 might bind to plasma membrane and secrete outside,thereby degrading hemicellulose in cell wall,which contributed to defense mechanism of peanut.