水稻MAPK基因OsMPK4的克隆鉴定、蛋白表达和转基因载体构建

克隆鉴定了一个水稻促分裂原活化蛋白激酶(mitogen-activated protein kinases, MAPK)基因OsMPK4.OsMPK4基因cDNA全长1483 bp,包含一个1131 bp的开放阅读框,编码一个由376个氨基酸组成的蛋白,预测分子量为42.8 kD.OsMPK4基因位于水稻第10号染色体上,由6个外显子和5个内含子组成.OsMPK4蛋白具有MAPK的11个保守结构域及磷酸化位点TEY模体.系统进化树分析表明,OsMPK4属于B组MAPK成员,与已知水稻MAPK蛋白有56%～74%的一致性.原核表达了OsMPK4基因,纯化获得重组OsMPK4融合蛋白,并构建OsMPK4的转基因双元载体,用于OsMPK4的生化功能及其生物学功能研究.

Molecular characterization of a rice mitogen-activated protein kinase gene OsMPK4 and purification of recombinant protein and construction of binary vector.

A rice gene,OsMPK4,encoding for mitogen-activated protein kinase,was cloned and characterized.The full-length cDNA of OsMPK4 consists of 1483 bp in size,containing an open reading frame of 1131 bp,which predicts to encode a protein of 376 amino acids with calculated molecular weight of 42.8 kDa.The OsMPK4 gene is located on chromosome 10 of the rice genome and consists of 6 exons and 5 introns.The OsMPK4 protein contains all 11 conserved domains that are characteristics of MAPKs and phosphorylation site of TEY motif.Phylogenetic trees analysis revealed that OsMPK4 belongs to group B of the plant MAPKs;however,OsMPK4 shows a relatively low level of identity to all other characterized rice MAPKs,indicating that OsMPK4 is a new MAPK gene in rice.The recombinant OsMPK4 protein was purified from E.coli expressing the OsMPK4 gene and a binary vector used for rice transformation was also constructed,which will be helpful to elucidate the biochemical and biological functions of OsMPK4 in future studies.