水稻MAPK基因Os MPK4的克隆鉴定、蛋白表达和转基因载体构建

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

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1483bp，包含一个1131bp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42．8kD．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．

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.