【摘要】 Rho族蛋白是Ras超家族小G蛋白最主要成员,在真核生物中极为保守,包括Rho、Rac、Cdc42等,作为分子开关,参与细胞极性、细胞运动、细胞形状、细胞间及细胞与其基质互作等多个信号转导途径。基因组数据库分析显示,稻瘟菌中含有30余个小G蛋白,其中7个可能是Rho族蛋白,包括Cdc42、Rac1及5个Rho亚家族蛋白。结构分析表明,7个推导的Rho族蛋白均具有典型结构域。进一步以半定量RT-PCR分析了稻瘟菌7个Rho族蛋白编码基因在菌丝、分生孢子、芽管以及附着胞等不同生长发育阶段的表达情况。结果表明,Rho族蛋白编码基因具有不同的表达模式。通过BLASTP搜索GenBank等数据库,获得迄今已公布的真菌Rho1、Cdc42和Rac1蛋白序列,建立了系统发育树,一定程度地反映了真菌进化关系,说明在真菌进化中Rho族蛋白的结构与功能也经历了共同演化的过程。更多还原

【Abstract】 The Rho family proteins are major members of the Ras superfamily small GTPases,conserved in the eukaryotic cells.The Rho GTPase family consists of subfamily members of Rho,Rac and Cdc42,which act as molecular switches in several signal transduction pathways,such as in the regulation of cell polarity,cell movement,cell shape,and cell-cell and cell-matrix interaction.To understand the function and evolution of the Rho family proteins in Magnaporthe grisea and other fungi,we searched the M.grisea genome database,and retrieved more than 30 small GTPase homologous proteins,and 7 putative Rho family proteins were confirmed by analyzing the presence of a set of conserved G box GDP/GTP-binding motif elements(G1-G5).We further analyzed the enconding gene expression of these proteins during the growth and development stages in M.grisea by semi-quantitive RT-PCR,and results showed that these genes have different expression(patterns).We also constructed a phylogenetic tree of Cdc42,Rac1 and Rho1 of fungi based on the sequences(available) in GenBank,the tree well reflected the evolutionary relationship of fungi.We concluded that the structure and the function of Rho family proteins have co-evoluted through the long evolutionary process of fungi.更多还原