球孢白僵菌Hog1 MAPK同源基因BbHog1的克隆及特征分析  

Cloning and characterization of a Hog1 MAPK homologous gene BbHog1 from Beauveria bassiana

作　　者：张永军[1] 赵建华[1] 蒋小东[1] 李尊华[1] 裴炎[1] 

机构地区：[1]农业部生物技术与作物品质改良重点实验室重庆市农业生物技术重点实验室,西南大学生物技术中心,重庆400716

出　　处：《菌物学报》2007年第1期76-83,共8页Mycosystema

基　　金：国家自然科学基金(30300235);国家重点基础研究计划(973)项目(2003CB114203);重庆市教委项目(20204)

摘　　要：根据几种丝状真菌Hog1 MAPK的保守氨基酸序列设计简并引物,从昆虫病原真菌球孢白僵菌中扩增出MAPK同源基因的部分片段,然后利用YADE法延伸该片段的上、下游邻接序列,获得MAPK编码基因的全长序列,命名为BbHog1。序列分析表明,该基因编码358个氨基酸的多肽,推测分子量为40.99kDa,等电点为5.49。BbHog1含有MAPK保守的蛋白激酶激活域(TGY),序列与粗糙脉孢霉os-2(AF297032)、烟曲霉OSM1(XM_747571)、隐球酵母HOG1(AF243531)和酿酒酵母Hog1(Z73285)等Hog1 MAPK高度同源,相似性分别为94%、89%、83%和80%。系统聚类结果表明,BbHog1与酵母Hog1 MAPK同源。Southern杂交表明,BbHog1在球孢白僵菌基因组中以单拷贝形式存在。Northern分析表明,BbHog1在高渗、亚高温和营养胁迫等条件下的表达明显升高。由此推测,BbHog1基因可能与球孢白僵菌对逆境胁迫的适应性调节密切相关。Degenerate PCR primers were designed according to the conserved amino acid sequence of several filamentous fungus MAPKs which were homologous to yeast Hogl MAPK, and partial DNA fragment encoding a MAPK was amplified from entomopathogenic fungus Beauveria bassiana using PCR. Thereafter, a whole DNA sequence encoding the MAPK, designated as BbHogl, was obtained from B. bassiana by extending upstream and downstream sequence of the amplified fragment using YADE method. Sequence analysis suggested that BbHogl encoded a protein of 358 amino acids with Mr of 40.99 KDa and PI of 5.49. The BbHogl contained the conserved TGY activation loop found in the stress-activated protein kinase subgroup of MAPKs and its amino acid sequence showed 94%, 89%, 83% and 80% identity to os-2 （AF297032） from Neurospora crassa, OSM1 （XM_747571） from Aspergillusfumigatus, HOG1 （AF243531） from Cryptococcus neoformans var. neoformans and Hogl （Z73285） from Saccharomyces cerevisiae, respectively. Phylogenetic clustering suggested that BbHogl is homologous to yeast Hogl MAPK. Southern analysis indicated that BbHogl was present as a single copy in B. bassiana. Northern blot analysis showed that BbHogl gene expression was obviously increased when the fungus was cultured under the condition of hyperosmotic stress, sub-high temperature and nutrition starvation, which suggested that BbHogl gene was involved in the stress adaptation regulation of Beauveria bassiana.

关 键 词：信号传导 昆虫病原真菌 逆境胁迫调节 

分 类 号：S476.12[农业科学—农业昆虫与害虫防治] Q78[农业科学—植物保护]