摘要
从水稻中分离克隆出一个双功能激酶(OsSTY)基因,它编码一个含417个氨基酸的蛋白,其分子量为45 926 Da,等电点为7·689。OsSTY参与多种胁迫条件下的信号传导途径。低温或高温(4℃和37℃)处理后,OsSTY激酶的表达显著提高。机械损伤、水杨酸、乙烯等处理也促进该基因转录。另外,OsSTY基因在酿酒酵母(Saccharomyces cerevisiae)ste7基因缺失株(ste7/ste7)中的异源表达能够抑制该菌株在氮源饥饿条件下假菌丝生长的缺陷。Ste7是酿酒酵母的一个丝氨酸/苏氨酸/酪氨酸双功能激酶,它与OsSTY的激酶功能域有32%的同源性和50%的相似性。这揭示出OsSTY激酶能够校正,至少能部分地校正酿酒酵母ste7基因缺失株的假菌丝生长缺陷。
We identified and isolated a dual-specificity kinase gene,OsSTY kinase （O. sative serine/threonine/ tyrosine kinase） gene,from rice. OsSTY kinase gene encoded a protein of 417 amino acids with calculated molecular weight 45 926 Da and isoelectric point 7. 689. OsSTY kinase is involved in the multiple stresses signaling pathway. Low- and high-temperature （4℃ and 37℃） stresses significantly induce the expression of OsSTY kinase. The kinase is also up-regulated upon wounding （ by cut） ,salicylic acid （SA） and ethophon （ET）. Moreover,ectopic expression of OsSTY kinase gene in yeast Saccharomyces cerevisiae ste7/ste7 mutant partially suppressed the pseudohyphal development defect of the strain under the condition of nitrogen starvation. Ste7 is a serine/threonine/tyrosine kinase of Saccharomyces cerevisiae,which shares 32% identity and 50% similarity with OsSTY kinase in the kinase domains. This finding suggested that OsSTY kinase could correct,at least partially,the defect of ste7/ste7 mutant.
