Cloning and characterization of a dual-specificity kinase gene in rice (Oryza sative).

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 45926 Da and isoelectric point 7.689. OsSTY kinase is involved in the multiple stresses signaling pathway. Low- and high-temperature (4 degrees C and 37 degrees C) 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.