IDENTIFICATION OF IMMUNE-RELATED PROTEIN-KINASES FROM MOSQUITOS (AEDES-AEGYPTI)

Protein kinases are known to be involved in signal transduction for nu merous physiological events. However, little is known about the roles of protein kinases in insect immunity. A fragment around 150 bp was am plified by polymerase chain reaction using cDNA templates from bacteri al inoculated mosquitoes and primers corresponding to the conserved do main of protein kinases. Based on sequence analysis, 11 groups of prot ein kinases were characterized including 3 nonreceptor tyrosine kinase s, 3 receptor tyrosine kinases, 3 serine/threonine kinases, and 2 nove l protein kinases. The most abundant kinase obtained in this study rev eals a high degree of similarity to human cholinesterase-related cell division controller (CHED) protein kinase. The expression of this mosq uito CHED-like kinase is not detectable in normal female mosquitoes, b ut induced only after bacterial inoculation and trauma. A mosquito pro tein kinase was demonstrated to share homology with a plant Tousled ge ne, but has not yet been characterized in the animal system. In additi on, analysis of the sequences of several protein kinases cloned from m osquitoes suggests that they might be involved in the regulation of ce llular or humoral immunity.