Phylogeny and distribution of protein kinase C variants in the zebrafish

Conventional protein kinases-consisting of α, β, and γ family members-play key roles in numerous signal transduction events. Phylogenetic analysis demonstrated the existence of five prkcs (the genes representing PKCs) in zebrafish, two paralogous forms of prkca and prkcb and one prkcg variant. mRNA expression analysis showed distinct, mainly nervous system specific expression, for all five prkc genes. For prkca and prkcb paralogs prominent expression can be seen in the telencephalon, in diencephalic regions such as the habenula or the optic tectum, in hypothalamic areas and in distinct cerebellar structures. Each transcript is additionally expressed in distinct areas: prkcaa is highly abundant in cranial sensory ganglia and in dorsal neurons of the hindbrain and the spinal cord, prkcab is strongly expressed in additional cerebellar regions, prkcba shows expression in the pectoral fin, the otic vesicle and in the proximal convoluted tubule of the kidney, and prkcbb shows prominent expression in different hypothalamic areas. Expression of prkcg is most striking in the cerebellum. As zebrafish PKCs are expressed in structures that are equivalent to mammals, the zebrafish model is well suited to study evolutionary conserved functions of PKCs in development and disease.