Protein kinases constitute a large superfamily of enzymes with key regulatory functions in nearly all signal transmission processes of eukaryotic cells; PKD2 is a novel phorbol ester and growth factor-stimulated protein kinase (1). PKD2 is widely expressed in human and murine tissues and in cell lines such as HL60. In vivo, phorbol ester has been shown to autophosphorylate PKD2 in a synergistic fashion. Phosphorylation of Ser(876) of PKD2 correlated with the activation status of the kinase. The first zinc finger-like domain shares 88% identity to the corresponding domains in PKD/PKC-mu and PKC-nu (2).
