Membrane Translocation of Novel Protein Kinase Cs Is Regulated by Phosphorylation of the C2 Domain

摘要: Ca(2+)-independent or novel protein kinase Cs (nPKCs) contain an N-terminal C2 domain of unknown function. Removal the Aplysia nPKC Apl II allows activation enzyme at lower concentrations phosphatidylserine, suggesting inhibitory role for in activation. However, mechanism domain-mediated inhibition is not known. Mapping autophosphorylation sites C (PKC) reveals four phosphopeptides regulatory PKC II, two which are serine 2 and 36. Unlike most sites, these serines could be phosphorylated trans. Interestingly, phosphorylation 36 increased binding to phosphatidylserine membranes vitro. In cells, was by activators, this position translocated more efficiently membranes. Moreover, mutation alanine significantly reduced membrane translocation II. We suggest that nPKCs regulated domain.