Protein kinase C

Protein kinase C (PKC) phosphorylate serine or threonine residues in proteins. They act in signal transduction pathways. Conventional PKC (CPKC) - α, β1, β2, γ – are activated by diacylglycerol (DAG), Ca+2 and a phospholipid. Novel PKC (NPKC) – δ, ε, η, θ – are activated by DAG. Atypical (APKC) do not require DAG or Ca+2 for activation. PKC consists of regulatory domain hinged to a catalytic domain. The regulatory domain contains the C1 region which binds DAG and phorbol esters and the C2 domain which is a Ca+2 sensor. PKC contains Pleckstrin Homology (PH) domain which binds phosphatidylinositol lipids (PTDINS). The PH domain is found in proteins involved in intracellular signaling.