Extending the C2 domain family: C2s in PKCs δ, ϵ,η,θ, phospholipases, GAPs, and perforin

Various membrane lipid metabolites, generated by phospholipases C and D (PLCs, PLDs), are known to regulate the activities of protein kinases C (PKCs) and GTP‐ase activating proteins (GAPs) in a range of cellular processes. Conventional Ca 2+ ‐dependent PKCs (α, βI, βII, and γ), PLCs, and various GAPs are all known to contain copies of a phospholipid‐binding domain, termed C2 or CalB. Here we recognize that C2 domains are also present in “new” Ca 2+ ‐independent PKCs (δ, η, η, and θ), other kinases, a eukaryotic PLD, the breakpoint cluster region (BCR ) gene product, and two further GAPS. Twenty‐two previously unrecognized C2 domain sequences are presented, which include a single copy in the mammalian poreforming proteins, perforin.