Expression and characterization of protein kinase C‐δ

Abstract

A cDNA encoding protein kinase C‐δ (PKC‐δ) was isolated from a rat brain library. The coding region was subcloned into the expression vector pmt2 and transfected into COS‐1 cells. Expression of the protein led to an 11‐fold increase in activity as determined with a synthetic peptide based on the PKC‐δ pseudosubstrate site. The Mr of PKC‐δ as determined by SDS/PAGE and immunoblot analysis using anti‐(PKC‐δ C‐terminal) antibodies was 77000. The enzyme was purified to near homogeneity and showed total dependency on phospholipid and diacylglycerol (or phorbol esters) for activity. Like PKC‐ɛ, PKC‐δ displays no Ca2+ dependence for activation. The substrate specificity of PCK‐δ is similar to that of PKC‐ɛ but quite different from other PKCs. Copyright © 1991, Wiley Blackwell. All rights reserved