Biochemical properties of rat protein kinase C‐η expressed in COS cells

Abstract
Using a PKC-ε cDNA probe a cDNA for PKC-η has been cloned from a rat lung cDNA library. When expressed in COS cells, rat PKC-η appeared as an 84 kDa protein. PKC-η expressed in COS cells. was solubilized by 1% Triton X-100 and purified away from the endogenous PKC-α by ammonium sulphate fractionation. The activity of this PKC-η preparation was characterized with respect to cofactor dependence and substrate specificity, Various PKC pseudosubstrate peptides are phosphorylated by PKC-η in a phospholipid and TPA-dependent but calcium-independent manner. The polypeptide histone IIIS is a poor substrate.