Identification of the structures of multiple subspecies of protein kinase C expressed in rat brain

Abstract

Rat brain protein kinase C purified to apparent homogeneity [(1986) Biochem. Biophys. Res. Commun. 135, 636–643] was resolved into three distinct fractions, type I, II and III, upon chromatography on a hydroxyapatite column connected to high-performance liquid chromatography. Comparison of each fraction with the four subspecies of protein kinase C, that were separately expressed in COS cells transfected by the respective cDNAs, α, βI,βII an d γ, identified the primary structures of these three fractions of protein kinase C. Type I corresponded to the enzyme encoded by the γ-sequence; type II was a mixture of the two subspecies determined by the βI- and βII-sequences; and type III had the structure encoded by the α-sequence. The structures and properties of these subspecies of protein kinase C were similar to each other.