Protein Kinase C Eta (PKCh)

By screening a human keratinocyte cDNA library using PRKCA fragments as probes, Bacher et al. (1991) isolated a cDNA encoding PRKCH, which they called PKCL. The predicted PRKCH protein contains 680 amino acids and shows highest homology with PRKCE. PRKCH has a consensus ATP-binding site, a catalytic kinase domain, and a conserved cysteine-rich domain. Northern blot analysis of rat tissues detected a 4.2-kb transcript at highest levels in lung, with lower levels in heart and skin. The PRKCH transcript was also detected in the human skin carcinoma cell line SCL-1, the human epidermoid carcinoma cell line A431, and in HaCaT human skin keratinocytes. Transfection of COS cells with a PRKCH expression vector determined that this protein has phorbol ester-binding ability and kinase activity.