Staurosporine‐related compounds, K252a and UCN‐01, inhibit both cPKC and nPKC

Abstract
The potent inhibitors of protein kinase C (PKC), H7, staurosporine, and staurosporine derivatives, were examined for their inhibitory effects on novel PKC (nPKC) isozymes δ and ε. H7 and staurosporine, usually used as selective inhibitors of PKC, showed similar inhibitory effects on cPKC (a mixture of cPKCα,β, and γ) and nPKCδ and ε. The inhibitory effects of K252a, a non-selective protein kinase inhibitor, on cPKC was 3.2- and 22-fold higher than those on nPKCε and δ, respectively. The staurosporine derivatives UCN-01 and UCN-01-Me also showed selective inhibition of cPKC.