Lack of an effect of novel inhibitors with high specificity for protein kinase C on the action of the phorbol ester 12-O-tetradecanoylphorbol-13-acetate on mouse skin in vivo.

The inhibitory effects of three novel staurosporine-derived compounds were tested with five different types of protein kinases, including protein kinase C (PKC). IC50 values of two of these compounds were found to be 300 to > 5000 times lower for PKC alpha beta gamma (a mixture of the PKC isoenzymes alpha, beta and gamma) than for any of the other protein kinases. The inhibitory action of the most selective inhibitor was tested also with the Ca(2+)-unresponsive PKC isoenzyme delta and was found to suppress PKC alpha beta gamma and PKC delta differentially.

Protein kinase C zeta and eta in murine epidermis. TPA induces down-regulation of PKC eta but not PKC zeta.

Murine epidermis contains PKC zeta and eta as evidenced by the application of specific antisera. PKC zeta predominates in the cytosol and PKC eta in the particulate fraction. PKC zeta is shown to be present also in other murine tissues, with large amounts found in lung.

Immunological demonstration of epsilon PKC. Murine tissue distribution, ontogeny, cellular localization and translocation.

An antiserum raised against an epsilon PKC-specific peptide recognizes epsilon PKC with an apparent molecular weight of 97 kDa in cytosol of mouse brain. No cross-reaction with alpha, beta, gamma PKC or the delta PKC-like p76-kinase is observed. Epsilon PKC is mainly present in brain.

Immunological demonstration of a calcium-unresponsive protein kinase C of the delta-type in different species and murine tissues. Predominance in epidermis.

An antiserum raised against a delta-protein kinase C (delta-PKC)-specific peptide recognized the purified calcium-unresponsive 76-kDa protein kinase of porcine spleen in the native and the denatured form. This antiserum was used to demonstrate the delta-PKC-like enzyme in spleen of different species, in various cell types and in murine tissues by immunoblotting of the respective extracts. Due to species differences, delta-PKC-like kinases with slightly different molecular weights were observed.

Purification and characterization of a calcium-unresponsive, phorbol ester/phospholipid-activated protein kinase from porcine spleen.

A calcium-unresponsive, phorbol ester/phospholipid-activated protein kinase was purified to apparent homogeneity from a Triton X-100 extract of an EGTA/EDTA-preextracted particulate fraction of porcine spleen by chromatography on S-Sepharose Fast Flow, phenyl-Sepharose Fast Flow, protamine-agarose, and Superdex 200. The enzyme had a Mr of 76,000, as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (p76-kinase). A similar value (78,000) was obtained by gel filtration.