Two isozymes of PKC found in HL-60 cells show a difference in activation by the phorbol ester TPA

Abstract

Cytosol from untreated cells and a detergent extract of the particulate fraction from TPA-treated HL-60 cells were analyzed for protein kinase C activity by consecutive column chromatography on Mono Q and hydroxyapatite. From both preparations two separate peaks of enzyme activity were obtained. The first peak, eluting at lower salt concentrations, is activated at lower TPA concentrations (3 × 10 −9 M) than the other (10 −7 M), which was eluted at higher salt concentrations.