The effects of protein kinase C (PKC) inhibitor polymyxin B (PMB) and PKC activators 12-0-tetradecanoylphorbol-13-acetate (TPA) and bryostatin on intact HL60 cells were examined. It was found that each of the three agents exhibited similar effects on phosphorylation of certain endogenous proteins, PKC translocation from cytoplasm to plasma membrane and formation of CDP-choline. TPA, however, was the only agent that stimulated phosphatidylcholine formation. Differentiation of HL60 cells was potently induced by TPA; in comparison bryostatin was a relatively weaker inducer and PMB was without effect. The data indicated that the effects of the PKC inhibitor PMB on intact cells could not be predicted by its in vitro activity, and that certain TPA-dependent but PKC-independent reactions might be crucial in HL60 cell differentiation.
|Original language||English (US)|
|Number of pages||8|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Jul 15 1987|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology