Bryostatin, an activator of the calcium phospholipid-dependent protein kinase, blocks phorbol ester-induced differentiation of human promyelocytic leukemia cells HL-60 - PubMed (original) (raw)

Bryostatin, an activator of the calcium phospholipid-dependent protein kinase, blocks phorbol ester-induced differentiation of human promyelocytic leukemia cells HL-60

A S Kraft et al. Proc Natl Acad Sci U S A. 1986 Mar.

Abstract

Phorbol esters bind to and activate a calcium phospholipid-dependent protein kinase (C kinase). Some researchers believe that activation of C kinase is necessary for the induction of phorbol ester biologic effects. Our research indicates that bryostatin, a macrocyclic lactone that binds to the phorbol ester receptor in human polymorphonuclear leukocytes, also binds to this receptor in the human promyelocytic leukemia cell line, HL-60. Bryostatin activates partially purified C kinase from HL-60 cells in vitro, and when applied to HL-60 cells in vivo, it decreases measurable cytoplasmic C kinase activity. Unlike the phorbol esters, bryostatin is unable to induce a macrophage-like differentiation of HL-60 cells; however, bryostatin, in a dose-dependent fashion, blocks phorbol ester-induced differentiation of HL-60 cells and, if applied within 48 hr of phorbol esters, halts further differentiation. These results suggest that activation of the C kinase by some agents is not sufficient for induction of HL-60 cell differentiation and imply that some of the biologic effects of phorbol esters may occur through a more complex mechanism than previously thought.

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References

    1. J Biol Chem. 1982 Jul 10;257(13):7847-51 - PubMed
    1. Blood. 1981 Aug;58(2):237-43 - PubMed
    1. J Biol Chem. 1982 Nov 25;257(22):13193-6 - PubMed
    1. Proc Natl Acad Sci U S A. 1983 Jan;80(1):36-40 - PubMed
    1. Nature. 1983 Feb 17-23;301(5901):621-3 - PubMed

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