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Phospholipase D activation in fibroblast membranes by the α and β isoforms of protein kinase C
Author(s) -
Conricode Kevin M.,
Smith Jennie L.,
Burns David J.,
Exton John H.
Publication year - 1994
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(94)80490-7
Subject(s) - protein kinase c , phospholipase d , activator (genetics) , pkc alpha , gene isoform , microbiology and biotechnology , phorbol , phosphatidylcholine , phospholipase c , fibroblast , biology , chemistry , biochemistry , signal transduction , receptor , membrane , in vitro , phospholipid , gene
The regulation of phosphatidylcholine‐hydrolyzing phospholipase D (PLD) by protein kinase C (PRC) in membranes of Chinese hamster lung fibroblasts (CCL39) was studied using conventional PKC isoforms α, β and γ isolated from rat brain and recombinant PKC isoforms. Cells were incubated with [ 14 C]choline to label endogenous phosphatidylcholine before membranes were prepared and assayed for release of 14 C]choline. PKCα was the most potent activator of PLD, producing a maximal effect at approximately 0.1 . PKCβ also stimulated PLD but was less potent and less efficacious, whereas PKCγ was ineffective. Stimulation required addition of a PKC activator, but the isoform specificity was the same whether phorbol 12‐myristate 13‐acetate (PMA) or Ca 2+ was used. Recombinant Ca 2+ ‐independent PKC isoforms δ, ϵ, and ζ, failed to stimulate PLD, but recombinant PKCβ 1 stimulated PLD in a manner similar to the purified brain PKCβ. Immunoblot analysis of the soluble fraction of CCL 39 fibroblasts detected only the α and ζ isoforms of PKC. The results suggest that PKCα and β are activators of PLD and that PKCα is responsible for the activation in these fibroblasts.