Proteolytic activation of protein kinase C in the extracts of cells treated for a short time with phorbol ester.
A 10 min treatment of human neutrophils with phorbol 12-myristate 13-acetate (PMA) has been reported to induce accumulation of the proteolytically activated Ca2+/phospholipid-independent catalytic fragment of protein kinase C in the cytosol of intact cells [(1986) J. Biol. Chem. 261, 4101-4105]. We investigated the proteolytic conversion of protein kinase C to Ca2+/phospholipid-independent form in the cytosol and membrane fractions of pig neutrophils. The activity of protein kinase C was measured with its specific oligopeptide substrate Ala-Ala-Ala-Ser-Phe-Lys-Ala-Lys-Lys-amide designed previously. In our experiments the short-term treatment of neutrophils with PMA did not induce the accumulation of the proteolytically activated form of protein kinase C in the cytosol of intact cells. However, treatment of cells with PMA enhanced the limited proteolysis of protein kinase C during the preparation of cell extracts.
Buday
L
L
1st Institute of Biochemistry, Semmelweis University Medical School, Budapest, Hungary.
Seprödi
J
J
Farkas
G
G
Mészáros
G
G
Romhányi
T
T
Bánhegyi
G
G
Mandl
J
J
Antoni
F
F
Faragó
A
A
D000818:Animals; D002451:Cell Compartmentation; D004789:Enzyme Activation / Q000187:drug effects; D066298:In Vitro Techniques; D008099:Liver / Q000166:cytology; D008214:Lymphocytes / Q000201:enzymology; D051379:Mice; D009504:Neutrophils / Q000187:drug effects*; D011480:Protease Inhibitors / Q000494:pharmacology*; D011493:Protein Kinase C / Q000378:metabolism*; D013347:Subcellular Fractions / Q000201:enzymology; D013552:Swine; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D011480:Protease Inhibitors; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate