Apparent "activation" of protein kinases by okadaic acid class tumor promoters.
A cytosolic fraction of mouse brain gave two peaks of protein kinase activity on DEAE-cellulose column chromatography. The first peak of protein kinase corresponded to protein kinase C. The second peak contained protein kinases that were "activated" dose-dependently by the okadaic acid class tumor promoters, okadaic acid and dinophysistoxin-1. This "activation" was not achieved by other tumor promoters, such as 12-0-tetradecanoyl-phorbol-13-acetate, teleocidin, aplysiatoxin, or palytoxin. In addition, the second peak contained phosphatases. The phosphate liberation from phosphorylated histone type III-S by incubation with the second peak was inhibited by okadaic acid or dinophysistoxin-1, dose-dependently. The resulting apparent "activation" of protein kinases by okadaic acid is indicated and would imply a new pathway of tumor promotion on mouse skin.
Sassa
T
T
Cancer Prevention Division, National Cancer Center Research Institute, Tokyo, Japan.
Richter
W W
WW
Uda
N
N
Suganuma
M
M
Suguri
H
H
Yoshizawa
S
S
Hirota
M
M
Fujiki
H
H
D000818:Animals; D001921:Brain / Q000201:enzymology*; D002273:Carcinogens / Q000494:pharmacology*; D002848:Chromatography, DEAE-Cellulose; D003600:Cytosol / Q000201:enzymology; D004789:Enzyme Activation; D004988:Ethers, Cyclic / Q000494:pharmacology*; D007527:Isoenzymes / Q000378:metabolism; D007700:Kinetics; D051379:Mice; D019319:Okadaic Acid; D011494:Protein Kinases / Q000302:isolation & purification / Q000378:metabolism*
D002273:Carcinogens; D004988:Ethers, Cyclic; D007527:Isoenzymes; D019319:Okadaic Acid; D011494:Protein Kinases