Retinoic acid effect on cyclic AMP-dependent protein kinases in embryonal carcinoma cells: studies with differentiation-defective sublines.
Retinoic acid induces the differentiation of PCC4.aza 1R and Nulli-SCC1 embryonal carcinoma (EC) cells. In response to retinoic acid treatment, the levels of cyclic AMP (cAMP)-dependent protein kinases are enhanced in the plasma membrane within 17 hours and in the cytosol fractions of these cells within 2 to 3 days, as determined by phosphotransferase activity and by 8-azido-cyclic [32P]AMP binding to the RI and RII regulatory subunits. PCC4 (RA)-1 and Nulli (RA)-1 are mutant EC lines that fail to differentiate in response to retinoic acid. The former line, but not the latter, lacks cellular retinoic acid-binding protein (cRABP). Basal levels of cAMP-dependent protein kinase activities are elevated in PCC4 (RA)-1 cells. When these cells are treated with retinoic acid, neither cAMP-dependent protein kinase activities nor cAMP binding activities are enhanced; rather, there is a decrease in cytosolic kinase activity and RI subunit. On the other hand, Nulli (RA)-1 cells exhibit increases both in cAMP-dependent protein kinase activities and cAMP binding in response to retinoic acid. These results raise the possibility that cRABP mediates the enhancement of regulatory and catalytic subunits of cAMP-dependent protein kinases in both the membrane and the cytosolic fractions of the teratocarcinoma cells. There also might be some effects of retinoic acid on the cAMP-dependent protein kinase that are unrelated to differentiation and to the presence of cRABP.
A
A
Plet
P
P
Gerbaud
M I
MI
Sherman
W B
WB
Anderson
D E
DE
Brion
D000818:Animals; D001696:Biomechanical Phenomena; D002454:Cell Differentiation; D002460:Cell Line; D054278:Embryonal Carcinoma Stem Cells; D051379:Mice; D014411:Neoplastic Stem Cells / Q000166:cytology / Q000201:enzymology* / Q000502:physiology; D011494:Protein Kinases / Q000378:metabolism*; D014212:Tretinoin / Q000494:pharmacology*
D014212:Tretinoin; D011494:Protein Kinases