Correlation of estrogen receptors and charge alterations of regulatory subunits of cAMP-dependent protein kinases in human mammary tumor cells.
The soluble cAMP-dependent protein kinase activities of two estrogen receptor-containing (MCF-7 and ZR-75-1) and two estrogen receptor-lacking (BT-20 and MDA-MB-231) established human mammary tumor cell lines were analyzed by DEAE-cellulose chromatography and photoaffinity labeling with 8-azido-[32P]cAMP. Predominantly, type I isoenzyme was present in MDA-MB-231 cells, type II protein kinase was the main form in ZR-75-1 and BT-20 cells; whereas MCF-7 cytosols contained equal amounts of both protein kinase types. No correlations between estrogen receptor content and cAMP-dependent protein kinase holoenzyme ratios of isoenzymes were found. A distinctly greater heterogeneity of charge isomers of cAMP-binding proteins (regulatory subunits) was observed in estrogen receptor-containing cells.
D001943:Breast Neoplasms / Q000032:analysis*; D002352:Carrier Proteins / Q000032:analysis*; D002460:Cell Line; D002848:Chromatography, DEAE-Cellulose; D002373:Cyclic AMP Receptor Protein; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000032:analysis; D008970:Molecular Weight; D011494:Protein Kinases / Q000032:analysis*; D011960:Receptors, Estrogen / Q000032:analysis*
D002352:Carrier Proteins; D002373:Cyclic AMP Receptor Protein; D007527:Isoenzymes; D011960:Receptors, Estrogen; D011494:Protein Kinases