Protein kinase activity can be separated from the purified activated rat liver glucocorticoid receptor.
Previous studies have shown that the purified rat liver glucocorticoid receptor (GR) has a protein kinase activity. In this report we show that the GR-associated kinase can be partially separated from the 94-kDa steroid-binding protein by DEAE-Sepharose chromatography. The kinase elutes from the column at a higher salt concentration than the 94-kDa GR protein. This GR copurifying protein kinase phosphorylates basic substrates such as various histone fractions and protamine. The phosphorylation occurs in the presence of Mg2+ ions, and is not supported by Ca2+ ions. The amino acid residues phosphorylated by the kinase are threonine and serine. This kinase also phosphorylates the 94-kDa GR protein and thus might be of physiological relevance for the GR function.
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D008099:Liver / Q000032:analysis*; D008274:Magnesium / Q000378:metabolism; D008297:Male; D008970:Molecular Weight; D010766:Phosphorylation; D011494:Protein Kinases / Q000302:isolation & purification*; D051381:Rats; D011919:Rats, Inbred Strains; D011965:Receptors, Glucocorticoid / Q000302:isolation & purification*; D013379:Substrate Specificity; D014222:Triamcinolone Acetonide / Q000378:metabolism
D011965:Receptors, Glucocorticoid; D011494:Protein Kinases; D014222:Triamcinolone Acetonide; D008274:Magnesium; D002118:Calcium