title: Purification and characterization of ribosomal protein S6 kinase I from Xenopus eggs.
abstract: Ribosomal protein S6 kinase I has been purified from unfertilized Xenopus eggs to near homogeneity as a Mr = 90,000 protein. S6 kinase I is phosphorylated when activated in vivo and can be phosphorylated by mitogen-activated protein kinase in vitro. The purified enzyme is inactivated upon treatment with protein phosphatase 2A. Immunological data and analysis of substrate specificity demonstrate that S6 kinase I is related to, but distinct from, the previously characterized S6 kinase II. Both enzymes are members of the ribosomal protein S6 kinase (rsk) gene family.
authors.affiliation: Department of Pharmacology, University of Colorado School of Medicine, Denver 80262.
authors.forename: E
authors.initials: E
authors.lastname: Erikson
authors.forename: J L
authors.initials: JL
authors.lastname: Maller
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002853:Chromatography, Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics; D008345:Manganese; D010063:Ovum / Q000201:enzymology*; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000737:chemistry / Q000302:isolation & purification*; D019893:Ribosomal Protein S6 Kinases; D014981:Xenopus
chemical_list: D047428:Protein Kinase Inhibitors; D008345:Manganese; D011494:Protein Kinases; D019893:Ribosomal Protein S6 Kinases