title: Glycogen synthase kinase 3beta is tyrosine phosphorylated by PYK2.
abstract: Glycogen synthase kinase 3beta (GSK3beta) is a Ser/Thr kinase that is involved in numerous cellular activities. GSK3beta is activated by tyrosine phosphorylation. However, very little is known about the tyrosine kinases that are responsible for phosphorylating GSK3beta. In this report, we investigated the ability of the calcium-dependent tyrosine kinase, proline-rich tyrosine kinase 2 (PYK2) to tyrosine phosphorylate GSK3beta. In transfected CHO cells, it was demonstrated that PYK2 tyrosine phosphorylates GSK3beta in situ. The two kinases also coimmunoprecipitated. Furthermore, GSK3beta was tyrosine phosphorylated in vitro by an active, wild type PYK2, but not by the inactive, kinase dead form of PYK2. Therefore, this study is the first to demonstrate that GSK3beta is a substrate of PYK2 both in vitro and in situ.
authors.affiliation: Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama 35294-0017, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Hartigan
authors.forename: W C
authors.initials: WC
authors.lastname: Xiong
authors.forename: G V
authors.initials: GV
authors.lastname: Johnson
mesh_terms: D000818:Animals; D016466:CHO Cells; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D006224:Cricetinae; D004789:Enzyme Activation / Q000235:genetics; D051418:Focal Adhesion Kinase 2; D038362:Glycogen Synthase Kinase 3; D038341:Glycogen Synthase Kinases; D015151:Immunoblotting; D007527:Isoenzymes / Q000378:metabolism; D009154:Mutation; D010766:Phosphorylation; D011233:Precipitin Tests; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D013379:Substrate Specificity / Q000235:genetics; D014162:Transfection; D014443:Tyrosine / Q000378:metabolism*
chemical_list: D007527:Isoenzymes; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; D051418:Focal Adhesion Kinase 2; D038341:Glycogen Synthase Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D038362:Glycogen Synthase Kinase 3