title: Phosphorylation and activation of p40 tyrosine kinase by casein kinase-1.
abstract: Because examination of regulatory trans-phosphorylations can help elucidate the cellular functions of tyrosyl protein kinases, we have investigated the effects of phosphorylation by casein kinase-1 on the activity of the p40 tyrosyl protein kinase. We find that casein kinase-1 can phosphorylate the p40 tyrosyl kinase on serine and threonine residues, in part on a unique tryptic peptide. The phosphorylation induces a substantial increase in the tyrosyl protein kinase activity of p40, in contrast to most instances in which serine/threonine phosphorylation inhibits activity of tyrosyl protein kinases. These findings raise the possibility that p40 might be part of a protein phosphorylation network in which casein kinase-1 participates.
authors.affiliation: Departament de Microbiologia, Hospital Clinic i Provincial de Barcelona, Facultat de Medicina, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Vila
authors.forename: D M
authors.initials: DM
authors.lastname: Payne
authors.forename: T F
authors.initials: TF
authors.lastname: Zioncheck
authors.forename: M L
authors.initials: ML
authors.lastname: Harrison
authors.forename: E
authors.initials: E
authors.lastname: Itarte
authors.forename: M J
authors.initials: MJ
authors.lastname: Weber
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D047388:Casein Kinases; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D004789:Enzyme Activation; D008970:Molecular Weight; D010748:Phosphopeptides / Q000302:isolation & purification; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D013950:Thymus Gland / Q000201:enzymology
chemical_list: D010748:Phosphopeptides; D000255:Adenosine Triphosphate; D011494:Protein Kinases; D011505:Protein-Tyrosine Kinases; D047388:Casein Kinases