title: Mitogen-activated protein kinase kinase 1 (MKK1) is negatively regulated by threonine phosphorylation.
abstract: Mitogen-activated protein kinase kinase 1 (MKK1), a dual-specificity tyrosine/threonine protein kinase, has been shown to be phosphorylated and activated by the raf oncogene product as part of the mitogen-activated protein kinase cascade. Here we report the phosphorylation and inactivation of MKK1 by phosphorylation on threonine 286 and threonine 292. MKK1 contains a consensus phosphorylation site for p34cdc2, a serine/threonine protein kinase that regulates the cell division cycle, at Thr-286 and a related site at Thr-292. p34cdc2 catalyzes the in vitro phosphorylation of MKK1 on both of these threonine residues and inactivates MKK1 enzymatic activity. Both sites are phosphorylated in vivo as well. The data presented in this report provide evidence that MKK1 is negatively regulated by threonine phosphorylation.
authors.affiliation: W. M. Keck Structural Biology Laboratory, Beckman Neuroscience Center, Cold Spring Harbor Laboratory, New York 11724.
authors.forename: A J
authors.initials: AJ
authors.lastname: Rossomando
authors.forename: P
authors.initials: P
authors.lastname: Dent
authors.forename: T W
authors.initials: TW
authors.lastname: Sturgill
authors.forename: D R
authors.initials: DR
authors.lastname: Marshak
mesh_terms: D000595:Amino Acid Sequence; D016203:CDC2 Protein Kinase / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D048369:MAP Kinase Kinase 1; D048370:MAP Kinase Kinase 2; D020929:Mitogen-Activated Protein Kinase Kinases; D008969:Molecular Sequence Data; D010449:Peptide Mapping; D010455:Peptides / Q000737:chemistry; D010769:Phosphothreonine / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011994:Recombinant Proteins
chemical_list: D010455:Peptides; D011994:Recombinant Proteins; D010769:Phosphothreonine; C482128:MAP2K2 protein, human; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D016203:CDC2 Protein Kinase; D048369:MAP Kinase Kinase 1; D048370:MAP Kinase Kinase 2; C482125:MAP2K1 protein, human; D020929:Mitogen-Activated Protein Kinase Kinases