title: Characterization of a novel low-molecular-mass dual specificity phosphatase-4 (LDP-4) expressed in brain.
abstract: Dual-specificity phosphatases (DSPs), which dephosphorylate proteins at Ser/Thr as well as Tyr residues, are thought to be involved in critical signaling events such as control of MAP kinases (MAPKs). We have isolated the cDNA for a novel DSP and termed it low molecular mass DSP-4 (LDP-4). LDP-4 is composed of 211 amino acids with a predicted molecular mass of 23.9-kDa. Northern blot analysis using various mouse tissues showed that the LDP-4 transcript was expressed exclusively in brain. In situ hybridization showed that brain expression of LDP-4 was ubiquitous except for the hippocampus. When expressed in COS-7 cells, FLAG-tagged LDP-4 protein was present within the nucleus and Golgi apparatus. LDP-4 expression did not reduce phosphorylation levels of MAPKs, but rather evoked activation of JNK and p38.
authors.affiliation: Division of Biochemical Oncology and Immunology, Institute for Genetic Medicine, Hokkaido University, Kita-15, Nishi-7, Kita-ku, Sapporo, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Takagaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shima
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Tanuma
authors.forename: Miyuki
authors.initials: M
authors.lastname: Nomura
authors.forename: Takeshi
authors.initials: T
authors.lastname: Satoh
authors.forename: Masahiko
authors.initials: M
authors.lastname: Watanabe
authors.forename: Kunimi
authors.initials: K
authors.lastname: Kikuchi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism*; D019556:COS Cells; D002522:Chlorocebus aethiops; D004789:Enzyme Activation; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D009419:Nerve Tissue Proteins; D048031:JNK Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C521117:LDP-4 protein, mouse; D010744:Phosphoric Monoester Hydrolases