Characterization of a novel low-molecular-mass dual specificity phosphatase-4 (LDP-4) expressed in brain.
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.
Takagaki
Kentaro
K
Division of Biochemical Oncology and Immunology, Institute for Genetic Medicine, Hokkaido University, Kita-15, Nishi-7, Kita-ku, Sapporo, Japan.
Shima
Hiroshi
H
Tanuma
Nobuhiro
N
Nomura
Miyuki
M
Satoh
Takeshi
T
Watanabe
Masahiko
M
Kikuchi
Kunimi
K
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
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