Molecular cloning and characterization of a novel dual-specificity phosphatase 23 gene from human fetal brain.
Most of dual-specificity protein phosphatases (DSPs) play an important role in the regulation of mitogenic signal transduction and controlling the cell cycle in response to extracellular stimuli. In this study, a novel human dual-specificity protein phosphatases gene named dual-specificity phosphatase 23 (DUSP23) was isolated by large-scale sequencing analysis of a human fetal brain cDNA library. Its cDNA was 726 bp in length, encoding a 150-amino acid polypeptide which contained a dual-specificity phosphatase catalytic (DSPc) domain but not a CDC25 homology (CH2) domain. Reverse transcription-PCR (RT-PCR) revealed that the DUSP23 was expressed in most fetal tissues and two adult tissues: testis and colon. Transient transfection experiment suggested that DUSP23 was localized in the cytoplasm of HEK293 cells. DUSP23 showed distinctive phosphatase activity toward p-nitrophenyl phosphate (pNPP), as well as oligopeptides containing phospho-tyrosine and phospho-threonine residues. Furthermore, DUSP23 could dephosphorylate p44ERK1 but not p38 and p54SAPKbeta in vitro. All the results indicated that DUSP23 was a novel protein phosphatase with dual substrate specificity.
Wu
Qihan
Q
State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai 200433, PR China.
Li
Yao
Y
Gu
Shaohua
S
Li
Ni
N
Zheng
Dan
D
Li
Dan
D
Zheng
Zhongzhou
Z
Ji
Chaoneng
C
Xie
Yi
Y
Mao
Yumin
Y
D000328:Adult; D000814:Aniline Compounds / Q000378:metabolism; D001483:Base Sequence; D001923:Brain Chemistry / Q000235:genetics; D002460:Cell Line; D003001:Cloning, Molecular; D003593:Cytoplasm / Q000737:chemistry; D054637:Dual-Specificity Phosphatases; D005333:Fetus; D015723:Gene Library; D006801:Humans; D009943:Organophosphorus Compounds / Q000378:metabolism; D010769:Phosphothreonine / Q000378:metabolism; D019000:Phosphotyrosine / Q000378:metabolism; D017027:Protein Tyrosine Phosphatases / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D014018:Tissue Distribution; D014162:Transfection
D000814:Aniline Compounds; D009943:Organophosphorus Compounds; D010769:Phosphothreonine; D019000:Phosphotyrosine; C068798:4-aminophenylphosphate; C497817:DUSP23 protein, human; D054637:Dual-Specificity Phosphatases; D017027:Protein Tyrosine Phosphatases