Molecular cloning and characterization of a novel dual specificity phosphatase, MKP-5.
A group of dual specificity protein phosphatases negatively regulates members of the mitogen-activated protein kinase (MAPK) superfamily, which consists of three major subfamilies, MAPK/extracellular signal-regulated kinase (ERK), stress-activated protein kinase (SAPK)/c-Jun N-terminal kinase (JNK), and p38. Nine members of this group of dual specificity phosphatases have previously been cloned. They show distinct substrate specificities for MAPKs, different tissue distribution and subcellular localization, and different modes of inducibility of their expression by extracellular stimuli. Here we have cloned and characterized a novel dual specificity phosphatase, which we have designated MKP-5. MKP-5 is a protein of 482 amino acids with a calculated molecular mass of 52.6 kDa and consists of 150 N-terminal amino acids of unknown function, two Cdc25 homology 2 regions in the middle, and a C-terminal catalytic domain. MKP-5 binds to p38 and SAPK/JNK, but not to MAPK/ERK, and inactivates p38 and SAPK/JNK, but not MAPK/ERK. p38 is a preferred substrate. The subcellular localization of MKP-5 is unique; it is present evenly in both the cytoplasm and the nucleus. MKP-5 mRNA is widely expressed in various tissues and organs, and its expression in cultured cells is elevated by stress stimuli. These results suggest that MKP-5 is a novel type of dual specificity phosphatase specific for p38 and SAPK/JNK.
Department of Biophysics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
T
T
Tanoue
T
T
Moriguchi
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E
Nishida
D000595:Amino Acid Sequence; D001483:Base Sequence; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000737:chemistry; D002460:Cell Line; D003001:Cloning, Molecular; D054637:Dual-Specificity Phosphatases; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D048031:JNK Mitogen-Activated Protein Kinases; D008099:Liver / Q000201:enzymology; D054639:Mitogen-Activated Protein Kinase Phosphatases; D020928:Mitogen-Activated Protein Kinases; D008969:Molecular Sequence Data; D010749:Phosphoprotein Phosphatases / Q000737:chemistry / Q000235:genetics*; D010766:Phosphorylation; D011485:Protein Binding; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics; D016415:Sequence Alignment; D013379:Substrate Specificity; D014162:Transfection; D015003:Yeasts / Q000235:genetics; D048051:p38 Mitogen-Activated Protein Kinases; D020666:ras-GRF1
D018797:Cell Cycle Proteins; D047908:Intracellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D020666:ras-GRF1; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C120407:DUSP10 protein, human; D054639:Mitogen-Activated Protein Kinase Phosphatases; D010749:Phosphoprotein Phosphatases; D054637:Dual-Specificity Phosphatases; D017027:Protein Tyrosine Phosphatases