| First Author | Ogata M | Year | 1999 |
| Journal | Biochem Biophys Res Commun | Volume | 256 |
| Issue | 1 | Pages | 52-6 |
| PubMed ID | 10066421 | Mgi Jnum | J:200341 |
| Mgi Id | MGI:5508300 | Doi | 10.1006/bbrc.1999.0278 |
| Citation | Ogata M, et al. (1999) Inactivation of mitogen-activated protein kinases by a mammalian tyrosine-specific phosphatase, PTPBR7. Biochem Biophys Res Commun 256(1):52-6 |
| abstractText | Mitogen-activated protein kinase (MAPK) is inactivated through dephosphorylation of tyrosyl and threonyl regulatory sites. In yeast, both dual-specificity and tyrosine-specific phosphatases are involved in dephosphorylation. In mammals, however, no tyrosine-specific phosphatase has been identified molecularly to dephosphorylate MAPK in vivo. Recently, we and others have cloned a murine tyrosine-specific phosphatase, PTPBR7/PTP-SL, which is expressed predominantly in the brain. Here we report inactivation of the extracellular signal-regulated kinase (ERK) family MAPK by PTPBR7. PTPBR7 made complexes with ERK1/ERK2 in vivo and dephosphorylated ERK1 in vitro. When overexpressed in mammalian cells, wild-type PTPBR7 suppressed the phosphorylation and activation of ERK by epidermal growth factor (EGF), nerve growth factor (NGF), and constitutively active MEK1, a mutant MAPK kinase. In contrast, catalytically inactive and ERK-binding-deficient mutants revealed little inhibition on the ERK cascade. These results indicate that PTPBR7 suppresses MAPK directly in vivo. |
