The Mechanism of Dephosphorylation of Extracellular Signal-regulated Kinase 2 by Mitogen-activated Protein Kinase Phosphatase 3

Research output: Contribution to journalArticlepeer-review

147 Scopus citations

Abstract

The mitogen-activated protein (MAP) kinase phosphatase-3 (MKP3) is a dual specificity phosphatase that specifically inactivates one subfamily of MAP kinases, the extracellular signal-regulated kinases (ERKs). Inactivation of MAP kinases occurs by dephosphorylation of Thr(P) and Tyr(P) in the TXY kinase activation motif. To gain insight into the mechanism of ERK2 inactivation by MKP3, we have carried out an analysis of the MKP3-catalyzed dephosphorylation of the phosphorylated ERK2. We find that ERK2/pTpY dephosphorylation by MKP3 involves an ordered, distributive mechanism in which MKP3 binds the bisphosphorylated ERK2/pTpY, dephosphorylates Tyr(P) first, dissociates and releases the monophosphorylated ERK2/pT, which is then subjected to dephosphorylation by a second MKP3, yielding the fully dephosphorylated ERK2. The bisphosphorylated ERK2 is a highly specific substrate for MKP3 with a k cat/Km of 3.8 × 106 M-1 s -1, which is more than 6 orders of magnitude higher than that for small molecule aryl phosphates and an ERK2-derived phosphopeptide encompassing the pTEpY motif. This strikingly high substrate specificity displayed by MKP3 may result from a combination of high affinity binding interactions between the N-terminal domain of MKP3 and ERK2 and specific ERK2-induced allosteric activation of the MKP3 C-terminal phosphatase domain.

Original languageEnglish (US)
Pages (from-to)32382-32391
Number of pages10
JournalJournal of Biological Chemistry
Volume276
Issue number34
DOIs
StatePublished - Aug 24 2001

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'The Mechanism of Dephosphorylation of Extracellular Signal-regulated Kinase 2 by Mitogen-activated Protein Kinase Phosphatase 3'. Together they form a unique fingerprint.

Cite this