Substrate Recognition Domains within Extracellular Signal-regulated Kinase Mediate Binding and Catalytic Activation of Mitogen-activated Protein Kinase Phosphatase-3

Harvard University, Cambridge, Massachusetts, United States
Journal of Biological Chemistry (Impact Factor: 4.6). 08/2000; 275(32):24613-24621. DOI: 10.1074/jbc.M001515200

ABSTRACT Mitogen-activated protein (MAP) kinase phosphatase-3 (MKP-3) is a dual specificity phosphatase that inactivates extracellular
signal-regulated kinase (ERK) MAP kinases. This reflects tight and specific binding between ERK and the MKP-3 amino terminus
with consequent phosphatase activation and dephosphorylation of the bound MAP kinase. We have used a series of p38/ERK chimeric
molecules to identify domains within ERK necessary for binding and catalytic activation of MKP-3. These studies demonstrate
that ERK kinase subdomains V-XI are necessary and sufficient for binding and catalytic activation of MKP-3. These domains
constitute the major COOH-terminal structural lobe of ERK. p38/ERK chimeras possessing these regions display increased sensitivity
to inactivation by MKP-3. These data also reveal an overlap between ERK domains interacting with MKP-3 and those known to
confer substrate specificity on the ERK MAP kinase. Consistent with this, we show that peptides representing docking sites
within the target substrates Elk-1 and p90rskinhibit ERK-dependent activation of MKP-3. In addition, abolition of ERK-dependent phosphatase activation following mutation
of a putative kinase interactionmotif (KIM) within the MKP-3 NH2 terminus suggests that key sites of contact for the ERK COOH-terminal structural lobe include residues localized between
the Cdc25 homology domains (CH2) found conserved between members of the DSP gene family.

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