ERK2 shows a restrictive and locally selective mechanism of recognition by its tyrosine phosphatase inactivators not shared by its activator MEK1.
The two regulatory residues that control the enzymatic activity of the mitogen-activated protein (MAP) kinase ERK2 are phosphorylated by the unique MAP kinase kinases MEK1/2 and dephosphorylated by several tyrosine-specific and dual specificity protein phosphatases. Selective docking interactions facilitate these phosphorylation and dephosphorylation events, controlling the specificity and duration of the MAP kinase activation-inactivation cycles. We have analyzed the contribution of specific residues of ERK2 in the physical and functional interaction with the ERK2 phosphatase inactivators PTP-SL and MKP-3 and with its activator MEK1. Single mutations in ERK2 that abrogated the dephosphorylation by endogenous tyrosine phosphatases from HEK293 cells still allowed efficient phosphorylation by endogenous MEK1/2. Discrete ERK2 mutations at the ERK2 docking groove differentially affected binding and inactivation by PTP-SL and MKP-3. Remarkably, the cytosolic retention of ERK2 by its activator MEK1 was not affected by any of the analyzed ERK2 single amino acid substitutions. A chimeric MEK1 protein, containing the kinase interaction motif of PTP-SL, bound tightly to ERK2 through its docking groove and behaved as a gain-of-function MAP kinase kinase that hyperactivated ERK2. Our results provide evidence that the ERK2 docking groove is more restrictive and selective for its tyrosine phosphatase inactivators than for MEK1/2 and indicate that distinct ERK2 residues modulate the docking interactions with activating and inactivating effectors.
Tárrega
Céline
C
Centro de Investigación Príncipe Felipe, Valencia, Spain.
Ríos
Pablo
P
Cejudo-Marín
Rocío
R
Blanco-Aparicio
Carmen
C
van den Berk
Lieke
L
Schepens
Jan
J
Hendriks
Wiljan
W
Tabernero
Lydia
L
Pulido
Rafael
R
D019943:Amino Acid Substitution; D000818:Animals; D002460:Cell Line; D003600:Cytosol / Q000378:metabolism; D054642:Dual Specificity Phosphatase 6; D004789:Enzyme Activation; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D048369:MAP Kinase Kinase 1 / Q000378:metabolism*; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D048308:Mitogen-Activated Protein Kinase 14 / Q000235:genetics / Q000378:metabolism; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D011485:Protein Binding; D017027:Protein Tyrosine Phosphatases / Q000235:genetics / Q000378:metabolism*; D054634:Receptor-Like Protein Tyrosine Phosphatases, Class 7; D011994:Recombinant Proteins; D013379:Substrate Specificity; D020798:Two-Hybrid System Techniques
D047908:Intracellular Signaling Peptides and Proteins; D011994:Recombinant Proteins; D019950:Mitogen-Activated Protein Kinase 1; D048308:Mitogen-Activated Protein Kinase 14; D048369:MAP Kinase Kinase 1; D010749:Phosphoprotein Phosphatases; C517035:DUSP6 protein, human; D054642:Dual Specificity Phosphatase 6; C517036:Dusp6 protein, mouse; C513469:PTPRR protein, human; D017027:Protein Tyrosine Phosphatases; C513472:Ptprr protein, mouse; D054634:Receptor-Like Protein Tyrosine Phosphatases, Class 7