p-MEK phosphorylates ERK Authored: Rothfels, K, 2011-08-15 EC Number: 2.7.11 MEK1/2 phosphorylate critical tyrosine and threonine residues on ERK1/2, activating the kinase activity of the MAPKs. In FGFR signaling, this reaction appears to be negatively regulated by IL17RD through an unknown mechanism, limiting the extent of MAPK signaling after FGF stimulation. Pubmed12807873 Pubmed12958313 Pubmed14742870 Pubmed17035228 Pubmed8388392 Reactome Database ID Release 431268210 Reactome, http://www.reactome.org ReactomeREACT_111117 Reviewed: Gotoh, N, 2011-08-26 has a Stoichiometric coefficient of 2 p-MEK:p-ERK p-MEK:ERK