p-MEK phosphorylates ERK 'IL17RD [cytosol]' negatively regulates 'p-MEK phosphorylates ERK' IL17RD, or SEF, is a negative regulator of FGF signaling. There are at least two isoforms in humans, a transmembrane version and a cytosolic splice variant. SEF appears to function at multiple points in the FGFR pathway, perhaps dependent on cell type. SEF appears to attenuate signaling through the MAPK pathway, although the precise point of action remains to be clarified. Some reports have indicated that SEF acts upstream of Ras, and indeed the plasma membrane form has been shown to coimmunoprecipitate with FGRFR1 and 2. Other reports show that MEK1/2 phosphorylation is unaffected by SEF, but that the regulator acts by inhibiting the phosphorylation of ERK1/2. INHIBITION Pubmed12807873 Pubmed12958313 Pubmed14742870 Pubmed17035228 Reactome Database ID Release 431268214 Reactome, http://www.reactome.org ReactomeREACT_111924 IL17RD