Extended Data Fig. 6. The asymmetric FGFR^P-FGFR^S interface observed in FGF23-FGFR-αKlotho-HS cryo-EM structures is required for multiple paracrine FGF signaling.

a, Immunoblots of whole cell extracts from untreated or FGF-treated (1 nM) untransfected and transfected L6 cell lines stably expressing FGFR1c^WT, FGFR1c^E249A, FGFR1c^R254A, FGFR1c^I256A, or FGFR1c^Y280A probed with antibodies against phosphorylated FGFR, PLCγ1 and FRS2α. b, Immunoblots of whole cell extracts from untreated or FGF-treated (1 nM for FGF1 and 2 nM for FGF3/7/10/22) treated untransfectedand transfected L6 cell lines stably expressing FGFR2b^WT, FGFR2b^E250A, FGFR2b^R255A, FGFR2b^I257A, or FGFR2b^Y281A probed with FGFR2b isoform specific antibody (top) or phosphospecific antibodies as in panel a. Experiments were performed in biological triplicates with similar results.