Fig. 3.

The ⁷⁵¹VLTVTSTDEY⁷⁶⁰ motif in FGFR3 is required for the interaction with ICK. (A) Averaged fluorescence intensities from three replicates of the peptide microarray involving peptides from FGFR3 C-terminal region. (B) Ribbon and surface representations of the crystal structure of the TK domain of FGFR3 (PDB ID code 4K33). Residue Y724 and C-terminal region implicated in ICK binding by co-IP experiments and peptide microarray analysis are highlighted in blue and orange/green, respectively. Orange, α-helix; green, the residue T⁷⁵⁵ (unstructured). Note that the absence of structural information for residues ⁷⁵⁶STDEY⁷⁶⁰ is suggestive of structural disorder. (C) The putative ICK interacting motif on FGFR3 (⁷⁵¹VLTVTSTDEY⁷⁶⁰) was replaced by the analogous sequence from FGFR2 (⁷⁶⁰ILTLTTNEEY⁷⁶⁹), creating the FGFR3-R2-C-t chimera. The co-IP of FGFR3-R2-C-t with ICK compared with wild-type FGFR3 (Student’s t test; ***P < 0.001).