Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor and similar proteins
Ig2_FGFR_like: domain similar to the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor. FGF receptors bind FGF signaling polypeptides. FGFs participate in multiple processes such as morphogenesis, development, and angiogenesis. FGFs bind to four FGF receptor tyrosine kinases (FGFR1, -2, -3, -4). Receptor diversity is controlled by alternative splicing producing splice variants with different ligand binding characteristics and different expression patterns. FGFRs have an extracellular region comprised of three Ig-like domains, a single transmembrane helix, and an intracellular tyrosine kinase domain. Ligand binding and specificity reside in the Ig-like domains 2 and 3, and the linker region that connects these two. FGFR activation and signaling depend on FGF-induced dimerization, a process involving cell surface heparin or heparin sulfate proteoglycans. This group also contains fibroblast growth factor (FGF) receptor_like-1(FGFRL1). FGFRL1 does not have a protein tyrosine kinase domain at its C terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.
Feature 1:FGF binding site [polypeptide binding site]
Structure:1E0O_B; human FGF1-FGFR2 interaction interface defined by 3.5A distance. - View structure with Cn3D
Comment:The FGF1-FGFR2-heparin complex is comprised of one heparin molecule linked to two FGF1 molecules, each FGF1 molecule of which is bound to a receptor ectodomain. Shown here is one FGF1 molecule bound to the receptor ectodomain.