Description
It is a single-pass transmembrane protein composed of three extracellular Ig-like domains, a transmembrane region, and a tyrosine kinase domain (1, 2). Tyrosine-protein kinase that acts as cell-surface receptor for fibroblast growth factors and plays an essential role in the regulation of embryonic development, cell proliferation, differentiation and migration (3, 4, 5). Required for normal mesoderm patterning and correct axial organization during embryonic development, normal skeletogenesis and normal development of the gonadotropin-releasing hormone (GnRH) neuronal system (6). Phosphorylates PLCG1, FRS2, GAB1 and SHB (6). Ligand binding leads to the activation of several signalling cascades. Activation of PLCG1 leads to the production of the cellular signalling molecules diacylglycerol and inositol 1,4,5-trisphosphate. Phosphorylation of FRS2 triggers recruitment of GRB2, GAB1, PIK3R1 and SOS1, and mediates activation of RAS, MAPK1/ERK2, MAPK3/ERK1 and the MAP kinase signalling pathway, as well as of the AKT1 signalling pathway (7, 8, 9). Promotes phosphorylation of SHC1, STAT1 and PTPN11/SHP2 (10). In the nucleus, enhances RPS6KA1 and CREB1 activity and contributes to the regulation of transcription (11).
FGFR1b is an alternatively spliced isoform representing epithelial variant of FGFR1