Handbook of Cell Signaling

Abstract

The fibroblast growth factor (FGF) signaling system is a ubiquitous cellular sensor of local environmental changes and mediator of cell-to-cell communication with broad roles in development and organ homeostasis in the adult. Through the interaction of heparan sulfate (HS) with both activating FGF polypeptides and transmembrane FGF receptor (FGFR) tyrosine kinases, the system is rigorously modulated by tissue architecture. Diversity and cell and tissue specificity of signaling result from the combinatorial oligomerization of a family of 23 FGF homologs, diverse oligosaccharide motifs within HS chains of proteoglycans, and a plethora of ectodomains resulting from splice variations from four genes coding for four intracellular tyrosine kinases.