Diversity does make a difference: fibroblast growth factor-heparin interactions

Fibroblast growth factors (FG Fs) are members of a protein family with a broad range of biological activities. The best characterized FG Fs interact with two distinct extracellular receptors - a transmembrane tyrosine kinase FGF receptor (FG FR) and a heparan sulfate-related proteoglycan of the extracellular matrix. These components form a FG F-FG FR-proteoglycan complex that activates the FGF-mediated signal transduction process through FGFR dimerization. Recent crystal structure determinations of FGF-heparin complexes have provided insights into both the interactions between these components and the role of heparin-like proteoglycans in FGF function. Future advances in this field will benefit enormously from an ability to specifically prepare homogenous heparin-based oligosaccharides of defined sequence for use in biochemical and structural studies of FGF and many other systems.