Fibroblast growth factor receptor substrate 2 (FRS2) is a 70-90kDA member of the FSR family of lipid-anchored docking protein. FRS2 contains Grb2 binding sites, a myristylation sequence and a PTP domain. Activation of FGFR leads to tyrosine phosphorylation of FRS2 and the binding of phosphorylated FRS2 to GRB2/SOS complexes. Once phosphorylated, FRS2 recruits SH2 domain-containing proteins including Grb2 and SHP-2 mediating downstream signalling. FRS2 thus, acts as an intermediary between FGF and Trk receptors that links receptor tyrosine kinase to Ras/MAPK signaling pathway.
