Figure 2.

FGF signaling pathway. The FGFRs consist of three extracellular immunoglobulin-type domains (D1–D3; blue balls in the receptor), a single-span trans-membrane domain and an intracellular split domain. FGFs interact with the D2 and D3 domains, and promote upon binding receptor dimerization and tyrosine kinase autophosphorylation of the FGFRs that results in the recruitment and assembly of signaling complexes. The main three downstream FGF/FGFR signaling complexes operating in the context of neural development are represented (the red balloons indicate the main components of the pathway): the Ras/MEK/MAPK/ERK; the PI3K/AKT and the PLCγ pathways. The blue balloons indicate the repressor regulators of the pathways.