FGF domain, beta-trefoil fold, found in the fibroblast growth factor 8 (FGF8)-like family
The FGF8-like family includes FGF8, FGF17 and FGF18. FGF8, also called androgen-induced growth factor (AIGF), or heparin-binding growth factor 8 (HBGF8), plays an important role in the regulation of embryonic development, cell proliferation, cell differentiation, and cell migration. It is required for normal brain, eye, ear,, and limb development during embryogenesis. It is also required for normal development of the gonadotropin-releasing hormone (GnRH) neuronal system. It plays a role in neurite outgrowth in hippocampal cells. FGF8 interacts with fibroblast growth factor receptors, FGFR1, FGFR2, FGFR3, and FGFR4. FGF17 plays an important role in the regulation of embryonic development and as signaling molecule in the induction and patterning of the embryonic brain. It is required for normal brain development. FGF17 interacts with FGFR3 and FGFR4. FGF18, also called zFGF5, plays an important role in the regulation of cell proliferation, cell differentiation, and cell migration. It is required for normal ossification and bone development. It stimulates hepatic and intestinal proliferation. FGF18 interacts FGFR3 and FGFR4. Members in this family contain a FGF domain with beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry.
Jiyao W et al.(2023). "The conserved domain database in 2023.",