FGF domain, beta-trefoil fold, found in the fibroblast growth factor 11 (FGF11)-like family
The FGF11-like family includes FGF11-14. FGF11, also called fibroblast growth factor homologous factor 3 (FHF3), may be involved in nervous system development and function. It plays roles in angiogenesis, tumorigenesis, adipogenesis, or liver regeneration. FGF12, also called fibroblast growth factor homologous factor 1 (FHF1), or myocyte-activating factor, is involved in nervous system development and function. It plays a role in the positive regulation of voltage-gated sodium channel activity. It promotes neuronal excitability by elevating the voltage dependence of neuronal sodium channel SCN8A fast inactivation. FGF12 interacts with the C-terminal region of SCN9A. FGF13, also called Fibroblast growth factor homologous factor 2 (FHF2), is a microtubule-binding protein which directly binds tubulin and is involved in both polymerization and stabilization of microtubules. Through its action on microtubules, it may participate in the refinement of axons by negatively regulating axonal and leading processes branching. FGF13 plays a crucial role in neuron polarization and migration in the cerebral cortex and the hippocampus. It may regulate voltage-gated sodium channels transport and function. It may also play a role in MAPK signaling. It is required for the development of axonal initial segment-targeting inhibitory GABAergic synapses made by chandelier neurons. FGF13 interacts with SCN1A, SCN5A, and SCN8A. It may also interact with SCN2A and SCN11A. FGF14, also called fibroblast growth factor homologous factor 4 (FH-4), may be involved in nervous system development and function. It interacts with SCN8A. 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.",