FGF domain, beta-trefoil fold, found in fibroblast growth factor 13 (FGF13) and similar proteins
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. FGF-13 contains 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.",