FYVE domain found in FYVE, RhoGEF and PH domain-containing protein facio-genital dysplasia FGD1, FGD2, FGD4
This family represents a group of Rho GTPase cell division cycle 42 (Cdc42)-specific guanine nucleotide exchange factors (GEFs), including FYVE, RhoGEF and PH domain-containing protein FGD1, FGD2 and FGD4. FGD1, also termed faciogenital dysplasia 1 protein, or Rho/Rac guanine nucleotide exchange factor FGD1 (Rho/Rac GEF), or zinc finger FYVE domain-containing protein 3, is a central regulator of extracellular matrix remodeling and belongs to the DBL family of GEFs that regulate the activation of the Rho GTPases. FGD1 is encoded by gene FGD1. Disabling mutations in the FGD1 gene cause the human X-linked developmental disorder faciogenital dysplasia (FGDY, also known as Aarskog-Scott syndrome). FGD2, also termed zinc finger FYVE domain-containing protein 4, is expressed in antigen-presenting cells, including B lymphocytes, macrophages, and dendritic cells. It localizes to early endosomes and active membrane ruffles. It plays a role in leukocyte signaling and vesicle trafficking in cells specialized to present antigen in the immune system. FGD4, also termed actin filament-binding protein frabin, or FGD1-related F-actin-binding protein, or zinc finger FYVE domain-containing protein 6, functions as an F-actin-binding (FAB) protein showing significant homology to FGD1. It induces the formation of filopodia through the activation of Cdc42 in fibroblasts. Those FGD proteins possess a similar domain organization that contains a DBL homology (DH) domain, a pleckstrin homology (PH) domain, a FYVE domain, and another PH domain in the C-terminus. However, each FGD has a unique N-terminal region that may directly or indirectly interact with F-actin. FGD1 and FGD4 have an N-terminal proline-rich domain (PRD) and an N-terminal F-actin binding (FAB) domain, respectively. This model corresponds to the FYVE domain, which has been found in many proteins involved in membrane trafficking and phosphoinositide metabolism, and has been defined by three signature sequences: an N-terminal WxxD motif (x for any residue), the central basic R(R/K)HHCR patch, and a C-terminal RVC motif, which form a compact phosphatidylinositol 3-phosphate (PtdIns3P or PI3P)-binding site. FGD1 possesses a FYVE-like domain that lack the N-terminal WxxD motif. Moreover, FGD2 is the only known RhoGEF family member shown to have a functional FYVE domain and endosomal binding activity.
Jiyao W et al.(2023). "The conserved domain database in 2023.",