FYVE-like domain found in FYVE, RhoGEF and PH domain-containing protein 3 (FGD3) and similar proteins
FGD3, also termed zinc finger FYVE domain-containing protein 5, is a putative Cdc42-specific guanine nucleotide exchange factor (GEF) that undergoes the ubiquitin ligase SCFFWD1/beta-TrCP-mediated proteasomal degradation. It is a homologue of FGD1 and contains a DBL homology (DH) domain and pleckstrin homology (PH) domain in the middle region, a FYVE domain, and another PH domain in the C-terminus, but lacks the N-terminal proline-rich domain (PRD) found in FGD1. Due to this difference, FGD3 may play different roles from that of FGD1 to regulate cell morphology or motility. The FYVE domain of FGD3 resembles a FYVE-like domain that is different from the canonical FYVE domains, since it lacks one of the three conserved signature motifs (the WxxD motif) that are involved in phosphatidylinositol 3-phosphate (PtdIns3P or PI3P) binding and exhibits altered lipid binding specificities.