FYVE-related domain found in protein spire homolog 2 (Spire2) and similar proteins
Spire2 is encoded by gene spir-2, which is expressed in the nervous system and highly expressed in the colonic epithelium. It functions as a new essential factor in asymmetric division of oocytes. It mediates asymmetric spindle positioning by assembling a cytoplasmic actin network. It is also required for polar body extrusion by promoting assembly of the cleavage furrow. Moreover, it cooperates synergistically with Fmn2 to assemble F-actin in oocytes. Spire2 contains an N-terminal protein-interaction KIND domain, WH2 actin-binding domains, a Rab GTPase-interaction Spir-box, and a C-terminal FYVE membrane-binding domain. The FYVE domain resembles a FYVE-related domain that is structurally similar to the canonical FYVE domains but lacks the three signature sequences: an N-terminal WxxD motif (x for any residue), the central basic R(R/K)HHCRxCG patch, and a C-terminal RVC motif, which form a binding pocket that specifically binds the phospholipid phosphatidylinositol 3-phosphate (PtdIns3P or PI3P).
Jiyao W et al.(2023). "The conserved domain database in 2023.",