FunctionThe mammalian zona pellucida, which mediates species-specific sperm binding, induction of the acrosome reaction and prevents post-fertilization polyspermy, is composed of three to four glycoproteins, ZP1, ZP2, ZP3, and ZP4. ZP4 may act as a sperm receptor.
Sequence similaritiesBelongs to the ZP domain family. ZPB subfamily. Contains 1 P-type (trefoil) domain. Contains 1 ZP domain.
DomainThe ZP domain is involved in the polymerization of the ZP proteins to form the zona pellucida.
Post-translational modificationsProteolytically cleaved before the transmembrane segment to yield the secreted ectodomain incorporated in the zona pellucida.
Cellular localizationSecreted > extracellular space > extracellular matrix and Cell membrane.