ZP2

The zona pellucida is an extracellular matrix that surrounds the oocyte and early embryo. It is composed primarily of three or four glycoproteins with various functions during fertilization and preimplantation development. The protein encoded by this gene is a structural component of the zona pellucida and functions in secondary binding and penetration of acrosome-reacted spermatozoa. The nascent protein contains a N-terminal signal peptide sequence, a conserved ZP domain, a consensus furin cleavage site, and a C-terminal transmembrane domain. It is hypothesized that furin cleavage results in release of the mature protein from the plasma membrane for subsequent incorporation into the zona pellucida matrix. However, the requirement for furin cleavage in this process remains controversial based on mouse studies. [provided by RefSeq]

Full Name

zona pellucida glycoprotein 2 (sperm receptor)

Function

Component of the zona pellucida, an extracellular matrix surrounding oocytes which mediates sperm binding, induction of the acrosome reaction and prevents post-fertilization polyspermy (PubMed:29895852).
The zona pellucida is composed of 3 to 4 glycoproteins, ZP1, ZP2, ZP3, and ZP4. ZP2 may act as a secondary sperm receptor (PubMed:29895852).

Biological Process

Biological Process binding of sperm to zona pellucida Source:UniProtKBBy Similarity
Biological Process prevention of polyspermy Source:UniProtKBBy Similarity

Cellular Location

Processed zona pellucida sperm-binding protein 2
Zona pellucida
Cell membrane

Involvement in disease

Oocyte maturation defect 6 (OOMD6):
An autosomal recessive infertility disorder characterized by oocyte fertilization failure, due to defective sperm-binding to an abnormally thin zona pellucida in patient oocytes.

Topology

Extracellular: 39-716
Helical: 717-736
Cytoplasmic: 737-745

PTM

Proteolytically cleaved before the transmembrane segment to yield the secreted ectodomain incorporated in the zona pellucida.
Proteolytically cleaved in the N-terminal part by the metalloendopeptidase ASTL exocytosed from cortical granules after fertilization, yielding a N-terminal peptide of about 30 kDa which remains covalently attached to the C-terminal peptide via disulfide bond(s). This cleavage may play an important role in the post-fertilization block to polyspermy. Additional proteolytically cleavage of the N-terminal peptide of 30 kDa occurs in one-cell and two-cell embryos.
N-glycosylated.
O-glycosylated; contains sulfate-substituted glycans.