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Zona pellucida sperm-binding protein 2; Zona pellucida glycoprotein ZP2; Zona pellucida protein A; contains: Processed zona pellucida sperm-binding protein 2 (ZP2 ZPA)
Function:
- the mammalian zona pellucida, which mediates species-specific sperm binding, induction of the acrosome reaction & prevents post-fertilization polyspermy, is composed of 3-4 glycoproteins, ZP1, ZP2, ZP3, & ZP4
- ZP2 may act as a secondary sperm receptor
- proteolytically cleaved before the transmembrane segment to yield the secreted ectodomain incorporated in the zona pellucida
- proteolytically cleaved in the N-terminal part after fertilization, yielding a N-terminal peptide of about 30 kD which remains covalently attached to the C-terminal peptide via disulfide bond(s); this cleavage may play a role in post-fertilization block to polyspermy (putative)
- O-glycosylated; contains sulfate-substituted glycans
- polymers of ZP2 & ZP3 organized into long filaments cross-linked by ZP1 homodimers (putative)
Structure:
- the ZP domain is involved in the polymerization of the ZP proteins to form the zona pellucida
- belongs to the ZP domain family, ZPA subfamily
- contains 1 ZP domain
Compartment:
- processed zona pellucida sperm-binding protein 2:
- secreted, extracellular space, extracellular matrix
- cell membrane; single-pass type 2 membrane protein
Expression:
- oocytes
- expressed during the 2-week growth phase of oogenesis, prior to ovulation
General
glycoprotein
matrix protein
membrane protein
receptor
Properties
SIZE: entity length = 745 aa
MW = 82 kD
COMPARTMENT: cellular membrane
MOTIF: signal sequence {1-38}
N-glycosylation site {N87}
cysteine residue {C88}
MODIFICATION: cysteine residue {C106}
N-glycosylation site {N105}
cysteine residue {C106}
MODIFICATION: cysteine residue {C88}
N-glycosylation site {N122}
peptide motif {172-173}
N-glycosylation site {N223}
N-glycosylation site {N269}
ZP domain {371-637}
MOTIF: cysteine residue {*1}
MODIFICATION: cysteine residue {*2}
cysteine residue {*2}
MODIFICATION: cysteine residue {*1}
cysteine residue {C372}
MODIFICATION: cysteine residue {C465}
N-glycosylation site {N400}
cysteine residue {C403}
MODIFICATION: cysteine residue {C424}
cysteine residue {C424}
MODIFICATION: cysteine residue {C403}
Thr glycosylation site {T462}
cysteine residue {C465}
MODIFICATION: cysteine residue {C372}
cysteine residue {C615}
MODIFICATION: cysteine residue {C620}
cysteine residue {C620}
MODIFICATION: cysteine residue {C615}
cysteine residue {C630}
MODIFICATION: cysteine residue {C634}
cysteine residue {C634}
MODIFICATION: cysteine residue {C630}
transmembrane domain {717-736}
Database Correlations
OMIM 182888
UniProt Q05996
Pfam PF00100
Entrez Gene 7783
Kegg hsa:7783
References
UniProt :accession Q05996