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Zona pellucida sperm-binding protein 3; Zona pellucida glycoprotein ZP3; Zona pellucida protein C; sperm receptor; ZP3A/ZP3B (ZP3, ZP3A, ZP3B, ZPC)
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
- ZP3 is essential for sperm binding & zona matrix formation
- proteolytically cleaved before the transmembrane segment to yield the secreted ectodomain incorporated in the zona pellucida
- polymers of ZP2 & ZP3 organized into long filaments cross-linked by ZP1 homodimers (putative)
Structure:
- N-glycosylated (putative)
- O-glycosylated; removal of O-linked glycans may play a role in post-fertilization block to polyspermy
- the ZP domain is involved in the polymerization of the ZP proteins to form the zona pellucida
- belongs to the ZP domain family, ZPC subfamily
- contains 1 ZP domain
Compartment:
- processed zona pellucida sperm-binding protein 3
- secreted, extracellular space, extracellular matrix
- cell membrane; single-pass type 1 membrane protein
Alternative splicing: named isoforms=3
Expression: oocytes
General
glycoprotein
matrix protein
membrane protein
receptor
Properties
SIZE: entity length = 424 aa
MW = 47 kD
COMPARTMENT: cellular membrane
MOTIF: signal sequence {1-22}
ZP domain {45-307}
MOTIF: cysteine residue {*1}
MODIFICATION: cysteine residue {*2}
cysteine residue {*2}
MODIFICATION: cysteine residue {*1}
cysteine residue {C46}
MODIFICATION: cysteine residue {C140}
cysteine residue {C78}
MODIFICATION: cysteine residue {C99}
cysteine residue {C99}
MODIFICATION: cysteine residue {C78}
N-glycosylation site {N125}
cysteine residue {C140}
MODIFICATION: cysteine residue {C46}
N-glycosylation site {N147}
Thr glycosylation site {T156}
Thr glycosylation site {T162}
Thr glycosylation site {T163}
cysteine residue {C217}
MODIFICATION: cysteine residue {C282}
N-glycosylation site {N226}
cysteine residue {C239}
MODIFICATION: cysteine residue {C300}
N-glycosylation site {N272}
cysteine residue {C282}
MODIFICATION: cysteine residue {C217}
cysteine residue {C300}
MODIFICATION: cysteine residue {C239}
transmembrane domain {388-408}
Database Correlations
OMIM 182889
UniProt P21754
Pfam PF00100
Entrez Gene 7784
Kegg hsa:7784
References
- UniProt :accession P21754
- Protein Spotlight; Note: molecular chastity -
Issue 93 of April 2008
http://www.expasy.org/spotlight/back_issues/sptlt093.shtml