ZP2

ZP2
Identifiers
Aliases ZP2, ZPA, Zp-2, zona pellucida glycoprotein 2
External IDs MGI: 99214 HomoloGene: 48194 GeneCards: ZP2
RNA expression pattern
More reference expression data
Orthologs
Species Human Mouse
Entrez

7783

22787

Ensembl

ENSG00000103310

ENSMUSG00000030911

UniProt

Q05996

P20239

RefSeq (mRNA)

NM_001290104
NM_003460

NM_011775

RefSeq (protein)

NP_001277033.1
NP_003451.1

NP_035905.1

Location (UCSC) Chr 16: 21.2 – 21.21 Mb Chr 7: 120.13 – 120.15 Mb
PubMed search [1] [2]
Wikidata
View/Edit HumanView/Edit Mouse

Zona pellucida sperm-binding protein 2 is a protein that in humans is encoded by the ZP2 gene.[3][4]

Function

The zona pellucida is an extracellular matrix that surrounds the oocyte and early embryo. It is composed primarily of three (mouse) or four (human) glycoproteins (ZP1-4) 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.[4]

The sperm-binding domain on the ZP2 protein is necessary in both humans and mice for oocyte-sperm recognition and penetration of the zona pellucida. It is also responsible for the primary block to polyspermy in mammals. The oocyte has cortical granules peripherally located under the cortex that contain a proteolytic protein called ovastacin. After the sperm binds to ZP2, the cortical granules are exocytosed releasing ovastacin into the perivitelline space. Ovastacin cleaves ZP2 at the N terminus, preventing more sperm from binding and penetrating the oocyte, thus hardening the zona pellucida. Ovastacin is only found in oocytes, and is part of the astacin family of metalloendoproteases. Female mice engineered without ovastacin showed that ZP2 was not cleaved after fertilization.[5][6]

References

  1. "Human PubMed Reference:".
  2. "Mouse PubMed Reference:".
  3. Liang LF, Dean J (Apr 1993). "Conservation of mammalian secondary sperm receptor genes enables the promoter of the human gene to function in mouse oocytes". Dev Biol. 156 (2): 399–408. doi:10.1006/dbio.1993.1087. PMID 8385033.
  4. 1 2 "Entrez Gene: ZP2 zona pellucida glycoprotein 2 (sperm receptor)".
  5. Burkart AD, Xiong B, Baibakov B, Jiménez-Movilla M, Dean J. "Ovastacin, a cortical granule protease, cleaves ZP2 in the zona pellucida to prevent polyspermy.". J Cell Biol. 197: 37–44. doi:10.1083/jcb.201112094. PMID 22472438.
  6. Avella MA, Baibakov B, Dean J. "A single domain of the ZP2 zona pellucida protein mediates gamete recognition in mice and humans.". J Cell Biol. 205: 801–809. doi:10.1083/jcb.201404025. PMID 24934154.

Further reading


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