Zona Pellucida Sperm-Binding Protein 3 (ZP3) Human Recombinant Protein

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 primary binding and induction of the sperm acrosome reaction. The nascent protein contains a N-terminal signal peptide sequence, a conserved ZP domain, a C-terminal consensus furin cleavage site, and a 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. A variation in the last exon of this gene has previously served as the basis for an additional ZP3 locus; however, sequence and literature review reveals that there is only one full-length ZP3 locus in the human genome. Another locus encoding a bipartite transcript designated POMZP3 contains a duplication of the last four exons of ZP3, including the above described variation, and maps closely to this gene. [provided by RefSeq, Jul 2008]

ZP3: The 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. ZP3 is essential for sperm binding and zona matrix formation. Belongs to the ZP domain family. ZPC subfamily. 3 isoforms of the human protein are produced by alternative splicing.

Protein type: Extracellular matrix; Membrane protein, integral

Chromosomal Location of Human Ortholog: 7q11.23

Cellular Component: acrosome; cytoplasm; endoplasmic reticulum; extracellular matrix; extracellular region; extracellular space; Golgi apparatus; integral to membrane; multivesicular body; perinuclear region of cytoplasm; plasma membrane; proteinaceous extracellular matrix; secretory granule

Molecular Function: acrosin binding; carbohydrate binding; manganese ion transmembrane transporter activity; protein binding; signal transducer activity; store-operated calcium channel activity

Biological Process: binding of sperm to zona pellucida; blastocyst formation; humoral immune response mediated by circulating immunoglobulin; intracellular protein transport; manganese ion transport; multicellular organism reproduction; negative regulation of transcription, DNA-dependent; oocyte development; phosphoinositide-mediated signaling; positive regulation of humoral immune response; positive regulation of inflammatory response; positive regulation of interferon-gamma production; positive regulation of interleukin-4 production; positive regulation of leukocyte migration; positive regulation of phosphatidylinositol biosynthetic process; positive regulation of protein kinase activity; positive regulation of protein kinase B signaling cascade; positive regulation of T cell proliferation; positive regulation of transcription, DNA-dependent; positive regulation of type IV hypersensitivity; single fertilization