title: Posttranslational modifications of zona pellucida proteins.
abstract: The zona pellucida (ZP), which surrounds the mammalian oocyte, functions in various aspects of fertilization. The ZP consists of three or four glycoproteins, which are derived from transmembrane proteins that lack the ability to self-assemble. Following posttranslational processing at specific sites, ectodomains of ZP precursor proteins are released from the membrane and begin to form a matrix. Glycosylational modification is thought to be involved in species-selective sperm recognition by ZP proteins. However, in mice, the supramolecular structure of the zona matrix is also important in sperm recognition. One ZP protein, ZP2, is processed at a specific site upon fertilization by ovastacin, which is released from cortical granules inside the oocyte. This phenomenon is involved in the block to polyspermy. The proteolysis of ubiquitinated ZP proteins by a sperm-associated proteasome is involved in penetration of the zona matrix by sperm, at least in the pigs. Thus, the posttranslational modification of ZP proteins is closely tied to ZP formation and the regulation of sperm-oocyte interactions.
authors.affiliation: Graduate School of Science, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan, nyoneza@faculty.chiba-u.jp.
authors.forename: Naoto
authors.initials: N
authors.lastname: Yonezawa
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D004220:Disulfides / Q000737:chemistry; D004527:Egg Proteins / Q000737:chemistry / Q000378:metabolism*; D005306:Fertilization / Q000502:physiology; D006031:Glycosylation; D006801:Humans; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D011499:Protein Processing, Post-Translational; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000378:metabolism*; D054875:Ubiquitination; D000072216:Zona Pellucida Glycoproteins
chemical_list: D004220:Disulfides; D004527:Egg Proteins; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; C000606515:ZP2 protein, human; D000072216:Zona Pellucida Glycoproteins; C000606520:Zp2 protein, mouse