title: Cloning and characterisation of a zona pellucida 3 cDNA from a marsupial, the brushtail possum Trichosurus vulpecula.
abstract: The mammalian zona pellucida (ZP) is an extracellular glycoprotein coat that plays vital roles throughout fertilisation and preimplantation development. Like that of eutherian mammals the brushtail possum ZP is composed of three glycosylated proteins of 137 kDa, 92 kDa and 62 kDa. The 62 kDa protein is a ZP3 orthologue based on its nucleotide and deduced amino acid sequence. The brushtail possum ZP3 cDNA isolated in this study is 1305 nucleotides with an open reading frame encoding a 422 amino acid peptide of 45.7 kDa. Possum ZP3 has a 46% amino acid identity with eutherian ZP3 and shares similar structural characteristics including 12 conserved cysteine residues, N-linked glycosylation sites and hydrophobic regions. Like human and rabbit ZP1 an altered furin cleavage site upstream of the C-terminal hydrophobic domain also occurs in possum ZP3 (S-R-K-R), suggestive of processing by a furin-related endoprotease. Expression of brushtail possum ZP3 is limited to the ovary. Characterisation of brushtail possum ZP3 will enable examination of its functional role in marsupial fertilisation and its effectiveness as an immunocontraceptive agent.
authors.affiliation: Cooperative Research Centre for Conservation and Management of Marsupials, School of Biological Sciences, Macquarie University, Australia.
authors.forename: C A
authors.initials: CA
authors.lastname: McCartney
authors.forename: K E
authors.initials: KE
authors.lastname: Mate
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D016384:Consensus Sequence; D006224:Cricetinae; D018076:DNA, Complementary; D004527:Egg Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D005260:Female; D006801:Humans; D008322:Mammals; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D009893:Opossums / Q000235:genetics*; D011817:Rabbits; D011956:Receptors, Cell Surface; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015044:Zona Pellucida / Q000378:metabolism*; D000072216:Zona Pellucida Glycoproteins
chemical_list: D018076:DNA, Complementary; D004527:Egg Proteins; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; C000606514:ZP1 protein, human; C000606517:ZP3 protein, human; D000072216:Zona Pellucida Glycoproteins; C000606519:Zp1 protein, mouse; C000606521:Zp3 protein, mouse