title: Identification and characterization of a unique Xenopus laevis egg envelope component, ZPD.
abstract: We report the identification of a previously undetected Xenopus laevis egg envelope component discovered through cloning experiments. A cDNA sequence was found that represented a mature protein of 32 kDa. Peptide antibodies were generated to probe for the protein in egg envelope samples and reactivity was found to a glycoprotein of approximately 80 kDa. When deglycosylated egg envelope samples were probed, a 32 kDa protein was labeled, confirming the size of the translated cDNA sequence. A BLAST analysis showed that it is most closely related (34% amino acid identity) to the ZP domains of mammalian tectorin, uromodulin and ZPA. From a dendrogram of known egg envelope glycoproteins, the new glycoprotein was shown to be unique among egg envelope components and was designated ZPD. A similar glycoprotein was identified by immunocrossreactivity in Xenopus tropicalis and Xenopus borealis egg envelopes.
authors.affiliation: Section of Molecular and Cellular Biology, University of California, Davis 95616, USA. lllindsay@ucdavis.edu
authors.forename: LeAnn L
authors.initials: LL
authors.lastname: Lindsay
authors.forename: Joy C
authors.initials: JC
authors.lastname: Yang
authors.forename: Jerry L
authors.initials: JL
authors.lastname: Hedrick
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004527:Egg Proteins / Q000235:genetics / Q000302:isolation & purification*; D005260:Female; D006023:Glycoproteins / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment; D014982:Xenopus laevis
chemical_list: D018076:DNA, Complementary; D004527:Egg Proteins; D006023:Glycoproteins; D008565:Membrane Proteins; C476537:ZPD protein, Xenopus