Human Homolog of the Mouse Sperm Receptor

• Published in: Proceedings of the National Academy of Sciences - PNAS 1990-08, Vol.87 (16), p.6014-6018
• Main Authors: Chamberlin, Margaret E., Dean, Jurrien
• Format: Article
• Language: English
• Subjects: 550200 - Biochemistry; AMINO ACID SEQUENCE; Amino acids; Animals; Base Sequence; BASIC BIOLOGICAL SCIENCES; Biological and medical sciences; BODY; Cell receptors; Cell structures and functions; Complementary DNA; DNA; DNA - genetics; DNA - isolation & purification; DNA SEQUENCING; Egg Proteins; Exons; Female; FEMALE GENITALS; Fundamental and applied biological sciences. Psychology; GAMETES; GENES; Genomic Library; Genomics; GERM CELLS; GLYCOPROTEINS; Glycoproteins - genetics; Humans; Male; Membrane Glycoproteins; Mice; Miscellaneous; Molecular and cellular biology; Molecular Sequence Data; MOLECULAR STRUCTURE; NUCLEIC ACIDS; Oligonucleotide Probes; OLIGONUCLEOTIDES; ORGANIC COMPOUNDS; ORGANS; OVA; Ovum - physiology; polymerase chain reaction; Protein Conformation; PROTEINS; Receptors, Cell Surface; Restriction Mapping; RNA, Messenger - genetics; Sequence Homology, Nucleic Acid; spermatoza; Spermatozoa; Spermatozoa - physiology; STRUCTURAL CHEMICAL ANALYSIS; UTERUS; Zona pellucida; Zona Pellucida - physiology; Zona Pellucida Glycoproteins; ZP3 protein
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.87.16.6014

The human zona pellucida, composed of three glycoproteins (ZP1, ZP2, and ZP3), forms an extracellular matrix that surrounds ovulated eggs and mediates species-specific fertilization. The genes that code for at least two of the zona proteins (ZP2 and ZP3) cross-hybridize with other mammalian DNA. The recently characterized mouse sperm receptor gene (Zp-3) was used to isolate its human homolog. The human homolog spans ≈ 18.3 kilobase pairs (kbp) (compared to 8.6 kbp for the mouse gene) and contains eight exons, the sizes of which are strictly conserved between the two species. Four short (8-15 bp) sequences within the first 250 bp of the 5' flanking region in the human Zp-3 homolog are also present upstream of mouse Zp-3. These elements may modulate oocyte-specific gene expression. By using the polymerase chain reaction, a full-length cDNA of human ZP3 was isolated from human ovarian poly(A)+RNA and used to deduce the structure of human ZP3 mRNA. Certain features of the human and mouse ZP3 transcripts are conserved. Both have unusually short 5' and 3' untranslated regions, both contain a single open reading frame that is 74% identical, and both code for 424 amino acid polypeptides that are 67% the same. The similarity between the two proteins may define domains that are important in maintaining the structural integrity of the zona pellucida, while the differences may play a role in mediating the species-specific events of mammalian fertilization.