Identification of a Binding Site in the Disintegrin Domain of Fertilin Required for Sperm-Egg Fusion

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 91; no. 10; pp. 4195 - 4198
• Main Authors: Myles, Diana G., Kimmel, Lida H., Blobel, Carl P., White, Judith M., Primakoff, Paul
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 10.05.1994; National Acad Sciences; National Academy of Sciences
• Subjects: ADAM Proteins; Amino Acid Sequence; Amino acids; Animals; Binding Sites; Cell membranes; Cellular biology; Disintegrins; Female; Fertilins; Fertilization; Guinea Pigs; Integrins; Male; Membrane Fusion - drug effects; Membrane Glycoproteins - chemistry; Membrane Glycoproteins - metabolism; Membrane proteins; Membranes; Metalloendopeptidases; Molecular Sequence Data; Oligopeptides - pharmacology; Oocytes; Oocytes - physiology; Ova; Peptides - chemistry; Reproduction; Sequence Homology, Amino Acid; Snake venoms; Sperm-Ovum Interactions - drug effects; Spermatozoa; Spermatozoa - physiology; Zona Pellucida - drug effects
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.91.10.4195

Fertilization and certain later stages in mammalian embryonic development require fusion between membranes of individual cells. The mechanism of eukaryotic cell-cell fusion is unknown, and no surface molecules required for this process have been unequivocally identified. The role of the sperm surface protein fertilin in sperm-egg fusion was tested by using peptide analogues of a potential integrin binding site in the fertilin β subunit. Peptide analogues that include a TDE sequence from the disintegrin region of fertilin β are able to bind to the egg plasma membrane and strongly inhibit sperm-egg fusion. These results show that the disintegrin domain of fertilin β binds to the egg plasma membrane and that this binding is required for membrane fusion.