Identification of a ZP3-binding protein on acrosome-intact mouse sperm by photoaffinity crosslinking.
During the process of fertilization in mammals, sperm bind in a relatively species-specific manner to the zona pellucida (ZP) of ovulated eggs. ZP3, a glycoprotein found in the mouse egg zona pellucida, serves as receptor for sperm during gamete adhesion. We report here that a Mr 56,000 protein found on mouse sperm has properties expected for a sperm component that recognizes and binds to ZP3. This sperm protein is radiolabeled preferentially by a photoactivatable heterobifunctional crosslinker ("Denny-Jaffee reagent") covalently linked to purified ZP3, binds very tightly to ZP3-affinity columns, and is localized to heads of acrosome-intact but not acrosome-reacted sperm. These and other findings suggest that this protein may be a "ZP3-binding protein" that, together with the sperm receptor, supports species-specific binding of mouse sperm to unfertilized eggs.
Bleil
J D
JD
Department of Cell and Developmental Biology, Roche Institute of Molecular Biology, Roche Research Center, Nutley, NJ 07110.
Wassarman
P M
PM
D000177:Acrosome / Q000378:metabolism / Q000648:ultrastructure*; D000818:Animals; D001345:Autoradiography; D001386:Azides; D003432:Cross-Linking Reagents; D004527:Egg Proteins; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006023:Glycoproteins / Q000378:metabolism*; D007457:Iodine Radioisotopes; D008297:Male; D008562:Membrane Glycoproteins; D051379:Mice; D008815:Mice, Inbred Strains; D010777:Photochemistry; D011956:Receptors, Cell Surface; D013075:Sperm Capacitation; D013094:Spermatozoa / Q000648:ultrastructure*; D015044:Zona Pellucida / Q000502:physiology; D000072216:Zona Pellucida Glycoproteins
D001386:Azides; D003432:Cross-Linking Reagents; D004527:Egg Proteins; D006023:Glycoproteins; D007457:Iodine Radioisotopes; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; D000072216:Zona Pellucida Glycoproteins; C000606521:Zp3 protein, mouse; C042649:N-(4-(4-azido-3-iodophenylazo)benzoyl)-3-aminopropyl-N'-oxysulfosuccinimide ester