Characterization of Bufo arenarum oocyte plasma membrane proteins that interact with sperm.
Sperm-oocyte plasma membrane interaction is an essential step in fertilization. In amphibians, the molecules involved have not been identified. Our aim was to detect and characterize oocyte molecules with binding affinity for sperm. We isolated plasma membranes free from vitelline envelope and yolk proteins from surface-biotinylated Bufo arenarum oocytes. Using binding assays we detected a biotinylated 100 kDa plasma membrane protein that consistently bound to sperm. Chromatographic studies confirmed the 100 kDa protein and detected two additional oocyte molecules of 30 and 70 kDa with affinity for sperm. Competition studies with an integrin-interacting peptide and cross-reaction with an anti-HSP70 antibody suggested that the 100 and 70 kDa proteins are members of the integrin family and HSP70, respectively. MS/MS analysis suggested extra candidates for a role in this step of fertilization. In conclusion, we provide evidence for the involvement of several proteins, including integrins and HSP70, in B. arenarum sperm-oocyte plasma membrane interactions.
División de Biología del Desarrollo, Instituto de Biología Molecular y Celular de Rosario, CONICET-UNR, Departamento de Ciencias Biológicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Argentina.
Gabriela
G
Coux
Marcelo O
MO
Cabada
D000818:Animals; D002022:Bufo arenarum / Q000378:metabolism*; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000032:analysis* / Q000378:metabolism; D016023:Integrins / Q000032:analysis* / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000032:analysis* / Q000378:metabolism; D009865:Oocytes / Q000737:chemistry* / Q000378:metabolism; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000378:metabolism
D018840:HSP70 Heat-Shock Proteins; D016023:Integrins; D008565:Membrane Proteins