title: Murine binder of sperm protein homolog 1: a new player in HDL-induced capacitation.
abstract: Binder of sperm (BSP) proteins are ubiquitous among mammals and are exclusively expressed in male genital tract. The main function associated with BSP proteins is their ability to promote sperm capacitation. In mice, two proteins (BSP protein homolog 1 (BSPH1) and BSPH2) have been studied. Using recombinant strategies, BSPH1 was found to bind to epididymal sperm membranes and promote sperm capacitation in vitro. The goal of this study was to evaluate the role of native murine BSPH1 protein in sperm capacitation induced by BSA and HDLs. The effect of antibodies, antigen-binding fragments (Fabs), and F(ab')2 specific for murine BSPH1 on BSA- and HDL-induced capacitation was tested. Results indicate that BSPH1 has no direct role in BSA-induced capacitation. However, antibodies, Fabs, and F(ab')(2) could block capacitation induced by HDLs and could inhibit the HDL-induced increase in tyrosine phosphorylation, suggesting a specific interaction between HDLs and BSPH1. Results indicate that murine BSPH1 proteins in mice could be a new important piece of the puzzle in sperm capacitation induced by HDLs. As murine BSPH1 is orthologous to human BSPH1, this study could also lead to new insights into the functions and the importance of the human protein in male fertility.
authors.affiliation: Maisonneuve-Rosemont Hospital Research Centre5415 L'Assomption Boulevard, Montreal, Quebec, Canada H1T 2M4Departments of Biochemistry and MedicineFaculty of Medicine, University of Montreal, C.P. 6128, Montreal, Quebec, Canada H3C 3J7 Maisonneuve-Rosemont Hospital Research Centre5415 L'Assomption Boulevard, Montreal, Quebec, Canada H1T 2M4Departments of Biochemistry and MedicineFaculty of Medicine, University of Montreal, C.P. 6128, Montreal, Quebec, Canada H3C 3J7.
authors.forename: Geneviève
authors.initials: G
authors.lastname: Plante
authors.affiliation: Maisonneuve-Rosemont Hospital Research Centre5415 L'Assomption Boulevard, Montreal, Quebec, Canada H1T 2M4Departments of Biochemistry and MedicineFaculty of Medicine, University of Montreal, C.P. 6128, Montreal, Quebec, Canada H3C 3J7 Maisonneuve-Rosemont Hospital Research Centre5415 L'Assomption Boulevard, Montreal, Quebec, Canada H1T 2M4Departments of Biochemistry and MedicineFaculty of Medicine, University of Montreal, C.P. 6128, Montreal, Quebec, Canada H3C 3J7 puttaswamy.manjunath@umontreal.ca.
authors.forename: Puttaswamy
authors.initials: P
authors.lastname: Manjunath
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D015153:Blotting, Western; D006801:Humans; D008075:Lipoproteins, HDL / Q000494:pharmacology*; D008297:Male; D051379:Mice; D010766:Phosphorylation; D029607:Seminal Vesicle Secretory Proteins / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D013075:Sperm Capacitation / Q000187:drug effects* / Q000502:physiology*; D014443:Tyrosine / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; C519892:Bsph1 protein, mouse; C519891:Bsph2 protein, mouse; D008075:Lipoproteins, HDL; D029607:Seminal Vesicle Secretory Proteins; D012710:Serum Albumin, Bovine; D014443:Tyrosine