Boar sperm AKAP4 is tyrosine-phosphorylated by Sperm Binding Glycoprotein

TEIJEIRO, J. M.; CANE, F; MARINI, P. E

Cordoba, Argentina

Simposio; The First South American Spring Symposium in Signal Transduction and Molecular Medicine.; 2010

During their journey in the female tract, sperm come into contact with epithelial cells that line the organs. Such interaction allows the selection of sperm with certain qualities. The pig oviductal glycoprotein Sperm Binding Glycoprotein (SBG) produces in vitro, acrosome alteration and the tyrosine-phosphorylation of a 97 kDa sperm protein (p97). The aim of this work was to identify this tyrosine-phosphorylated protein and gain some insight about its possible phosphorylation pathway. The outcome of LC-MS/MS analysis indicated that p97 contains peptides also present in canine AKAP4. A pig EST containing the same sequences was used for fusion protein expression. Antibodies generated against this protein were used for its immunolocalization on sperm and testicular tissue. The involvement of cAMP/PKA and PKC signalizing pathways was studied using dbcAMP, IBMX and phorbol 12-myristate 13 acetate, correspondingly. Our results indicate that AKAP4 is phosphorylated during boar sperm-SBG interaction and that the PKC signalizing pathway may be involved in this tyrosine-phosphorylation.