PARTICIPATION OF TIROSINE KINASE SRC FAMILY IN RAT SPERM CAPACITATION

BATTISTONE MA,; MALDERA JA; WEIGEL MUÑOZ M; KRAPF D; VISCONTI P; CUASNICU PS

Buenos Aires

Jornada; XII Jornadas Multidisciplinarias de la Sociedad Argentina de Biología (SAB); 2010

Sociedad Argentina de Biología (SAB)

11.PARTICIPATION OF TIROSINE KINASE SRC FAMILY INRAT SPERM CAPACITATIONBattistone MA, Maldera JA, Weigel Muñoz M, Krapf D, Visconti P,Cuasnicu PS.IBYME-CONICET, Argentina. E-mail: battistone@dna.uba.arSperm capacitation relies on an increase in protein tyrosine phosphorylationmediated by PKA activation. Recent studies have suggestedthat Src tyrosine kinase family (SKF) is involved either director indirectly in capacitation-associated protein tyrosine phosphorylation.In order to elucidate between these two possibilities,we investigated whether SFK is involved in the signaling eventsleading to rat sperm capacitation. Results showed that sperm capacitatedin the presence of a SFK inhibitor (SU6656), exhibitedlow levels of both tyrosine and PKA- substrates phosphorylation.Based on the described inhibition of ser/thr phosphatases by SFK,sperm were exposed to a Ser/Thr phosphatases inhibitor (okadaicacid, OA) observing a reversion of the impaired-phosphorylationproduced by SU6656. However, OA was unable to induce tyrosinephosphorylation in both uncapacitated sperm and sperm capacitatedin the presence of a PKA inhibitor. Finally, addition of both acAMP agonist and a phosphodiesterase inhibitor did not overcomethe inhibition produced by SU6656. Altogether, these results showthe indirect involvement of SFK in rat sperm tyrosine phosphorylationsupporting the existence of two parallel pathways leading tocapacitation: one requiring PKA activation, and the other involvingthe inactivation of ser/thr phosphatases.