Functional Human Sperm Capacitation Requires both Bicarbonate DependentPKA Activation and Downregulation of Ser/Thr Phosphatases by Src Family Kinases

BATTISTONE MA; DA ROS VG; SALICIONI AM; NAVARRETE F; KRAPF D; VISCONTI PE; CUASNICÚ PS

Holdeness

Seminario; Fertilization & Activation of Development Gordon Research Seminar (GRS).; 2013

Sperm capacitation correlates with an increase in protein tyrosine (Tyr) phosphorylation mediated by cAMP/PKA activation. In addition, recent studies in mice suggested that the Src tyrosine kinase family (SFK) is involved in Tyr phosphorylation through the inactivation of Ser/Thr phosphatases. In view of these observations and with the aim of getting a better understanding of the signaling pathways involved in human sperm capacitation, in the present work we investigated both the cAMP/PKA and SFK/phosphatase pathways in relation to the capacitation state of the cells. Analysis of the cAMP/PKA pathway revealed a very early bicarbonate-dependent activation of PKA indicated by the rapid (1 min) increase in both PKA substrate phosphorylation and cAMP levels (p