Lysine acetylation modulates mouse sperm capacitation

Carla Ritagliati, Guillermina M. Luque, Cintia Stival, Carolina Baro Graf, Mariano G. Buffone & Dario Krapf

Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET-UNR, Rosario, 2000, Argentina; Laboratory of Cellular and Molecular Reproductive Biology, Instituto de Biología y Medicina Experimental (IBYME), CONICET, Buenos Aires, C1428ADN, Argentina

Abstract: Mammalian sperm are unable to fertilize the egg immediately after ejaculation. To gain fertilization competence, they need to undergo a series of modifications inside the female reproductive tract, known as capacitation. Capacitation involves several molecular events such as phosphorylation cascades, hyperpolarization of the plasma membrane and intracellular Ca2+ changes, which prepare the sperm to develop two essential features for fertilization competence: hyperactivation and acrosome reaction. Since sperm cells lack new protein biosynthesis, post-translational modification of existing proteins plays a crucial role to obtain full functionality. Here, we show the presence of acetylated proteins in murine sperm, which increase during capacitation. Pharmacological hyperacetylation of lysine residues in non-capacitated sperm induces activation of PKA, hyperpolarization of the sperm plasma membrane, CatSper opening and Ca2+ influx, all capacitation-associated molecular events. Furthermore, hyperacetylation of non-capacitated sperm promotes hyperactivation and prepares the sperm to undergo acrosome reaction. Together, these results indicate that acetylation could be involved in the acquisition of fertilization competence of mammalian sperm.

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https://doi.org/10.1038/s41598-018-31557-5