Sperm surface protein AQ1 spermadhesin and ubiquitin-proteasome pathway in porcine anti-polyspermy defense

0380390 - BTÚ 2013 RIV DK eng A - Abstrakt
Jonáková, Věra - Postlerová, Pavla - Young-Joo, Y. - Sutovsky, P. - Pěknicová, Jana
Sperm surface protein AQ1 spermadhesin and ubiquitin-proteasome pathway in porcine anti-polyspermy defense.
American Journal of Reproductive Immunology. Roč. 67, Issue Supplement s1 (2012), s. 8-9. ISSN 1046-7408. E-ISSN 1600-0897.
[13th International Symposium for Immunology of reproduction "From the roots to the tops of Reproductive Immunology". 22.06.2012-24.06.2012, Varna]
Grant CEP: GA ČR(CZ) GA523/09/1793; GA ČR(CZ) GAP503/12/1834
Výzkumný záměr: CEZ:AV0Z50520701
Klíčová slova: spermadhesin * ubiquitin * proteasome
Kód oboru RIV: CE - Biochemie

Problem. One of the boar seminal plasma proteins called AQN1 spermadhesin binds to the sperm plasma membrane at ejaculation. This protein has been implicated in sperm binding to zona pellucid of the ovum as well as in sperm interactions with the epithelium of the oviductal sperm reservoir. The 26S proteasome is a multi-subunit protease specific to ubiquitinated substrate proteins. It is composed of a 20S proteasomal core with substrate degradation activity, and a 19S regulatory complex that acts in substrate recognition, deubiquitination, priming and transport to the 20S core. A high proteasome degradation activity and a high deubiquitinating activity were detected in the acrosome of boar spermatozoa. This study examined the role of two components of the 19S proteasome regulatory complex with deubiquitinating activity, ubiquitin C-terminal hydrolase UCHL3 and PSMD8, in the AQN1 spermadhesin-mediated boar sperm binding to zona pellucida. Results. We found that the activity and turnover of the porcine AQN1 sperm plasma membrane protein (and thus the efficiency of the sperm-ovum recognition process) may be controlled by elements of the sperm surface-bound ubiquitin-proteasome pathway, in particular by UCHL3, and by subunit PSMD8 of the 19S proteasomal regulatory complex. Ubiquitinated isoforms of AQN1 were detected in boar sperm extracts. The UCH inhibitor ubiquitin aldehyde and the antibodies against UCHL3 or PSMD8 increased the rate of sperm-ZP penetration and polyspermy during porcine in vitro fertilization. In contrast, the addition of recombinant UCHL3 into fertilization medium reduced polyspermy rates while maintaining a satisfactory monospermic fertilization rate of approx. 50%. Conclusion. These results are of practical significance. They suggest that reduction of the unfavorably high level of polyspermy (~50%), currently observed during porcine IVF for commercial embryo transfer, might be achieved e.g. by the modulation of the UCHL and/or PSMD8 activity.
Trvalý link: http://hdl.handle.net/11104/0217284