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Porcine Aurora A accelerates Cyclin B and Mos synthesis and promotes meiotic resumption of porcine oocytes.

Porcine Aurora A accelerates Cyclin B and Mos synthesis and promotes meiotic resumption of porcine oocytes.

Authors :
Nishimura Y
Endo T
Kano K
Naito K
Source :
Animal reproduction science [Anim Reprod Sci] 2009 Jul; Vol. 113 (1-4), pp. 114-24. Date of Electronic Publication: 2008 Jul 09.
Publication Year :
2009

Abstract

Full-grown oocytes arrested at germinal vesicle stage contain many dormant maternal mRNAs, and Aurora A has been reported to play a key role for the translation of these maternal mRNAs in Xenopus oocytes. Although the presence of Aurora A has been reported in mammals, the functions of Aurora A on the protein synthesis and the meiotic resumption have never been elucidated in mammalian oocytes. In the present study, the effects of porcine Aurora A on meiotic resumption of porcine oocytes were examined. At first, we cloned porcine Aurora A from total RNA of immature porcine oocytes by RT-PCR and obtained full-length cDNA that was 77%, 86% and 54% homologous with mouse, human and Xenopus Aurora A, respectively. The Aurora A mRNA and large amounts of protein were present throughout maturation period in porcine oocytes. The overexpression of porcine Aurora A by the mRNA injection into immature porcine oocytes had no effects on Cyclin B synthesis and meiotic resumption. Therefore we constructed a mutated Aurora A (AA-Aurora A), which was replaced the expecting inhibitory phosphorylation sites, serines 283 and 284, to non-phosphorylatable alanines. The oocytes expressed AA-Aurora A were accelerated their Cyclin B synthesis and Rsk phosphorylation, an indicator of Mos synthesis, then their meiotic resumption was promoted significantly. These results suggest for the first time in mammalian oocytes that mammalian Aurora A stimulates the protein synthesis and promotes the meiotic resumption. In addition, we identified the inhibitory phosphorylation sites of porcine Aurora A, and indicate the presence of phosphorylation-dependent regulation mechanisms in mammalian Aurora A.

Details

Language :
English
ISSN :
1873-2232
Volume :
113
Issue :
1-4
Database :
MEDLINE
Journal :
Animal reproduction science
Publication Type :
Academic Journal
Accession number :
18614302
Full Text :
https://doi.org/10.1016/j.anireprosci.2008.05.074