The binding of mRNAs to ribosomes is mediated by the protein complex eIF4F in conjunction with eIF4B (eukaryotic initiation factor 4F and 4B). EIF4F is a three subunit complex consisting of eIF4A (RNA helicase), eIF4E (mRNA cap binding protein), and eIF4G (bridging protein). The crucial role is played by eIF4E, which directly binds the 5'-cap structure of the mRNA and facilitates the recruitment to the mRNA of other translation factors and the 40S ribosomal subunit. EIF4E binding to mRNA and to other initiation factors is regulated on several levels, including its phosphorylation on Ser-209, and association with its regulatory protein 4E-binding protein (4E-BP1). In this study we document that both the translation initiation factor eIF4E and its regulator 4E-BP1 become dephosphorylated in the early stage porcine zygotes already 8 hr post-activation. Similarly, the activities of ERK1/2 MAP and Mnk1 kinases, which are both involved in eIF4E phosphorylation, gradually decrease during this period with the timing similar to that of eIF4E dephosphorylation. The formation of an active eIF4F complex is also diminished after 9-15 hr post-activation, although substantial amounts of this complex have been detected also 24 hr post-activation (2-cell stage). The overall protein synthesis in the parthenotes decreases gradually from 12 hr post-activation reaching a minimum after 48 hr (4-cell stage). Although the translation is gradually decreasing during early preimplantation development, the eIF4F complex, which is temporarily formed, might be a premise for the translation of a small subset of mRNAs at this period of development.

• MeSH
• časové faktory MeSH
• embryo savčí cytologie   metabolismus   MeSH
• eukaryotické iniciační faktory metabolismus   MeSH
• eukaryotický iniciační faktor 4F metabolismus   MeSH
• kultivované buňky MeSH
• mitogenem aktivovaná proteinkinasa 1 metabolismus   MeSH
• mitogenem aktivovaná proteinkinasa 3 metabolismus   MeSH
• partenogeneze fyziologie   MeSH
• prasata MeSH
• proteosyntéza fyziologie   MeSH
• ribozomy metabolismus   MeSH
• RNA čepičky metabolismus   MeSH
• transportní proteiny metabolismus   MeSH
• zvířata MeSH
• zygota cytologie   metabolismus   MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• eIF-4B MeSH Prohlížeč
• eukaryotické iniciační faktory MeSH
• eukaryotický iniciační faktor 4F MeSH
• mitogenem aktivovaná proteinkinasa 1 MeSH
• mitogenem aktivovaná proteinkinasa 3 MeSH
• RNA čepičky MeSH
• transportní proteiny MeSH