Insights into cytoplasmatic polyadenylation mediated by Drosophila Dicer-2
Cytoplasmic polyadenylation is a widespread mechanism to control mRNA translation. In vertebrates, this mechanism requires two sequence elements in the 3’ UTR of substrate mRNAs, the U-rich Cytoplasmic Polyadenylation Element (CPE) and the AAUAAA polyadenylation hexanucleotide (HN). In Drosophila ea...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2017 |
| País: | España |
| Institución: | CBUC, CESCA |
| Repositorio: | TDR. Tesis Doctorales en Red |
| OAI Identifier: | oai:www.tdx.cat:10803/664810 |
| Acceso en línea: | http://hdl.handle.net/10803/664810 |
| Access Level: | acceso abierto |
| Palabra clave: | Cytoplasmic polyadenylation Drosophila Dicer-2 RNA binding proteins 3'UTR Translation Poliadenilación citoplasmática Proteínas de unión a ARN Traducción 576 |
| Sumario: | Cytoplasmic polyadenylation is a widespread mechanism to control mRNA translation. In vertebrates, this mechanism requires two sequence elements in the 3’ UTR of substrate mRNAs, the U-rich Cytoplasmic Polyadenylation Element (CPE) and the AAUAAA polyadenylation hexanucleotide (HN). In Drosophila early embryos, the cytoplasmic polyadenylation of Toll mRNA occurs independently of these elements, and requires Dicer-2, a factor previously known for its functions in RNA interference (RNAi), in addition to the poly(A) polymerase Wispy. To understand this novel function of Dicer-2 in cytoplasmic polyadenylation and translation, we aimed to dissect the required cisacting requirements in Toll mRNA, and to identify Dicer-2 protein partners and mRNA targets. We found that multiple signals in the 3’ UTR of Toll cooperate for polyadenylation, and that in early embryos the non-canonical signals dominate, probably due to the presence of inhibitory elements for canonical polyadenylation. Interactome analysis using affinity purification of Dicer-2 and mass spectrometry revealed that Dicer-2 interacts with multiple proteins outside the RNAi pathway. Importantly, proteins involved in poly(A) tailmediated translational regulation and PABP binding were identified, suggesting potential co-factors of Dicer-2 in polyadenylation. Furthermore, RIP-Seq analysis of Dicer-2 revealed enrichment of mRNAs which were previously found downregulated in wispy mutants. These results suggest that the role of Dicer-2 in cytoplasmic viii polyadenylation might be widespread, and provide the basis for future investigation. |
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