Translational regulation is an important mechanism for regulating gene expression. Regulation of specific transcripts is often mediated by elements present in the 3′ untranslated region (UTR) of the mRNA. In the Drosophila embryo, translational repression of nanos mRNA is mediated by Smaug protein bound to specific sequences present in the 3′ UTR of the mRNA. Here I show that Smaug recruits Cup protein to the mRNA and that Cup in turn binds to the translation initiation factor eIF4E that is present at the 5′. The interaction between Cup and eIF4E prevents formation of a productive translation initiation complex on the mRNA. Therefore, Smaug-dependent translational repression functions at the initiation step via the indirect interaction of Smaug with eIF4E, which is mediated by Cup. In the second example of translational regulation presented here, I show that an element present in the 3′ untranslated region of the Hsp83 mRNA mediates translational enhancement in the Drosophila embryo. I have identified three proteins, Hrp48, DDP1 and PABP that interact with this element and have demonstrated that Hrp48 and DDP1 function in translational enhancement.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OTU.1807/16718 |
| Date | 19 January 2009 |
| Creators | Nelson, Meryl |
| Contributors | Smibert, Craig |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
| Format | 1761406 bytes, application/pdf |
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