microRNAs (miRNAs) are small, noncoding RNAs that may regulate more than half of human genes, yet the molecular mechanism of miRNA-mediated repression remains obscure. Using a cell-free assay of miRNA activity, we show that miRNA-targeted mRNAs are enriched for components of the 40S, but not 60S ribosomal subunit. Additionally, a molecular toeprint of 18 nucleotides 3' relative to the start codon, consistent with nucleotide protection by 40S ribosomal subunits, is enriched on miRNA-targeted mRNAs. Our results suggest that miRNAs repress translation initiation in a cell-free system by preventing 60S ribosomal subunit joining to 40S subunits positioned at the start codon.
| Identifer | oai:union.ndltd.org:harvard.edu/oai:dash.harvard.edu:1/12274340 |
| Date | 04 June 2015 |
| Creators | Yanez, Adrienne Gail |
| Contributors | Novina, Carl D, Buratowski, Stephen |
| Publisher | Harvard University |
| Source Sets | Harvard University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis or Dissertation |
| Rights | open |
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