Seminar: Hanah Margalit

The multiple facets of post-transcriptional regulation by non-coding RNAs

2017-06-22: by Hanah Margalit, The Hebrew University of Jerusalem. The seminar will take place June 22, 15.00-16.00 at University of Copenhagen, SUND/SCIENCE, Building 1-04, Grønnegårdsvej 7, 1st floor library, Frederiksberg C.

Abstract:
Post-transcriptional regulation of gene expression by small non-coding RNAs has established itself as a major regulation layer in the cell. Bacterial small RNAs (sRNAs) are 50-400 nucleotide-long RNA molecules, which act as post-transcriptional regulators of gene expression by base-pairing with their target mRNAs, often when both the sRNA and target mRNA are bound to the RNA chaperon protein Hfq. Deciphering the sRNA-target interactome is an essential step towards understanding the roles of sRNAs in the cellular networks. To this end, we developed a methodology termed RIL-seq (RNA Interaction by Ligation and sequencing), which integrates experimental and computational tools for in-vivo transcriptome-wide identification of sRNA-target pairs. By applying this methodology to Escherichia coli we discovered an extensive network of interactions involving RNA pairs showing sequence complementarity. We expand the ensemble of targets for known sRNAs, discover putative novel sRNAs encoded in 3'UTR, 5'UTR, CDS, intergenic-regions and antisense of genes along with their trans targets, and reveal also sRNA-sRNA interactions. The novel sRNAs and novel interactions we revealed have led to the discovery of new structures of efficient regulatory circuits, determined by a sRNA and a protein encoded in the same transcript.  The sRNA-sRNA interactions we discovered seem to play a role in re-wiring of the post-transcriptional regulatory network upon change in growth conditions.


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