André Verdel
Host institution: INSERM
Laboratory: IAB (INSERM/UJF/CNRS/CHU)
Call for projects: Starting (LS2)
Project Name: RNAIEPIMOD – RNA and epigenetics: RNAi-induced chromatin modifications
Amount: € 0.9 M
Description :
RNA interference (RNAi) mediates chromatin changes in fungi, plants, Drosophila, and spawns.
In the fission yeast Schizosaccharomyces pombe, where the molecular mechanisms are most detailed, small interfering RNAs (siRNAs) are thought to guide the RITS (RNA-Induced Transcriptional Silencing) complex to specific regions of chromatin to designate the formation of heterochromatin.
Although it is clear that siRNAs are required for the localization of RITS to chromatin, the important events in the siRNA-dependent recruitment of RITS remain to be elucidated.
Furthermore, critical aspects of the mechanism of heterochromatin formation following RITS need to be clarified.
Genetic data indicate that among the proteins necessary for heterochromatin assembly, some are involved very early in this process to the point that they could interact directly or with RITS.
However, no physical link between RITS and these enzymes has yet been found.
This project proposes to address these fundamental aspects of heterochromatin assembly by RNAi in S. pombe, by coupling interdisciplinary and innovative approaches to classical protein affinity purifications, yeast molecular genetics and techniques of chromatin.
The first part of the project focuses on the characterization of a novel physical connection between RITS and chromatin modification activity.
In parallel, we propose to develop two complementary approaches to identify new proteins that physically and/or genetically interact with RITS.
Finally, using a UV light-induced crosslinking technology, we intend to study the recruitment of RITS to chromatin by analyzing its direct interaction with nucleic acids both in vitro and in vivo.
As RNAi’s control of chromatin structure is conserved through evolution, our studies have the potential to provide general insights into how chromatin changes on RNAi occur. and are regulated in the eukaryotic kingdom.