SIRENseek · Exploring silencer functions via their associated chromatin factors

Distal regulatory elements in the genome play a key role in orchestrating tissue- and context- specific transcriptional programs. While activating elements (enhancers) have been broadly studied in the last decades, repressive elements (silencers) remain a ‘mysterious’ class of regulatory regions of the genome, whose characteristics have never been systematically elucidated. In the ""seeking the SIlencer-associated REpressive protein Network” (SIRENseek) project, I aim to identify and functionally characterize silencers and silencer-binding proteins (SBPs) to gain insight into their mechanism of action and ultimately unlock their untapped potential for gene regulation and targeted therapy. To this aim, I will combine state-of-the-art proteomic analyses and high-throughput epigenomic profiling to identify SBPs and assess their relevance in shaping the chromatin landscape. First, I will focus on a repressive transcription factor known to bind silencers and I will use novel proximity labeling technologies to isolate its interacting proteins, thus unveiling other chromatin factors involved in silencer functions. Then, I will interrogate multiple candidate SBPs via a CRISPR screening and test their ability to rewire the chromatin landscape via ATAC-seq. Finally, by integrating this information with epigenomic data, I will identify SBPs with a functional role at silencers and test their ability to establish long-range chromatin interactions via 3D genomic approaches. Together, this interdisciplinary proposal will allow me to map for the first time silencer elements, their associated chromatin factors and the potential 3D interactions that they mediate to repress target genes, thus addressing the existing gap in our understanding of repressive elements.""