Poster Presentation 44th Lorne Genome Conference 2023

SSSavi: A modular dCas9-based recruitment platform for combinatorial epigenome editing (#251)

Tessa Swain 1 2 , Christian Pflueger 1 2 , Saskia Freytag 3 , Daniel Poppe 1 2 , Jahnvi Pflueger 4 , Trung Nguyen 1 2 , Ji (Kevin) Li 5 , Ryan Lister 1 2
  1. The University of Western Australia, Crawley, WA, Australia
  2. Epigenetics and Genomics, The Harry Perkins Institute of Medical Research, Nedlands, WA, Australia
  3. The Brain Cancer Centre, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
  4. PYC Therapeutics, Nedlands, Western Australia, Australia
  5. Harry Perkins Institute of Medical Research, Nedlands, WA, Australia

Targeted epigenome editing tools allow precise manipulation and investigation of genome modifications, however they often display high context dependency and variable efficacy between target genes and cell types. While systems that simultaneously recruit multiple distinct ‘effector’ chromatin regulators can improve efficacy, they generally lack control over effector composition and spatial organisation. To overcome this we have created a modular combinatorial epigenome editing platform, called SSSavi. This system is an interchangeable and reconfigurable docking platform fused to dCas9 that enables simultaneous recruitment of up to four different effectors, allowing precise control of effector composition and spatial ordering. We demonstrate the activity and specificity of the SSSavi system and compare it to existing multi-effector targeting systems, demonstrating its efficacy. Furthermore, we demonstrate the importance of the effector recruitment order for effective transcriptional regulation. Together, this enables exploration of combinatorial effector co-recruitment to enhance manipulation of chromatin contexts previously resistant to targeted editing.