Fusion of DNA double-strand break (DSB) proteins to the Cas9 nuclease to enhance gene editing via site-specific HR.

The potential of CRISPR-Cas9 to enhance template-based gene editing at DSBs induced by Cas9 is limited by the fact that such DSBs are predominantly repaired by non-homologous end joining (NHEJ). Thus, in collaboration with Punam Malik’s laboratory at Cincinnati Children's Hospital Medical Center, we fused a dominant-negative form of a key NHEJ protein, 53BP1, to Cas9 to locally inhibit NHEJ and promote HR-mediated DSB repair. Related strategies to further improve this approach are being explored.