Alex Rojas

Alexander Rojas, a junior chemistry and biology major at Emory University, evolved a small reverse transcriptase for improved activity in the prime editing system.

Prime editing (PE) is a versatile genome editing technology capable of precisely installing small insertions, deletions, and all point mutations into the genome of living cells. BSRP 2022 has been one of the most valuable experiences in my academic career so far. When BSRP first began, I doubted my capabilities as a researcher, but the BSRP staff and cohort quickly taught me that I belonged here. Seeing everyone in my cohort excel in the Broad’s intense environment motivated me to work hard and do the same. I had never been more curious and ambitious in my life, and thanks to BSRP, I am equipped with the tools necessary to explore this curiosity and ambition. I am so grateful to now have such a large network of established and rising scientists. BSRP really fosters a family, and everyone in my cohort holds a special place in my heart.PE systems contain the prime editor protein, a fusion of a programmable DNA nickase and a reverse transcriptase (RT). The large size of the canonical prime editor protein can pose challenges for the in vivo delivery of prime editors using adeno-associated viruses (AAVs), an FDA-approved class of gene delivery vehicles. In this project, we reduce the size of PEs by replacing the canonical Moloney Murine Leukemia Virus (M-MLV) RT with two smaller alternatives. To improve the activity of the smaller PE systems, we use phage assisted continuous evolution (PACE) and phage assisted non-continuous evolution (PANCE), directed evolution platforms developed by the Liu Group to enhance protein of interest activity. Finally, we will assess editing efficiencies of our evolved variants in bacterial and mammalian cells.

Project: Optimizing the prime editing system using directed evolution

Mentor: Smriti Pandey, Liu Group