Danielle Sawyer

Danielle Sawyer

MD-PhD Student

Research Advisor:

Joann Sweasy, PhD

Research Topic:

My research focuses on DNA Polymerase beta (Pol B) which is a polymerase that lacks inherent proofreading capacity and plays a major role in the short-patch base excision repair pathway. Base excision repair is responsible for the removal of 20,000-50,000 DNA base lesions per cell per day, and when dysfunctional it can lead to genomic instability and cellular transformation. My work studies variants of Pol B, using kinetic studies as well as cellular approaches in order to further understand how polymerases without proofreading capacity are able to select the correct nucleotide from a pool of similarly structured dNTPs and how variants affect DNA repair capacity in vivo.

Selected Publications:

Monroy, B.Y., Sawyer, D.L., Ackermann, B.E. et al. Competition between microtubule-associated proteins directs motor transport. Nature Communications 9, 1487 (2018) doi:10.1038/s41467-018-03909-2

Sawyer, D.L., Gratreak, B.D. Medical schools must do more to open the door to first generation and low income students. BMJ (2022); 377 :o1246 doi:10.1136/bmj.o1246

Sawyer, D.L., Sweasy, J.B. DNA Polymerase Beta in the Context of Cancer. Critical Reviews in Oncogenesis (2022); https://doi.org/10.1615/CritRevOncog.2022043477

Robbins, C. E., Patel, B., Sawyer, D. L., Wilkinson, B., Kennedy, B. K., &; McCormick, M. A.  Cytosolic and mitochondrial trna synthetase inhibitors increase lifespan in a GCN4/ATF-4-dependent manner. IScience (2022). https://doi.org/10.1016/j.isci.2022.105410

Selected Awards/Honors:

Outstanding Senior Award, UC Davis 2017 

ARCS Scholar, University of Arizona 2022-2023 

Selected Presentations:

Sawyer, D.L. and Sweasy, J.B. “DNA Polymerase β Variants in the Context of Cancer Development.” The ARCS Foundation Award Student Poster Session 2022, Tucson, AZ; April 2022.

Sawyer, D.L., Sweasy, J.B. “Biochemical Characterization of DNA Polymerase β Variants to Understand Fidelity and Cancer Drivers”. University of Arizona College of Medicine Research Day, Tucson, AZ; May 2022.


  • B.S. in Cellular Biology from University of California, Davis: 2017
  • A.S. Biology from Santa Rosa Junior College: 2015
  • A.S. Natural Sciences from Santa Rosa Junior College: 2015