Institute Seminar - Preventing DNA damage during mitosis

The Huis lab studies the molecular machinery that orchestrates chromosome segregation and maintains genome stability during mitosis. We investigate i) how DNA translocases, helicases, and topoisomerases cooperate during mitosis to complete chromosome segregation and ii) how cells deal with DNA lesions in the context of mitotic chromosome organization. To address these questions, we integrate a bottom-up biochemical reconstitution with cell biology, structural biology, and single-molecule biophysics.

How mitotic cells deal with DNA lesions on highly condensed chromosomes remains enigmatic. Since homologous recombination (HR) and non-homologous end-joining (NHEJ) DNA repair pathways are suppressed, repair in mitosis relies on microhomology-mediated end-joining (MMEJ). Mitotic MMEJ critically depends on CIP2A, a protein that is reported to tether DNA fragments. How CIP2A, together with TOPBP1, functions at DNA lesions is not well understood. I will discuss unpublished mechanistic insight into CIP2A’s ability to guide MMEJ during mitosis.