The Department of Chemical and Systems Biology Presents Cutting Lecture Series: David Cortez, PhD
David Cortez, Ph.D.
Richard Armstrong Professor for Innovation in Biochemistry
Chair, Department of Biochemistry
Associate Director of Basic Sciences and Co-Leader, Genome Maintenance Program
Vanderbilt-Ingram Cancer Center
Vanderbilt University
Friday, October 28, 2022
12:30 PM – 1:30 PM (Pacific Time)
Munzer Auditorium (In-person)
Talk Title: “The curious case when generating DNA damage and blocking DNA repair protects genome stability”
Abstract: Replication-coupled DNA repair and damage tolerance mechanisms overcome replication challenges to help cells complete DNA synthesis. DNA damage is a common form of replication stress that blocks DNA polymerases. The most frequent of these lesions are abasic sites with thousands forming in every cell each day. While most abasic sites are repaired through base excision repair (BER) in duplex DNA, some will be encountered by the replication machinery. In this context, abasic sites can no longer be repaired by BER. We recently discovered a new mechanism, dependent on the evolutionarily conserved protein HMCES, that recognizes and manages abasic sites present in single-stranded DNA especially during DNA replication. Surprisingly, HMCES generates a DNA-protein crosslink and blocks excision repair. I will describe our current model for how this evolutionarily conserved mechanism preserves genome stability.