Investigating roles of nonhomologous end-joining and recombination genes in repair of site-specific DNA double-strand breaks in Saccharomyces cerevisiae
Date
2024-04
Authors
Mahmood, Anika
Lewis, L. Kevin
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Abstract
The DNA in eukaryotic cells such as human and yeast cells are constantly subjected to endogenous and exogenous sources of damage through exposure to radiation and mutagenic chemicals. Among these lesions, double-strand breaks (DSBs) are one of the most lethal damages which have two DNA repair pathways dedicated to them known as the nonhomologous end-joining (NHEJ) and homologous recombination (HDR) pathways. Unlike the highly accurate HR system, the error prone NHEJ pathway in yeast cells does not require a template strand for repair and uses three major protein machineries. These are the Yku complex which binds and protects the DSB ends and recruits Mrx that tethers the DSB ends together. Mrx then recruits the Dnl4 complex, which ligates the ends together. The most commonly used assay for NHEJ repair involves transfer of circular plasmids containing a single site-specific DSB into yeast cells. NHEJ mutants (yku-, mrx- , or dnl4- yeast strains) show reduced efficiency of repair. The goals of this research project were to: (1) Investigate the role of the Mrx protein complex in the steps of the NHEJ pathway and (2) develop new assays to measure repair of DSBs by both HR and NHEJ simultaneously.
Description
Keywords
NHEJ, HR, Saccharomyces cerevisiae, DNA repair pathway, double-stranded breaks, DNA damage
Citation
Mahmood, A., & Lewis, L. K. (2024). Investigating roles of nonhomologous end-joining and recombination genes in repair of site-specific DNA double-strand breaks in Saccharomyces cerevisiae. Poster presented at the Graduate Student Research Conference, San Marcos, Texas.