TY - JOUR
T1 - The ATPase Irc20 facilitates Rad51 chromatin enrichment during homologous recombination in yeast Saccharomyces cerevisiae
AU - Jalal, Deena
AU - Chalissery, Jisha
AU - Iqbal, Mehwish
AU - Hassan, Ahmed H.
N1 - Funding Information:
This work was supported by funding from United Arab Emirates University-UPAR ; and Terry Fox Foundation [to A.H.H].
Publisher Copyright:
© 2020
PY - 2021/1
Y1 - 2021/1
N2 - DNA double-strand breaks (DSBs) constitute one of the most cytotoxic forms of DNA damage and pose a significant threat to cell viability, survival, and homeostasis. DSBs have the potential to promote aneuploidy, cell death and potentially deleterious mutations that promote tumorigenesis. Homologous recombination (HR) is one of the main DSB repair pathways and while being essential for cell survival under genotoxic stress, it requires proper regulation to avoid chromosome rearrangements. Here, we characterize the Saccharomyces cerevisiae E3 ubiquitin ligase/putative helicase Irc20 as a regulator of HR. Using purified Irc20, we show that it can hydrolyze ATP in the presence and absence of DNA, but does not increase access to DNA within a nucleosome. In addition, we show that both the ATPase and ubiquitin ligase activities of Irc20 are required for suppressing the spontaneous formation of recombination foci. Finally, we demonstrate a role for Irc20 in promoting Rad51 chromatin association and the removal of Rad52 recombinase from chromatin, thus facilitating subsequent HR steps and directing recombination to more error-free modes.
AB - DNA double-strand breaks (DSBs) constitute one of the most cytotoxic forms of DNA damage and pose a significant threat to cell viability, survival, and homeostasis. DSBs have the potential to promote aneuploidy, cell death and potentially deleterious mutations that promote tumorigenesis. Homologous recombination (HR) is one of the main DSB repair pathways and while being essential for cell survival under genotoxic stress, it requires proper regulation to avoid chromosome rearrangements. Here, we characterize the Saccharomyces cerevisiae E3 ubiquitin ligase/putative helicase Irc20 as a regulator of HR. Using purified Irc20, we show that it can hydrolyze ATP in the presence and absence of DNA, but does not increase access to DNA within a nucleosome. In addition, we show that both the ATPase and ubiquitin ligase activities of Irc20 are required for suppressing the spontaneous formation of recombination foci. Finally, we demonstrate a role for Irc20 in promoting Rad51 chromatin association and the removal of Rad52 recombinase from chromatin, thus facilitating subsequent HR steps and directing recombination to more error-free modes.
KW - DNA repair
KW - Homologous recombination
KW - Irc20
KW - SUMO
KW - Ubiquitin ligase
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U2 - 10.1016/j.dnarep.2020.103019
DO - 10.1016/j.dnarep.2020.103019
M3 - Article
C2 - 33202365
AN - SCOPUS:85096148364
SN - 1568-7864
VL - 97
JO - DNA Repair
JF - DNA Repair
M1 - 103019
ER -