Regulation of the abundance of Y-family polymerases in the cell cycle of budding yeast in response to DNA damage

Abstract

Y-family DNA polymerases mediate DNA damage tolerance via translesion synthesis (TLS). Because of the intrinsically error-prone nature of these enzymes, their activities are regulated at several levels. Here, we demonstrate the common regulation of the cellular abundance of Y-family polymerases, polymerase eta (Pol eta), and Rev1, in response to DNA damage at various stages of the cell cycle. UV radiation influenced polymerase abundance more when cells were exposed in S-phase than in G1-or G2-phases. We noticed two opposing effects of UV radiation in S-phase. On one hand, exposure to increasing doses of UV radiation at the beginning of this phase increasingly delayed S-phase progression. As a result, the accumulation of Pol eta and Rev1, which in nonirradiated yeast is initiated at the S/G2-phase boundary, was gradually shifted into the prolonged S-phase. On the other hand, the extent of polymerase accumulation was inversely proportional to the dose of irradiation, such that the accumulation was significantly lower after exposure to 80 J/m 2 in S-phase than after exposure to 50 J/m 2 or 10 J/m 2 . The limitation of polymerase accumulation in S-phase-arrested cells in response to high UV dose was suppressed upon RAD9 (but not MRC1) deletion. Additionally, hydroxyurea, which activates mainly the Mrc1-dependent checkpoint, did not limit Pol eta or Rev1 accumulation in S-phase-arrested cells. The results show that the accumulation of Y-family TLS polymerases is limited in S-phase-arrested cells due to high levels of DNA damage and suggest a role of the Rad9 checkpoint protein in this process.Keywords Polymerase eta · Rev1 · Y-family polymerases · S-phase checkpoint · DNA damage response · S. cerevisiae Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

A role for the putative error-prone polymeraseREV1in DNA damage and antifungal drug resistance inCandida albicans

“…Here, we find that putative error-prone polymerases are similarly upregulated in C. albicans in response to DNA-damaging conditions. While this phenomenon had not previously been investigated in C. albicans, previous research in S. cerevisiae highlighted the role of REV1 as an essential component of the translesion DNA synthesis pathway, whose expression is induced in the presence of DNA damage 55 . Further, research in S. cerevisiae indicates that the deletion of REV1 results in increased sensitivity to MMS, UV radiation, and oxidative stress 45,56 .…”

Beyond the Lesion: Back to High Fidelity DNA Synthesis

“…In fact, altered expression of the TLS Pols have been linked with increased mutation rates ( Pavlov et al, 2001 ; Qi et al, 2012 ; Sasatani et al, 2017 ), correlated with various cancers ( O-Wang et al, 2001 ; Albertella et al, 2005b ; Flanagan et al, 2007 ; Wang et al, 2010 ), and give rise to chemotherapeutic resistance ( Saha et al, 2021 ). There is evidence that TLS Pols are cell cycle regulated under normal conditions, peaking in G2 phase to facilitate any required TLS prior to cell division ( Waters and Walker, 2006 ; Plachta et al, 2015 ; Sobolewska et al, 2020 ). Even reorganization of Pol δ in eukaryotes from a three to four subunit enzyme ( Zhang et al, 2007 ; Lee et al, 2019 ) or exchanging with Rev3/7 to form Pol ζ ( Rizzo et al, 2018 ) can impact activity.…”