Cell Reports (Feb 2024)

The ARID1A-METTL3-m6A axis ensures effective RNase H1-mediated resolution of R-loops and genome stability

  • Jun Zhang,
  • Feng Chen,
  • Ming Tang,
  • Wenchao Xu,
  • Yuan Tian,
  • Zhichao Liu,
  • Yuxin Shu,
  • Hui Yang,
  • Qian Zhu,
  • Xiaopeng Lu,
  • Bin Peng,
  • Xiangyu Liu,
  • Xingzhi Xu,
  • Monika Gullerova,
  • Wei-Guo Zhu

Journal volume & issue
Vol. 43, no. 2
p. 113779

Abstract

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Summary: R-loops are three-stranded structures that can pose threats to genome stability. RNase H1 precisely recognizes R-loops to drive their resolution within the genome, but the underlying mechanism is unclear. Here, we report that ARID1A recognizes R-loops with high affinity in an ATM-dependent manner. ARID1A recruits METTL3 and METTL14 to the R-loop, leading to the m6A methylation of R-loop RNA. This m6A modification facilitates the recruitment of RNase H1 to the R-loop, driving its resolution and promoting DNA end resection at DSBs, thereby ensuring genome stability. Depletion of ARID1A, METTL3, or METTL14 leads to R-loop accumulation and reduced cell survival upon exposure to cytotoxic agents. Therefore, ARID1A, METTL3, and METTL14 function in a coordinated, temporal order at DSB sites to recruit RNase H1 and to ensure efficient R-loop resolution. Given the association of high ARID1A levels with resistance to genotoxic therapies in patients, these findings open avenues for exploring potential therapeutic strategies for cancers with ARID1A abnormalities.

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