N^(6)-methyladenosine(m^(6)A)in RNA within R-loops plays pivotal roles in transcription regulation and genome stability.However,the precise impacts and distinct mechanisms of m^(6)A on both regulatory and aberrant R-l...N^(6)-methyladenosine(m^(6)A)in RNA within R-loops plays pivotal roles in transcription regulation and genome stability.However,the precise impacts and distinct mechanisms of m^(6)A on both regulatory and aberrant R-loops remain poorly understood.Here,we reveal that METTL3,the nuclear m^(6)A writer,ensures genome integrity by differentially modulating R-loops in a position-and length-dependent manner.In mouse embryonic stem cells(m ESCs),Mettl3 depletion results in impaired cell proliferation and increased cell death due to excessive DNA damage.Notably,Mettl3 knockout reduces the overall abundance of R-loops,with a decrease in broad R-loops and an increase in sharp Rloops.R-loops are diminished near transcription end sites(TESs),leading to transcriptional readthrough of genes with m^(6)A-modified transcripts and potentially contributing to genome instability.Conversely,increased sharp R-loops located in the antisense orientation relative to gene transcription are associated with DNA damage hotspots.These findings unveil a dual regulatory mechanism in which METTL3-m^(6)A orchestrates transcription fidelity and genome stability through distinct R-loop-dependent manners.展开更多
基金supported by the National Key Research and Development Program of China(2024YFA1802100)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB0570101)+5 种基金the National Natural Science Foundation of China(32370644,32121001)the National Key Research and Development Program of China(2024YFC3405901,2020YFA0803401)the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(ZDBS-LYSM013)Beijing Natural Science Foundation(L244023)Next-Generation Bioinformatics Algorithms(XDA0460302)CAS Youth Interdisciplinary Team。
文摘N^(6)-methyladenosine(m^(6)A)in RNA within R-loops plays pivotal roles in transcription regulation and genome stability.However,the precise impacts and distinct mechanisms of m^(6)A on both regulatory and aberrant R-loops remain poorly understood.Here,we reveal that METTL3,the nuclear m^(6)A writer,ensures genome integrity by differentially modulating R-loops in a position-and length-dependent manner.In mouse embryonic stem cells(m ESCs),Mettl3 depletion results in impaired cell proliferation and increased cell death due to excessive DNA damage.Notably,Mettl3 knockout reduces the overall abundance of R-loops,with a decrease in broad R-loops and an increase in sharp Rloops.R-loops are diminished near transcription end sites(TESs),leading to transcriptional readthrough of genes with m^(6)A-modified transcripts and potentially contributing to genome instability.Conversely,increased sharp R-loops located in the antisense orientation relative to gene transcription are associated with DNA damage hotspots.These findings unveil a dual regulatory mechanism in which METTL3-m^(6)A orchestrates transcription fidelity and genome stability through distinct R-loop-dependent manners.
