Department of Chemistry, Department of Biochemistry and Molecular Biology, and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA.
Howard Hughes Medical Institute, Chicago, IL, USA.
Nat Cell Biol. 2023 Sep;25(9):1359-1368. doi: 10.1038/s41556-023-01213-w. Epub 2023 Aug 28.
N-methyladenosine (mA) methylation can be deposited on chromatin-associated RNAs (caRNAs) by the RNA methyltransferase complex (MTC) to regulate chromatin state and transcription. However, the mechanism by which MTC is recruited to distinct genomic loci remains elusive. Here we identify RBFOX2, a well-studied RNA-binding protein, as a chromatin factor that preferentially recognizes mA on caRNAs. RBFOX2 can recruit RBM15, an MTC component, to facilitate methylation of promoter-associated RNAs. RBM15 also physically interacts with YTHDC1 and recruits polycomb repressive complex 2 (PRC2) to the RBFOX2-bound loci for chromatin silencing and transcription suppression. Furthermore, we found that this RBFOX2/mA/RBM15/YTHDC1/PRC2 axis plays a critical role in myeloid leukaemia. Downregulation of RBFOX2 notably inhibits survival/proliferation of acute myeloid leukaemia cells and promotes their myeloid differentiation. RBFOX2 is also required for self-renewal of leukaemia stem/initiation cells and acute myeloid leukaemia maintenance. Our study presents a pathway of mA MTC recruitment and mA deposition on caRNAs, resulting in locus-selective chromatin regulation, which has potential therapeutic implications in leukaemia.
N6-甲基腺苷(m6A)甲基化可通过 RNA 甲基转移酶复合物(MTC)沉积在与染色质相关的 RNA(caRNA)上,从而调节染色质状态和转录。然而,MTC 被募集到不同基因组位置的机制仍不清楚。在这里,我们鉴定了 RBFOX2,一种研究充分的 RNA 结合蛋白,作为一种染色质因子,它优先识别 caRNA 上的 m6A。RBFOX2 可以募集 MTC 成分 RBM15,以促进启动子相关 RNA 的甲基化。RBM15 还与 YTHDC1 相互作用,并募集多梳抑制复合物 2(PRC2)到 RBFOX2 结合的基因座,以进行染色质沉默和转录抑制。此外,我们发现 RBFOX2/m6A/RBM15/YTHDC1/PRC2 轴在髓性白血病中起着关键作用。RBFOX2 的下调显著抑制急性髓系白血病细胞的存活/增殖,并促进其髓系分化。RBFOX2 也是白血病干细胞自我更新和急性髓系白血病维持所必需的。我们的研究提出了 m6A MTC 募集和 caRNA 上 m6A 沉积的途径,导致基因座选择性染色质调控,这在白血病的治疗中有潜在的意义。