Laboratory of Genetics and Genomics, National Institute on Aging (NIA) Intramural Research Program (IRP), National Institutes of Health (NIH), Baltimore, MD, USA.
Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan.
Nucleic Acids Res. 2024 Jul 8;52(12):7261-7278. doi: 10.1093/nar/gkae322.
RNA modifications, including N6-methyladenosine (m6A), critically modulate protein expression programs in a range of cellular processes. Although the transcriptomes of cells undergoing senescence are strongly regulated, the landscape and impact of m6A modifications during senescence are poorly understood. Here, we report a robust m6A modification of PTCHD4 mRNA, encoding Patched Domain-Containing Protein 4, in senescent cells. The METTL3/METTL14 complex was found to incorporate the m6A modification on PTCHD4 mRNA; addition of m6A rendered PTCHD4 mRNA more stable and increased PTCHD4 production. MeRIP RT-qPCR and eCLIP analyses were used to map this m6A modification to the last exon of PTCHD4 mRNA. Further investigation identified IGF2BP1, but not other m6A readers, as responsible for the stabilization and increased abundance of m6A-modified PTCHD4 mRNA. Silencing PTCHD4, a transmembrane protein, enhanced growth arrest and DNA damage in pre-senescent cells and sensitized them to senolysis and apoptosis. Our results indicate that m6A modification of PTCHD4 mRNA increases the production of PTCHD4, a protein associated with senescent cell survival, supporting the notion that regulating m6A modification on specific mRNAs could be exploited to eliminate senescent cells for therapeutic benefit.
RNA 修饰,包括 N6-甲基腺苷(m6A),在多种细胞过程中对蛋白质表达程序进行关键调控。尽管衰老细胞的转录组受到强烈调控,但 m6A 修饰在衰老过程中的情况和影响还知之甚少。在这里,我们报告了衰老细胞中 PTCHD4 mRNA(编码 Patched 结构域蛋白 4)上的 m6A 修饰的稳健性。发现 METTL3/METTL14 复合物将 m6A 修饰引入 PTCHD4 mRNA;m6A 的加入使 PTCHD4 mRNA 更加稳定,并增加了 PTCHD4 的产生。MeRIP RT-qPCR 和 eCLIP 分析用于将这种 m6A 修饰映射到 PTCHD4 mRNA 的最后一个外显子上。进一步的研究确定 IGF2BP1,而不是其他 m6A 阅读器,是负责 m6A 修饰的 PTCHD4 mRNA 稳定和丰度增加的原因。沉默跨膜蛋白 PTCHD4 可增强衰老前细胞的生长停滞和 DNA 损伤,并使它们对细胞溶解和细胞凋亡敏感。我们的结果表明,PTCHD4 mRNA 的 m6A 修饰增加了 PTCHD4 的产生,PTCHD4 是与衰老细胞存活相关的一种蛋白,这支持了这样一种观点,即调节特定 mRNA 上的 m6A 修饰可能被用于消除衰老细胞以获得治疗益处。