ABSTRACT

Hypoxia causes a series of responses supporting cells to survive in harsh environments. Substantial post-transcriptional and translational regulation during hypoxia has been observed. However, detailed regulatory mechanism in response to hypoxia is still far from complete. RNA m⁶A modification has been proven to govern the life cycle of RNAs. Here, we reported that total m⁶A level of mRNAs was decreased during hypoxia, which might be mediated by the induction of m⁶A eraser, ALKBH5. Meanwhile, expression levels of most YTH family members of m⁶A readers were systematically down-regulated. Transcriptome-wide analysis of m⁶A revealed a drastic reprogramming of m⁶A epitranscriptome during cellular hypoxia. Integration of m⁶A epitranscriptome with either RNA-seq based transcriptome analysis or mass spectrometry (LC-MS/MS) based proteome analysis of cells upon hypoxic stress revealed that reprogramming of m⁶A epitranscriptome reshaped the transcriptome and proteome, thereby supporting efficient generation of energy for adaption to hypoxia. Moreover, ATP production was blocked when silencing an m⁶A eraser, ALKBH5, under hypoxic condition, demonstrating that m⁶A pathway is an important regulator during hypoxic response. Collectively, our studies indicate that crosstalk between m⁶A and HIF1 pathway is essential for cellular response to hypoxia, providing insights into the underlying molecular mechanisms during hypoxia.

摘要

缺氧会导致一系列反应，支持细胞在恶劣的环境中生存。已观察到缺氧期间的大量转录后和翻译调节。然而，响应缺氧的详细调控机制还远未完成。RNA m ⁶一种修饰已被​​证明可以控制 RNA 的生命周期。在这里，我们报告了缺氧期间 mRNA 的总 m ⁶ A 水平降低，这可能是由 m ⁶ A 橡皮擦 ALKBH5的诱导介导的。同时，m ⁶ A 阅读器的大多数 YTH 家族成员的表达水平被系统地下调。的米全转录物分析⁶甲揭示的米急剧重编程⁶细胞缺氧期间的表观转录组。m ⁶ A 表观转录组与基于 RNA-seq 的转录组分析或基于质谱(LC-MS/MS) 的细胞蛋白质组分析的整合表明，m ⁶ A 表观转录组的重编程重塑了转录组和蛋白质组，从而支持高效生成适应缺氧的能量。此外，当在缺氧条件下使 m ⁶ A 橡皮擦 ALKBH5沉默时，ATP 产生被阻断，这表明 m ⁶ A 通路是缺氧反应过程中的重要调节剂。总的来说，我们的研究表明 m ⁶A 和 HIF1 通路对于细胞对缺氧的反应至关重要，提供了对缺氧期间潜在分子机制的见解。