N⁶-methyladenosine (m⁶A) is the most abundant mRNA modification and is installed by the METTL3-METTL14-WTAP methyltransferase complex. Although the importance of m⁶A methylation in mRNA metabolism has been well documented recently, regulation of the m⁶A machinery remains obscure. Through a genome-wide CRISPR screen, we identify the ERK pathway and USP5 as positive regulators of the m⁶A deposition. We find that ERK phosphorylates METTL3 at S43/S50/S525 and WTAP at S306/S341, followed by deubiquitination by USP5, resulting in stabilization of the m⁶A methyltransferase complex. Lack of METTL3/WTAP phosphorylation reduces decay of m⁶A-labeled pluripotent factor transcripts and traps mouse embryonic stem cells in the pluripotent state. The same phosphorylation can also be found in ERK-activated human cancer cells and contribute to tumorigenesis. Our study reveals an unrecognized function of ERK in regulating m⁶A methylation.

N ⁶ -甲基腺苷 (m ⁶ A) 是最丰富的 mRNA 修饰，由 METTL3-METTL14-WTAP 甲基转移酶复合物安装。尽管 m ⁶ A 甲基化在 mRNA 代谢中的重要性最近已得到充分证明，但 m ⁶ A 机制的调节仍然模糊不清。通过全基因组 CRISPR 筛选，我们将 ERK 通路和 USP5 鉴定为 m ⁶ A 沉积的正调节因子。我们发现 ERK 在 S43/S50/S525 磷酸化 METTL3，在 S306/S341 磷酸化 WTAP，然后通过 USP5 去泛素化，从而稳定 m ⁶ A 甲基转移酶复合物。缺乏 METTL3/WTAP 磷酸化减少了 m ^{6 的}衰变A 标记的多能因子转录并捕获处于多能状态的小鼠胚胎干细胞。在 ERK 激活的人类癌细胞中也可以发现相同的磷酸化，并有助于肿瘤发生。我们的研究揭示了 ERK 在调节 m ⁶ A 甲基化方面的未被认识的功能。