Figure 1.

Scheme of m⁶A modifications. The writers, erasers, and readers of N6-methyladenosine (m⁶A). The m⁶A writer complex, which comprises the core methyltransferase-like protein 3 (METTL3) and its adaptors, is located in the nucleus. m⁶A demethylation is executed by two demethylases FTO and ALKBH5. The m⁶A erasers also are localized in the nucleus. In the nucleus, m⁶A can bind specific nuclear reader proteins such as YTHDC1 and HNRNPA2/B1, which may affect RNA splicing and mRNA export. Upon mRNA being exported to the cytoplasm, m⁶A binds to specific reader proteins, which affects stability, translation and/or localization of mRNAs. In the cytoplasm, translation of m⁶A modified mRNAs is mediated by the m⁶A readers YTHDF1, YTHDF3, and YTHDC2, the eukaryotic translation initiation factor eIF3, and METTL3. YTHDF2 and YTHDF3 regulate degradation of m⁶A modified mRNAs, while the insulin-like growth factor 2 mRNA-binding proteins (IGF2BPs) enhances stability m⁶A modified mRNAs.