Fig. 1: An overview of N6-methyladenosine (m6A) and m6A-associated enzymes.
From: Biological roles of the RNA m6A modification and its implications in cancer
A m6A methyltransferase complex is composed of core m6A writer components (METTL3, METTL14, and WTAP) and regulatory proteins (VIRMA, RBM15/RBM15B, HAKAI, and ZC3H13). The m6A writer adds a methyl group to the N6-position of adenosine within the consensus sequence ([G > A](m6A)C[A/C/U]) of an RNA transcript (mRNA, lncRNA, and so on). Another methyltransferase comprising METTL16, METTL5 and ZCCHC4 specifically methylates snRNA, rRNA and a few noncoding RNAs. WTAP is an adapter in the regulation of the nuclear localization and activity of methyltransferase with regulatory proteins. The m6A erasers are ALKBH5 and FTO. ALKBH5 is a primary m6A demethylase that removes the methyl group from N6 adenosine from target mRNAs. FTO demethylates both internal m6A and N6,2′-O-dimethyladenosine in the 5′ cap (m6Am). This image was created with BioRender (https://biorender.com/).
