show Abstracthide Abstractm6A is catalyzed by the activity of Mettl3, which depends on additional proteins whose precise functions remain poorly understood. Here we identified Zc3h13 as a novel interactor of m6A methyltransferase complex components in mouse. Like other components of this complex, Zc3h13 controls m6A levels. Overall design: We performed m6A-RIP-seq on oligo-dT selected mRNA from wild type, Mettl3-/-, and Zc3h13-/- mESCs. Similar to Mettl3 KO cells, ablation of Zc3h13 resulted in a drastic reduction of m6A enrichment, particularly at the 3' end of target mRNAs