Ythdf2 regulates cardiac remodeling through its m6A-mRNA target transcripts

m 6 A mRNA methylation controls cardiomyocyte function and increased overall m 6 A levels are a stereotyping finding in heart failure independent of the underlying etiology. However, it is largely unknown how the information is read by m 6 A reader proteins in heart failure. Here we show that the m 6 A reader protein Ythdf2 controls cardiac function and identified a novel mechanism how reader proteins control gene expression and cardiac function. Deletion of Ythdf2 in cardiomyocytes in vivo leads to cardiac hypertrophy, reduced heart function, and increased fibrosis during pressure overload as well as during aging. Similarly, in vitro the knockdown of Ythdf2 results in cardiomyocyte growth and remodeling. Mechanistically, we identified the eucaryotic elongation factor 2 as a major target of Ythdf2 using cell type specific Ribo-seq data. Our study expands our understanding on the regulatory functions of m 6 A methylation in cardiomyocytes and how cardiac function is controlled by the m 6 A reader protein Ythdf2.