Identification of YTH Domain-Containing Proteins as the Readers for N1-Methyladenosine in RNA

Nl-methyladenosine (m(1)A) is an important post-transcriptional modification in RNA; however, the exact biological role of m(1)A remains to be determined. By employing a quantitative proteomics method, we identified multiple putative protein readers of m(1)A in RNA, including several YTH domain family proteins. We showed that YTHDF1-3 and YTHDC1, but not YTHDC2, could bind directly to m(1)A in RNA. We also found that Trp(432) in YTHDF2, a conserved residue in the hydrophobic pocket of the YTH domain that is necessary for its binding to N-6-methyladenosine (m(6)A), is required for its recognition of m(1)A. An analysis of previously published data revealed transcriptome-wide colocalization of YTH domain-containing proteins and m(1)A sites in HeLa cells, suggesting that YTH domain-containing proteins can bind to m(1)A in cells. Together, our results uncovered YTH domain-containing proteins as readers for m(1)A in RNA and provided new insight into the functions of m(1)A in RNA biology.