Germline NPM1 mutations lead to altered rRNA 2'-O-methylation and cause dyskeratosis congenita (HITS-CLIP)

We identify nucleophosmin (NPM1) as an essential regulator of 2'-O-methylation on rRNA by directly binding C/D box small nucleolar RNAs (snoRNAs), thereby modulating translation. We demonstrate the importance of 2'-O-Me regulated translation for cellular growth, differentiation and hematopoietic stem cells (HSC) maintenance, and show that Npm1-inactivation in adult HSCs results in bone marrow failure (BMF). We identify NPM1 germline mutations in DC patients presenting with BMF; and demonstrate that they are deficient in snoRNA binding. CRISPR knock-in mice harboring the DC germline NPM1 mutation recapitulate both hematological and non-hematological features of DC. Thus, our findings provide a direct demonstration of the role of 2'-O-Me in the pathogenesis of human disease Overall design: HITS-CLIP analysis to determine that RNA molecules bound by NPM1 was perform using Trp53-/- and Trp53-/-;Npm1-/- mouse embryonic cells.