SLERT regulates DDX21 rings associated with Pol I transcription

• Yu-Hang Xing ^[1] ; Run-Wen Yao ^[1] ; Yang Zhang ^[1]
  1. [1] Chinese Academy of Sciences

     Chinese Academy of Sciences

     China

     
• Localización: Cell, ISSN 0092-8674, Vol. 169, Nº. 4, 2017, págs. 664-678
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • Dysregulated rRNA synthesis by RNA polymerase I (Pol I) is associated with uncontrolled cell proliferation. Here, we report a box H/ACA small nucleolar RNA (snoRNA)-ended long noncoding RNA (lncRNA) that enhances pre-rRNA transcription (SLERT). SLERT requires box H/ACA snoRNAs at both ends for its biogenesis and translocation to the nucleolus. Deletion of SLERT impairs pre-rRNA transcription and rRNA production, leading to decreased tumorigenesis. Mechanistically, SLERT interacts with DEAD-box RNA helicase DDX21 via a 143-nt non-snoRNA sequence. Super-resolution images reveal that DDX21 forms ring-shaped structures surrounding multiple Pol I complexes and suppresses pre-rRNA transcription. Binding by SLERT allosterically alters individual DDX21 molecules, loosens the DDX21 ring, and evicts DDX21 suppression on Pol I transcription. Together, our results reveal an important control of ribosome biogenesis by SLERT lncRNA and its regulatory role in DDX21 ring-shaped arrangements acting on Pol I complexes.