Mol. Cell https://doi.org/10.1016/j.molcel.2019.08.014 (2019)
The most abundant RNA components in cells are ribosomal (r)RNA, which are transcribed and processed within the nucleolus. However, the rapid processing of pre-rRNAs makes it challenging to study the underlying mechanisms. Using multiple high-resolution optical imaging approaches, Yao et al. found that pre-rRNA processing factors, including FBL, formed clusters in dense fibrillar components (DFC) surrounding the active rDNA and Pol I complex localized at the border of fibrillar centers of nucleoli. FBL underwent phase separation via self-association of its GAR domain and guided nascent 47S pre-rRNA into DFC through interaction with the 5′ terminus of pre-rRNA. The length of intrinsically disordered regions (IDRs) in GAR domains is correlated to its self-association ability and is associated with pre-rRNA processing. Interruption of the interaction between FBL and pre-rRNA impairs the formation of FBL clusters. Replacement of the GAR domain with different IDRs rescued FBL-knockout-induced abnormality in pre-rRNA sorting and processing. This study reveals the roles of IDRs in sub-organelle organization and deepens our understanding of connections between spatial organization and biological function.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Song, Y. Disorder guides order. Nat Chem Biol 15, 1029 (2019). https://doi.org/10.1038/s41589-019-0398-z
Published:
Issue Date:
DOI: https://doi.org/10.1038/s41589-019-0398-z