The association of late-acting snoRNPs with human pre-ribosomal complexes requires the RNA helicase DDX21

Abstract

Translation fidelity and efficiency require multiple ribosomal (r)RNA modifications that are mostly mediated by small nucleolar (sno)RNPs during ribosome production. Overlapping basepairing of snoRNAs with pre-rRNAs often necessitates sequential and efficient association and dissociation of the snoRNPs, however, how such hierarchy is established has remained unknown so far. Here, we identify several late-acting snoRNAs that bind pre-40S particles in human cells and show that their association and function in pre-40S complexes is regulated by the RNA helicase DDX21. We map DDX21 crosslinking sites on pre-rRNAs and show their overlap with the basepairing sites of the affected snoRNAs. While DDX21 activity is required for recruitment of the late-acting snoRNAs SNORD56 and SNORD68, earlier snoRNAs are not affected by DDX21 depletion. Together, these observations provide an understanding of the timing and ordered hierarchy of snoRNP action in pre-40S maturation and reveal a novel mode of regulation of snoRNP function by an RNA helicase in human cells. mehr

Mehr zum Titel

Titel	The association of late-acting snoRNPs with human pre-ribosomal complexes requires the RNA helicase DDX21
Medien	Nucleic Acids Research
Heft	1
Band	43
ISSN	1362-4962
Verfasser	Katherine Sloan, Matthias Leisegang, Carmen Doebele, Ana Ramírez, Prof. Dr. Stefan Simm, Charlotta Safferthal, Jens Kretschmer, Tobias Schorge, Stavroula Markoutsa, Sara Haag, Michael Karas, Ingo Ebersberger, Enrico Schleiff, Nicholas Watkins, Markus Bohnsack
Seiten	553–564
Veröffentlichungsdatum	1.2015
Zitation	Sloan, Katherine; Leisegang, Matthias; Doebele, Carmen; Ramírez, Ana; Simm, Stefan; Safferthal, Charlotta; Kretschmer, Jens; Schorge, Tobias; Markoutsa, Stavroula; Haag, Sara; Karas, Michael; Ebersberger, Ingo; Schleiff, Enrico; Watkins, Nicholas; Bohnsack, Markus (2015): The association of late-acting snoRNPs with human pre-ribosomal complexes requires the RNA helicase DDX21. Nucleic Acids Research 43 (1), 553–564. DOI: 10.1093/nar/gku1291