EMBO Fellows Meeting 2012

Simon Lebaron
EMBO Fellows Meeting 2012
The translation machinery participates in proof-reading small ribosomal subunit
(40S) maturation
Abstract
Ribosome biogenesis is a complex and essential process in all living cells, leading to production of mature 40S
and 60S subunits. The final steps in maturation of both ribosomal subunits occur in the cytoplasm, where
translation is initiated. We are determining how the translation machinery differentiates translation competent,
mature ribosomal subunits from incompetent pre-ribosomal subunits.
The last step in maturation of the 40S subunit is cleavage of 20S pre-rRNA to 18S rRNA by the PIN-domain
endonuclease Nob1. To study the regulation of this cleavage we developed an in vitro maturation assay on
purified particles. This assay demonstrated that both the translation initiation factor eIF5b and the large subunit
(60S) were involved in establishing cleavage competence. We conclude that final maturation of pre-40S
particles requires interaction with the translation initiation machinery and 60S subunits. These presumably act
as a functional quality control system, avoiding unproductive interactions of pre-40S with the translation
machinery.
Simon Lebaron 1 , Claudia Schneider 1,2 , Robert W. van Nues 2 , Agata Swiatkowska, Sander Granneman, Nicholas J. Watkins 2 ,
David Tollervey 1
1 Wellcome Trust Centre for Cell Biology, The University of Edinburgh, Scotland, UK
2 ICaMB, Newcastle University, Newcastle upon Tyne, UK
14-17 June 2012, Heidelberg, Germany