Linear ubiquitin fusion to Rps31 and its subsequent cleavage are required for the efficient production and functional integrity of 40S ribosomal subunits

Article Article scientifique Article Linear ubiquitin fusion to Rps31 and its subsequent cleavage are required for the efficient production and functional integrity of 40S ribosomal subunits eng 2009 author Lacombe Thierry 507989 author Garcia-Gomez Juan J. author de la Cruz J. author Roser D. author Hurt E. author Linder Patrick 61214 author Kressler Dieter 99763 69-84 10.1111/j.1365-2958.2009.06622.x 19210616 0950-382X http://onlinelibrary.wiley.com/store/10.1111/j.1365-2958.2009.06622.x/asset/j.1365-2958.2009.06622.x.pdf?v=1&t=gzs4lbut&s=a48cbd1dc943880763ef12f38b2dfc16f17c569b The post-translational modifier ubiquitin is generated exclusively by proteolytic cleavage of precursor proteins. In Saccharomyces cerevisiae, cleavage of the linear precursor proteins releases ubiquitin and the C-terminally fused ribosomal proteins Rpl40 (Ubi1/2 precursor) and Rps31 (Ubi3 precursor), which are part of mature 60S and 40S ribosomal subunits respectively. In this study, we analysed the effects of ubi3 mutations that interfere with cleavage of the ubiquitin-Rps31 fusion protein. Strikingly, the lethal ubi3+P77 mutation, which abolished cleavage almost completely, led to a rapid G1 cell cycle arrest upon genetic depletion of wild-type UBI3. Under these conditions, the otherwise unstable Ubi3+P77 protein was efficiently assembled into translation-competent 40S ribosomal subunits. In contrast to the cleavage-affecting mutations, deletion of the ubiquitin moiety from UBI3 led to a decrease in 40S ribosomal subunits and to the incorporation of the 20S pre-rRNA into polyribosomes. Altogether, our findings provide additional evidence that the initial presence of the ubiquitin moiety of Ubi3 contributes to the efficient production of 40S ribosomal subunits and they suggest that ubiquitin release is a prerequisite for their functional integrity. Cell Cycle Mutation Polyribosomes/metabolism RNA Precursors/genetics/metabolism RNA Processing, Post-Transcriptional Ribosome Subunits, Small, Eukaryotic/genetics/*metabolism Saccharomyces cerevisiae/cytology/genetics/*metabolism Saccharomyces cerevisiae Proteins/genetics/*metabolism Ubiquitin/*metabolism Dewey 616 54 Département de microbiologie et médecine moléculaire 21B false 63 Acquisition et expression de facteurs de virulence chez Staphylococcus aureus 86 Molecular microbiology 72 1 78e02d48-809e-4504-b422-881d94f210d4 Article Restricted file1.pdf 591769 application/pdf restrictedAccess Faculté de médecine / Section de médecine fondamentale / Département de microbiologie et médecine moléculaire

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Linear ubiquitin fusion to Rps31 and its subsequent cleavage are required for the efficient production and functional integrity of 40S ribosomal subunits	Molecular microbiology			2009	585	0

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