Nucleolar proteome analysis and proteasomal activity assays reveal a link between nucleolus and 26S proteasome in A. thaliana

  • In all eukaryotic cells, the nucleolus is functionally and structurally linked to rRNA synthesis and ribosome biogenesis. This compartment contains as well factors involved in other cellular activities, but the functional interconnection between non-ribosomal activities and the nucleolus (structure and function) still remains an open question. Here, we report a novel mass spectrometry analysis of isolated nucleoli from Arabidopsis thaliana plants using the FANoS (Fluorescence Assisted Nucleolus Sorting) strategy. We identified many ribosome biogenesis factors (RBF) and proteins non-related with ribosome biogenesis, in agreement with the recognized multi-functionality of the nucleolus. Interestingly, we found that 26S proteasome subunits localize in the nucleolus and demonstrated that proteasome activity and nucleolus organization are intimately linked to each other. Proteasome subunits form discrete foci in the disorganized nucleolus of nuc1.2 plants. Nuc1.2 protein extracts display reduced proteasome activity in vitro compared to WT protein extracts. Remarkably, proteasome activity in nuc1.2 is similar to proteasome activity in WT plants treated with proteasome inhibitors (MG132 or ALLN). Finally, we show that MG132 treatment induces disruption of nucleolar structures in WT but not in nuc1.2 plants. Altogether, our data suggest a functional interconnection between nucleolus structure and proteasome activity.

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Author:Charlotte Montacié, Nathalie Durut, Alison Opsomer, Denise Palm, Pascale Comella, Claire Picart, Marie-Christine Carpentier, Frederic Pontvianne, Christine Carapito, Enrico SchleiffORCiDGND, Julio Sáez-Vásquez
Pubmed Id:
Parent Title (English):Frontiers in plant science
Publisher:Frontiers Media
Place of publication:Lausanne
Contributor(s):Munetaka Sugiyama
Document Type:Article
Year of Completion:2017
Date of first Publication:2017/10/20
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2019/10/23
Tag:Arabidopsis; FANoS; nucleolin; nucleolus; proteasome
Issue:Art. 1815
Page Number:13
First Page:1
Last Page:13
Copyright: © 2017 Montacié, Durut, Opsomer, Palm, Comella, Picart, Carpentier, Pontvianne, Carapito, Schleiff and Sáez-Vásquez. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
Institutes:Biowissenschaften / Biowissenschaften
Exzellenzcluster / Exzellenzcluster Makromolekulare Komplexe
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 58 Pflanzen (Botanik) / 580 Pflanzen (Botanik)
Licence (German):License LogoCreative Commons - Namensnennung 4.0