title: Three distinct ribosome assemblies modulated by translation are the building blocks of polysomes.
abstract: Translation is increasingly recognized as a central control layer of gene expression in eukaryotic cells. The overall organization of mRNA and ribosomes within polysomes, as well as the possible role of this organization in translation are poorly understood. Here we show that polysomes are primarily formed by three distinct classes of ribosome assemblies. We observe that these assemblies can be connected by naked RNA regions of the transcript. We show that the relative proportions of the three classes of ribosome assemblies reflect, and probably dictate, the level of translational activity. These results reveal the existence of recurrent supra-ribosomal building blocks forming polysomes and suggest the presence of unexplored translational controls embedded in the polysome structure.
authors.affiliation: Institute of Biophysics, National Research Council (CNR) Unit at Trento, 38123 Povo, Italy Laboratory of Translational Genomics, Centre for Integrative Biology, University of Trento, 38123 Mattarello, Italy gabriella.viero@cnr.it alessandro.quattrone@unit.it.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Viero
authors.affiliation: Laboratory of Biomolecular Sequence and Structure Analysis for Health, Fondazione Bruno Kessler, 38123 Povo, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Lunelli
authors.affiliation: Department of Information Engineering and Computer Science, University of Trento, 38123 Povo, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Passerini
authors.affiliation: Nanophysics Department, Italian Institute of Technology, 16163 Genova, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Bianchini
authors.affiliation: Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, England, UK.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Gilbert
authors.affiliation: Institute of Biophysics, National Research Council (CNR) Unit at Trento, 38123 Povo, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Bernabò
authors.affiliation: Laboratory of Translational Genomics, Centre for Integrative Biology, University of Trento, 38123 Mattarello, Italy.
authors.forename: Toma
authors.initials: T
authors.lastname: Tebaldi
authors.affiliation: Nanophysics Department, Italian Institute of Technology, 16163 Genova, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Diaspro
authors.affiliation: Laboratory of Biomolecular Sequence and Structure Analysis for Health, Fondazione Bruno Kessler, 38123 Povo, Italy.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Pederzolli
authors.affiliation: Laboratory of Translational Genomics, Centre for Integrative Biology, University of Trento, 38123 Mattarello, Italy gabriella.viero@cnr.it alessandro.quattrone@unit.it.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Quattrone
mesh_terms: D045744:Cell Line, Tumor; D006801:Humans; D011132:Polyribosomes / Q000378:metabolism*; D014176:Protein Biosynthesis / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger