title: Extensive translation of small Open Reading Frames revealed by Poly-Ribo-Seq.
abstract: Thousands of small Open Reading Frames (smORFs) with the potential to encode small peptides of fewer than 100 amino acids exist in our genomes. However, the number of smORFs actually translated, and their molecular and functional roles are still unclear. In this study, we present a genome-wide assessment of smORF translation by ribosomal profiling of polysomal fractions in Drosophila. We detect two types of smORFs bound by multiple ribosomes and thus undergoing productive translation. The 'longer' smORFs of around 80 amino acids resemble canonical proteins in translational metrics and conservation, and display a propensity to contain transmembrane motifs. The 'dwarf' smORFs are in general shorter (around 20 amino-acid long), are mostly found in 5'-UTRs and non-coding RNAs, are less well conserved, and have no bioinformatic indicators of peptide function. Our findings indicate that thousands of smORFs are translated in metazoan genomes, reinforcing the idea that smORFs are an abundant and fundamental genome component.
authors.affiliation: School of Life Sciences, University of Sussex, Brighton, United Kingdom.
authors.forename: Julie L
authors.initials: JL
authors.lastname: Aspden
authors.affiliation: School of Life Sciences, University of Sussex, Brighton, United Kingdom.
authors.forename: Ying Chen
authors.initials: YC
authors.lastname: Eyre-Walker
authors.affiliation: School of Life Sciences, University of Sussex, Brighton, United Kingdom.
authors.forename: Rose J
authors.initials: RJ
authors.lastname: Phillips
authors.affiliation: School of Life Sciences, University of Sussex, Brighton, United Kingdom.
authors.forename: Unum
authors.initials: U
authors.lastname: Amin
authors.affiliation: School of Life Sciences, University of Sussex, Brighton, United Kingdom.
authors.forename: Muhammad Ali S
authors.initials: MA
authors.lastname: Mumtaz
authors.affiliation: School of Life Sciences, University of Sussex, Brighton, United Kingdom.
authors.forename: Michele
authors.initials: M
authors.lastname: Brocard
authors.affiliation: School of Life Sciences, University of Sussex, Brighton, United Kingdom.
authors.forename: Juan-Pablo
authors.initials: JP
authors.lastname: Couso
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D000818:Animals; D002460:Cell Line; D019295:Computational Biology / Q000379:methods; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics*; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics*; D016678:Genome / Q000235:genetics; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods*; D008970:Molecular Weight; D016366:Open Reading Frames / Q000235:genetics*; D010455:Peptides / Q000737:chemistry / Q000235:genetics; D011132:Polyribosomes / Q000235:genetics / Q000378:metabolism; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D022661:RNA, Untranslated / Q000235:genetics; D015203:Reproducibility of Results; D012270:Ribosomes / Q000235:genetics / Q000378:metabolism
chemical_list: D020413:3' Untranslated Regions; D029721:Drosophila Proteins; D010455:Peptides; D012333:RNA, Messenger; D022661:RNA, Untranslated
keywords: biochemistry; d. melanogaster; evolutionary biology; genomics; non-coding RNAs; small open reading Frames; transmembrane peptides