miRNA-Mediated Gene Silencing by Translational Repression Followed by mRNA Deadenylation and Decay

• Published in: Science (American Association for the Advancement of Science) Vol. 336; no. 6078; pp. 237 - 240
• Main Authors: Djuranovic, Sergej, Nahvi, Ali, Green, Rachel
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 13.04.2012; The American Association for the Advancement of Science
• Subjects: 3' Untranslated Regions; Animals; Binding sites; Biological and medical sciences; Cell Line; Decay; Drosophila; Drosophila melanogaster - genetics; Drosophila melanogaster - metabolism; Drosophila Proteins - genetics; Elongation; Fundamental and applied biological sciences. Psychology; Gene expression; Gene Silencing; Inductive reasoning; Kinetics; Messenger RNA; MicroRNA; MicroRNAs - genetics; MicroRNAs - metabolism; Molecular and cellular biology; Molecular genetics; Peptide Chain Elongation, Translational; Peptide Chain Initiation, Translational; Protein Biosynthesis; Protein synthesis; Proteins; Repression; Ribonucleic acid; RNA; RNA Stability; RNA, Messenger - genetics; RNA, Messenger - metabolism; Stall; Transcription. Transcription factor. Splicing. Rna processing; Translation; translation (genetics); Gene silencing; RNA interference; Arthropoda; Insecta; Invertebrata; Drosophila melanogaster; Diptera; Mechanism; Drosophilidae
• ISSN: 0036-8075; 1095-9203; 1095-9203
• DOI: 10.1126/science.1215691

microRNAs (miRNAs) regulate gene expression through translational repression and/or messenger RNA (mRNA) deadenylation and decay. Because translation, deadenylation, and decay are closely linked processes, it is important to establish their ordering and thus to define the molecular mechanism of silencing. We have investigated the kinetics of these events in miRNA-mediated gene silencing by using a Drosophila S2 cell-based controllable expression system and show that mRNAs with both natural and engineered 3' untranslated regions with miRNA target sites are first subject to translational inhibition, followed by effects on deadenylation and decay. We next used a natural translational elongation stall to show that miRNA-mediated silencing inhibits translation at an early step, potentially translation initiation.