title: Ribosome profiling shows that miR-430 reduces translation before causing mRNA decay in zebrafish.
abstract: MicroRNAs regulate gene expression through deadenylation, repression, and messenger RNA (mRNA) decay. However, the contribution of each mechanism in non-steady-state situations remains unclear. We monitored the impact of miR-430 on ribosome occupancy of endogenous mRNAs in wild-type and dicer mutant zebrafish embryos and found that miR-430 reduces the number of ribosomes on target mRNAs before causing mRNA decay. Translational repression occurs before complete deadenylation, and disrupting deadenylation with use of an internal polyadenylate tail did not block target repression. Lastly, we observed that ribosome density along the length of the message remains constant, suggesting that translational repression occurs by reducing the rate of initiation rather than affecting elongation or causing ribosomal drop-off. These results show that miR-430 regulates translation initiation before inducing mRNA decay during zebrafish development.
authors.affiliation: Department of Genetics, Yale University School of Medicine, New Haven, CT 06510, USA.
authors.forename: Ariel A
authors.initials: AA
authors.lastname: Bazzini
authors.forename: Miler T
authors.initials: MT
authors.lastname: Lee
authors.forename: Antonio J
authors.initials: AJ
authors.lastname: Giraldez
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D004625:Embryo, Nonmammalian / Q000378:metabolism; D047108:Embryonic Development; D018507:Gene Expression Regulation, Developmental; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D010442:Peptide Chain Initiation, Translational; D011061:Poly A / Q000378:metabolism; D014176:Protein Biosynthesis; D020871:RNA Stability; D012333:RNA, Messenger / Q000378:metabolism*; D043244:Ribonuclease III / Q000235:genetics; D012270:Ribosomes / Q000378:metabolism*; D015027:Zebrafish / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D029961:Zebrafish Proteins / Q000096:biosynthesis / Q000235:genetics
chemical_list: D020413:3' Untranslated Regions; D035683:MicroRNAs; C557527:Mirn430 microRNA, zebrafish; D012333:RNA, Messenger; D029961:Zebrafish Proteins; D011061:Poly A; D043244:Ribonuclease III