Mechanism of translational regulation by miR-2 from sites in the 5¢ untranslated region or the open reading frame. Rna

European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany.
RNA (Impact Factor: 4.94). 10/2010; 16(12):2493-502. DOI: 10.1261/rna.2384610
Source: PubMed


MicroRNAs (miRs) commonly regulate translation from target mRNA 3' untranslated regions (UTRs). While effective miR-binding sites have also been identified in 5' untranslated regions (UTRs) or open reading frames (ORFs), the mechanism(s) of miR-mediated regulation from these sites has not been defined. Here, we systematically investigate how the position of miR-binding sites influences translational regulation and characterize their mechanistic basis. We show that specific translational regulation is elicited in vitro and in vivo not only from the 3'UTR, but equally effectively from six Drosophila miR-2-binding sites in the 5'UTR or the ORF. In all cases, miR-2 triggers mRNA deadenylation and inhibits translation initiation in a cap-dependent fashion. In contrast, single or dual miR-2-binding sites in the 5'UTR or the ORF yield rather inefficient or no regulation. This work represents the first demonstration that 5'UTR and ORF miR-binding sites can function mechanistically similarly to the intensively investigated 3'UTR sites. Using single or dual binding sites, it also reveals a biological rationale for the high prevalence of miR regulatory sites in the 3'UTR.

Download full-text


Available from: Francesca Moretti, Jan 24, 2014
23 Reads
  • Source
    • "The mechanism by which a miRNA can diminish protein expression is unclear, but several proposals are there from different experimental evidences. miRNAs can interfere with translation process at the stage of initiation (Figure 2) or elongation (Figure 3), or target mRNA may be affected by isolating it from ribosomal machinery [8] [9] [10]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The production of different types of blood cells including their formation, development, and differentiation is collectively known as haematopoiesis. Blood cells are divided into three lineages erythriod (erythrocytes), lymphoid (B and T cells), and myeloid (granulocytes, megakaryocytes, and macrophages). Haematopoiesis is a complex process regulated by several mechanisms including microRNAs (miRNAs). miRNAs are small RNAs which regulate the expression of a number of genes involved in commitment and differentiation of hematopoietic stem cells. Evidence shows that miRNAs play an important role in haematopoiesis; for example, myeloid and erythroid differentiation is blocked by the overexpression of miR-15a. miR-221, miR-222, and miR-24 inhibit the erythropoiesis, whereas miR-150 plays a role in B and T cell differentiation. miR-146 and miR-10a are downregulated in megakaryopoiesis. Aberrant expression of miRNAs was observed in hematological malignancies including chronic myelogenous leukemia, chronic lymphocytic leukemia, multiple myelomas, and B cell lymphomas. In this review we have focused on discussing the role of miRNA in haematopoiesis.
    Advances in Hematology 12/2013; 2013(8):695754. DOI:10.1155/2013/695754
  • Source
    • "In animals, miRNAs are phylogenetically conserved and primarily inhibit transcript translation by binding in the 3′ untranslated region (UTR) sequences of targeted gene transcripts (Bartel, 2004; Lee et al., 1993; Wightman et al., 1993). However, there is growing evidence that miRNAs also posttranscriptionally regulate gene expression through complementary binding in the 5′ UTRs (Lee et al., 2009; Lytle et al., 2007; Moretti et al., 2010) and coding regions (Tay et al., 2008; Zhou et al., 2009). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Testicular toxicity is an important safety endpoint in drug development and risk assessment, but reliable and translatable biomarkers for predicting injury have eluded researchers. However, this area shows great potential for improvement, with several avenues currently being pursued. This was the topic of a symposium session during the 2013 Society of Toxicology Annual Meeting in San Antonio, TX, entitled (")Translatable Indicators of Testicular Toxicity: Inhibin B, microRNAs, and Sperm Signatures.(") This symposium brought together stakeholders from academia, government, and industry to present the limitations and drawbacks of currently used indicators of injury, and discussed the ongoing efforts in developing more predictive biomarkers of injury. The presentations highlighted the early challenges of using circulating inhibin B and microRNA levels, and sperm mRNA transcript abundance and DNA methylation profiles, as novel biomarkers of testicular toxicity.
    Toxicological Sciences 09/2013; 136(2). DOI:10.1093/toxsci/kft207 · 3.85 Impact Factor
  • Source
    • "These molecules have critical roles in the regulation of many diverse biological pathways, including those associated with various pathologies.3, 4 To date, over 1000 differentially expressed miRNAs in the human genome, only a small fraction of existent miRNAs, have been characterized and cataloged in the miRNA database ( In developing tissues, miRNAs are differentially expressed at high dynamic ranges, and this variation in miRNA expression has been etiologically linked with numerous pathological conditions.5, 6, 7 The expression levels of at least 30% of all genes, including genes critical during differentiation processes in developing mammalian cells, are regulated by miRNAs. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The microRNA (miRNA) regulation mechanisms associated with atherosclerosis are largely undocumented. Specific selection and efficient validation of miRNA regulation pathways involved in atherosclerosis development may be better assessed by contemporary microarray platforms applying cross-verification methodology. A screening platform was established using both miRNA and genomic microarrays. Microarray analysis was then simultaneously performed on pooled atherosclerotic aortic tissues from 10 Apolipoprotein E (apoE) knockout mice (apoE-/-) and 10 healthy C57BL/6 (B6) mice. Differentiated miRNAs were screened and cross-verified against an mRNA screen database to explore integrative mRNA-miRNA regulation. Gene set enrichment analysis was conducted to describe the potential pathways regulated by these mRNA-miRNA interactions. High-throughput data analysis of miRNA and genomic microarrays of knockout and healthy control mice revealed 75 differentially expressed miRNAs in apoE-/- mice at a threshold value of 2. The six miRNAs with the greatest differentiation expression were confirmed by real-time quantitative reverse-transcription PCR (qRT-PCR) in atherosclerotic tissues. Significantly enriched pathways, such as the type 2 diabetes mellitus pathway, were observed by a gene-set enrichment analysis. The enriched molecular pathways were confirmed through qRT-PCR evaluation by observing the presence of suppressor of cytokine signaling 3 (SOCS3) and SOCS3-related miRNAs, miR-30a, miR-30e and miR-19b. Cross-verified high-throughput microarrays are optimally accurate and effective screening methods for miRNA regulation profiles associated with atherosclerosis. The identified SOCS3 pathway is a potentially valuable target for future development of targeted miRNA therapies to control atherosclerosis development and progression.
    03/2013; 45(3):e13. DOI:10.1038/emm.2013.31
Show more