1
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Zhao R, Huang S, Li J, Gu A, Fu M, Hua W, Mao Y, Lei QY, Lu B, Wen W. Excessive STAU1 condensate drives mTOR translation and autophagy dysfunction in neurodegeneration. J Cell Biol 2024; 223:e202311127. [PMID: 38913026 PMCID: PMC11194678 DOI: 10.1083/jcb.202311127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 03/20/2024] [Accepted: 05/03/2024] [Indexed: 06/25/2024] Open
Abstract
The double-stranded RNA-binding protein Staufen1 (STAU1) regulates a variety of physiological and pathological events via mediating RNA metabolism. STAU1 overabundance was observed in tissues from mouse models and fibroblasts from patients with neurodegenerative diseases, accompanied by enhanced mTOR signaling and impaired autophagic flux, while the underlying mechanism remains elusive. Here, we find that endogenous STAU1 forms dynamic cytoplasmic condensate in normal and tumor cell lines, as well as in mouse Huntington's disease knockin striatal cells. STAU1 condensate recruits target mRNA MTOR at its 5'UTR and promotes its translation both in vitro and in vivo, and thus enhanced formation of STAU1 condensate leads to mTOR hyperactivation and autophagy-lysosome dysfunction. Interference of STAU1 condensate normalizes mTOR levels, ameliorates autophagy-lysosome function, and reduces aggregation of pathological proteins in cellular models of neurodegenerative diseases. These findings highlight the importance of balanced phase separation in physiological processes, suggesting that modulating STAU1 condensate may be a strategy to mitigate the progression of neurodegenerative diseases with STAU1 overabundance.
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Affiliation(s)
- Ruiqian Zhao
- Department of Neurosurgery, Huashan Hospital, The Shanghai Key Laboratory of Medical Epigenetics, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Shijing Huang
- Department of Neurosurgery, Huashan Hospital, The Shanghai Key Laboratory of Medical Epigenetics, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Jingyu Li
- Department of Neurosurgery, Huashan Hospital, The Shanghai Key Laboratory of Medical Epigenetics, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Aihong Gu
- Department of Neurosurgery, Huashan Hospital, The Shanghai Key Laboratory of Medical Epigenetics, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Minjie Fu
- Department of Neurosurgery, Huashan Hospital, The Shanghai Key Laboratory of Medical Epigenetics, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Wei Hua
- Department of Neurosurgery, Huashan Hospital, The Shanghai Key Laboratory of Medical Epigenetics, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Ying Mao
- Department of Neurosurgery, Huashan Hospital, The Shanghai Key Laboratory of Medical Epigenetics, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Qun-Ying Lei
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Boxun Lu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, New Cornerstone Science Laboratory, School of Life Sciences, Fudan University, Shanghai, China
| | - Wenyu Wen
- Department of Neurosurgery, Huashan Hospital, The Shanghai Key Laboratory of Medical Epigenetics, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Fudan University, Shanghai, China
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2
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Haugen RJ, Barnier C, Elrod ND, Luo H, Jensen MK, Ji P, Smibert CA, Lipshitz HD, Wagner EJ, Freddolino PL, Goldstrohm AC. Regulation of the Drosophila transcriptome by Pumilio and the CCR4-NOT deadenylase complex. RNA (NEW YORK, N.Y.) 2024; 30:866-890. [PMID: 38627019 PMCID: PMC11182014 DOI: 10.1261/rna.079813.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 04/04/2024] [Indexed: 05/07/2024]
Abstract
The sequence-specific RNA-binding protein Pumilio (Pum) controls Drosophila development; however, the network of mRNAs that it regulates remains incompletely characterized. In this study, we use knockdown and knockout approaches coupled with RNA-seq to measure the impact of Pum on the transcriptome of Drosophila cells in culture. We also use an improved RNA coimmunoprecipitation method to identify Pum-bound mRNAs in Drosophila embryos. Integration of these data sets with the locations of Pum-binding motifs across the transcriptome reveals novel direct Pum target genes involved in neural, muscle, wing, and germ cell development and in cellular proliferation. These genes include components of Wnt, TGF-β, MAPK/ERK, and Notch signaling pathways, DNA replication, and lipid metabolism. We identify the mRNAs regulated by the CCR4-NOT deadenylase complex, a key factor in Pum-mediated repression, and observe concordant regulation of Pum:CCR4-NOT target mRNAs. Computational modeling reveals that Pum binding, binding site number, clustering, and sequence context are important determinants of regulation. In contrast, we show that the responses of direct mRNA targets to Pum-mediated repression are not influenced by the content of optimal synonymous codons. Moreover, contrary to a prevailing model, we do not detect a role for CCR4-NOT in the degradation of mRNAs with low codon optimality. Together, the results of this work provide new insights into the Pum regulatory network and mechanisms and the parameters that influence the efficacy of Pum-mediated regulation.
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Affiliation(s)
- Rebecca J Haugen
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Catherine Barnier
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Nathan D Elrod
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas 77550, USA
| | - Hua Luo
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5G 1M1, Canada
| | - Madeline K Jensen
- Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, New York 14642, USA
| | - Ping Ji
- Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, New York 14642, USA
| | - Craig A Smibert
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5G 1M1, Canada
| | - Howard D Lipshitz
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5G 1M1, Canada
| | - Eric J Wagner
- Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, New York 14642, USA
| | - P Lydia Freddolino
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan 48109, USA
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Aaron C Goldstrohm
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA
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3
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Pasterczyk KR, Li XL, Singh R, Zibitt MS, Hartford CCR, Pongor L, Jenkins LM, Hu Y, Zhao PX, Muys BR, Kumar S, Roper N, Aladjem MI, Pommier Y, Grammatikakis I, Lal A. Staufen1 Represses the FOXA1-Regulated Transcriptome by Destabilizing FOXA1 mRNA in Colorectal Cancer Cells. Mol Cell Biol 2024; 44:43-56. [PMID: 38347726 PMCID: PMC10950277 DOI: 10.1080/10985549.2024.2307574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 01/13/2024] [Indexed: 02/25/2024] Open
Abstract
Transcription factors play key roles in development and disease by controlling gene expression. Forkhead box A1 (FOXA1), is a pioneer transcription factor essential for mouse development and functions as an oncogene in prostate and breast cancer. In colorectal cancer (CRC), FOXA1 is significantly downregulated and high FOXA1 expression is associated with better prognosis, suggesting potential tumor suppressive functions. We therefore investigated the regulation of FOXA1 expression in CRC, focusing on well-differentiated CRC cells, where FOXA1 is robustly expressed. Genome-wide RNA stability assays identified FOXA1 as an unstable mRNA in CRC cells. We validated FOXA1 mRNA instability in multiple CRC cell lines and in patient-derived CRC organoids, and found that the FOXA1 3'UTR confers instability to the FOXA1 transcript. RNA pulldowns and mass spectrometry identified Staufen1 (STAU1) as a potential regulator of FOXA1 mRNA. Indeed, STAU1 knockdown resulted in increased FOXA1 mRNA and protein expression due to increased FOXA1 mRNA stability. Consistent with these data, RNA-seq following STAU1 knockdown in CRC cells revealed that FOXA1 targets were upregulated upon STAU1 knockdown. Collectively, this study uncovers a molecular mechanism by which FOXA1 is regulated in CRC cells and provides insights into our understanding of the complex mechanisms of gene regulation in cancer.
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Affiliation(s)
- Katherine R. Pasterczyk
- Regulatory RNAs and Cancer Section, Genetics Branch, Center for Cancer Research (CCR), National Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Xiao Ling Li
- Regulatory RNAs and Cancer Section, Genetics Branch, Center for Cancer Research (CCR), National Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Ragini Singh
- Regulatory RNAs and Cancer Section, Genetics Branch, Center for Cancer Research (CCR), National Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Meira S. Zibitt
- Regulatory RNAs and Cancer Section, Genetics Branch, Center for Cancer Research (CCR), National Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Corrine Corrina R. Hartford
- Regulatory RNAs and Cancer Section, Genetics Branch, Center for Cancer Research (CCR), National Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Lorinc Pongor
- DNA Replication Group, Developmental Therapeutics Branch, CCR, NCI, NIH, Bethesda, Maryland, USA
| | - Lisa M. Jenkins
- Mass Spectrometry Section, Laboratory of Cell Biology, CCR, NCI, NIH, Bethesda, Maryland, USA
| | - Yue Hu
- Omics Bioinformatic Facility, Genetics Branch, CCR, NCI, NIH, Bethesda, Maryland, USA
| | - Patrick X. Zhao
- Omics Bioinformatic Facility, Genetics Branch, CCR, NCI, NIH, Bethesda, Maryland, USA
| | - Bruna R. Muys
- Regulatory RNAs and Cancer Section, Genetics Branch, Center for Cancer Research (CCR), National Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Suresh Kumar
- Molecular Pharmacology Group, Developmental Therapeutics Branch, CCR, NCI, NIH, Bethesda, Maryland, USA
| | - Nitin Roper
- Molecular Pharmacology Group, Developmental Therapeutics Branch, CCR, NCI, NIH, Bethesda, Maryland, USA
| | - Mirit I. Aladjem
- DNA Replication Group, Developmental Therapeutics Branch, CCR, NCI, NIH, Bethesda, Maryland, USA
| | - Yves Pommier
- Molecular Pharmacology Group, Developmental Therapeutics Branch, CCR, NCI, NIH, Bethesda, Maryland, USA
| | - Ioannis Grammatikakis
- Regulatory RNAs and Cancer Section, Genetics Branch, Center for Cancer Research (CCR), National Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Ashish Lal
- Regulatory RNAs and Cancer Section, Genetics Branch, Center for Cancer Research (CCR), National Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda, Maryland, USA
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4
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Eichler CE, Li H, Grunberg ME, Gavis ER. Localization of oskar mRNA by agglomeration in ribonucleoprotein granules. PLoS Genet 2023; 19:e1010877. [PMID: 37624861 PMCID: PMC10484445 DOI: 10.1371/journal.pgen.1010877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 09/07/2023] [Accepted: 07/19/2023] [Indexed: 08/27/2023] Open
Abstract
Localization of oskar mRNA to the posterior of the Drosophila oocyte is essential for abdominal patterning and germline development. oskar localization is a multi-step process involving temporally and mechanistically distinct transport modes. Numerous cis-acting elements and trans-acting factors have been identified that mediate earlier motor-dependent transport steps leading to an initial accumulation of oskar at the posterior. Little is known, however, about the requirements for the later localization phase, which depends on cytoplasmic flows and results in the accumulation of large oskar ribonucleoprotein granules, called founder granules, by the end of oogenesis. Using super-resolution microscopy, we show that founder granules are agglomerates of smaller oskar transport particles. In contrast to the earlier kinesin-dependent oskar transport, late-phase localization depends on the sequence as well as on the structure of the spliced oskar localization element (SOLE), but not on the adjacent exon junction complex deposition. Late-phase localization also requires the oskar 3' untranslated region (3' UTR), which targets oskar to founder granules. Together, our results show that 3' UTR-mediated targeting together with SOLE-dependent agglomeration leads to accumulation of oskar in large founder granules at the posterior of the oocyte during late stages of oogenesis. In light of previous work showing that oskar transport particles are solid-like condensates, our findings indicate that founder granules form by a process distinct from that of well-characterized ribonucleoprotein granules like germ granules, P bodies, and stress granules. Additionally, they illustrate how an individual mRNA can be adapted to exploit different localization mechanisms depending on the cellular context.
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Affiliation(s)
- Catherine E. Eichler
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Hui Li
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Michelle E. Grunberg
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Elizabeth R. Gavis
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
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5
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Chakrabarti AM, Iosub IA, Lee FCY, Ule J, Luscombe NM. A computationally-enhanced hiCLIP atlas reveals Staufen1-RNA binding features and links 3' UTR structure to RNA metabolism. Nucleic Acids Res 2023; 51:3573-3589. [PMID: 37013995 PMCID: PMC10164587 DOI: 10.1093/nar/gkad221] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 02/08/2023] [Accepted: 03/31/2023] [Indexed: 04/05/2023] Open
Abstract
The structure of mRNA molecules plays an important role in its interactions with trans-acting factors, notably RNA binding proteins (RBPs), thus contributing to the functional consequences of this interplay. However, current transcriptome-wide experimental methods to chart these interactions are limited by their poor sensitivity. Here we extend the hiCLIP atlas of duplexes bound by Staufen1 (STAU1) ∼10-fold, through careful consideration of experimental assumptions, and the development of bespoke computational methods which we apply to existing data. We present Tosca, a Nextflow computational pipeline for the processing, analysis and visualisation of proximity ligation sequencing data generally. We use our extended duplex atlas to discover insights into the RNA selectivity of STAU1, revealing the importance of structural symmetry and duplex-span-dependent nucleotide composition. Furthermore, we identify heterogeneity in the relationship between transcripts with STAU1-bound 3' UTR duplexes and metabolism of the associated RNAs that we relate to RNA structure: transcripts with short-range proximal 3' UTR duplexes have high degradation rates, but those with long-range duplexes have low rates. Overall, our work enables the integrative analysis of proximity ligation data delivering insights into specific features and effects of RBP-RNA structure interactions.
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Affiliation(s)
| | - Ira A Iosub
- The Francis Crick Institute, London, NW1 4AT, UK
| | - Flora C Y Lee
- The Francis Crick Institute, London, NW1 4AT, UK
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Jernej Ule
- The Francis Crick Institute, London, NW1 4AT, UK
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
- UK Dementia Research Institute at King's College London, Institute of Psychiatry, Psychology and Neuroscience, London, SE5 9RX, UK
| | - Nicholas M Luscombe
- The Francis Crick Institute, London, NW1 4AT, UK
- Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa904-0495, Japan
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6
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Grzejda D, Mach J, Schweizer JA, Hummel B, Rezansoff AM, Eggenhofer F, Panhale A, Lalioti ME, Cabezas Wallscheid N, Backofen R, Felsenberg J, Hilgers V. The long noncoding RNA mimi scaffolds neuronal granules to maintain nervous system maturity. SCIENCE ADVANCES 2022; 8:eabo5578. [PMID: 36170367 PMCID: PMC9519039 DOI: 10.1126/sciadv.abo5578] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 08/15/2022] [Indexed: 05/29/2023]
Abstract
RNA binding proteins and messenger RNAs (mRNAs) assemble into ribonucleoprotein granules that regulate mRNA trafficking, local translation, and turnover. The dysregulation of RNA-protein condensation disturbs synaptic plasticity and neuron survival and has been widely associated with human neurological disease. Neuronal granules are thought to condense around particular proteins that dictate the identity and composition of each granule type. Here, we show in Drosophila that a previously uncharacterized long noncoding RNA, mimi, is required to scaffold large neuronal granules in the adult nervous system. Neuronal ELAV-like proteins directly bind mimi and mediate granule assembly, while Staufen maintains condensate integrity. mimi granules contain mRNAs and proteins involved in synaptic processes; granule loss in mimi mutant flies impairs nervous system maturity and neuropeptide-mediated signaling and causes phenotypes of neurodegeneration. Our work reports an architectural RNA for a neuronal granule and provides a handle to interrogate functions of a condensate independently of those of its constituent proteins.
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Affiliation(s)
- Dominika Grzejda
- Max-Planck-Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
- Faculty of Biology, Albert Ludwig University of Freiburg, Freiburg 79104, Germany
- International Max Planck Research School for Molecular and Cellular Biology (IMPRS- MCB), Freiburg 79108, Germany
| | - Jana Mach
- Max-Planck-Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - Johanna Aurelia Schweizer
- Friedrich Miescher Institute for Biomedical Research (FMI), Basel 4058, Switzerland
- University of Basel, Basel 4001, Switzerland
| | - Barbara Hummel
- Max-Planck-Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | | | - Florian Eggenhofer
- Department of Computer Science, Albert Ludwig University of Freiburg, Freiburg 79110, Germany
| | - Amol Panhale
- Max-Planck-Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | - Maria-Eleni Lalioti
- Max-Planck-Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
| | | | - Rolf Backofen
- Department of Computer Science, Albert Ludwig University of Freiburg, Freiburg 79110, Germany
- BIOSS and CIBSS Centres for Biological Signalling Studies, University of Freiburg, Freiburg 79104, Germany
| | - Johannes Felsenberg
- Friedrich Miescher Institute for Biomedical Research (FMI), Basel 4058, Switzerland
| | - Valérie Hilgers
- Max-Planck-Institute of Immunobiology and Epigenetics, Freiburg 79108, Germany
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg 79104, Germany
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7
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Emerging Roles of RNA-Binding Proteins in Neurodevelopment. J Dev Biol 2022; 10:jdb10020023. [PMID: 35735914 PMCID: PMC9224834 DOI: 10.3390/jdb10020023] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/02/2022] [Accepted: 06/08/2022] [Indexed: 02/06/2023] Open
Abstract
Diverse cell types in the central nervous system (CNS) are generated by a relatively small pool of neural stem cells during early development. Spatial and temporal regulation of stem cell behavior relies on precise coordination of gene expression. Well-studied mechanisms include hormone signaling, transcription factor activity, and chromatin remodeling processes. Much less is known about downstream RNA-dependent mechanisms including posttranscriptional regulation, nuclear export, alternative splicing, and transcript stability. These important functions are carried out by RNA-binding proteins (RBPs). Recent work has begun to explore how RBPs contribute to stem cell function and homeostasis, including their role in metabolism, transport, epigenetic regulation, and turnover of target transcripts. Additional layers of complexity are provided by the different target recognition mechanisms of each RBP as well as the posttranslational modifications of the RBPs themselves that alter function. Altogether, these functions allow RBPs to influence various aspects of RNA metabolism to regulate numerous cellular processes. Here we compile advances in RNA biology that have added to our still limited understanding of the role of RBPs in neurodevelopment.
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8
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Song C, Leahy SN, Rushton EM, Broadie K. RNA-binding FMRP and Staufen sequentially regulate the Coracle scaffold to control synaptic glutamate receptor and bouton development. Development 2022; 149:274991. [PMID: 35394012 PMCID: PMC9148565 DOI: 10.1242/dev.200045] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 03/23/2022] [Indexed: 12/16/2022]
Abstract
Both mRNA-binding Fragile X mental retardation protein (FMRP; Fmr1) and mRNA-binding Staufen regulate synaptic bouton formation and glutamate receptor (GluR) levels at the Drosophila neuromuscular junction (NMJ) glutamatergic synapse. Here, we tested whether these RNA-binding proteins act jointly in a common mechanism. We found that both dfmr1 and staufen mutants, and trans-heterozygous double mutants, displayed increased synaptic bouton formation and GluRIIA accumulation. With cell-targeted RNA interference, we showed a downstream Staufen role within postsynaptic muscle. With immunoprecipitation, we showed that FMRP binds staufen mRNA to stabilize postsynaptic transcripts. Staufen is known to target actin-binding, GluRIIA anchor Coracle, and we confirmed that Staufen binds to coracle mRNA. We found that FMRP and Staufen act sequentially to co-regulate postsynaptic Coracle expression, and showed that Coracle, in turn, controls GluRIIA levels and synaptic bouton development. Consistently, we found that dfmr1, staufen and coracle mutants elevate neurotransmission strength. We also identified that FMRP, Staufen and Coracle all suppress pMad activation, providing a trans-synaptic signaling linkage between postsynaptic GluRIIA levels and presynaptic bouton development. This work supports an FMRP-Staufen-Coracle-GluRIIA-pMad pathway regulating structural and functional synapse development.
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Affiliation(s)
- Chunzhu Song
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Shannon N. Leahy
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Emma M. Rushton
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Kendal Broadie
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA,Kennedy Center for Research on Human Development, Vanderbilt University and Medical Center, Nashville, TN 37235, USA,Vanderbilt Brain Institute, Vanderbilt University and Medical Center, Nashville, TN 37235, USA,Author for correspondence ()
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9
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RGS4 RNA Secondary Structure Mediates Staufen2 RNP Assembly in Neurons. Int J Mol Sci 2021; 22:ijms222313021. [PMID: 34884825 PMCID: PMC8657808 DOI: 10.3390/ijms222313021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/25/2021] [Accepted: 11/26/2021] [Indexed: 11/26/2022] Open
Abstract
RNA-binding proteins (RBPs) act as posttranscriptional regulators controlling the fate of target mRNAs. Unraveling how RNAs are recognized by RBPs and in turn are assembled into neuronal RNA granules is therefore key to understanding the underlying mechanism. While RNA sequence elements have been extensively characterized, the functional impact of RNA secondary structures is only recently being explored. Here, we show that Staufen2 binds complex, long-ranged RNA hairpins in the 3′-untranslated region (UTR) of its targets. These structures are involved in the assembly of Staufen2 into RNA granules. Furthermore, we provide direct evidence that a defined Rgs4 RNA duplex regulates Staufen2-dependent RNA localization to distal dendrites. Importantly, disrupting the RNA hairpin impairs the observed effects. Finally, we show that these secondary structures differently affect protein expression in neurons. In conclusion, our data reveal the importance of RNA secondary structure in regulating RNA granule assembly, localization and eventually translation. It is therefore tempting to speculate that secondary structures represent an important code for cells to control the intracellular fate of their mRNAs.
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10
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Alluri RK, Li Z, McCrae KR. Stress Granule-Mediated Oxidized RNA Decay in P-Body: Hypothetical Role of ADAR1, Tudor-SN, and STAU1. Front Mol Biosci 2021; 8:672988. [PMID: 34150849 PMCID: PMC8211916 DOI: 10.3389/fmolb.2021.672988] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 05/11/2021] [Indexed: 12/26/2022] Open
Abstract
Reactive oxygen species (ROS) generated under oxidative stress (OS) cause oxidative damage to RNA. Recent studies have suggested a role for oxidized RNA in several human disorders. Under the conditions of oxidative stress, mRNAs released from polysome dissociation accumulate and initiate stress granule (SG) assembly. SGs are highly enriched in mRNAs, containing inverted repeat (IR) Alus in 3′ UTRs, AU-rich elements, and RNA-binding proteins. SGs and processing bodies (P-bodies) transiently interact through a docking mechanism to allow the exchange of RNA species. However, the types of RNA species exchanged, and the mechanisms and outcomes of exchange are still unknown. Specialized RNA-binding proteins, including adenosine deaminase acting on RNA (ADAR1-p150), with an affinity toward inverted repeat Alus, and Tudor staphylococcal nuclease (Tudor-SN) are specifically recruited to SGs under OS along with an RNA transport protein, Staufen1 (STAU1), but their precise biochemical roles in SGs and SG/P-body docking are uncertain. Here, we critically review relevant literature and propose a hypothetical mechanism for the processing and decay of oxidized-RNA in SGs/P-bodies, as well as the role of ADAR1-p150, Tudor-SN, and STAU1.
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Affiliation(s)
- Ravi Kumar Alluri
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Zhongwei Li
- Biomedical Science Department, College of Medicine, Florida Atlantic University, Boca Raton, FL, United States
| | - Keith R McCrae
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States.,Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH, United States
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11
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Bonnet-Magnaval F, DesGroseillers L. The Staufen1-dependent cell cycle regulon or how a misregulated RNA-binding protein leads to cancer. Biol Rev Camb Philos Soc 2021; 96:2192-2208. [PMID: 34018319 DOI: 10.1111/brv.12749] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 05/11/2021] [Accepted: 05/13/2021] [Indexed: 12/12/2022]
Abstract
In recent years, an increasing number of reports have linked the RNA-binding protein Staufen1 (STAU1) to the control of cell decision making. In non-transformed cells, STAU1 balances the expression of messenger RNA (mRNA) regulons that regulate differentiation and well-ordered cell division. Misregulation of STAU1 expression and/or functions changes the fragile balance in the expression of pro- and anti-proliferative and apoptotic genes and favours a novel equilibrium that supports cell proliferation and cancer development. The misregulation of STAU1 functions causes multiple coordinated modest effects in the post-transcriptional regulation of many RNA targets that code for cell cycle regulators, leading to dramatic consequences at the cellular level. The new tumorigenic equilibrium in STAU1-mediated gene regulation observed in cancer cells can be further altered by a slight increase in STAU1 expression that favours expression of pro-apoptotic genes and cell death. The STAU1-dependent cell cycle regulon is a good model to study how abnormal expression of an RNA-binding protein promotes cell growth and provides an advantageous selection of malignant cells in the first step of cancer development.
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Affiliation(s)
- Florence Bonnet-Magnaval
- Département de biochimie et médecine moléculaire, Faculté de médecine, Université de Montréal, 2900 Édouard Montpetit, Montréal, QC, H3T 1J4, Canada
| | - Luc DesGroseillers
- Département de biochimie et médecine moléculaire, Faculté de médecine, Université de Montréal, 2900 Édouard Montpetit, Montréal, QC, H3T 1J4, Canada
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12
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Opposing roles for Egalitarian and Staufen in transport, anchoring and localization of oskar mRNA in the Drosophila oocyte. PLoS Genet 2021; 17:e1009500. [PMID: 33798193 PMCID: PMC8046350 DOI: 10.1371/journal.pgen.1009500] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 04/14/2021] [Accepted: 03/19/2021] [Indexed: 11/19/2022] Open
Abstract
Localization of oskar mRNA includes two distinct phases: transport from nurse cells to the oocyte, a process typically accompanied by cortical anchoring in the oocyte, followed by posterior localization within the oocyte. Signals within the oskar 3' UTR directing transport are individually weak, a feature previously hypothesized to facilitate exchange between the different localization machineries. We show that alteration of the SL2a stem-loop structure containing the oskar transport and anchoring signal (TAS) removes an inhibitory effect such that in vitro binding by the RNA transport factor, Egalitarian, is elevated as is in vivo transport from the nurse cells into the oocyte. Cortical anchoring within the oocyte is also enhanced, interfering with posterior localization. We also show that mutation of Staufen recognized structures (SRSs), predicted binding sites for Staufen, disrupts posterior localization of oskar mRNA just as in staufen mutants. Two SRSs in SL2a, one overlapping the Egalitarian binding site, are inferred to mediate Staufen-dependent inhibition of TAS anchoring activity, thereby promoting posterior localization. The other three SRSs in the oskar 3' UTR are also required for posterior localization, including two located distant from any known transport signal. Staufen, thus, plays multiple roles in localization of oskar mRNA.
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13
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Yamaguchi M, Lee IS, Jantrapirom S, Suda K, Yoshida H. Drosophila models to study causative genes for human rare intractable neurological diseases. Exp Cell Res 2021; 403:112584. [PMID: 33812867 DOI: 10.1016/j.yexcr.2021.112584] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/25/2021] [Accepted: 03/27/2021] [Indexed: 12/11/2022]
Abstract
Drosophila is emerging as a convenient model for investigating human diseases. Functional homologues of almost 75% of human disease-related genes are found in Drosophila. Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disease that causes defects in motoneurons. Charcot-Marie-Tooth disease (CMT) is one of the most commonly found inherited neuropathies affecting both motor and sensory neurons. No effective therapy has been established for either of these diseases. In this review, after overviewing ALS, Drosophila models targeting several ALS-causing genes, including TDP-43, FUS and Ubiquilin2, are described with their genetic interactants. Then, after overviewing CMT, examples of Drosophila models targeting several CMT-causing genes, including mitochondria-related genes and FIG 4, are also described with their genetic interactants. In addition, we introduce Sotos syndrome caused by mutations in the epigenetic regulator gene NSD1. Lastly, several genes and pathways that commonly interact with ALS- and/or CMT-causing genes are described. In the case of ALS and CMT that have many causative genes, it may be not practical to perform gene therapy for each of the many disease-causing genes. The possible uses of the common genes and pathways as novel diagnosis markers and effective therapeutic targets are discussed.
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Affiliation(s)
- Masamitsu Yamaguchi
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan; Kansai Gakken Laboratory, Kankyo Eisei Yakuhin Co. Ltd., Seika-cho, Kyoto, 619-0237, Japan
| | - Im-Soon Lee
- Department of Biological Sciences, Konkuk University, Seoul, Republic of Korea
| | - Salinee Jantrapirom
- Department of Pharmacology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Kojiro Suda
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan
| | - Hideki Yoshida
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan.
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14
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The RNA-Binding Protein Rasputin/G3BP Enhances the Stability and Translation of Its Target mRNAs. Cell Rep 2021; 30:3353-3367.e7. [PMID: 32160542 DOI: 10.1016/j.celrep.2020.02.066] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 01/13/2020] [Accepted: 02/14/2020] [Indexed: 12/14/2022] Open
Abstract
G3BP RNA-binding proteins are important components of stress granules (SGs). Here, we analyze the role of the Drosophila G3BP Rasputin (RIN) in unstressed cells, where RIN is not SG associated. Immunoprecipitation followed by microarray analysis identifies over 550 mRNAs that copurify with RIN. The mRNAs found in SGs are long and translationally silent. In contrast, we find that RIN-bound mRNAs, which encode core components of the transcription, splicing, and translation machinery, are short, stable, and highly translated. We show that RIN is associated with polysomes and provide evidence for a direct role for RIN and its human homologs in stabilizing and upregulating the translation of their target mRNAs. We propose that when cells are stressed, the resulting incorporation of RIN/G3BPs into SGs sequesters them away from their short target mRNAs. This would downregulate the expression of these transcripts, even though they are not incorporated into stress granules.
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15
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May JP, Simon AE. Targeting of viral RNAs by Upf1-mediated RNA decay pathways. Curr Opin Virol 2020; 47:1-8. [PMID: 33341474 DOI: 10.1016/j.coviro.2020.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 11/10/2020] [Accepted: 11/12/2020] [Indexed: 12/25/2022]
Abstract
Viral RNAs are susceptible to co-translational RNA decay pathways mediated by the RNA helicase Upstream frameshift 1 (Upf1). Upf1 is a key component in nonsense-mediated decay (NMD), Staufen1-mediated mRNA decay (SMD), and structure-mediated RNA decay (SRD) pathways, among others. Diverse families of viruses have features that predispose them to Upf1 targeting, but have evolved means to escape decay through the action of cis-acting or trans-acting viral factors. Studies aimed at understanding how viruses are subjected to and circumvent NMD have increased our understanding of NMD target selection of host mRNAs. This review focuses on the knowledge gained from studying NMD in viral systems as well as related Upf1-dependent pathways and how these pathways restrict virus replication.
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Affiliation(s)
- Jared P May
- Department of Cell and Molecular Biology and Biochemistry, School of Biological and Chemical Sciences, University of Missouri-Kansas City, Kansas City, MO 64110, USA.
| | - Anne E Simon
- Department of Cell Biology and Molecular Genetics, University of Maryland - College Park, College Park, MD, USA.
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16
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Hassine S, Bonnet-Magnaval F, Benoit Bouvrette LP, Doran B, Ghram M, Bouthillette M, Lecuyer E, DesGroseillers L. Staufen1 localizes to the mitotic spindle and controls the localization of RNA populations to the spindle. J Cell Sci 2020; 133:jcs247155. [PMID: 32576666 DOI: 10.1242/jcs.247155] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 06/07/2020] [Indexed: 12/20/2022] Open
Abstract
Staufen1 (STAU1) is an RNA-binding protein involved in the post-transcriptional regulation of mRNAs. We report that a large fraction of STAU1 localizes to the mitotic spindle in colorectal cancer HCT116 cells and in non-transformed hTERT-RPE1 cells. Spindle-associated STAU1 partly co-localizes with ribosomes and active sites of translation. We mapped the molecular determinant required for STAU1-spindle association within the first 88 N-terminal amino acids, a domain that is not required for RNA binding. Interestingly, transcriptomic analysis of purified mitotic spindles revealed that 1054 mRNAs and the precursor ribosomal RNA (pre-rRNA), as well as the long non-coding RNAs and small nucleolar RNAs involved in ribonucleoprotein assembly and processing, are enriched on spindles compared with cell extracts. STAU1 knockout causes displacement of the pre-rRNA and of 154 mRNAs coding for proteins involved in actin cytoskeleton organization and cell growth, highlighting a role for STAU1 in mRNA trafficking to spindle. These data demonstrate that STAU1 controls the localization of subpopulations of RNAs during mitosis and suggests a novel role of STAU1 in pre-rRNA maintenance during mitosis, ribogenesis and/or nucleoli reassembly.
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Affiliation(s)
- Sami Hassine
- Département de biochimie et médecine moléculaire, Faculté de médecine, Université de Montréal, 2900 Édouard Montpetit, Montréal, QC H3T 1J4, Canada
| | - Florence Bonnet-Magnaval
- Département de biochimie et médecine moléculaire, Faculté de médecine, Université de Montréal, 2900 Édouard Montpetit, Montréal, QC H3T 1J4, Canada
| | - Louis Philip Benoit Bouvrette
- Département de biochimie et médecine moléculaire, Faculté de médecine, Université de Montréal, 2900 Édouard Montpetit, Montréal, QC H3T 1J4, Canada
- Institut de Recherches Cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC H2W 1R7, Canada
| | - Bellastrid Doran
- Département de biochimie et médecine moléculaire, Faculté de médecine, Université de Montréal, 2900 Édouard Montpetit, Montréal, QC H3T 1J4, Canada
| | - Mehdi Ghram
- Département de biochimie et médecine moléculaire, Faculté de médecine, Université de Montréal, 2900 Édouard Montpetit, Montréal, QC H3T 1J4, Canada
| | - Mathieu Bouthillette
- Département de biochimie et médecine moléculaire, Faculté de médecine, Université de Montréal, 2900 Édouard Montpetit, Montréal, QC H3T 1J4, Canada
| | - Eric Lecuyer
- Département de biochimie et médecine moléculaire, Faculté de médecine, Université de Montréal, 2900 Édouard Montpetit, Montréal, QC H3T 1J4, Canada
- Institut de Recherches Cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC H2W 1R7, Canada
| | - Luc DesGroseillers
- Département de biochimie et médecine moléculaire, Faculté de médecine, Université de Montréal, 2900 Édouard Montpetit, Montréal, QC H3T 1J4, Canada
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17
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Tang S, Han T, Wang Z, Yue N, Liu Z, Tang S, Yang X, Zhang Z, Zhou Y, Yuan W, Hao H, Sleman S, Pan D, Xuan B, Zhou W, Qian Z. Facile and Modular Pipeline for Protein-Specific Antibody Customization. ACS APPLIED BIO MATERIALS 2020; 3:4380-4387. [DOI: 10.1021/acsabm.0c00385] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Shubing Tang
- Guangzhou Institute of Pediatrics, Department of Neonatology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, 510623 Guangzhou, China
- CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, University of the Chinese Academy of Sciences, 200031 Shanghai, China
- Shanghai Public Health Clinical Center, Fudan University, 201058 Shanghai, China
| | - Tian Han
- CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, University of the Chinese Academy of Sciences, 200031 Shanghai, China
| | - Zewei Wang
- CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, University of the Chinese Academy of Sciences, 200031 Shanghai, China
| | - Nan Yue
- CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, University of the Chinese Academy of Sciences, 200031 Shanghai, China
| | - Zhi Liu
- CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, University of the Chinese Academy of Sciences, 200031 Shanghai, China
| | - Shuhua Tang
- Tianjin Key Laboratory of Food Biotechnology, College of Biotechnology and Food Science, Tianjin University of Commerce, 300134 Tianjin, China
| | - Xiaoqi Yang
- Guangzhou Institute of Pediatrics, Department of Neonatology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, 510623 Guangzhou, China
| | - Zhe Zhang
- Guangzhou Institute of Pediatrics, Department of Neonatology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, 510623 Guangzhou, China
| | - Yan Zhou
- Guangzhou Institute of Pediatrics, Department of Neonatology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, 510623 Guangzhou, China
| | - Weiming Yuan
- Guangzhou Institute of Pediatrics, Department of Neonatology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, 510623 Guangzhou, China
| | - Hongyun Hao
- CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, University of the Chinese Academy of Sciences, 200031 Shanghai, China
| | - Sirwan Sleman
- CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, University of the Chinese Academy of Sciences, 200031 Shanghai, China
| | - Deng Pan
- Shanghai Public Health Clinical Center, Fudan University, 201058 Shanghai, China
| | - Baoqin Xuan
- CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, University of the Chinese Academy of Sciences, 200031 Shanghai, China
| | - Wei Zhou
- Guangzhou Institute of Pediatrics, Department of Neonatology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, 510623 Guangzhou, China
| | - Zhikang Qian
- CAS Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, University of the Chinese Academy of Sciences, 200031 Shanghai, China
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18
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Ghram M, Bonnet-Magnaval F, Hotea DI, Doran B, Ly S, DesGroseillers L. Staufen1 is Essential for Cell-Cycle Transitions and Cell Proliferation Via the Control of E2F1 Expression. J Mol Biol 2020; 432:3881-3897. [DOI: 10.1016/j.jmb.2020.04.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/14/2020] [Accepted: 04/20/2020] [Indexed: 12/16/2022]
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19
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Carazo F, Romero JP, Rubio A. Upstream analysis of alternative splicing: a review of computational approaches to predict context-dependent splicing factors. Brief Bioinform 2020; 20:1358-1375. [PMID: 29390045 DOI: 10.1093/bib/bby005] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 12/14/2017] [Indexed: 12/13/2022] Open
Abstract
Alternative splicing (AS) has shown to play a pivotal role in the development of diseases, including cancer. Specifically, all the hallmarks of cancer (angiogenesis, cell immortality, avoiding immune system response, etc.) are found to have a counterpart in aberrant splicing of key genes. Identifying the context-specific regulators of splicing provides valuable information to find new biomarkers, as well as to define alternative therapeutic strategies. The computational models to identify these regulators are not trivial and require three conceptual steps: the detection of AS events, the identification of splicing factors that potentially regulate these events and the contextualization of these pieces of information for a specific experiment. In this work, we review the different algorithmic methodologies developed for each of these tasks. Main weaknesses and strengths of the different steps of the pipeline are discussed. Finally, a case study is detailed to help the reader be aware of the potential and limitations of this computational approach.
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20
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Yadav DK, Zigáčková D, Zlobina M, Klumpler T, Beaumont C, Kubíčková M, Vaňáčová Š, Lukavsky PJ. Staufen1 reads out structure and sequence features in ARF1 dsRNA for target recognition. Nucleic Acids Res 2020; 48:2091-2106. [PMID: 31875226 PMCID: PMC7038937 DOI: 10.1093/nar/gkz1163] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 11/22/2019] [Accepted: 12/05/2019] [Indexed: 12/13/2022] Open
Abstract
Staufen1 (STAU1) is a dsRNA binding protein mediating mRNA transport and localization, translational control and STAU1-mediated mRNA decay (SMD). The STAU1 binding site (SBS) within human ADP-ribosylation factor1 (ARF1) 3′UTR binds STAU1 and this downregulates ARF1 cytoplasmic mRNA levels by SMD. However, how STAU1 recognizes specific mRNA targets is still under debate. Our structure of the ARF1 SBS–STAU1 complex uncovers target recognition by STAU1. STAU1 dsRNA binding domain (dsRBD) 4 interacts with two pyrimidines and one purine from the minor groove side via helix α1, the β1–β2 loop anchors the dsRBD at the end of the dsRNA and lysines in helix α2 bind to the phosphodiester backbone from the major groove side. STAU1 dsRBD3 displays the same binding mode with specific recognition of one guanine base. Mutants disrupting minor groove recognition of ARF1 SBS affect in vitro binding and reduce SMD in vivo. Our data thus reveal how STAU1 recognizes minor groove features in dsRNA relevant for target selection.
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Affiliation(s)
- Deepak Kumar Yadav
- Central European Institute of Technology, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
| | - Dagmar Zigáčková
- Central European Institute of Technology, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
| | - Maria Zlobina
- Central European Institute of Technology, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
| | - Tomáš Klumpler
- Central European Institute of Technology, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
| | - Christelle Beaumont
- Central European Institute of Technology, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
| | - Monika Kubíčková
- Central European Institute of Technology, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
| | - Štěpánka Vaňáčová
- Central European Institute of Technology, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
| | - Peter J Lukavsky
- Central European Institute of Technology, Masaryk University, Kamenice 753/5, 62500, Brno, Czech Republic
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21
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Visentin S, Cannone G, Doutch J, Harris G, Gleghorn ML, Clifton L, Smith BO, Spagnolo L. A multipronged approach to understanding the form and function of hStaufen protein. RNA (NEW YORK, N.Y.) 2020; 26:265-277. [PMID: 31852734 PMCID: PMC7025507 DOI: 10.1261/rna.072595.119] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 12/09/2019] [Indexed: 05/09/2023]
Abstract
Staufen is a dsRNA-binding protein involved in many aspects of RNA regulation, such as mRNA transport, Staufen-mediated mRNA decay and the regulation of mRNA translation. It is a modular protein characterized by the presence of conserved consensus amino acid sequences that fold into double-stranded RNA binding domains (RBDs) as well as degenerated RBDs that are instead involved in protein-protein interactions. The variety of biological processes in which Staufen participates in the cell suggests that this protein associates with many diverse RNA targets, some of which have been identified experimentally. Staufen binding mediates the recruitment of effectors via protein-protein and protein-RNA interactions. The structural determinants of a number of these interactions, as well as the structure of full-length Staufen, remain unknown. Here, we present the first solution structure models for full-length hStaufen155, showing that its domains are arranged as beads-on-a-string connected by flexible linkers. In analogy with other nucleic acid-binding proteins, this could underpin Stau1 functional plasticity.
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Affiliation(s)
- Silvia Visentin
- Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow G12 8QQ, United Kingdom
- Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JQ, United Kingdom
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council (STFC), Rutherford Appleton Laboratory, Didcot OX11 OQX, United Kingdom
| | - Giuseppe Cannone
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JQ, United Kingdom
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - James Doutch
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council (STFC), Rutherford Appleton Laboratory, Didcot OX11 OQX, United Kingdom
| | - Gemma Harris
- Research Complex at Harwell, Rutherford Appleton Laboratory, Research Complex at Harwell, Didcot OX11 0FA, United Kingdom
| | - Michael L Gleghorn
- School of Chemistry and Materials Science, College of Science, Rochester Institute of Technology, Rochester, New York 14623, USA
| | - Luke Clifton
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council (STFC), Rutherford Appleton Laboratory, Didcot OX11 OQX, United Kingdom
| | - Brian O Smith
- Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Laura Spagnolo
- Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow G12 8QQ, United Kingdom
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22
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Chen KW, Chen JA. Functional Roles of Long Non-coding RNAs in Motor Neuron Development and Disease. J Biomed Sci 2020; 27:38. [PMID: 32093746 PMCID: PMC7041250 DOI: 10.1186/s12929-020-00628-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 02/12/2020] [Indexed: 12/14/2022] Open
Abstract
Long non-coding RNAs (lncRNAs) have gained increasing attention as they exhibit highly tissue- and cell-type specific expression patterns. LncRNAs are highly expressed in the central nervous system and their roles in the brain have been studied intensively in recent years, but their roles in the spinal motor neurons (MNs) are largely unexplored. Spinal MN development is controlled by precise expression of a gene regulatory network mediated spatiotemporally by transcription factors, representing an elegant paradigm for deciphering the roles of lncRNAs during development. Moreover, many MN-related neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA), are associated with RNA metabolism, yet the link between MN-related diseases and lncRNAs remains obscure. In this review, we summarize lncRNAs known to be involved in MN development and disease, and discuss their potential future therapeutic applications.
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Affiliation(s)
- Kuan-Wei Chen
- Institute of Molecular Biology, Academia Sinica, Taipei, 11529, Taiwan.
| | - Jun-An Chen
- Institute of Molecular Biology, Academia Sinica, Taipei, 11529, Taiwan.
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23
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Cataloguing and Selection of mRNAs Localized to Dendrites in Neurons and Regulated by RNA-Binding Proteins in RNA Granules. Biomolecules 2020; 10:biom10020167. [PMID: 31978946 PMCID: PMC7072219 DOI: 10.3390/biom10020167] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/18/2020] [Accepted: 01/20/2020] [Indexed: 12/15/2022] Open
Abstract
Spatiotemporal translational regulation plays a key role in determining cell fate and function. Specifically, in neurons, local translation in dendrites is essential for synaptic plasticity and long-term memory formation. To achieve local translation, RNA-binding proteins in RNA granules regulate target mRNA stability, localization, and translation. To date, mRNAs localized to dendrites have been identified by comprehensive analyses. In addition, mRNAs associated with and regulated by RNA-binding proteins have been identified using various methods in many studies. However, the results obtained from these numerous studies have not been compiled together. In this review, we have catalogued mRNAs that are localized to dendrites and are associated with and regulated by the RNA-binding proteins fragile X mental retardation protein (FMRP), RNA granule protein 105 (RNG105, also known as Caprin1), Ras-GAP SH3 domain binding protein (G3BP), cytoplasmic polyadenylation element binding protein 1 (CPEB1), and staufen double-stranded RNA binding proteins 1 and 2 (Stau1 and Stau2) in RNA granules. This review provides comprehensive information on dendritic mRNAs, the neuronal functions of mRNA-encoded proteins, the association of dendritic mRNAs with RNA-binding proteins in RNA granules, and the effects of RNA-binding proteins on mRNA regulation. These findings provide insights into the mechanistic basis of protein-synthesis-dependent synaptic plasticity and memory formation and contribute to future efforts to understand the physiological implications of local regulation of dendritic mRNAs in neurons.
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24
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Insights into the assembly and architecture of a Staufen-mediated mRNA decay (SMD)-competent mRNP. Nat Commun 2019; 10:5054. [PMID: 31699982 PMCID: PMC6838198 DOI: 10.1038/s41467-019-13080-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Accepted: 10/18/2019] [Indexed: 02/07/2023] Open
Abstract
The mammalian Staufen proteins (Stau1 and Stau2) mediate degradation of mRNA containing complex secondary structures in their 3’-untranslated region (UTR) through a pathway known as Staufen-mediated mRNA decay (SMD). This pathway also involves the RNA helicase UPF1, which is best known for its role in the nonsense-mediated mRNA decay (NMD) pathway. Here we present a biochemical reconstitution of the recruitment and activation of UPF1 in context of the SMD pathway. We demonstrate the involvement of UPF2, a core NMD factor and a known activator of UPF1, in SMD. UPF2 acts as an adaptor between Stau1 and UPF1, stimulates the catalytic activity of UPF1 and plays a central role in the formation of an SMD-competent mRNP. Our study elucidates the molecular mechanisms of SMD and points towards extensive cross-talk between UPF1-mediated mRNA decay pathways in cells. The Staufen proteins recognize secondary structures in 3’-untranslated regions in mRNA transcripts and induce degradation of these mRNAs with the help of the RNA helicase UPF1. Here the authors report that the nonsense-mediated mRNA decay factor UPF2 mediates the interaction between Stau1 and UPF1 in Staufen-mediated mRNA decay.
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Heber S, Gáspár I, Tants JN, Günther J, Moya SMF, Janowski R, Ephrussi A, Sattler M, Niessing D. Staufen2-mediated RNA recognition and localization requires combinatorial action of multiple domains. Nat Commun 2019; 10:1659. [PMID: 30971701 PMCID: PMC6477676 DOI: 10.1038/s41467-019-09655-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 03/20/2019] [Indexed: 11/08/2022] Open
Abstract
Throughout metazoans, Staufen (Stau) proteins are core factors of mRNA localization particles. They consist of three to four double-stranded RNA binding domains (dsRBDs) and a C-terminal dsRBD-like domain. Mouse Staufen2 (mStau2)-like Drosophila Stau (dmStau) contains four dsRBDs. Existing data suggest that only dsRBDs 3-4 are necessary and sufficient for mRNA binding. Here, we show that dsRBDs 1 and 2 of mStau2 bind RNA with similar affinities and kinetics as dsRBDs 3 and 4. While RNA binding by these tandem domains is transient, all four dsRBDs recognize their target RNAs with high stability. Rescue experiments in Drosophila oocytes demonstrate that mStau2 partially rescues dmStau-dependent mRNA localization. In contrast, a rescue with mStau2 bearing RNA-binding mutations in dsRBD1-2 fails, confirming the physiological relevance of our findings. In summary, our data show that the dsRBDs 1-2 play essential roles in the mRNA recognition and function of Stau-family proteins of different species.
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Affiliation(s)
- Simone Heber
- Institute of Pharmaceutical Biotechnology, 89081 Ulm University, Ulm, Germany
- Institute of Structural Biology, Helmholtz Zentrum München, 85764, Neuherberg, Germany
| | - Imre Gáspár
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117, Heidelberg, Germany
- Institute of Molecular Biotechnology, 1030, Vienna, Austria
| | - Jan-Niklas Tants
- Center for Integrated Protein Science Munich at Chair of Biomolecular NMR Spectroscopy, Department Chemistry, Technische Universität München, 85747, Garching, Germany
| | - Johannes Günther
- Center for Integrated Protein Science Munich at Chair of Biomolecular NMR Spectroscopy, Department Chemistry, Technische Universität München, 85747, Garching, Germany
| | - Sandra M Fernandez Moya
- Biomedical Center Munich, Department of Cell Biology, Ludwig-Maximilians-Universität München, 82152, Planegg-Martinsried, Germany
| | - Robert Janowski
- Institute of Structural Biology, Helmholtz Zentrum München, 85764, Neuherberg, Germany
| | - Anne Ephrussi
- Developmental Biology Unit, European Molecular Biology Laboratory, 69117, Heidelberg, Germany
| | - Michael Sattler
- Institute of Structural Biology, Helmholtz Zentrum München, 85764, Neuherberg, Germany
- Center for Integrated Protein Science Munich at Chair of Biomolecular NMR Spectroscopy, Department Chemistry, Technische Universität München, 85747, Garching, Germany
| | - Dierk Niessing
- Institute of Pharmaceutical Biotechnology, 89081 Ulm University, Ulm, Germany.
- Institute of Structural Biology, Helmholtz Zentrum München, 85764, Neuherberg, Germany.
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Attig J, Ule J. Genomic Accumulation of Retrotransposons Was Facilitated by Repressive RNA-Binding Proteins: A Hypothesis. Bioessays 2019; 41:e1800132. [DOI: 10.1002/bies.201800132] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 11/14/2018] [Indexed: 12/19/2022]
Affiliation(s)
- Jan Attig
- Dr. J. Attig, Prof. J. Ule; The Francis Crick Institute; 1 Midland Road London NW1 1AT UK
| | - Jernej Ule
- Dr. J. Attig, Prof. J. Ule; The Francis Crick Institute; 1 Midland Road London NW1 1AT UK
- Prof. J. Ule; Department of Molecular Neuroscience; UCL Institute of Neurology; Queen Square London WC1N 3BG UK
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Lazzaretti D, Bandholz-Cajamarca L, Emmerich C, Schaaf K, Basquin C, Irion U, Bono F. The crystal structure of Staufen1 in complex with a physiological RNA sheds light on substrate selectivity. Life Sci Alliance 2018; 1:e201800187. [PMID: 30456389 PMCID: PMC6238398 DOI: 10.26508/lsa.201800187] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/03/2018] [Accepted: 10/05/2018] [Indexed: 01/29/2023] Open
Abstract
Combination of in vitro and in vivo data show that RNA sequence influences Staufen target recognition and that protein–RNA base contacts are required for Staufen function in Drosophila. During mRNA localization, RNA-binding proteins interact with specific structured mRNA localization motifs. Although several such motifs have been identified, we have limited structural information on how these interact with RNA-binding proteins. Staufen proteins bind structured mRNA motifs through dsRNA-binding domains (dsRBD) and are involved in mRNA localization in Drosophila and mammals. We solved the structure of two dsRBDs of human Staufen1 in complex with a physiological dsRNA sequence. We identified interactions between the dsRBDs and the RNA sugar–phosphate backbone and direct contacts of conserved Staufen residues to RNA bases. Mutating residues mediating nonspecific backbone interactions only affected Staufen function in Drosophila when in vitro binding was severely reduced. Conversely, residues involved in base-directed interactions were required in vivo even when they minimally affected in vitro binding. Our work revealed that Staufen can read sequence features in the minor groove of dsRNA and suggests that these influence target selection in vivo.
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Affiliation(s)
| | | | | | - Kristina Schaaf
- Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Claire Basquin
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Uwe Irion
- Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Fulvia Bono
- Max Planck Institute for Developmental Biology, Tübingen, Germany.,Living Systems Institute, University of Exeter, Exeter, UK
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28
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Subcellular Specialization and Organelle Behavior in Germ Cells. Genetics 2018; 208:19-51. [PMID: 29301947 DOI: 10.1534/genetics.117.300184] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Accepted: 08/17/2017] [Indexed: 11/18/2022] Open
Abstract
Gametes, eggs and sperm, are the highly specialized cell types on which the development of new life solely depends. Although all cells share essential organelles, such as the ER (endoplasmic reticulum), Golgi, mitochondria, and centrosomes, germ cells display unique regulation and behavior of organelles during gametogenesis. These germ cell-specific functions of organelles serve critical roles in successful gamete production. In this chapter, I will review the behaviors and roles of organelles during germ cell differentiation.
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Muraoka Y, Nakamura A, Tanaka R, Suda K, Azuma Y, Kushimura Y, Lo Piccolo L, Yoshida H, Mizuta I, Tokuda T, Mizuno T, Nakagawa M, Yamaguchi M. Genetic screening of the genes interacting with Drosophila FIG4 identified a novel link between CMT-causing gene and long noncoding RNAs. Exp Neurol 2018; 310:1-13. [PMID: 30165075 DOI: 10.1016/j.expneurol.2018.08.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 08/08/2018] [Accepted: 08/21/2018] [Indexed: 12/18/2022]
Abstract
Neuron-specific knockdown of the dFIG4 gene, a Drosophila homologue of human FIG4 and one of the causative genes for Charcot-Marie-Tooth disease (CMT), reduces the locomotive abilities of adult flies, as well as causing defects at neuromuscular junctions, such as reduced synaptic branch length in presynaptic terminals of the motor neurons in third instar larvae. Eye imaginal disc-specific knockdown of dFIG4 induces abnormal morphology of the adult compound eye, the rough eye phenotype. In this study, we carried out modifier screening of the dFIG4 knockdown-induced rough eye phenotype using a set of chromosomal deficiency lines on the second chromosome. By genetic screening, we detected 9 and 15 chromosomal regions whose deletions either suppressed or enhanced the rough eye phenotype induced by the dFIG4 knockdown. By further genetic screening with mutants of individual genes in one of these chromosomal regions, we identified the gene CR18854 that suppressed the rough eye phenotype and the loss-of-cone cell phenotype. The CR18854 gene encodes a long non-coding RNA (lncRNA) consisting of 2566 bases. Mutation and knockdown of CR18854 patially suppressed the enlarged lysosome phenotype induced by Fat body-specific knockdown of dFIG4. Further characterization of CR18854, and a few other lncRNAs in relation to dFIG4 in neuron, using neuron-specific dFIG4 knockdown flies indicated a genetic link between the dFIG4 gene and lncRNAs including CR18854 and hsrω. We also obtained data indicating genetic interaction between CR18854 and Cabeza, a Drosophila homologue of human FUS, which is one of the causing genes for amyotrophic lateral sclerosis (ALS). These results suggest that lncRNAs such as CR18854 and hsrω are involved in a common pathway in CMT and ALS pathogenesis.
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Affiliation(s)
- Yuuka Muraoka
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan; The Center for Advanced Insect Research, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Aya Nakamura
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan; The Center for Advanced Insect Research, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Ryo Tanaka
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan; The Center for Advanced Insect Research, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Kojiro Suda
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan; The Center for Advanced Insect Research, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Yumiko Azuma
- Department of Neurology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566, Japan
| | - Yukie Kushimura
- Department of Neurology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566, Japan
| | - Luca Lo Piccolo
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Hideki Yoshida
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan; The Center for Advanced Insect Research, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Ikuko Mizuta
- Department of Neurology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566, Japan
| | - Takahiko Tokuda
- Department of Neurology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566, Japan; Department of Molecular Pathobiology of Brain Diseases, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566, Japan
| | - Toshiki Mizuno
- Department of Neurology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566, Japan
| | - Masanori Nakagawa
- Department of Neurology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566, Japan; North Medical Center, Kyoto Prefectural University of Medicine, 481 otokoyama, yosano-cho, yosa-gun, Kyoto 629-2291, Japan
| | - Masamitsu Yamaguchi
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan; The Center for Advanced Insect Research, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan.
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Landskron L, Steinmann V, Bonnay F, Burkard TR, Steinmann J, Reichardt I, Harzer H, Laurenson AS, Reichert H, Knoblich JA. The asymmetrically segregating lncRNA cherub is required for transforming stem cells into malignant cells. eLife 2018; 7:31347. [PMID: 29580384 PMCID: PMC5871330 DOI: 10.7554/elife.31347] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 02/06/2018] [Indexed: 12/20/2022] Open
Abstract
Tumor cells display features that are not found in healthy cells. How they become immortal and how their specific features can be exploited to combat tumorigenesis are key questions in tumor biology. Here we describe the long non-coding RNA cherub that is critically required for the development of brain tumors in Drosophila but is dispensable for normal development. In mitotic Drosophila neural stem cells, cherub localizes to the cell periphery and segregates into the differentiating daughter cell. During tumorigenesis, de-differentiation of cherub-high cells leads to the formation of tumorigenic stem cells that accumulate abnormally high cherub levels. We show that cherub establishes a molecular link between the RNA-binding proteins Staufen and Syncrip. As Syncrip is part of the molecular machinery specifying temporal identity in neural stem cells, we propose that tumor cells proliferate indefinitely, because cherub accumulation no longer allows them to complete their temporal neurogenesis program. Many biological signals control how cells grow and divide. However, cancer cells do not obey these growth-restricting signals, and as a result large tumors may develop. Recent experiments have suggested that stem cells – the precursors to the different types of specialized cells found in the body – are particularly important for generating tumors. A stem cell normally divides unequally to form a self-renewing cell and a more specialized cell (often a progenitor cell that will give rise to increasingly specialized cell types). The timing of when the specialization occurs can be key to guiding the ultimately produced cell progenies to their final identity. However, in a tumor cells can retain the ability to self-renew. Ultimately, the resulting ‘tumor stem cells’ become immortal and proliferate indefinitely. It is not fully understood why this uncontrolled proliferation occurs. Just like mammals (including humans), fruit flies can develop tumors. Some of the DNA mutations responsible for tumor development were already identified in flies as early as in the 1970s. This has made fruit flies a well-studied model system for uncovering the principle defects that cause tumors to form. Landskron et al. have now studied the neural stem cells found in brain tumors in fruit flies. Additional DNA mutations were not responsible for these cells becoming immortal. Instead, certain RNA molecules – products that are ‘transcribed’ from the DNA – were present in different amounts in tumor cells. The RNA that showed the greatest increase in tumor cells is a so-called long non-coding RNA named cherub. This RNA molecule has no important role in normal fruit flies, but is critical for tumor formation. Landskron et al. found that during cell division cherub segregates from the neural stem cells to the newly formed progenitor cells, where it breaks down over time. Progenitor cells that contain high levels of cherub give rise to tumor-generating neural stem cells. At the molecular level, cherubhelps two proteins to interact with each other: one called Syncrip that makes the neural stem cells take on a older identity, and another one (Staufen) that tethers it to the cell membrane. By restricting Syncrip to a particular location in the cell, cherub alters the timing of stem cell specialization, which contributes to tumor formation. Overall, the results presented by Landskron et al. reveal a new role for long non-coding RNAs: controlling the localization of the proteins that determine the fate of the cell. They also highlight a critical link between the timing of stem cell development and the proliferation of the cells. Further work is now needed to test whether the same control mechanism works in species other than fruit flies.
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Affiliation(s)
- Lisa Landskron
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Victoria Steinmann
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Francois Bonnay
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Thomas R Burkard
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Jonas Steinmann
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Ilka Reichardt
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Heike Harzer
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | | | | | - Jürgen A Knoblich
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
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31
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Oh Y, Park J, Kim JI, Chang MY, Lee SH, Cho YH, Hwang J. Lin28B and miR-142-3p regulate neuronal differentiation by modulating Staufen1 expression. Cell Death Differ 2017; 25:432-443. [PMID: 29099484 DOI: 10.1038/cdd.2017.182] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 08/15/2017] [Accepted: 09/19/2017] [Indexed: 02/06/2023] Open
Abstract
Staufen1 (STAU1) and Lin28B are RNA-binding proteins that are involved in neuronal differentiation as a function of post-transcriptional regulation. STAU1 triggers post-transcriptional regulation, including mRNA export, mRNA relocation, translation and mRNA decay. Lin28B also has multiple functions in miRNA biogenesis and the regulation of translation. Here, we examined the connection between STAU1 and Lin28B and found that Lin28B regulates the abundance of STAU1 mRNA via miRNA maturation. Decreases in the expression of both STAU1 and Lin28B were observed during neuronal differentiation. Depletion of STAU1 or Lin28B inhibited neuronal differentiation, and overexpression of STAU1 or Lin28B enhanced neuronal differentiation. Interestingly, the stability of STAU1 mRNA was modulated by miR-142-3p, whose maturation was regulated by Lin28B. Thus, miR-142-3p expression increased as Lin28B expression decreased during differentiation, leading to the reduction of STAU1 expression. The transcriptome from Staufen-mediated mRNA decay (SMD) targets during differentiation was analyzed, confirming that STAU1 was a key factor in neuronal differentiation. In support of this finding, regulation of STAU1 expression in mouse neural precursor cells had the same effects on neuronal differentiation as it did in human neuroblastoma cells. These results revealed the collaboration of two RNA-binding proteins, STAU1 and Lin28B, as a regulatory mechanism in neuronal differentiation.
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Affiliation(s)
- Younseo Oh
- Graduate School for Biomedical Science & Engineering, Seoul, Korea
| | - Jungyun Park
- Graduate School for Biomedical Science & Engineering, Seoul, Korea
| | - Jin-Il Kim
- Graduate School for Biomedical Science & Engineering, Seoul, Korea
| | | | - Sang-Hun Lee
- Department of Biochemistry and Molecular Biology, College of Medicine, Seoul, Korea
| | - Youl-Hee Cho
- Department of Medical Genetics, College of Medicine, Hanyang University, Seoul, Korea
| | - Jungwook Hwang
- Graduate School for Biomedical Science & Engineering, Seoul, Korea.,Department of Medical Genetics, College of Medicine, Hanyang University, Seoul, Korea
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32
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Rissland OS, Subtelny AO, Wang M, Lugowski A, Nicholson B, Laver JD, Sidhu SS, Smibert CA, Lipshitz HD, Bartel DP. The influence of microRNAs and poly(A) tail length on endogenous mRNA-protein complexes. Genome Biol 2017; 18:211. [PMID: 29089021 PMCID: PMC5664449 DOI: 10.1186/s13059-017-1330-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 09/29/2017] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND All mRNAs are bound in vivo by proteins to form mRNA-protein complexes (mRNPs), but changes in the composition of mRNPs during posttranscriptional regulation remain largely unexplored. Here, we have analyzed, on a transcriptome-wide scale, how microRNA-mediated repression modulates the associations of the core mRNP components eIF4E, eIF4G, and PABP and of the decay factor DDX6 in human cells. RESULTS Despite the transient nature of repressed intermediates, we detect significant changes in mRNP composition, marked by dissociation of eIF4G and PABP, and by recruitment of DDX6. Furthermore, although poly(A)-tail length has been considered critical in post-transcriptional regulation, differences in steady-state tail length explain little of the variation in either PABP association or mRNP organization more generally. Instead, relative occupancy of core components correlates best with gene expression. CONCLUSIONS These results indicate that posttranscriptional regulatory factors, such as microRNAs, influence the associations of PABP and other core factors, and do so without substantially affecting steady-state tail length.
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Affiliation(s)
- Olivia S Rissland
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA. .,Howard Hughes Medical Institute, Cambridge, MA, 02142, USA. .,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA. .,Molecular Medicine Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada. .,Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada. .,Present address: Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO, 80045, USA.
| | - Alexander O Subtelny
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA.,Howard Hughes Medical Institute, Cambridge, MA, 02142, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Miranda Wang
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Andrew Lugowski
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Beth Nicholson
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada
| | - John D Laver
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Sachdev S Sidhu
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada.,Donnelly Centre, University of Toronto, Toronto, ON, Canada
| | - Craig A Smibert
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Howard D Lipshitz
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - David P Bartel
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA. .,Howard Hughes Medical Institute, Cambridge, MA, 02142, USA. .,Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
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Retrotransposons Mimic Germ Plasm Determinants to Promote Transgenerational Inheritance. Curr Biol 2017; 27:3010-3016.e3. [PMID: 28966088 DOI: 10.1016/j.cub.2017.08.036] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Revised: 07/14/2017] [Accepted: 08/15/2017] [Indexed: 11/21/2022]
Abstract
Retrotransposons are a pervasive class of mobile elements present in the genomes of virtually all forms of life [1, 2]. In metazoans, these are preferentially active in the germline, which, in turn, mounts defenses that restrain their activity [3, 4]. Here we report that certain classes of retrotransposons ensure transgenerational inheritance by invading presumptive germ cells before they are formed. Using sensitized Drosophila and zebrafish models, we found that diverse classes of retrotransposons migrate to the germ plasm, a specialized region of the oocyte that prefigures germ cells and specifies the germline of descendants in the fertilized egg. In Drosophila, we found evidence for a "stowaway" model, whereby Tahre retroelements traffic to the germ plasm by mimicking oskar RNAs and engaging the Staufen-dependent active transport machinery. Consistent with this, germ plasm determinants attracted retroelement RNAs even when these components were ectopically positioned in bipolar oocytes. Likewise, vertebrate retrotransposons similarly migrated to the germ plasm in zebrafish oocytes. Together, these results suggest that germ plasm targeting represents a fitness strategy adopted by some retrotransposons to ensure transgenerational propagation.
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Sharangdhar T, Sugimoto Y, Heraud-Farlow J, Fernández-Moya SM, Ehses J, Ruiz de Los Mozos I, Ule J, Kiebler MA. A retained intron in the 3'-UTR of Calm3 mRNA mediates its Staufen2- and activity-dependent localization to neuronal dendrites. EMBO Rep 2017; 18:1762-1774. [PMID: 28765142 DOI: 10.15252/embr.201744334] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 06/30/2017] [Accepted: 07/05/2017] [Indexed: 11/09/2022] Open
Abstract
Dendritic localization and hence local mRNA translation contributes to synaptic plasticity in neurons. Staufen2 (Stau2) is a well-known neuronal double-stranded RNA-binding protein (dsRBP) that has been implicated in dendritic mRNA localization. The specificity of Stau2 binding to its target mRNAs remains elusive. Using individual-nucleotide resolution CLIP (iCLIP), we identified significantly enriched Stau2 binding to the 3'-UTRs of 356 transcripts. In 28 (7.9%) of those, binding occurred to a retained intron in their 3'-UTR The strongest bound 3'-UTR intron was present in the longest isoform of Calmodulin 3 (Calm3L ) mRNA Calm3L 3'-UTR contains six Stau2 crosslink clusters, four of which are in this retained 3'-UTR intron. The Calm3L mRNA localized to neuronal dendrites, while lack of the 3'-UTR intron impaired its dendritic localization. Importantly, Stau2 mediates this dendritic localization via the 3'-UTR intron, without affecting its stability. Also, NMDA-mediated synaptic activity specifically promoted the dendritic mRNA localization of the Calm3L isoform, while inhibition of synaptic activity reduced it substantially. Together, our results identify the retained intron as a critical element in recruiting Stau2, which then allows for the localization of Calm3L mRNA to distal dendrites.
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Affiliation(s)
| | - Yoichiro Sugimoto
- Department of Molecular Neuroscience, University College London Institute of Neurology, London, UK.,The Francis Crick Institute, London, UK
| | | | | | - Janina Ehses
- Division of Cell Biology, Biomedical Center, LMU Munich, Martinsried, Germany
| | - Igor Ruiz de Los Mozos
- Department of Molecular Neuroscience, University College London Institute of Neurology, London, UK.,The Francis Crick Institute, London, UK
| | - Jernej Ule
- Department of Molecular Neuroscience, University College London Institute of Neurology, London, UK.,The Francis Crick Institute, London, UK
| | - Michael A Kiebler
- Division of Cell Biology, Biomedical Center, LMU Munich, Martinsried, Germany
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Ramat A, Hannaford M, Januschke J. Maintenance of Miranda Localization in Drosophila Neuroblasts Involves Interaction with the Cognate mRNA. Curr Biol 2017; 27:2101-2111.e5. [PMID: 28690114 PMCID: PMC5526833 DOI: 10.1016/j.cub.2017.06.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 05/01/2017] [Accepted: 06/07/2017] [Indexed: 11/28/2022]
Abstract
How cells position their proteins is a key problem in cell biology. Targeting mRNAs to distinct regions of the cytoplasm contributes to protein localization by providing local control over translation. Here, we reveal that an interdependence of a protein and cognate mRNA maintains asymmetric protein distribution in mitotic Drosophila neural stem cells. We tagged endogenous mRNA or protein products of the gene miranda that is required for fate determination with GFP. We find that the mRNA localizes like the protein it encodes in a basal crescent in mitosis. We then used GFP-specific nanobodies fused to localization domains to alter the subcellular distribution of the GFP-tagged mRNA or protein. Altering the localization of the mRNA resulted in mislocalization of the protein and vice versa. Protein localization defects caused by mislocalization of the cognate mRNA were rescued by introducing untagged mRNA coding for mutant non-localizable protein. Therefore, by combining the MS2 system and subcellular nanobody expression, we uncovered that maintenance of Mira asymmetric localization requires interaction with the cognate mRNA.
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Affiliation(s)
- Anne Ramat
- Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dow Street, DD5 1EH Dundee, UK
| | - Matthew Hannaford
- Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dow Street, DD5 1EH Dundee, UK
| | - Jens Januschke
- Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dow Street, DD5 1EH Dundee, UK.
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Geuens T, De Winter V, Rajan N, Achsel T, Mateiu L, Almeida-Souza L, Asselbergh B, Bouhy D, Auer-Grumbach M, Bagni C, Timmerman V. Mutant HSPB1 causes loss of translational repression by binding to PCBP1, an RNA binding protein with a possible role in neurodegenerative disease. Acta Neuropathol Commun 2017; 5:5. [PMID: 28077174 PMCID: PMC5225548 DOI: 10.1186/s40478-016-0407-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 12/16/2016] [Indexed: 12/12/2022] Open
Abstract
The small heat shock protein HSPB1 (Hsp27) is an ubiquitously expressed molecular chaperone able to regulate various cellular functions like actin dynamics, oxidative stress regulation and anti-apoptosis. So far disease causing mutations in HSPB1 have been associated with neurodegenerative diseases such as distal hereditary motor neuropathy, Charcot-Marie-Tooth disease and amyotrophic lateral sclerosis. Most mutations in HSPB1 target its highly conserved α-crystallin domain, while other mutations affect the C- or N-terminal regions or its promotor. Mutations inside the α-crystallin domain have been shown to enhance the chaperone activity of HSPB1 and increase the binding to client proteins. However, the HSPB1-P182L mutation, located outside and downstream of the α-crystallin domain, behaves differently. This specific HSPB1 mutation results in a severe neuropathy phenotype affecting exclusively the motor neurons of the peripheral nervous system. We identified that the HSPB1-P182L mutant protein has a specifically increased interaction with the RNA binding protein poly(C)binding protein 1 (PCBP1) and results in a reduction of its translational repressive activity. RNA immunoprecipitation followed by RNA sequencing on mouse brain lead to the identification of PCBP1 mRNA targets. These targets contain larger 3′- and 5′-UTRs than average and are enriched in an RNA motif consisting of the CTCCTCCTCCTCC consensus sequence. Interestingly, next to the clear presence of neuronal transcripts among the identified PCBP1 targets we identified known genes associated with hereditary peripheral neuropathies and hereditary spastic paraplegias. We therefore conclude that HSPB1 can mediate translational repression through interaction with an RNA binding protein further supporting its role in neurodegenerative disease.
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Di Tomasso G, Miller Jenkins LM, Legault P. ARiBo pull-down for riboproteomic studies based on label-free quantitative mass spectrometry. RNA (NEW YORK, N.Y.) 2016; 22:1760-1770. [PMID: 27659051 PMCID: PMC5066628 DOI: 10.1261/rna.057513.116] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 08/11/2016] [Indexed: 06/06/2023]
Abstract
As part of their normal life cycle, most RNA molecules associate with several proteins that direct their fate and regulate their function. Here, we describe a novel method for identifying proteins that associate with a target RNA. The procedure is based on the ARiBo method for affinity purification of RNA, which was originally developed to quickly purify RNA with high yields and purity under native conditions. The ARiBo method was further optimized using in vitro transcribed RNA to capture RNA-associating proteins from cellular extracts with high yields and low background protein contamination. For these RNA pull-downs, stem-loops present in the immature forms of let-7 miRNAs (miRNA stem-loops) were used as the target RNAs. Label-free quantitative mass spectrometry analysis allowed for the reliable identification of proteins that are specific to the stem-loops present in the immature forms of two miRNAs, let-7a-1 and let-7g. Several proteins known to bind immature forms of these let-7 miRNAs were identified, but with an improved coverage compared to previous studies. In addition, several novel proteins were identified that better define the protein interactome of the let-7 miRNA stem-loops and further link let-7 biogenesis to important biological processes such as development and tumorigenesis. Thus, combining the ARiBo pull-down method with label-free quantitative mass spectrometry provides an effective proteomic approach for identification of proteins that associate with a target RNA.
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Affiliation(s)
- Geneviève Di Tomasso
- Département de biochimie et médecine moléculaire, Université de Montréal, Succursale Centre-Ville, Montréal, Québec H3C 3J7, Canada
| | - Lisa M Miller Jenkins
- Laboratory of Cell Biology, National Cancer Institute, Bethesda, Maryland 20892, USA
| | - Pascale Legault
- Département de biochimie et médecine moléculaire, Université de Montréal, Succursale Centre-Ville, Montréal, Québec H3C 3J7, Canada
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Bondy-Chorney E, Crawford Parks TE, Ravel-Chapuis A, Jasmin BJ, Côté J. Staufen1s role as a splicing factor and a disease modifier in Myotonic Dystrophy Type I. Rare Dis 2016; 4:e1225644. [PMID: 27695661 PMCID: PMC5027583 DOI: 10.1080/21675511.2016.1225644] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 06/23/2016] [Accepted: 08/11/2016] [Indexed: 12/19/2022] Open
Abstract
In a recent issue of PLOS Genetics, we reported that the double-stranded RNA-binding protein, Staufen1, functions as a disease modifier in the neuromuscular disorder Myotonic Dystrophy Type I (DM1). In this work, we demonstrated that Staufen1 regulates the alternative splicing of exon 11 of the human Insulin Receptor, a highly studied missplicing event in DM1, through Alu elements located in an intronic region. Furthermore, we found that Staufen1 overexpression regulates numerous alternative splicing events, potentially resulting in both positive and negative effects in DM1. Here, we discuss our major findings and speculate on the details of the mechanisms by which Staufen1 could regulate alternative splicing, in both normal and DM1 conditions. Finally, we highlight the importance of disease modifiers, such as Staufen1, in the DM1 pathology in order to understand the complex disease phenotype and for future development of new therapeutic strategies.
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Affiliation(s)
- Emma Bondy-Chorney
- Department of Cellular and Molecular Medicine, University of Ottawa, Center for Neuromuscular Disease , Ottawa, Ontario, Canada
| | - Tara E Crawford Parks
- Department of Cellular and Molecular Medicine, University of Ottawa, Center for Neuromuscular Disease , Ottawa, Ontario, Canada
| | - Aymeric Ravel-Chapuis
- Department of Cellular and Molecular Medicine, University of Ottawa, Center for Neuromuscular Disease , Ottawa, Ontario, Canada
| | - Bernard J Jasmin
- Department of Cellular and Molecular Medicine, University of Ottawa, Center for Neuromuscular Disease , Ottawa, Ontario, Canada
| | - Jocelyn Côté
- Department of Cellular and Molecular Medicine, University of Ottawa, Center for Neuromuscular Disease , Ottawa, Ontario, Canada
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Mahoney RE, Azpurua J, Eaton BA. Insulin signaling controls neurotransmission via the 4eBP-dependent modification of the exocytotic machinery. eLife 2016; 5:e16807. [PMID: 27525480 PMCID: PMC5012858 DOI: 10.7554/elife.16807] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 08/14/2016] [Indexed: 12/26/2022] Open
Abstract
Altered insulin signaling has been linked to widespread nervous system dysfunction including cognitive dysfunction, neuropathy and susceptibility to neurodegenerative disease. However, knowledge of the cellular mechanisms underlying the effects of insulin on neuronal function is incomplete. Here, we show that cell autonomous insulin signaling within the Drosophila CM9 motor neuron regulates the release of neurotransmitter via alteration of the synaptic vesicle fusion machinery. This effect of insulin utilizes the FOXO-dependent regulation of the thor gene, which encodes the Drosophila homologue of the eif-4e binding protein (4eBP). A critical target of this regulatory mechanism is Complexin, a synaptic protein known to regulate synaptic vesicle exocytosis. We find that the amounts of Complexin protein observed at the synapse is regulated by insulin and genetic manipulations of Complexin levels support the model that increased synaptic Complexin reduces neurotransmission in response to insulin signaling.
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Affiliation(s)
- Rebekah Elizabeth Mahoney
- Department of Physiology, University of Texas Health Sciences Center at San Antonio, San Antonio, United States
- Barshop Institute of Aging and Longevity Studies, University of Texas Health Sciences Center at San Antonio, San Antonio, United States
| | - Jorge Azpurua
- Department of Physiology, University of Texas Health Sciences Center at San Antonio, San Antonio, United States
| | - Benjamin A Eaton
- Department of Physiology, University of Texas Health Sciences Center at San Antonio, San Antonio, United States
- Barshop Institute of Aging and Longevity Studies, University of Texas Health Sciences Center at San Antonio, San Antonio, United States
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Na H, Laver JD, Jeon J, Singh F, Ancevicius K, Fan Y, Cao WX, Nie K, Yang Z, Luo H, Wang M, Rissland O, Westwood JT, Kim PM, Smibert CA, Lipshitz HD, Sidhu SS. A high-throughput pipeline for the production of synthetic antibodies for analysis of ribonucleoprotein complexes. RNA (NEW YORK, N.Y.) 2016; 22:636-655. [PMID: 26847261 PMCID: PMC4793217 DOI: 10.1261/rna.055186.115] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 12/12/2015] [Indexed: 06/05/2023]
Abstract
Post-transcriptional regulation of mRNAs plays an essential role in the control of gene expression. mRNAs are regulated in ribonucleoprotein (RNP) complexes by RNA-binding proteins (RBPs) along with associated protein and noncoding RNA (ncRNA) cofactors. A global understanding of post-transcriptional control in any cell type requires identification of the components of all of its RNP complexes. We have previously shown that these complexes can be purified by immunoprecipitation using anti-RBP synthetic antibodies produced by phage display. To develop the large number of synthetic antibodies required for a global analysis of RNP complex composition, we have established a pipeline that combines (i) a computationally aided strategy for design of antigens located outside of annotated domains, (ii) high-throughput antigen expression and purification in Escherichia coli, and (iii) high-throughput antibody selection and screening. Using this pipeline, we have produced 279 antibodies against 61 different protein components of Drosophila melanogaster RNPs. Together with those produced in our low-throughput efforts, we have a panel of 311 antibodies for 67 RNP complex proteins. Tests of a subset of our antibodies demonstrated that 89% immunoprecipitate their endogenous target from embryo lysate. This panel of antibodies will serve as a resource for global studies of RNP complexes in Drosophila. Furthermore, our high-throughput pipeline permits efficient production of synthetic antibodies against any large set of proteins.
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Affiliation(s)
- Hong Na
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada M5S 3E1
| | - John D Laver
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Jouhyun Jeon
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada M5S 3E1
| | - Fateh Singh
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada M5S 3E1
| | - Kristin Ancevicius
- Department of Biology, University of Toronto at Mississauga, Mississauga, Ontario, Canada L5L 1C6 Department of Cell and Systems Biology, University of Toronto at Mississauga, Mississauga, Ontario, Canada L5L 1C6
| | - Yujie Fan
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Wen Xi Cao
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Kun Nie
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada M5S 3E1 Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Zhenglin Yang
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Hua Luo
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Miranda Wang
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8 Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada M5G 0A4
| | - Olivia Rissland
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8 Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada M5G 0A4
| | - J Timothy Westwood
- Department of Biology, University of Toronto at Mississauga, Mississauga, Ontario, Canada L5L 1C6 Department of Cell and Systems Biology, University of Toronto at Mississauga, Mississauga, Ontario, Canada L5L 1C6
| | - Philip M Kim
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada M5S 3E1 Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8 Department of Computer Science, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Craig A Smibert
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8 Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Howard D Lipshitz
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Sachdev S Sidhu
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada M5S 3E1 Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8
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41
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A Smaug2-Based Translational Repression Complex Determines the Balance between Precursor Maintenance versus Differentiation during Mammalian Neurogenesis. J Neurosci 2016; 35:15666-81. [PMID: 26609159 DOI: 10.1523/jneurosci.2172-15.2015] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
UNLABELLED Here, we have asked about post-transcriptional mechanisms regulating murine developmental neurogenesis, focusing upon the RNA-binding proteins Smaug2 and Nanos1. We identify, in embryonic neural precursors of the murine cortex, a Smaug2 protein/nanos1 mRNA complex that is present in cytoplasmic granules with the translational repression proteins Dcp1 and 4E-T. We show that Smaug2 inhibits and Nanos1 promotes neurogenesis, with Smaug2 knockdown enhancing neurogenesis and depleting precursors, and Nanos1 knockdown inhibiting neurogenesis and maintaining precursors. Moreover, we show that Smaug2 likely regulates neurogenesis by silencing nanos1 mRNA. Specifically, Smaug2 knockdown inappropriately increases Nanos1 protein, and the Smaug2 knockdown-mediated neurogenesis is rescued by preventing this increase. Thus, Smaug2 and Nanos1 function as a bimodal translational repression switch to control neurogenesis, with Smaug2 acting in transcriptionally primed precursors to silence mRNAs important for neurogenesis, including nanos1 mRNA, and Nanos1 acting during the transition to neurons to repress the precursor state. SIGNIFICANCE STATEMENT The mechanisms instructing neural stem cells to generate the appropriate progeny are still poorly understood. Here, we show that the RNA-binding proteins Smaug2 and Nanos1 are critical regulators of this balance and provide evidence supporting the idea that neural precursors are transcriptionally primed to generate neurons but translational regulation maintains these precursors in a stem cell state until the appropriate developmental time.
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Iavello A, Frech VSL, Gai C, Deregibus MC, Quesenberry PJ, Camussi G. Role of Alix in miRNA packaging during extracellular vesicle biogenesis. Int J Mol Med 2016; 37:958-66. [PMID: 26935291 PMCID: PMC4790646 DOI: 10.3892/ijmm.2016.2488] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 01/21/2016] [Indexed: 02/07/2023] Open
Abstract
Evidence indicates that Alix, an accessory protein of the endosomal sorting complex required for transport (ESCRT), is involved in the biogenesis of extracellular vesicles (EVs). EVs contain selected patterns of microRNAs (miRNAs or miRs); however, little is known about the mechanisms of miRNA enrichment in EVs. The aim of the present study was to evaluate whether Alix is involved in the packaging of miRNAs within EVs released by human liver stem-like cells (HLSCs). EVs released from HLSCs were enriched with miRNAs and expressed Alix and several RNA-binding proteins, including Argonaute 2 (Ago2), a member of the Argonaute family known to be involved in the transport and the processing of miRNAs. Co-immunoprecipitation experiments revealed an association between Alix and Ago2. The results from RT-qPCR indicated that in the Alix/Ago2 immunoprecipitates, miRNAs were detectable. EVs were instrumental in transferring selected miRNAs from HLSCs to human endothelial cells absent in the latter cells. Alix knockdown did not influence the number of EVs released by HLSCs, but it significantly decreased miRNA expression levels in the EVs and consequently their transfer to the endothelium. Our findings indicate that Alix binds to Ago2 and miRNAs, suggesting that it plays a key role in miRNA enrichment during EV biogenesis. These results may represent a novel function of Alix, demonstrating its involvement in the EV-mediated transfer of miRNAs.
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Affiliation(s)
- Alessandra Iavello
- Department of Medical Sciences and Molecular Biotechnology Center, University of Torino, 10126 Torino, Italy
| | - Valeska S L Frech
- Department of Medical Sciences and Molecular Biotechnology Center, University of Torino, 10126 Torino, Italy
| | - Chiara Gai
- Department of Medical Sciences and Molecular Biotechnology Center, University of Torino, 10126 Torino, Italy
| | - Maria Chiara Deregibus
- Department of Medical Sciences and Molecular Biotechnology Center, University of Torino, 10126 Torino, Italy
| | - Peter J Quesenberry
- Department of Medicine, The Warren Alpert Medical School of Brown University, Providence, RI 02903, USA
| | - Giovanni Camussi
- Department of Medical Sciences and Molecular Biotechnology Center, University of Torino, 10126 Torino, Italy
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Bondy-Chorney E, Crawford Parks TE, Ravel-Chapuis A, Klinck R, Rocheleau L, Pelchat M, Chabot B, Jasmin BJ, Côté J. Staufen1 Regulates Multiple Alternative Splicing Events either Positively or Negatively in DM1 Indicating Its Role as a Disease Modifier. PLoS Genet 2016; 12:e1005827. [PMID: 26824521 PMCID: PMC4733145 DOI: 10.1371/journal.pgen.1005827] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 01/05/2016] [Indexed: 01/10/2023] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a neuromuscular disorder caused by an expansion of CUG repeats in the 3' UTR of the DMPK gene. The CUG repeats form aggregates of mutant mRNA, which cause misregulation and/or sequestration of RNA-binding proteins, causing aberrant alternative splicing in cells. Previously, we showed that the multi-functional RNA-binding protein Staufen1 (Stau1) was increased in skeletal muscle of DM1 mouse models and patients. We also showed that Stau1 rescues the alternative splicing profile of pre-mRNAs, e.g. the INSR and CLC1, known to be aberrantly spliced in DM1. In order to explore further the potential of Stau1 as a therapeutic target for DM1, we first investigated the mechanism by which Stau1 regulates pre-mRNA alternative splicing. We report here that Stau1 regulates the alternative splicing of exon 11 of the human INSR via binding to Alu elements located in intron 10. Additionally, using a high-throughput RT-PCR screen, we have identified numerous Stau1-regulated alternative splicing events in both WT and DM1 myoblasts. A number of these aberrant ASEs in DM1, including INSR exon 11, are rescued by overexpression of Stau1. However, we find other ASEs in DM1 cells, where overexpression of Stau1 shifts the splicing patterns away from WT conditions. Moreover, we uncovered that Stau1-regulated ASEs harbour Alu elements in intronic regions flanking the alternative exon more than non-Stau1 targets. Taken together, these data highlight the broad impact of Stau1 as a splicing regulator and suggest that Stau1 may act as a disease modifier in DM1.
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Affiliation(s)
- Emma Bondy-Chorney
- Department of Cellular and Molecular Medicine, University of Ottawa; Centre for Neuromuscular Disease, Ottawa, Ontario, Canada
| | - Tara E. Crawford Parks
- Department of Cellular and Molecular Medicine, University of Ottawa; Centre for Neuromuscular Disease, Ottawa, Ontario, Canada
| | - Aymeric Ravel-Chapuis
- Department of Cellular and Molecular Medicine, University of Ottawa; Centre for Neuromuscular Disease, Ottawa, Ontario, Canada
| | - Roscoe Klinck
- Département de microbiologie et d'infectiologie, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Lynda Rocheleau
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Martin Pelchat
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Benoit Chabot
- Département de microbiologie et d'infectiologie, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Bernard J. Jasmin
- Department of Cellular and Molecular Medicine, University of Ottawa; Centre for Neuromuscular Disease, Ottawa, Ontario, Canada
| | - Jocelyn Côté
- Department of Cellular and Molecular Medicine, University of Ottawa; Centre for Neuromuscular Disease, Ottawa, Ontario, Canada
- * E-mail:
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44
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Abstract
The localization of mRNAs to specific subcellular sites is widespread, allowing cells to spatially restrict and regulate protein production, and playing important roles in development and cellular physiology. This process has been studied in mechanistic detail for several RNAs. However, the generality or specificity of RNA localization systems and mechanisms that impact the many thousands of localized mRNAs has been difficult to assess. In this review, we discuss the current state of the field in determining which RNAs localize, which RNA sequences mediate localization, the protein factors involved, and the biological implications of localization. For each question, we examine prominent systems and techniques that are used to study individual messages, highlight recent genome-wide studies of RNA localization, and discuss the potential for adapting other high-throughput approaches to the study of localization.
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Affiliation(s)
- J Matthew Taliaferro
- a Department of Biology; Massachusetts Institute of Technology ; Cambridge , MA USA
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45
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Fernández Moya SM, Kiebler MA. CLIPing Staufen to secondary RNA structures: size and location matter! Bioessays 2015; 37:1062-6. [PMID: 26252431 DOI: 10.1002/bies.201500052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
hiCLIP (RNA hybrid and individual-nucleotide resolution ultraviolet cross-linking and immunoprecipitation), is a novel technique developed by Sugimoto et al. (2015). Here, the use of different adaptors permits a controlled ligation of the two strands of a RNA duplex allowing the identification of each arm in the duplex upon sequencing. The authors chose a notoriously difficult to study double-stranded RNA-binding protein (dsRBP) termed Staufen1, a mammalian homolog of Drosophila Staufen involved in mRNA localization and translational control. Using hiCLIP, they discovered a dominance of intramolecular RNA duplexes compared to the total RNA duplexes identified. Importantly, the authors discovered two different types of intramolecular duplexes in the cell: highly translated mRNAs with long-range duplexes in their 3'-UTRs and poorly translated mRNAs with duplexes in their coding region. In conclusion, the authors establish hiCLIP as an important novel technique for the identification of RNA secondary structures that serve as in vivo binding sites for dsRBPs.
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Affiliation(s)
- Sandra M Fernández Moya
- BioMedical Center, Department for Anatomy and Cell Biology, Ludwig-Maximilians-University, Munich, Germany
| | - Michael A Kiebler
- BioMedical Center, Department for Anatomy and Cell Biology, Ludwig-Maximilians-University, Munich, Germany
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46
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Laver JD, Li X, Ray D, Cook KB, Hahn NA, Nabeel-Shah S, Kekis M, Luo H, Marsolais AJ, Fung KY, Hughes TR, Westwood JT, Sidhu SS, Morris Q, Lipshitz HD, Smibert CA. Brain tumor is a sequence-specific RNA-binding protein that directs maternal mRNA clearance during the Drosophila maternal-to-zygotic transition. Genome Biol 2015; 16:94. [PMID: 25962635 PMCID: PMC4460960 DOI: 10.1186/s13059-015-0659-4] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 04/22/2015] [Indexed: 11/30/2022] Open
Abstract
Background Brain tumor (BRAT) is a Drosophila member of the TRIM-NHL protein family. This family is conserved among metazoans and its members function as post-transcriptional regulators. BRAT was thought to be recruited to mRNAs indirectly through interaction with the RNA-binding protein Pumilio (PUM). However, it has recently been demonstrated that BRAT directly binds to RNA. The precise sequence recognized by BRAT, the extent of BRAT-mediated regulation, and the exact roles of PUM and BRAT in post-transcriptional regulation are unknown. Results Genome-wide identification of transcripts associated with BRAT or with PUM in Drosophila embryos shows that they bind largely non-overlapping sets of mRNAs. BRAT binds mRNAs that encode proteins associated with a variety of functions, many of which are distinct from those implemented by PUM-associated transcripts. Computational analysis of in vitro and in vivo data identified a novel RNA motif recognized by BRAT that confers BRAT-mediated regulation in tissue culture cells. The regulatory status of BRAT-associated mRNAs suggests a prominent role for BRAT in post-transcriptional regulation, including a previously unidentified role in transcript degradation. Transcriptomic analysis of embryos lacking functional BRAT reveals an important role in mediating the decay of hundreds of maternal mRNAs during the maternal-to-zygotic transition. Conclusions Our results represent the first genome-wide analysis of the mRNAs associated with a TRIM-NHL protein and the first identification of an RNA motif bound by this protein family. BRAT is a prominent post-transcriptional regulator in the early embryo through mechanisms that are largely independent of PUM. Electronic supplementary material The online version of this article (doi:10.1186/s13059-015-0659-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- John D Laver
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada.
| | - Xiao Li
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada. .,Donnelly Centre, University of Toronto, 160 College Street, Toronto, Ontario, M5S 3E1, Canada.
| | - Debashish Ray
- Donnelly Centre, University of Toronto, 160 College Street, Toronto, Ontario, M5S 3E1, Canada.
| | - Kate B Cook
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada. .,Donnelly Centre, University of Toronto, 160 College Street, Toronto, Ontario, M5S 3E1, Canada.
| | - Noah A Hahn
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada.
| | - Syed Nabeel-Shah
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada.
| | - Mariana Kekis
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada. .,Donnelly Centre, University of Toronto, 160 College Street, Toronto, Ontario, M5S 3E1, Canada.
| | - Hua Luo
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada.
| | - Alexander J Marsolais
- Department of Biochemistry, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada.
| | - Karen Yy Fung
- Department of Biochemistry, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada.
| | - Timothy R Hughes
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada. .,Donnelly Centre, University of Toronto, 160 College Street, Toronto, Ontario, M5S 3E1, Canada.
| | - J Timothy Westwood
- Department of Biology, University of Toronto, Mississauga, 3359 Mississauga Road, Mississauga, Ontario, L5L 1C6, Canada.
| | - Sachdev S Sidhu
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada. .,Donnelly Centre, University of Toronto, 160 College Street, Toronto, Ontario, M5S 3E1, Canada.
| | - Quaid Morris
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada. .,Donnelly Centre, University of Toronto, 160 College Street, Toronto, Ontario, M5S 3E1, Canada. .,Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario, M5S 3G4, Canada. .,Department of Computer Science, University of Toronto, 40 St. George Street, Toronto, Ontario, M5S 2E4, Canada.
| | - Howard D Lipshitz
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada.
| | - Craig A Smibert
- Department of Molecular Genetics, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada. .,Department of Biochemistry, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada.
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47
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Sugimoto Y, Vigilante A, Darbo E, Zirra A, Militti C, D’Ambrogio A, Luscombe NM, Ule J. hiCLIP reveals the in vivo atlas of mRNA secondary structures recognized by Staufen 1. Nature 2015; 519:491-4. [PMID: 25799984 PMCID: PMC4376666 DOI: 10.1038/nature14280] [Citation(s) in RCA: 214] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Accepted: 02/02/2015] [Indexed: 02/02/2023]
Abstract
The structure of messenger RNA is important for post-transcriptional regulation, mainly because it affects binding of trans-acting factors. However, little is known about the in vivo structure of full-length mRNAs. Here we present hiCLIP, a biochemical technique for transcriptome-wide identification of RNA secondary structures interacting with RNA-binding proteins (RBPs). Using this technique to investigate RNA structures bound by Staufen 1 (STAU1) in human cells, we uncover a dominance of intra-molecular RNA duplexes, a depletion of duplexes from coding regions of highly translated mRNAs, an unexpected prevalence of long-range duplexes in 3' untranslated regions (UTRs), and a decreased incidence of single nucleotide polymorphisms in duplex-forming regions. We also discover a duplex spanning 858 nucleotides in the 3' UTR of the X-box binding protein 1 (XBP1) mRNA that regulates its cytoplasmic splicing and stability. Our study reveals the fundamental role of mRNA secondary structures in gene expression and introduces hiCLIP as a widely applicable method for discovering new, especially long-range, RNA duplexes.
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Affiliation(s)
- Yoichiro Sugimoto
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
| | - Alessandra Vigilante
- Cancer Research UK London Research Institute, 44 Lincoln’s Inn Fields, London WC2A 3LY, UK
- UCL Genetics Institute, Department of Genetics, Evolution & Environment, University College London, Gower Street, London WC1E 6BT, UK
| | - Elodie Darbo
- Cancer Research UK London Research Institute, 44 Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Alexandra Zirra
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK
| | - Cristina Militti
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK
| | - Andrea D’Ambrogio
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK
| | - Nicholas M Luscombe
- Cancer Research UK London Research Institute, 44 Lincoln’s Inn Fields, London WC2A 3LY, UK
- UCL Genetics Institute, Department of Genetics, Evolution & Environment, University College London, Gower Street, London WC1E 6BT, UK
- Okinawa Institute of Science & Technology, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan
| | - Jernej Ule
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, WC1N 3BG, UK
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48
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Abstract
RNA-binding proteins (RBPs) are important regulators of eukaryotic gene expression. Genomes typically encode dozens to hundreds of proteins containing RNA-binding domains, which collectively recognize diverse RNA sequences and structures. Recent advances in high-throughput methods for assaying the targets of RBPs in vitro and in vivo allow large-scale derivation of RNA-binding motifs as well as determination of RNA–protein interactions in living cells. In parallel, many computational methods have been developed to analyze and interpret these data. The interplay between RNA secondary structure and RBP binding has also been a growing theme. Integrating RNA–protein interaction data with observations of post-transcriptional regulation will enhance our understanding of the roles of these important proteins.
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49
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Abstract
Localization and the associated translational control of mRNA is a well established mechanism for segregating cellular protein expression. Drosophila has been instrumental in deciphering the prevailing mechanisms of mRNA localization and regulation. This review will discuss the diverse roles of mRNA localization in the Drosophila germline, the cis-elements and cellular components regulating localization and the superimposition of translational regulatory mechanisms. Despite a history of discovery, there are still many fundamental questions regarding mRNA localization that remain unanswered. Take home messages, outstanding questions and future approaches that will likely lead to resolving these unknowns in the future are summarized at the end.
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Affiliation(s)
- Timothy T Weil
- a Department of Zoology ; University of Cambridge ; Cambridge , UK
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50
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Ravel-Chapuis A, Crawford TE, Blais-Crépeau ML, Bélanger G, Richer CT, Jasmin BJ. The RNA-binding protein Staufen1 impairs myogenic differentiation via a c-myc-dependent mechanism. Mol Biol Cell 2014; 25:3765-78. [PMID: 25208565 PMCID: PMC4230783 DOI: 10.1091/mbc.e14-04-0895] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The expression pattern of Staufen1 during mouse skeletal muscle development is described. Sustained expression of Staufen1 in myoblasts prevents normal differentiation by causing decreases in the expression of key myogenic markers by an SMD-independent mechanism and by promoting the translational regulation of c-myc. Recent work has shown that Staufen1 plays key roles in skeletal muscle, yet little is known about its pattern of expression during embryonic and postnatal development. Here we first show that Staufen1 levels are abundant in mouse embryonic muscles and that its expression decreases thereafter, reaching low levels in mature muscles. A similar pattern of expression is seen as cultured myoblasts differentiate into myotubes. Muscle degeneration/regeneration experiments revealed that Staufen1 increases after cardiotoxin injection before returning to the low levels seen in mature muscles. We next prevented the decrease in Staufen1 during differentiation by generating stable C2C12 muscle cell lines overexpressing Staufen1. Cells overexpressing Staufen1 differentiated poorly, as evidenced by reductions in the differentiation and fusion indices and decreases in MyoD, myogenin, MEF2A, and MEF2C, independently of Staufen-mediated mRNA decay. However, levels of c-myc, a factor known to inhibit differentiation, were increased in C2C12 cells overexpressing Staufen1 through enhanced translation. By contrast, the knockdown of Staufen1 decreased c-myc levels in myoblasts. Collectively our results show that Staufen1 is highly expressed during early stages of differentiation/development and that it can impair differentiation by regulating c-myc, thereby highlighting the multifunctional role of Staufen1 in skeletal muscle cells.
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Affiliation(s)
- Aymeric Ravel-Chapuis
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Tara E Crawford
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Marie-Laure Blais-Crépeau
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Guy Bélanger
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Chase T Richer
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Bernard J Jasmin
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
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