1
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Vatandaslar H, Garzia A, Meyer C, Godbersen S, Brandt LTL, Griesbach E, Chao JA, Tuschl T, Stoffel M. In vivo PAR-CLIP (viP-CLIP) of liver TIAL1 unveils targets regulating cholesterol synthesis and secretion. Nat Commun 2023; 14:3386. [PMID: 37296170 PMCID: PMC10256721 DOI: 10.1038/s41467-023-39135-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 05/31/2023] [Indexed: 06/12/2023] Open
Abstract
System-wide cross-linking and immunoprecipitation (CLIP) approaches have unveiled regulatory mechanisms of RNA-binding proteins (RBPs) mainly in cultured cells due to limitations in the cross-linking efficiency of tissues. Here, we describe viP-CLIP (in vivo PAR-CLIP), a method capable of identifying RBP targets in mammalian tissues, thereby facilitating the functional analysis of RBP-regulatory networks in vivo. We applied viP-CLIP to mouse livers and identified Insig2 and ApoB as prominent TIAL1 target transcripts, indicating an important role of TIAL1 in cholesterol synthesis and secretion. The functional relevance of these targets was confirmed by showing that TIAL1 influences their translation in hepatocytes. Mutant Tial1 mice exhibit altered cholesterol synthesis, APOB secretion and plasma cholesterol levels. Our results demonstrate that viP-CLIP can identify physiologically relevant RBP targets by finding a factor implicated in the negative feedback regulation of cholesterol biosynthesis.
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Affiliation(s)
- Hasan Vatandaslar
- Institute of Molecular Health Sciences, ETH Zurich, Otto-Stern-Weg 7, 8093, Zürich, Switzerland
| | - Aitor Garzia
- Laboratory of RNA Molecular Biology, The Rockefeller University, 1230 York Avenue, New York, NY, 10021, USA
| | - Cindy Meyer
- Laboratory of RNA Molecular Biology, The Rockefeller University, 1230 York Avenue, New York, NY, 10021, USA
| | - Svenja Godbersen
- Institute of Molecular Health Sciences, ETH Zurich, Otto-Stern-Weg 7, 8093, Zürich, Switzerland
| | - Laura T L Brandt
- Institute of Molecular Health Sciences, ETH Zurich, Otto-Stern-Weg 7, 8093, Zürich, Switzerland
| | - Esther Griesbach
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058, Basel, Switzerland
| | - Jeffrey A Chao
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058, Basel, Switzerland
| | - Thomas Tuschl
- Laboratory of RNA Molecular Biology, The Rockefeller University, 1230 York Avenue, New York, NY, 10021, USA
| | - Markus Stoffel
- Institute of Molecular Health Sciences, ETH Zurich, Otto-Stern-Weg 7, 8093, Zürich, Switzerland.
- Medical Faculty, University of Zürich, 8091, Zürich, Switzerland.
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2
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Salerno-Kochan A, Horn A, Ghosh P, Nithin C, Kościelniak A, Meindl A, Strauss D, Krutyhołowa R, Rossbach O, Bujnicki JM, Gaik M, Medenbach J, Glatt S. Molecular insights into RNA recognition and gene regulation by the TRIM-NHL protein Mei-P26. Life Sci Alliance 2022; 5:5/8/e202201418. [PMID: 35512835 PMCID: PMC9070667 DOI: 10.26508/lsa.202201418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 02/06/2023] Open
Abstract
The TRIM-NHL protein Meiotic P26 (Mei-P26) acts as a regulator of cell fate in Drosophila Its activity is critical for ovarian germline stem cell maintenance, differentiation of oocytes, and spermatogenesis. Mei-P26 functions as a post-transcriptional regulator of gene expression; however, the molecular details of how its NHL domain selectively recognizes and regulates its mRNA targets have remained elusive. Here, we present the crystal structure of the Mei-P26 NHL domain at 1.6 Å resolution and identify key amino acids that confer substrate specificity and distinguish Mei-P26 from closely related TRIM-NHL proteins. Furthermore, we identify mRNA targets of Mei-P26 in cultured Drosophila cells and show that Mei-P26 can act as either a repressor or activator of gene expression on different RNA targets. Our work reveals the molecular basis of RNA recognition by Mei-P26 and the fundamental functional differences between otherwise very similar TRIM-NHL proteins.
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Affiliation(s)
- Anna Salerno-Kochan
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland.,Postgraduate School of Molecular Medicine, Warsaw, Poland
| | - Andreas Horn
- Biochemistry I, University of Regensburg, Regensburg, Germany
| | - Pritha Ghosh
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Chandran Nithin
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Anna Kościelniak
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Andreas Meindl
- Biochemistry I, University of Regensburg, Regensburg, Germany
| | - Daniela Strauss
- Biochemistry I, University of Regensburg, Regensburg, Germany
| | | | - Oliver Rossbach
- Institute of Biochemistry, University of Giessen, Giessen, Germany
| | - Janusz M Bujnicki
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology, Warsaw, Poland.,Bioinformatics Laboratory, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznan, Poland
| | - Monika Gaik
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Jan Medenbach
- Biochemistry I, University of Regensburg, Regensburg, Germany
| | - Sebastian Glatt
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
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3
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Korn SM, Ulshöfer CJ, Schneider T, Schlundt A. Structures and target RNA preferences of the RNA-binding protein family of IGF2BPs: An overview. Structure 2021; 29:787-803. [PMID: 34022128 DOI: 10.1016/j.str.2021.05.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 03/12/2021] [Accepted: 04/30/2021] [Indexed: 02/08/2023]
Abstract
Insulin-like growth factor 2 mRNA-binding proteins (IMPs, IGF2BPs) act in mRNA transport and translational control but are oncofetal tumor marker proteins. The IMP protein family represents a number of bona fide multi-domain RNA-binding proteins with up to six RNA-binding domains, resulting in a high complexity of possible modes of interactions with target mRNAs. Their exact mechanism in stability control of oncogenic mRNAs is only partially understood. Our and other laboratories' recent work has significantly pushed the understanding of IMP protein specificities both toward RNA engagement and between each other from NMR and crystal structures serving the basis for systematic biochemical and functional investigations. We here summarize the known structural and biochemical information about IMP RNA-binding domains and their RNA preferences. The article also touches on the respective roles of RNA secondary and protein tertiary structures for specific RNA-protein complexes, including the limited knowledge about IMPs' protein-protein interactions, which are often RNA mediated.
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Affiliation(s)
- Sophie Marianne Korn
- Institute for Molecular Biosciences and Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Corinna Jessica Ulshöfer
- Institute of Biochemistry, Justus-Liebig-University of Giessen, Heinrich-Buff-Ring 17, 35392 Giessen, Germany
| | - Tim Schneider
- Institute of Biochemistry, Justus-Liebig-University of Giessen, Heinrich-Buff-Ring 17, 35392 Giessen, Germany
| | - Andreas Schlundt
- Institute for Molecular Biosciences and Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany.
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4
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Hollmann NM, Jagtap PKA, Masiewicz P, Guitart T, Simon B, Provaznik J, Stein F, Haberkant P, Sweetapple LJ, Villacorta L, Mooijman D, Benes V, Savitski MM, Gebauer F, Hennig J. Pseudo-RNA-Binding Domains Mediate RNA Structure Specificity in Upstream of N-Ras. Cell Rep 2020; 32:107930. [PMID: 32697992 PMCID: PMC7383231 DOI: 10.1016/j.celrep.2020.107930] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/03/2020] [Accepted: 06/29/2020] [Indexed: 12/12/2022] Open
Abstract
RNA-binding proteins (RBPs) commonly feature multiple RNA-binding domains (RBDs), which provide these proteins with a modular architecture. Accumulating evidence supports that RBP architectural modularity and adaptability define the specificity of their interactions with RNA. However, how multiple RBDs recognize their cognate single-stranded RNA (ssRNA) sequences in concert remains poorly understood. Here, we use Upstream of N-Ras (Unr) as a model system to address this question. Although reported to contain five ssRNA-binding cold-shock domains (CSDs), we demonstrate that Unr includes an additional four CSDs that do not bind RNA (pseudo-RBDs) but are involved in mediating RNA tertiary structure specificity by reducing the conformational heterogeneity of Unr. Disrupting the interactions between canonical and non-canonical CSDs impacts RNA binding, Unr-mediated translation regulation, and the Unr-dependent RNA interactome. Taken together, our studies reveal a new paradigm in protein-RNA recognition, where interactions between RBDs and pseudo-RBDs select RNA tertiary structures, influence RNP assembly, and define target specificity.
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Affiliation(s)
- Nele Merret Hollmann
- Structural and Computational Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany; Collaboration for Joint PhD Degree between EMBL and Heidelberg University, Faculty of Biosciences, Heidelberg, Germany
| | | | - Pawel Masiewicz
- Structural and Computational Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Tanit Guitart
- Gene Regulation, Stem Cells and Cancer Programme, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, 08003 Barcelona, Spain
| | - Bernd Simon
- Structural and Computational Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Jan Provaznik
- Genomics Core Facility, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Frank Stein
- Proteomics Core Facility, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Per Haberkant
- Proteomics Core Facility, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Lara Jayne Sweetapple
- Structural and Computational Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Laura Villacorta
- Genomics Core Facility, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Dylan Mooijman
- Developmental Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Vladimir Benes
- Genomics Core Facility, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Mikhail M Savitski
- Proteomics Core Facility, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany; Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Fátima Gebauer
- Gene Regulation, Stem Cells and Cancer Programme, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, 08003 Barcelona, Spain; Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
| | - Janosch Hennig
- Structural and Computational Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany.
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5
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GIGYF1/2-Driven Cooperation between ZNF598 and TTP in Posttranscriptional Regulation of Inflammatory Signaling. Cell Rep 2020; 26:3511-3521.e4. [PMID: 30917308 DOI: 10.1016/j.celrep.2019.03.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 01/03/2019] [Accepted: 02/27/2019] [Indexed: 12/15/2022] Open
Abstract
Inflammatory signaling is restricted through degradation and the translational repression of cytokine mRNAs. A key factor in this regulation is tristetraprolin (TTP), an RNA-binding protein (RBP) that recruits RNA-destabilizing factors and the translation inhibitory complex 4EHP-GIGYF1/2 to AU-rich element (ARE)-containing mRNAs. Here, we show that the RBP ZNF598 contributes to the same regulatory module in a TTP-like manner. Similar to TTP, ZNF598 harbors three proline-rich motifs that bind the GYF domain of GIGYF1. RNA sequencing experiments showed that ZNF598 is required for the regulation of known TTP targets, including IL-8 and CSF2 mRNA. Furthermore, we demonstrate that ZNF598 binds to IL-8 mRNA, but not TNF mRNA. Collectively, our findings highlight that ZNF598 functions as an RBP that buffers the level of a range of mRNAs. We propose that ZNF598 is a TTP-like factor that can contribute to the regulation of the inflammatory potential of cytokine-producing cells.
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6
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Ren F, Lin Q, Gong G, Du X, Dan H, Qin W, Miao R, Xiong Y, Xiao R, Li X, Gui JF, Mei J. Igf2bp3 maintains maternal RNA stability and ensures early embryo development in zebrafish. Commun Biol 2020; 3:94. [PMID: 32127635 PMCID: PMC7054421 DOI: 10.1038/s42003-020-0827-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 02/11/2020] [Indexed: 12/22/2022] Open
Abstract
Early embryogenesis relies on maternally inherited mRNAs. Although the mechanism of maternal mRNA degradation during maternal-to-zygotic transition (MZT) has been extensively studied in vertebrates, how the embryos maintain maternal mRNA stability remains unclear. Here, we identify Igf2bp3 as an important regulator of maternal mRNA stability in zebrafish. Depletion of maternal igf2bp3 destabilizes maternal mRNAs prior to MZT and leads to severe developmental defects, including abnormal cytoskeleton organization and cell division. However, the process of oogenesis and the expression levels of maternal mRNAs in unfertilized eggs are normal in maternal igf2bp3 mutants. Gene ontology analysis revealed that these functions are largely mediated by Igf2bp3-bound mRNAs. Indeed, Igf2bp3 depletion destabilizes while its overexpression enhances its targeting maternal mRNAs. Interestingly, igf2bp3 overexpression in wild-type embryos also causes a developmental delay. Altogether, these findings highlight an important function of Igf2bp3 in controlling early zebrafish embryogenesis by binding and regulating the stability of maternal mRNAs.
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Affiliation(s)
- Fan Ren
- College of Fisheries, Huazhong Agricultural University, 430070, Wuhan, China
| | - Qiaohong Lin
- College of Fisheries, Huazhong Agricultural University, 430070, Wuhan, China
| | - Gaorui Gong
- College of Fisheries, Huazhong Agricultural University, 430070, Wuhan, China
| | - Xian Du
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, and Department of Hematology, Zhongnan Hospital of Wuhan University, Wuhan University, 430071, Wuhan, China
| | - Hong Dan
- College of Fisheries, Huazhong Agricultural University, 430070, Wuhan, China
| | - Wenying Qin
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, and Department of Hematology, Zhongnan Hospital of Wuhan University, Wuhan University, 430071, Wuhan, China
| | - Ran Miao
- College of Fisheries, Huazhong Agricultural University, 430070, Wuhan, China
| | - Yang Xiong
- College of Fisheries, Huazhong Agricultural University, 430070, Wuhan, China
| | - Rui Xiao
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, and Department of Hematology, Zhongnan Hospital of Wuhan University, Wuhan University, 430071, Wuhan, China
| | - Xiaohui Li
- College of Fisheries, Huazhong Agricultural University, 430070, Wuhan, China
| | - Jian-Fang Gui
- College of Fisheries, Huazhong Agricultural University, 430070, Wuhan, China
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, University of the Chinese Academy of Sciences, 430072, Wuhan, China
| | - Jie Mei
- College of Fisheries, Huazhong Agricultural University, 430070, Wuhan, China.
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7
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Samuels TJ, Järvelin AI, Ish-Horowicz D, Davis I. Imp/IGF2BP levels modulate individual neural stem cell growth and division through myc mRNA stability. eLife 2020; 9:e51529. [PMID: 31934860 PMCID: PMC7025822 DOI: 10.7554/elife.51529] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 01/13/2020] [Indexed: 12/24/2022] Open
Abstract
The numerous neurons and glia that form the brain originate from tightly controlled growth and division of neural stem cells, regulated systemically by important known stem cell-extrinsic signals. However, the cell-intrinsic mechanisms that control the distinctive proliferation rates of individual neural stem cells are unknown. Here, we show that the size and division rates of Drosophila neural stem cells (neuroblasts) are controlled by the highly conserved RNA binding protein Imp (IGF2BP), via one of its top binding targets in the brain, myc mRNA. We show that Imp stabilises myc mRNA leading to increased Myc protein levels, larger neuroblasts, and faster division rates. Declining Imp levels throughout development limit myc mRNA stability to restrain neuroblast growth and division, and heterogeneous Imp expression correlates with myc mRNA stability between individual neuroblasts in the brain. We propose that Imp-dependent regulation of myc mRNA stability fine-tunes individual neural stem cell proliferation rates.
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Affiliation(s)
- Tamsin J Samuels
- Department of BiochemistryThe University of OxfordOxfordUnited Kingdom
| | - Aino I Järvelin
- Department of BiochemistryThe University of OxfordOxfordUnited Kingdom
| | - David Ish-Horowicz
- Department of BiochemistryThe University of OxfordOxfordUnited Kingdom
- MRC Laboratory for Molecular Cell BiologyUniversity CollegeLondonUnited Kingdom
| | - Ilan Davis
- Department of BiochemistryThe University of OxfordOxfordUnited Kingdom
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8
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Vejnar CE, Abdel Messih M, Takacs CM, Yartseva V, Oikonomou P, Christiano R, Stoeckius M, Lau S, Lee MT, Beaudoin JD, Musaev D, Darwich-Codore H, Walther TC, Tavazoie S, Cifuentes D, Giraldez AJ. Genome wide analysis of 3' UTR sequence elements and proteins regulating mRNA stability during maternal-to-zygotic transition in zebrafish. Genome Res 2019; 29:1100-1114. [PMID: 31227602 PMCID: PMC6633259 DOI: 10.1101/gr.245159.118] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 06/07/2019] [Indexed: 12/16/2022]
Abstract
Posttranscriptional regulation plays a crucial role in shaping gene expression. During the maternal-to-zygotic transition (MZT), thousands of maternal transcripts are regulated. However, how different cis-elements and trans-factors are integrated to determine mRNA stability remains poorly understood. Here, we show that most transcripts are under combinatorial regulation by multiple decay pathways during zebrafish MZT. By using a massively parallel reporter assay, we identified cis-regulatory sequences in the 3′ UTR, including U-rich motifs that are associated with increased mRNA stability. In contrast, miR-430 target sequences, UAUUUAUU AU-rich elements (ARE), CCUC, and CUGC elements emerged as destabilizing motifs, with miR-430 and AREs causing mRNA deadenylation upon genome activation. We identified trans-factors by profiling RNA–protein interactions and found that poly(U)-binding proteins are preferentially associated with 3′ UTR sequences and stabilizing motifs. We show that this activity is antagonized by C-rich motifs and correlated with protein binding. Finally, we integrated these regulatory motifs into a machine learning model that predicts reporter mRNA stability in vivo.
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Affiliation(s)
- Charles E Vejnar
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Mario Abdel Messih
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Carter M Takacs
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA.,University of New Haven, West Haven, Connecticut 06516, USA
| | - Valeria Yartseva
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA.,Department of Neuroscience, Genentech, Incorporated, South San Francisco, California 94080, USA
| | - Panos Oikonomou
- Department of Systems Biology, Columbia University, New York, New York 10032, USA
| | - Romain Christiano
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts 02115, USA
| | - Marlon Stoeckius
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA.,New York Genome Center, New York, New York 10013, USA
| | - Stephanie Lau
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Miler T Lee
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA.,Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Jean-Denis Beaudoin
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Damir Musaev
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Hiba Darwich-Codore
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Tobias C Walther
- Department of Genetics and Complex Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts 02115, USA.,Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA.,Broad Institute of Harvard and MIT, Cambridge, Massachusetts 02124, USA.,Howard Hughes Medical Institute, Boston, Massachusetts 02115, USA
| | - Saeed Tavazoie
- Department of Biochemistry and Molecular Biophysics, and Department of Systems Biology, Columbia University, New York, New York 10032, USA
| | - Daniel Cifuentes
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA.,Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | - Antonio J Giraldez
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA.,Yale Stem Cell Center, Yale University School of Medicine, New Haven, Connecticut 06510, USA.,Yale Cancer Center, Yale University School of Medicine, New Haven, Connecticut 06510, USA
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9
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Fic W, Faria C, St Johnston D. IMP regulates Kuzbanian to control the timing of Notch signalling in Drosophila follicle cells. Development 2019; 146:dev.168963. [PMID: 30635283 PMCID: PMC6361131 DOI: 10.1242/dev.168963] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 12/19/2018] [Indexed: 12/31/2022]
Abstract
The timing of Drosophila egg chamber development is controlled by a germline Delta signal that activates Notch in the follicle cells to induce them to cease proliferation and differentiate. Here, we report that follicle cells lacking the RNA-binding protein IMP go through one extra division owing to a delay in the Delta-dependent S2 cleavage of Notch. The timing of Notch activation has previously been shown to be controlled by cis-inhibition by Delta in the follicle cells, which is relieved when the miRNA pathway represses Delta expression. imp mutants are epistatic to Delta mutants and give an additive phenotype with belle and Dicer-1 mutants, indicating that IMP functions independently of both cis-inhibition and the miRNA pathway. We find that the imp phenotype is rescued by overexpression of Kuzbanian, the metalloprotease that mediates the Notch S2 cleavage. Furthermore, Kuzbanian is not enriched at the apical membrane in imp mutants, accumulating instead in late endosomes. Thus, IMP regulates Notch signalling by controlling the localisation of Kuzbanian to the apical domain, where Notch cleavage occurs, revealing a novel regulatory step in the Notch pathway.
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Affiliation(s)
| | | | - Daniel St Johnston
- The Gurdon Institute and The Department of Genetics, University of Cambridge, Tennis Court Rd, Cambridge CB2 1QN, UK
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10
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Wang Q, Abruzzi KC, Rosbash M, Rio DC. Striking circadian neuron diversity and cycling of Drosophila alternative splicing. eLife 2018; 7:35618. [PMID: 29863472 PMCID: PMC6025963 DOI: 10.7554/elife.35618] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 05/31/2018] [Indexed: 11/13/2022] Open
Abstract
Although alternative pre-mRNA splicing (AS) significantly diversifies the neuronal proteome, the extent of AS is still unknown due in part to the large number of diverse cell types in the brain. To address this complexity issue, we used an annotation-free computational method to analyze and compare the AS profiles between small specific groups of Drosophila circadian neurons. The method, the Junction Usage Model (JUM), allows the comprehensive profiling of both known and novel AS events from specific RNA-seq libraries. The results show that many diverse and novel pre-mRNA isoforms are preferentially expressed in one class of clock neuron and also absent from the more standard Drosophila head RNA preparation. These AS events are enriched in potassium channels important for neuronal firing, and there are also cycling isoforms with no detectable underlying transcriptional oscillations. The results suggest massive AS regulation in the brain that is also likely important for circadian regulation.
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Affiliation(s)
- Qingqing Wang
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.,Center for RNA Systems Biology (CRSB), University of California, Berkeley, Berkeley, United States.,California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, Berkeley, United States
| | - Katharine C Abruzzi
- Department of Biology, Howard Hughes Medical Institute, Brandeis University, Waltham, United States.,National Center for Behavior Genomics, Brandeis University, Waltham, United States
| | - Michael Rosbash
- Department of Biology, Howard Hughes Medical Institute, Brandeis University, Waltham, United States.,National Center for Behavior Genomics, Brandeis University, Waltham, United States
| | - Donald C Rio
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.,Center for RNA Systems Biology (CRSB), University of California, Berkeley, Berkeley, United States.,California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, Berkeley, United States
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11
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Köster T, Meyer K. Plant Ribonomics: Proteins in Search of RNA Partners. TRENDS IN PLANT SCIENCE 2018; 23:352-365. [PMID: 29429586 DOI: 10.1016/j.tplants.2018.01.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 01/08/2018] [Accepted: 01/15/2018] [Indexed: 06/08/2023]
Abstract
Research into the regulation of gene expression underwent a shift from focusing on DNA-binding proteins as key transcriptional regulators to RNA-binding proteins (RBPs) that come into play once transcription has been initiated. RBPs orchestrate all RNA-processing steps in the cell. To obtain a global view of in vivo targets, the RNA complement associated with particular RBPs is determined via immunoprecipitation of the RBP and subsequent identification of bound RNAs via RNA-seq. Here, we describe technical advances in identifying RBP in vivo targets and their binding motifs. We provide an up-to-date view of targets of nucleocytoplasmic RBPs collected in arabidopsis. We also discuss current experimental limitations and provide an outlook on how the approaches may advance our understanding of post-transcriptional networks.
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Affiliation(s)
- Tino Köster
- RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, 33615 Bielefeld, Germany.
| | - Katja Meyer
- RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, 33615 Bielefeld, Germany
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12
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Garzia A, Morozov P, Sajek M, Meyer C, Tuschl T. PAR-CLIP for Discovering Target Sites of RNA-Binding Proteins. Methods Mol Biol 2018; 1720:55-75. [PMID: 29236251 DOI: 10.1007/978-1-4939-7540-2_5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
RNA-binding proteins (RBPs) establish posttranscriptional gene regulation (PTGR) by coordinating the maturation, editing, transport, stability, and translation of cellular RNAs. A variety of experimental approaches have been developed to characterize the RNAs associated with RBPs in vitro as well as in vivo. Our laboratory developed Photoactivatable-Ribonucleoside-Enhanced Cross-Linking and Immunoprecipitation (PAR-CLIP), which in combination with next-generation sequencing enables the identification of RNA targets of RBPs at a nucleotide-level resolution. Here we present an updated and condensed step-by-step PAR-CLIP protocol followed by the description of our RNA-seq data analysis pipeline.
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Affiliation(s)
- Aitor Garzia
- Laboratory of RNA Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
| | - Pavel Morozov
- Laboratory of RNA Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
| | - Marcin Sajek
- Laboratory of RNA Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
| | - Cindy Meyer
- Laboratory of RNA Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
| | - Thomas Tuschl
- Laboratory of RNA Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA.
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13
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Nicastro G, Candel AM, Uhl M, Oregioni A, Hollingworth D, Backofen R, Martin SR, Ramos A. Mechanism of β-actin mRNA Recognition by ZBP1. Cell Rep 2017; 18:1187-1199. [PMID: 28147274 PMCID: PMC5300891 DOI: 10.1016/j.celrep.2016.12.091] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 11/17/2016] [Accepted: 12/28/2016] [Indexed: 01/23/2023] Open
Abstract
Zipcode binding protein 1 (ZBP1) is an oncofetal RNA-binding protein that mediates the transport and local translation of β-actin mRNA by the KH3-KH4 di-domain, which is essential for neuronal development. The high-resolution structures of KH3-KH4 with their respective target sequences show that KH4 recognizes a non-canonical GGA sequence via an enlarged and dynamic hydrophobic groove, whereas KH3 binding to a core CA sequence occurs with low specificity. A data-informed kinetic simulation of the two-step binding reaction reveals that the overall reaction is driven by the second binding event and that the moderate affinities of the individual interactions favor RNA looping. Furthermore, the concentration of ZBP1, but not of the target RNA, modulates the interaction, which explains the functional significance of enhanced ZBP1 expression during embryonic development. The dynamic groove of ZBP1’s KH4 domain allows recognition of a G-rich RNA sequence ZBP1’s KH3 and KH4 domains bind their target RNA sequences with similar affinities RNA looping drives the ZBP1-β-actin interaction The protein, rather than the RNA, concentration regulates ZBP1-β-actin mRNA binding
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Affiliation(s)
- Giuseppe Nicastro
- Macromolecular Structure Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Adela M Candel
- At the former MRC National Institute for Medical Research, Mill Hill, London
| | - Michael Uhl
- Bioinformatics Group, Department of Computer Science, University of Freiburg, 79110 Freiburg, Germany
| | - Alain Oregioni
- MRC Biomedical NMR Centre, The Francis Crick Institute, London NW1 1AT, UK
| | - David Hollingworth
- Mycobacterial Systems Biology Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Rolf Backofen
- Bioinformatics Group, Department of Computer Science, University of Freiburg, 79110 Freiburg, Germany; Centre for Biological Signaling Studies (BIOSS), University of Freiburg, 79110 Freiburg, Germany
| | - Stephen R Martin
- Structural Biology Science Technology Platform, The Francis Crick Institute, London NW1 1AT, UK
| | - Andres Ramos
- Institute of Structural and Molecular Biology, University College London, London WC1E 6XA, UK; The Francis Crick Institute, London NW1 1AT, UK.
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14
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Meyer K, Köster T, Nolte C, Weinholdt C, Lewinski M, Grosse I, Staiger D. Adaptation of iCLIP to plants determines the binding landscape of the clock-regulated RNA-binding protein AtGRP7. Genome Biol 2017; 18:204. [PMID: 29084609 PMCID: PMC5663106 DOI: 10.1186/s13059-017-1332-x] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 09/29/2017] [Indexed: 12/11/2022] Open
Abstract
Background Functions for RNA-binding proteins in orchestrating plant development and environmental responses are well established. However, the lack of a genome-wide view of their in vivo binding targets and binding landscapes represents a gap in understanding the mode of action of plant RNA-binding proteins. Here, we adapt individual nucleotide resolution crosslinking and immunoprecipitation (iCLIP) genome-wide to determine the binding repertoire of the circadian clock-regulated Arabidopsis thaliana glycine-rich RNA-binding protein AtGRP7. Results iCLIP identifies 858 transcripts with significantly enriched crosslink sites in plants expressing AtGRP7-GFP that are absent in plants expressing an RNA-binding-dead AtGRP7 variant or GFP alone. To independently validate the targets, we performed RNA immunoprecipitation (RIP)-sequencing of AtGRP7-GFP plants subjected to formaldehyde fixation. Of the iCLIP targets, 452 were also identified by RIP-seq and represent a set of high-confidence binders. AtGRP7 can bind to all transcript regions, with a preference for 3′ untranslated regions. In the vicinity of crosslink sites, U/C-rich motifs are overrepresented. Cross-referencing the targets against transcriptome changes in AtGRP7 loss-of-function mutants or AtGRP7-overexpressing plants reveals a predominantly negative effect of AtGRP7 on its targets. In particular, elevated AtGRP7 levels lead to damping of circadian oscillations of transcripts, including DORMANCY/AUXIN ASSOCIATED FAMILY PROTEIN2 and CCR-LIKE. Furthermore, several targets show changes in alternative splicing or polyadenylation in response to altered AtGRP7 levels. Conclusions We have established iCLIP for plants to identify target transcripts of the RNA-binding protein AtGRP7. This paves the way to investigate the dynamics of posttranscriptional networks in response to exogenous and endogenous cues. Electronic supplementary material The online version of this article (doi:10.1186/s13059-017-1332-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Katja Meyer
- RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, Bielefeld, Germany
| | - Tino Köster
- RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, Bielefeld, Germany
| | - Christine Nolte
- RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, Bielefeld, Germany
| | - Claus Weinholdt
- Institute of Computer Science, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Martin Lewinski
- RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, Bielefeld, Germany
| | - Ivo Grosse
- Institute of Computer Science, Martin Luther University Halle-Wittenberg, Halle, Germany.,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
| | - Dorothee Staiger
- RNA Biology and Molecular Physiology, Faculty of Biology, Bielefeld University, Bielefeld, Germany.
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15
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Garzia A, Meyer C, Morozov P, Sajek M, Tuschl T. Optimization of PAR-CLIP for transcriptome-wide identification of binding sites of RNA-binding proteins. Methods 2017; 118-119:24-40. [PMID: 27765618 PMCID: PMC5393971 DOI: 10.1016/j.ymeth.2016.10.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 10/11/2016] [Accepted: 10/14/2016] [Indexed: 12/21/2022] Open
Abstract
Photoactivatable-Ribonucleoside-Enhanced Crosslinking and Immunoprecipitation (PAR-CLIP) in combination with next-generation sequencing is a powerful method for identifying endogenous targets of RNA-binding proteins (RBPs). Depending on the characteristics of each RBP, key steps in the PAR-CLIP procedure must be optimized. Here we present a comprehensive step-by-step PAR-CLIP protocol with detailed explanations of the critical steps. Furthermore, we report the application of a new PAR-CLIP data analysis pipeline to three distinct RBPs targeting different annotation categories of cellular RNAs.
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Affiliation(s)
- Aitor Garzia
- Laboratory of RNA Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Cindy Meyer
- Laboratory of RNA Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Pavel Morozov
- Laboratory of RNA Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Marcin Sajek
- Laboratory of RNA Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Thomas Tuschl
- Laboratory of RNA Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
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16
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Plass M, Rasmussen SH, Krogh A. Highly accessible AU-rich regions in 3' untranslated regions are hotspots for binding of regulatory factors. PLoS Comput Biol 2017; 13:e1005460. [PMID: 28410363 PMCID: PMC5409497 DOI: 10.1371/journal.pcbi.1005460] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 04/28/2017] [Accepted: 03/14/2017] [Indexed: 12/24/2022] Open
Abstract
Post-transcriptional regulation is regarded as one of the major processes involved in the regulation of gene expression. It is mainly performed by RNA binding proteins and microRNAs, which target RNAs and typically affect their stability. Recent efforts from the scientific community have aimed at understanding post-transcriptional regulation at a global scale by using high-throughput sequencing techniques such as cross-linking and immunoprecipitation (CLIP), which facilitates identification of binding sites of these regulatory factors. However, the diversity in the experimental procedures and bioinformatics analyses has hindered the integration of multiple datasets and thus limited the development of an integrated view of post-transcriptional regulation. In this work, we have performed a comprehensive analysis of 107 CLIP datasets from 49 different RBPs in HEK293 cells to shed light on the complex interactions that govern post-transcriptional regulation. By developing a more stringent CLIP analysis pipeline we have discovered the existence of conserved regulatory AU-rich regions in the 3’UTRs where miRNAs and RBPs that regulate several processes such as polyadenylation or mRNA stability bind. Analogous to promoters, many factors have binding sites overlapping or in close proximity in these hotspots and hence the regulation of the mRNA may depend on their relative concentrations. This hypothesis is supported by RBP knockdown experiments that alter the relative concentration of RBPs in the cell. Upon AGO2 knockdown (KD), transcripts containing “free” target sites show increased expression levels compared to those containing target sites in hotspots, which suggests that target sites within hotspots are less available for miRNAs to bind. Interestingly, these hotspots appear enriched in genes with regulatory functions such as DNA binding and RNA binding. Taken together, our results suggest that hotspots are functional regulatory elements that define an extra layer of regulation of post-transcriptional regulatory networks. All the cells in a given organism contain the same genome, yet their phenotype can be very diverse. The vast majority of this diversity arises from the differences in the expression of genes and proteins in them. One of the main mechanisms involved in controlling the protein and mRNA repertoire in cells is post-transcriptional regulation. The recent development of high-throughput sequencing techniques gives us now an unprecedented opportunity to investigate how post-transcriptional regulation works and which are the elements involved in defining the final set of mRNAs and proteins inside cells. In this work, we have performed a comprehensive computational analysis of several post-transcriptional regulators in a commonly used human cell line in order to understand which factors are involved in post-transcriptional regulation and how they coordinate their function. The results of our analysis show that this process is orchestrated around small regions in the mRNAs where many regulators bind and may compete with each other to regulate the mRNAs. The investigation and characterization of these regions gives us insight into the underlying combinatorial control that causes gene expression to differ across cell types and in diseases.
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Affiliation(s)
- Mireya Plass
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, Copenhagen, Denmark
- * E-mail: (MP); (AK)
| | - Simon H. Rasmussen
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, Copenhagen, Denmark
| | - Anders Krogh
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, Copenhagen, Denmark
- * E-mail: (MP); (AK)
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17
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Nicholson CO, Friedersdorf M, Keene JD. Quantifying RNA binding sites transcriptome-wide using DO-RIP-seq. RNA (NEW YORK, N.Y.) 2017; 23:32-46. [PMID: 27742911 PMCID: PMC5159647 DOI: 10.1261/rna.058115.116] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 09/30/2016] [Indexed: 05/27/2023]
Abstract
RNA-binding proteins (RBPs) and noncoding RNAs orchestrate post-transcriptional processes through the recognition of specific sites on targeted transcripts. Thus, understanding the connection between binding to specific sites and active regulation of the whole transcript is essential. Many immunoprecipitation techniques have been developed that identify either whole transcripts or binding sites of RBPs on each transcript using cell lysates. However, none of these methods simultaneously measures the strength of each binding site and quantifies binding to whole transcripts. In this study, we compare current procedures and present digestion optimized (DO)-RIP-seq, a simple method that locates and quantifies RBP binding sites using a continuous metric. We have used the RBP HuR/ELAVL1 to demonstrate that DO-RIP-seq can quantify HuR binding sites with high coverage across the entire human transcriptome, thereby generating metrics of relative RNA binding strength. We demonstrate that this quantitative enrichment of binding sites is proportional to the relative in vitro binding strength for these sites. In addition, we used DO-RIP-seq to quantify and compare HuR's binding to whole transcripts, thus allowing for seamless integration of binding site data with whole-transcript measurements. Finally, we demonstrate that DO-RIP-seq is useful for identifying functional mRNA target sets and binding sites where combinatorial interactions between HuR and AGO-microRNAs regulate the fate of the transcripts. Our data indicate that DO-RIP-seq will be useful for quantifying RBP binding events that regulate dynamic biological processes.
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Affiliation(s)
- Cindo O Nicholson
- Department of Molecular Genetics and Microbiology, Center for RNA Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Matthew Friedersdorf
- Department of Molecular Genetics and Microbiology, Center for RNA Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Jack D Keene
- Department of Molecular Genetics and Microbiology, Center for RNA Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
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18
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Nicholson CO, Friedersdorf MB, Bisogno LS, Keene JD. DO-RIP-seq to quantify RNA binding sites transcriptome-wide. Methods 2016; 118-119:16-23. [PMID: 27840290 DOI: 10.1016/j.ymeth.2016.11.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 10/21/2016] [Accepted: 11/07/2016] [Indexed: 01/20/2023] Open
Abstract
Post-transcriptional processes orchestrate gene expression through dynamic protein-RNA interactions. These interactions occur at specific sites determined by RNA sequence, secondary structure, or nucleotide modifications. Methods have been developed either to quantify binding of whole transcripts or to identify the binding sites, but there is none proven to quantify binding at both the whole transcript and binding site levels. Here we describe digestion optimized RNA immunoprecipitation with deep sequencing (DO-RIP-seq) as a method that quantitates at the whole transcript target (RIP-Seq-Like or RSL) level and at the binding site level (BSL) using continuous metrics. DO-RIP-seq methodology was developed using the RBP HuR/ELAVL1 as a test case (Nicholson et al., 2016). DO-RIP-seq employs treatment of cell lysates with a nuclease under optimized conditions to yield partially digested RNA fragments bound by RNA binding proteins, followed by immunoprecipitations that capture the digested RNA-protein complexes and assess non-specific or background interactions. Analyses of sequenced cDNA libraries made from the bound RNA fragments yielded two types of enrichment scores; one for RSL binding events and the other for BSL events (Nicholson et al., 2016). These analyses plus the extensive read coverage of DO-RIP-seq allows seamless integration of binding site and whole transcript information. Therefore, DO-RIP-seq is useful for quantifying RBP binding events that are regulated during dynamic biological processes.
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Affiliation(s)
- Cindo O Nicholson
- Department of Molecular Genetics & Microbiology, USA; Duke University Medical Center, Durham, NC 27710, USA.
| | - Matthew B Friedersdorf
- Department of Molecular Genetics & Microbiology, USA; Duke University Medical Center, Durham, NC 27710, USA.
| | | | - Jack D Keene
- Department of Molecular Genetics & Microbiology, USA; Duke University Medical Center, Durham, NC 27710, USA.
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19
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Abstract
Understanding the molecular mechanisms behind the capacity of cancer cells to adapt to the tumor microenvironment and to anticancer therapies is a major challenge. In this context, cancer is believed to be an evolutionary process where random mutations and the selection process shape the mutational pattern and phenotype of cancer cells. This article challenges the notion of randomness of some cancer-associated mutations by describing molecular mechanisms involving stress-mediated biogenesis of mRNA-derived small RNAs able to target and increase the local mutation rate of the genomic loci they originate from. It is proposed that the probability of some mutations at specific loci could be increased in a stress-specific and RNA-depending manner. This would increase the probability of generating mutations that could alleviate stress situations, such as those triggered by anticancer drugs. Such a mechanism is made possible because tumor- and anticancer drug-associated stress situations trigger both cellular reprogramming and inflammation, which leads cancer cells to express molecular tools allowing them to “attack” and mutate their own genome in an RNA-directed manner.
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Affiliation(s)
- Didier Auboeuf
- Univ Lyon, ENS de Lyon, Univ Claude Bernard, CNRS UMR 5239, INSERM U1210, Laboratory of Biology and Modelling of the Cell, Lyon, France
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20
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IGF2BP3 Modulates the Interaction of Invasion-Associated Transcripts with RISC. Cell Rep 2016; 15:1876-83. [PMID: 27210763 DOI: 10.1016/j.celrep.2016.04.083] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Revised: 02/08/2016] [Accepted: 04/21/2016] [Indexed: 11/21/2022] Open
Abstract
Insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3) expression correlates with malignancy, but its role(s) in pathogenesis remains enigmatic. We interrogated the IGF2BP3-RNA interaction network in pancreatic ductal adenocarcinoma (PDAC) cells. Using a combination of genome-wide approaches, we have identified 164 direct mRNA targets of IGF2BP3. These transcripts encode proteins enriched for functions such as cell migration, proliferation, and adhesion. Loss of IGF2BP3 reduced PDAC cell invasiveness and remodeled focal adhesion junctions. Individual nucleotide resolution crosslinking immunoprecipitation (iCLIP) revealed significant overlap of IGF2BP3 and microRNA (miRNA) binding sites. IGF2BP3 promotes association of the RNA-induced silencing complex (RISC) with specific transcripts. Our results show that IGF2BP3 influences a malignancy-associated RNA regulon by modulating miRNA-mRNA interactions.
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21
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Abstract
Eukaryotic mRNAs are monocistronic, and therefore mechanisms exist that coordinate the synthesis of multiprotein complexes in order to obtain proper stoichiometry at the appropriate intracellular locations. RNA‐binding proteins containing low‐complexity sequences are prone to generate liquid droplets via liquid‐liquid phase separation, and in this way create cytoplasmic assemblages of functionally related mRNAs. In a recent iCLIP study, we showed that the Drosophila RNA‐binding protein Imp, which exhibits a C‐terminal low‐complexity sequence, increases the formation of F‐actin by binding to 3′ untranslated regions of mRNAs encoding components participating in F‐actin biogenesis. We hypothesize that phase transition is a mechanism the cell employs to increase the local mRNA concentration considerably, and in this way synchronize protein production in cytoplasmic territories, as discussed in the present review.
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Affiliation(s)
- Finn Cilius Nielsen
- Center for Genomic Medicine, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Heidi Theil Hansen
- Department of Biology, Center for Computational and Applied Transcriptomics, University of Copenhagen, Copenhagen, Denmark
| | - Jan Christiansen
- Department of Biology, Center for Computational and Applied Transcriptomics, University of Copenhagen, Copenhagen, Denmark
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22
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Zhang KX, Tan L, Pellegrini M, Zipursky SL, McEwen JM. Rapid Changes in the Translatome during the Conversion of Growth Cones to Synaptic Terminals. Cell Rep 2016; 14:1258-1271. [PMID: 26832407 DOI: 10.1016/j.celrep.2015.12.102] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 12/04/2015] [Accepted: 12/21/2015] [Indexed: 12/01/2022] Open
Abstract
A common step in the formation of neural circuits is the conversion of growth cones to presynaptic terminals. Characterizing patterns of global gene expression during this process is problematic due to the cellular diversity of the brain and the complex temporal dynamics of development. Here, we take advantage of the synchronous conversion of Drosophila photoreceptor growth cones into presynaptic terminals to explore global changes in gene expression during presynaptic differentiation. Using a tandemly tagged ribosome trap (T-TRAP) and RNA sequencing (RNA-seq) at multiple developmental times, we observed dramatic changes in coding and non-coding RNAs with presynaptic differentiation. Marked changes in the mRNA encoding transmembrane and secreted proteins occurred preferentially. The 3' UTRs of transcripts encoding synaptic proteins were preferentially lengthened, and these extended UTRs were preferentially enriched for sites recognized by RNA binding proteins. These data provide a rich resource for uncovering the regulatory logic underlying presynaptic differentiation.
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Affiliation(s)
- Kelvin Xi Zhang
- Department of Biological Chemistry, Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles CA 90095, USA
| | - Liming Tan
- Department of Biological Chemistry, Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles CA 90095, USA
| | - Matteo Pellegrini
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, P.O. Box 951606, Los Angeles, CA 90095, USA
| | - S Lawrence Zipursky
- Department of Biological Chemistry, Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles CA 90095, USA.
| | - Jason M McEwen
- Department of Biological Chemistry, Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles CA 90095, USA
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