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Kanwal N, Krogh N, Memet I, Lemus-Diaz N, Thomé C, Welp L, Mizi A, Hackert P, Papantonis A, Urlaub H, Nielsen H, Bohnsack K, Bohnsack M. GPATCH4 regulates rRNA and snRNA 2'-O-methylation in both DHX15-dependent and DHX15-independent manners. Nucleic Acids Res 2024; 52:1953-1974. [PMID: 38113271 PMCID: PMC10939407 DOI: 10.1093/nar/gkad1202] [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: 08/10/2023] [Revised: 12/01/2023] [Accepted: 12/05/2023] [Indexed: 12/21/2023] Open
Abstract
Regulation of RNA helicase activity, often accomplished by protein cofactors, is essential to ensure target specificity within the complex cellular environment. The largest family of RNA helicase cofactors are the G-patch proteins, but the cognate RNA helicases and cellular functions of numerous human G-patch proteins remain elusive. Here, we discover that GPATCH4 is a stimulatory cofactor of DHX15 that interacts with the DEAH box helicase in the nucleolus via residues in its G-patch domain. We reveal that GPATCH4 associates with pre-ribosomal particles, and crosslinks to the transcribed ribosomal DNA locus and precursor ribosomal RNAs as well as binding to small nucleolar- and small Cajal body-associated RNAs that guide rRNA and snRNA modifications. Loss of GPATCH4 impairs 2'-O-methylation at various rRNA and snRNA sites leading to decreased protein synthesis and cell growth. We demonstrate that the regulation of 2'-O-methylation by GPATCH4 is both dependent on, and independent of, its interaction with DHX15. Intriguingly, the ATPase activity of DHX15 is necessary for efficient methylation of DHX15-dependent sites, suggesting a function of DHX15 in regulating snoRNA-guided 2'-O-methylation of rRNA that requires activation by GPATCH4. Overall, our findings extend knowledge on RNA helicase regulation by G-patch proteins and also provide important new insights into the mechanisms regulating installation of rRNA and snRNA modifications, which are essential for ribosome function and pre-mRNA splicing.
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Affiliation(s)
- Nidhi Kanwal
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Nicolai Krogh
- Department of Cellular and Molecular Medicine, University of Copenhagen, 3B Blegdamsvej, 2200N Copenhagen, Denmark
| | - Indira Memet
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Nicolas Lemus-Diaz
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Chairini C Thomé
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Luisa M Welp
- Max Planck Institute for Multidisciplinary Sciences, Bioanalytical Mass Spectrometry, Am Fassberg 11, 37077 Göttingen, Germany
- Institute for Clinical Chemistry, University Medical Center Göttingen, Robert-Koch-Straße 40, 35075 Göttingen, Germany
| | - Athanasia Mizi
- Institute of Pathology, University Medical Center Göttingen, Robert-Koch-Straße 40, 35075 Göttingen, Germany
| | - Philipp Hackert
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Argyris Papantonis
- Institute of Pathology, University Medical Center Göttingen, Robert-Koch-Straße 40, 35075 Göttingen, Germany
| | - Henning Urlaub
- Max Planck Institute for Multidisciplinary Sciences, Bioanalytical Mass Spectrometry, Am Fassberg 11, 37077 Göttingen, Germany
- Institute for Clinical Chemistry, University Medical Center Göttingen, Robert-Koch-Straße 40, 35075 Göttingen, Germany
- Göttingen Center for Molecular Biosciences, Georg-August University Göttingen, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany
- Cluster of Excellence ‘Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells’ (MBExC), University of Göttingen, Göttingen
| | - Henrik Nielsen
- Department of Cellular and Molecular Medicine, University of Copenhagen, 3B Blegdamsvej, 2200N Copenhagen, Denmark
| | - Katherine E Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
- Göttingen Center for Molecular Biosciences, Georg-August University Göttingen, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
- Göttingen Center for Molecular Biosciences, Georg-August University Göttingen, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany
- Cluster of Excellence ‘Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells’ (MBExC), University of Göttingen, Göttingen
- Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany
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2
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Bohnsack KE, Kanwal N, Bohnsack MT. Prp43/DHX15 exemplify RNA helicase multifunctionality in the gene expression network. Nucleic Acids Res 2022; 50:9012-9022. [PMID: 35993807 PMCID: PMC9458436 DOI: 10.1093/nar/gkac687] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 07/10/2022] [Accepted: 08/01/2022] [Indexed: 12/24/2022] Open
Abstract
Dynamic regulation of RNA folding and structure is critical for the biogenesis and function of RNAs and ribonucleoprotein (RNP) complexes. Through their nucleotide triphosphate-dependent remodelling functions, RNA helicases are key modulators of RNA/RNP structure. While some RNA helicases are dedicated to a specific target RNA, others are multifunctional and engage numerous substrate RNAs in different aspects of RNA metabolism. The discovery of such multitasking RNA helicases raises the intriguing question of how these enzymes can act on diverse RNAs but also maintain specificity for their particular targets within the RNA-dense cellular environment. Furthermore, the identification of RNA helicases that sit at the nexus between different aspects of RNA metabolism raises the possibility that they mediate cross-regulation of different cellular processes. Prominent and extensively characterized multifunctional DEAH/RHA-box RNA helicases are DHX15 and its Saccharomyces cerevisiae (yeast) homologue Prp43. Due to their central roles in key cellular processes, these enzymes have also served as prototypes for mechanistic studies elucidating the mode of action of this type of enzyme. Here, we summarize the current knowledge on the structure, regulation and cellular functions of Prp43/DHX15, and discuss the general concept and implications of RNA helicase multifunctionality.
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Affiliation(s)
- Katherine E Bohnsack
- Correspondence may also be addressed to Katherine E. Bohnsack. Tel: +49 551 3969305; Fax: +49 551 395960;
| | - Nidhi Kanwal
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Markus T Bohnsack
- To whom correspondence should be addressed. Tel: +49 551 395968; Fax: +49 551 395960;
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3
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Maul-Newby HM, Amorello AN, Sharma T, Kim JH, Modena MS, Prichard BE, Jurica MS. A model for DHX15 mediated disassembly of A-complex spliceosomes. RNA (NEW YORK, N.Y.) 2022; 28:583-595. [PMID: 35046126 PMCID: PMC8925973 DOI: 10.1261/rna.078977.121] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 01/03/2022] [Indexed: 06/14/2023]
Abstract
A critical step of pre-mRNA splicing is the recruitment of U2 snRNP to the branch point sequence of an intron. U2 snRNP conformation changes extensively during branch helix formation, and several RNA-dependent ATPases are implicated in the process. However, the molecular mechanisms involved remain to be fully dissected. We took advantage of the differential nucleotide triphosphates requirements for DExD/H-box enzymes to probe their contributions to in vitro spliceosome assembly. Both ATP and GTP hydrolysis support the formation of A-complex, indicating the activity of a DEAH-enzyme because DEAD-enzymes are selective for ATP. We immunodepleted DHX15 to assess its involvement, and although splicing efficiency decreases with reduced DHX15, A-complex accumulation incongruently increases. DHX15 depletion also results in the persistence of the atypical ATP-independent interaction between U2 snRNP and a minimal substrate that is otherwise destabilized in the presence of either ATP or GTP. These results lead us to hypothesize that DHX15 plays a quality control function in U2 snRNP's engagement with an intron. In efforts to identify the RNA target of DHX15, we determined that an extended polypyrimidine tract is not necessary for disruption of the atypical interaction between U2 snRNP and the minimal substrate. We also examined U2 snRNA by RNase H digestion and identified nucleotides in the branch binding region that become accessible with both ATP and GTP hydrolysis, again implicating a DEAH-enzyme. Together, our results demonstrate that multiple ATP-dependent rearrangements are likely involved in U2 snRNP addition to the spliceosome and that DHX15 may have an expanded role in maintaining splicing fidelity.
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Affiliation(s)
- Hannah M Maul-Newby
- Department of Molecular Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, California 95064, USA
- Center for Molecular Biology of RNA, University of California Santa Cruz, Santa Cruz, California 95064, USA
| | - Angela N Amorello
- Department of Molecular Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, California 95064, USA
- Center for Molecular Biology of RNA, University of California Santa Cruz, Santa Cruz, California 95064, USA
| | - Turvi Sharma
- Department of Molecular Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, California 95064, USA
- Center for Molecular Biology of RNA, University of California Santa Cruz, Santa Cruz, California 95064, USA
| | - John H Kim
- Department of Molecular Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, California 95064, USA
- Center for Molecular Biology of RNA, University of California Santa Cruz, Santa Cruz, California 95064, USA
| | - Matthew S Modena
- Department of Molecular Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, California 95064, USA
- Center for Molecular Biology of RNA, University of California Santa Cruz, Santa Cruz, California 95064, USA
| | - Beth E Prichard
- Department of Molecular Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, California 95064, USA
- Center for Molecular Biology of RNA, University of California Santa Cruz, Santa Cruz, California 95064, USA
| | - Melissa S Jurica
- Department of Molecular Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, California 95064, USA
- Center for Molecular Biology of RNA, University of California Santa Cruz, Santa Cruz, California 95064, USA
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Mouffok S, Capeyrou R, Belhabich-Baumas K, Joret C, Henras AK, Humbert O, Henry Y. The G-patch activators Pfa1 and PINX1 exhibit different modes of interaction with the Prp43 RNA helicase. RNA Biol 2020; 18:510-522. [PMID: 32882145 DOI: 10.1080/15476286.2020.1818458] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Prp43 is a DEAH-box RNA helicase involved in both splicing and ribosome biogenesis. Its activities are directly stimulated by several co-activators that share a G-patch domain. The substrates of Prp43, its mechanism of action and the modes of interaction with and activation by G-patch proteins have been only partially characterized. We investigated how Pfa1 and PINX1, two G-patch proteins involved in ribosome biogenesis, interact with Prp43. We demonstrate that a protruding loop connecting the β4 and β5 strands of Prp43 OB fold is crucial for the binding of the G-patch domain of Pfa1. However, neither this loop nor the entire OB fold of Prp43 is essential for PINX1 binding. We conclude that the binding modes of Pfa1 and PINX1 G-patches to Prp43 are different. Nevertheless, stimulation of the ATPase and helicase activities of Prp43 by both full-length Pfa1 and PINX1 requires the β4-β5 loop. Moreover, we show that disruption of this loop completely abrogates Prp43 activity during yeast ribosome biogenesis but does not prevent its integration within pre-ribosomal particles. We propose that the β4-β5 loop plays a crucial role in the transmission of conformational changes induced by binding of the G-patch to Prp43 active site and substrate RNA.
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Affiliation(s)
- Saïda Mouffok
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Régine Capeyrou
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Kamila Belhabich-Baumas
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Clément Joret
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Anthony K Henras
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Odile Humbert
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Yves Henry
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
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5
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Nuclear bodies formed by polyQ-ataxin-1 protein are liquid RNA/protein droplets with tunable dynamics. Sci Rep 2020; 10:1557. [PMID: 32005838 PMCID: PMC6994494 DOI: 10.1038/s41598-020-57994-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 01/02/2020] [Indexed: 12/27/2022] Open
Abstract
A mutant form of the ataxin-1 protein with an expanded polyglutamine (polyQ) tract is the underlying cause of the inherited neurodegenerative disease spinocerebellar ataxia 1 (SCA1). In probing the biophysical features of the nuclear bodies (NBs) formed by polyQ-ataxin-1, we defined ataxin-1 NBs as spherical liquid protein/RNA droplets capable of rapid fusion. We observed dynamic exchange of the ataxin-1 protein into these NBs; notably, cell exposure to a pro-oxidant stress could trigger a transition to slower ataxin-1 exchange, typical of a hydrogel state, which no longer showed the same dependence on RNA or sensitivity to 1,6-hexanediol. Furthermore, we could alter ataxin-1 exchange dynamics either through modulating intracellular ATP levels, RNA helicase inhibition, or siRNA-mediated depletion of select RNA helicases. Collectively, these findings reveal the tunable dynamics of the liquid RNA/protein droplets formed by polyQ-ataxin-1.
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6
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Evans HT, Bodea LG, Götz J. Cell-specific non-canonical amino acid labelling identifies changes in the de novo proteome during memory formation. eLife 2020; 9:e52990. [PMID: 31904341 PMCID: PMC6944461 DOI: 10.7554/elife.52990] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 12/13/2019] [Indexed: 12/15/2022] Open
Abstract
The formation of spatial long-term memory (LTM) requires the de novo synthesis of distinct sets of proteins; however, a non-biased examination of the de novo proteome in this process is lacking. Here, we generated a novel mouse strain, which enables cell-type-specific labelling of newly synthesised proteins with non-canonical amino acids (NCAAs) by genetically restricting the expression of the mutant tRNA synthetase, NLL-MetRS, to hippocampal neurons. By combining this labelling technique with an accelerated version of the active place avoidance task and bio-orthogonal non-canonical amino acid tagging (BONCAT) followed by SWATH quantitative mass spectrometry, we identified 156 proteins that were altered in synthesis in hippocampal neurons during spatial memory formation. In addition to observing increased synthesis of known proteins important in memory-related processes, such as glutamate receptor recycling, we also identified altered synthesis of proteins associated with mRNA splicing as a potential mechanism involved in spatial LTM formation.
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Affiliation(s)
- Harrison Tudor Evans
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain InstituteThe University of QueenslandBrisbaneAustralia
| | - Liviu-Gabriel Bodea
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain InstituteThe University of QueenslandBrisbaneAustralia
| | - Jürgen Götz
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain InstituteThe University of QueenslandBrisbaneAustralia
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7
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Pattabhi S, Knoll ML, Gale M, Loo YM. DHX15 Is a Coreceptor for RLR Signaling That Promotes Antiviral Defense Against RNA Virus Infection. J Interferon Cytokine Res 2019; 39:331-346. [PMID: 31090472 PMCID: PMC6590726 DOI: 10.1089/jir.2018.0163] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 03/01/2019] [Indexed: 12/23/2022] Open
Abstract
RNA helicases play an important role in the response to microbial infection. Retinoic acid inducible gene-I (RIG-I) and members of the RIG-I-like receptor (RLR) family of helicases function as cytoplasmic pattern recognition receptors (PRRs) whose actions are essential for recognition of RNA viruses. RIG-I association with pathogen-associated molecular patterns (PAMPs) within viral RNA leads to its activation and signaling via the mitochondrial antiviral signaling (MAVS) adapter protein. This interaction mediates downstream signaling events that drive the innate immune response to virus infection. Here we identify the DEAH-box RNA helicase DHX15 as a RLR binding partner and signaling cofactor. In human cells, DHX15 is required for virus-induced RLR signaling of innate immune gene expression. Knockdown of DHX15 increased susceptibility to infection by RNA viruses of diverse genera, including Paramyxoviridae, Rhabdoviridae, and Picornaviridae. DHX15 associates with RIG-I caspase activation and recruitment domains (CARDs) through its amino terminus, in which the complex is recruited to MAVS on virus infection. Importantly, although DHX15 cannot substitute for RIG-I in innate immune signaling, DHX15 selectively binds PAMP RNA to promote RIG-I ATP hydrolysis and signaling activation in response to viral RNA. Our results define DHX15 as a coreceptor required for RLR innate immune responses to control RNA virus infection.
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Affiliation(s)
- Sowmya Pattabhi
- Department of Global Health, University of Washington, Seattle, Washington
- Department of Immunology, Center for Innate Immunity and Immune Disease, University of Washington, Seattle, Washington
| | - Megan L. Knoll
- Department of Immunology, Center for Innate Immunity and Immune Disease, University of Washington, Seattle, Washington
- Department of Immunology, University of Washington, Seattle, Washington
| | - Michael Gale
- Department of Global Health, University of Washington, Seattle, Washington
- Department of Immunology, Center for Innate Immunity and Immune Disease, University of Washington, Seattle, Washington
- Department of Immunology, University of Washington, Seattle, Washington
| | - Yueh-Ming Loo
- Department of Immunology, Center for Innate Immunity and Immune Disease, University of Washington, Seattle, Washington
- Department of Immunology, University of Washington, Seattle, Washington
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8
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Sloan KE, Bohnsack MT. Unravelling the Mechanisms of RNA Helicase Regulation. Trends Biochem Sci 2018; 43:237-250. [PMID: 29486979 DOI: 10.1016/j.tibs.2018.02.001] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 01/28/2018] [Accepted: 02/01/2018] [Indexed: 12/22/2022]
Abstract
RNA helicases are critical regulators at the nexus of multiple pathways of RNA metabolism, and in the complex cellular environment, tight spatial and temporal regulation of their activity is essential. Dedicated protein cofactors play key roles in recruiting helicases to specific substrates and modulating their catalytic activity. Alongside individual RNA helicase cofactors, networks of cofactors containing evolutionarily conserved domains such as the G-patch and MIF4G domains highlight the potential for cross-regulation of different aspects of gene expression. Structural analyses of RNA helicase-cofactor complexes now provide insight into the diverse mechanisms by which cofactors can elicit specific and coordinated regulation of RNA helicase action. Furthermore, post-translational modifications (PTMs) and long non-coding RNA (lncRNA) regulators have recently emerged as novel modes of RNA helicase regulation.
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Affiliation(s)
- Katherine E Sloan
- Department of Molecular Biology, University Medical Centre Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Centre Göttingen, Humboldtallee 23, 37073 Göttingen, Germany; Göttingen Center for Molecular Biosciences, University of Göttingen, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany.
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9
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Moriel-Carretero M, Ovejero S, Gérus-Durand M, Vryzas D, Constantinou A. Fanconi anemia FANCD2 and FANCI proteins regulate the nuclear dynamics of splicing factors. J Cell Biol 2017; 216:4007-4026. [PMID: 29030393 PMCID: PMC5716273 DOI: 10.1083/jcb.201702136] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 08/02/2017] [Accepted: 08/25/2017] [Indexed: 01/20/2023] Open
Abstract
Moriel-Carretero et al. show that the Fanconi anemia proteins FANCI and FANCD2 associate with the splicing factor SF3B1 and that DNA replication stress induces the FANCI-dependent release of SF3B1 from nuclear speckles. FANCI and FANCD2 prevent accumulation of postcatalytic intron lariats, suggesting that they help coordinate DNA replication and transcription. Proteins disabled in the cancer-prone disorder Fanconi anemia (FA) ensure the maintenance of chromosomal stability during DNA replication. FA proteins regulate replication dynamics, coordinate replication-coupled repair of interstrand DNA cross-links, and mitigate conflicts between replication and transcription. Here we show that FANCI and FANCD2 associate with splicing factor 3B1 (SF3B1), a key spliceosomal protein of the U2 small nuclear ribonucleoprotein (U2 snRNP). FANCI is in close proximity to SF3B1 in the nucleoplasm of interphase and mitotic cells. Furthermore, we find that DNA replication stress induces the release of SF3B1 from nuclear speckles in a manner that depends on FANCI and on the activity of the checkpoint kinase ATR. In chromatin, both FANCD2 and FANCI associate with SF3B1, prevent accumulation of postcatalytic intron lariats, and contribute to the timely eviction of splicing factors. We propose that FANCD2 and FANCI contribute to the organization of functional domains in chromatin, ensuring the coordination of DNA replication and cotranscriptional processes.
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Affiliation(s)
- María Moriel-Carretero
- Institute of Human Genetics, Centre National de la Recherche Scientifique UMR 9002, Université de Montpellier, Montpellier, France
| | - Sara Ovejero
- Institute of Human Genetics, Centre National de la Recherche Scientifique UMR 9002, Université de Montpellier, Montpellier, France
| | - Marie Gérus-Durand
- Institute of Human Genetics, Centre National de la Recherche Scientifique UMR 9002, Université de Montpellier, Montpellier, France
| | - Dimos Vryzas
- Institute of Human Genetics, Centre National de la Recherche Scientifique UMR 9002, Université de Montpellier, Montpellier, France
| | - Angelos Constantinou
- Institute of Human Genetics, Centre National de la Recherche Scientifique UMR 9002, Université de Montpellier, Montpellier, France
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10
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Asselin-Mullen P, Chauvin A, Dubois ML, Drissi R, Lévesque D, Boisvert FM. Protein interaction network of alternatively spliced NudCD1 isoforms. Sci Rep 2017; 7:12987. [PMID: 29021621 PMCID: PMC5636827 DOI: 10.1038/s41598-017-13441-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 09/25/2017] [Indexed: 12/16/2022] Open
Abstract
NudCD1, also known as CML66 or OVA66, is a protein initially identified as overexpressed in patients with chronic myelogenous leukemia. The mRNA of NudCD1 is expressed in heart and testis of normal tissues, and is overexpressed in several cancers. Previous studies have shown that the expression level of the protein correlates with tumoral phenotype, possibly interacting upstream of the Insulin Growth Factor - 1 Receptor (IGF-1R). The gene encoding the NudCD1 protein consists of 12 exons that can be alternative spliced, leading to the expression of three different isoforms. These isoforms possess a common region of 492 amino acids in their C-terminus region and have an isoform specific N-terminus. To determine the distinct function of each isoforms, we have localised the isoforms within the cells using immunofluorescence microscopy and used a quantitative proteomics approach (SILAC) to identify specific protein interaction partners for each isoforms. Localization studies showed a different subcellular distribution for the different isoforms, with the first isoform being nuclear, while the other two isoforms have distinct cytoplasmic and nuclear location. We found that the different NudCD1 isoforms have unique interacting partners, with the first isoform binding to a putative RNA helicase named DHX15 involved in mRNA splicing.
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Affiliation(s)
- Patrick Asselin-Mullen
- Department of Anatomy and Cell Biology, Université de Sherbrooke, 3201 Jean-Mignault, Sherbrooke, Québec, J1E 4K8, Canada
| | - Anaïs Chauvin
- Department of Anatomy and Cell Biology, Université de Sherbrooke, 3201 Jean-Mignault, Sherbrooke, Québec, J1E 4K8, Canada
| | - Marie-Line Dubois
- Department of Anatomy and Cell Biology, Université de Sherbrooke, 3201 Jean-Mignault, Sherbrooke, Québec, J1E 4K8, Canada
| | - Romain Drissi
- Department of Anatomy and Cell Biology, Université de Sherbrooke, 3201 Jean-Mignault, Sherbrooke, Québec, J1E 4K8, Canada
| | - Dominique Lévesque
- Department of Anatomy and Cell Biology, Université de Sherbrooke, 3201 Jean-Mignault, Sherbrooke, Québec, J1E 4K8, Canada
| | - François-Michel Boisvert
- Department of Anatomy and Cell Biology, Université de Sherbrooke, 3201 Jean-Mignault, Sherbrooke, Québec, J1E 4K8, Canada.
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11
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Memet I, Doebele C, Sloan KE, Bohnsack MT. The G-patch protein NF-κB-repressing factor mediates the recruitment of the exonuclease XRN2 and activation of the RNA helicase DHX15 in human ribosome biogenesis. Nucleic Acids Res 2017; 45:5359-5374. [PMID: 28115624 PMCID: PMC5435916 DOI: 10.1093/nar/gkx013] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 01/04/2017] [Indexed: 01/05/2023] Open
Abstract
In eukaryotes, the synthesis of ribosomal subunits, which involves the maturation of the ribosomal (r)RNAs and assembly of ribosomal proteins, requires the co-ordinated action of a plethora of ribosome biogenesis factors. Many of these cofactors remain to be characterized in human cells. Here, we demonstrate that the human G-patch protein NF-κB-repressing factor (NKRF) forms a pre-ribosomal subcomplex with the DEAH-box RNA helicase DHX15 and the 5΄-3΄ exonuclease XRN2. Using UV crosslinking and analysis of cDNA (CRAC), we reveal that NKRF binds to the transcribed spacer regions of the pre-rRNA transcript. Consistent with this, we find that depletion of NKRF, XRN2 or DHX15 impairs an early pre-rRNA cleavage step (A’). The catalytic activity of DHX15, which we demonstrate is stimulated by NKRF functioning as a cofactor, is required for efficient A’ cleavage, suggesting that a structural remodelling event may facilitate processing at this site. In addition, we show that depletion of NKRF or XRN2 also leads to the accumulation of excised pre-rRNA spacer fragments and that NKRF is essential for recruitment of the exonuclease to nucleolar pre-ribosomal complexes. Our findings therefore reveal a novel pre-ribosomal subcomplex that plays distinct roles in the processing of pre-rRNAs and the turnover of excised spacer fragments.
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Affiliation(s)
- Indira Memet
- Institute for Molecular Biology, University Medical Center Göttingen, Georg-August-University, 37073 Göttingen, Germany
| | - Carmen Doebele
- Institute for Molecular Biology, University Medical Center Göttingen, Georg-August-University, 37073 Göttingen, Germany
| | - Katherine E Sloan
- Institute for Molecular Biology, University Medical Center Göttingen, Georg-August-University, 37073 Göttingen, Germany
| | - Markus T Bohnsack
- Institute for Molecular Biology, University Medical Center Göttingen, Georg-August-University, 37073 Göttingen, Germany.,Göttingen Centre for Molecular Biosciences, Georg-August-University, 37073 Göttingen, Germany
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12
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Limited portability of G-patch domains in regulators of the Prp43 RNA helicase required for pre-mRNA splicing and ribosomal RNA maturation in Saccharomyces cerevisiae. Genetics 2015; 200:135-47. [PMID: 25808954 DOI: 10.1534/genetics.115.176461] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 03/22/2015] [Indexed: 12/16/2022] Open
Abstract
The Prp43 DExD/H-box protein is required for progression of the biochemically distinct pre-messenger RNA and ribosomal RNA (rRNA) maturation pathways. In Saccharomyces cerevisiae, the Spp382/Ntr1, Sqs1/Pfa1, and Pxr1/Gno1 proteins are implicated as cofactors necessary for Prp43 helicase activation during spliceosome dissociation (Spp382) and rRNA processing (Sqs1 and Pxr1). While otherwise dissimilar in primary sequence, these Prp43-binding proteins each contain a short glycine-rich G-patch motif required for function and thought to act in protein or nucleic acid recognition. Here yeast two-hybrid, domain-swap, and site-directed mutagenesis approaches are used to investigate G-patch domain activity and portability. Our results reveal that the Spp382, Sqs1, and Pxr1 G-patches differ in Prp43 two-hybrid response and in the ability to reconstitute the Spp382 and Pxr1 RNA processing factors. G-patch protein reconstitution did not correlate with the apparent strength of the Prp43 two-hybrid response, suggesting that this domain has function beyond that of a Prp43 tether. Indeed, while critical for Pxr1 activity, the Pxr1 G-patch appears to contribute little to the yeast two-hybrid interaction. Conversely, deletion of the primary Prp43 binding site within Pxr1 (amino acids 102-149) does not impede rRNA processing but affects small nucleolar RNA (snoRNA) biogenesis, resulting in the accumulation of slightly extended forms of select snoRNAs, a phenotype unexpectedly shared by the prp43 loss-of-function mutant. These and related observations reveal differences in how the Spp382, Sqs1, and Pxr1 proteins interact with Prp43 and provide evidence linking G-patch identity with pathway-specific DExD/H-box helicase activity.
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13
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Regulation of DEAH/RHA helicases by G-patch proteins. BIOMED RESEARCH INTERNATIONAL 2015; 2015:931857. [PMID: 25692149 PMCID: PMC4322301 DOI: 10.1155/2015/931857] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 10/19/2014] [Accepted: 10/24/2014] [Indexed: 11/20/2022]
Abstract
RNA helicases from the DEAH/RHA family are present in all the processes of RNA metabolism. The function of two helicases from this family, Prp2 and Prp43, is regulated by protein partners containing a G-patch domain. The G-patch is a glycine-rich domain discovered by sequence alignment, involved in protein-protein and protein-nucleic acid interaction. Although it has been shown to stimulate the helicase's enzymatic activities, the precise role of the G-patch domain remains unclear. The role of G-patch proteins in the regulation of Prp43 activity has been studied in the two biological processes in which it is involved: splicing and ribosome biogenesis. Depending on the pathway, the activity of Prp43 is modulated by different G-patch proteins. A particular feature of the structure of DEAH/RHA helicases revealed by the Prp43 structure is the OB-fold domain in C-terminal part. The OB-fold has been shown to be a platform responsible for the interaction with G-patch proteins and RNA. Though there is still no structural data on the G-patch domain, in the current model, the interaction between the helicase, the G-patch protein, and RNA leads to a cooperative binding of RNA and conformational changes of the helicase.
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14
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Lanouette S, Davey JA, Elisma F, Ning Z, Figeys D, Chica RA, Couture JF. Discovery of substrates for a SET domain lysine methyltransferase predicted by multistate computational protein design. Structure 2014; 23:206-215. [PMID: 25533488 DOI: 10.1016/j.str.2014.11.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 11/04/2014] [Accepted: 11/05/2014] [Indexed: 01/01/2023]
Abstract
Characterization of lysine methylation has proven challenging despite its importance in biological processes such as gene transcription, protein turnover, and cytoskeletal organization. In contrast to other key posttranslational modifications, current proteomics techniques have thus far shown limited success at characterizing methyl-lysine residues across the cellular landscape. To complement current biochemical characterization methods, we developed a multistate computational protein design procedure to probe the substrate specificity of the protein lysine methyltransferase SMYD2. Modeling of substrate-bound SMYD2 identified residues important for substrate recognition and predicted amino acids necessary for methylation. Peptide- and protein- based substrate libraries confirmed that SMYD2 activity is dictated by the motif [LFM]-1-K(∗)-[AFYMSHRK]+1-[LYK]+2 around the target lysine K(∗). Comprehensive motif-based searches and mutational analysis further established four additional substrates of SMYD2. Our methodology paves the way to systematically predict and validate posttranslational modification sites while simultaneously pairing them with their associated enzymes.
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Affiliation(s)
- Sylvain Lanouette
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
| | - James A Davey
- Department of Chemistry, University of Ottawa, Ottawa, ON, K1N 6N5, Canada; Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Fred Elisma
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
| | - Zhibin Ning
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
| | - Daniel Figeys
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada; Department of Chemistry, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Roberto A Chica
- Department of Chemistry, University of Ottawa, Ottawa, ON, K1N 6N5, Canada; Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, ON, K1N 6N5, Canada.
| | - Jean-François Couture
- Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada; Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, ON, K1N 6N5, Canada.
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15
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Lu H, Lu N, Weng L, Yuan B, Liu YJ, Zhang Z. DHX15 senses double-stranded RNA in myeloid dendritic cells. THE JOURNAL OF IMMUNOLOGY 2014; 193:1364-72. [PMID: 24990078 DOI: 10.4049/jimmunol.1303322] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Many members of the DEXD/H box helicase family play important roles in the innate immune system against viral infection. Therefore, we isolated dsRNA complex in myeloid dendritic cells. We found that DHx15, a DEXDc helicase family member, is one of the components of this complex. Knockdown of DHX15 expression by short hairpin RNA efficiently reduced the ability of myeloid dendritic cells to produce IFN-β, IL-6, and TNF-α in response to dsRNA and RNA virus. DHX15 specifically bound polyinosine-polycytidylic acid via its helicase C-terminal domain. DHX15 interacted with MAVS and formed a complex following stimulation with polyinosine-polycytidylic acid. The N-terminal domain containing a DEXDc motif in DHX15 bound the C terminus of MAVS. DHX15 is required to activate IRF3 phosphorylation as well as NF-κB and MAPK signaling during RNA virus infection. We, therefore, identified DHX15 as a new RNA virus sensor mediated by MAVS to activate the immune responses to RNA.
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Affiliation(s)
- Hongbo Lu
- Baylor Institute for Immunology Research, Baylor Research Institute, Dallas, TX 75204; and
| | - Ning Lu
- Baylor Institute for Immunology Research, Baylor Research Institute, Dallas, TX 75204; and
| | - Leiyun Weng
- Baylor Institute for Immunology Research, Baylor Research Institute, Dallas, TX 75204; and
| | - Bin Yuan
- Immunobiology and Transplant Research, Houston Methodist Hospital and Houston Methodist Research Institute, Houston, TX 77030
| | - Yong-Jun Liu
- Baylor Institute for Immunology Research, Baylor Research Institute, Dallas, TX 75204; and
| | - Zhiqiang Zhang
- Baylor Institute for Immunology Research, Baylor Research Institute, Dallas, TX 75204; and Immunobiology and Transplant Research, Houston Methodist Hospital and Houston Methodist Research Institute, Houston, TX 77030
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Yoshimoto R, Okawa K, Yoshida M, Ohno M, Kataoka N. Identification of a novel component C2ORF3 in the lariat-intron complex: lack of C2ORF3 interferes with pre-mRNA splicing via intron turnover pathway. Genes Cells 2013; 19:78-87. [DOI: 10.1111/gtc.12114] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 10/14/2013] [Indexed: 12/18/2022]
Affiliation(s)
- Rei Yoshimoto
- Chemical Genetics Laboratory; RIKEN Advanced Science Institute; Wako Saitama 351-0198 Japan
- Institute for Virus Research; Kyoto University; Sakyo-ku Kyoto 606-8507 Japan
| | - Katsuya Okawa
- Drug Research Laboratories; Kyowa Hakko Kirin Co., Ltd; Nagaizumi Shizuoka 411-8731 Japan
| | - Minoru Yoshida
- Chemical Genetics Laboratory; RIKEN Advanced Science Institute; Wako Saitama 351-0198 Japan
| | - Mutsuhito Ohno
- Institute for Virus Research; Kyoto University; Sakyo-ku Kyoto 606-8507 Japan
| | - Naoyuki Kataoka
- Laboratory for Malignancy Control Research; Medical Innovation Center; Kyoto University Graduate School of Medicine; Sakyo-ku Kyoto 606-8507 Japan
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17
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Hu L, Yang F, Liu X, Xu D, Dai W. Nuclear protein IK undergoes dynamic subcellular translocation and forms unique nuclear bodies during the cell cycle. Biomark Res 2013; 1:11. [PMID: 24252166 PMCID: PMC4177551 DOI: 10.1186/2050-7771-1-11] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Accepted: 01/27/2013] [Indexed: 02/06/2023] Open
Abstract
IK is a nuclear protein containing a unique domain named RED due to the presence of a repetitive arginine (R), aspartic (E), and glutamic acid (D) sequence. To date, the function of this protein remains largely unknown despite of a couple of previous studies in the literature. Here we report that depletion of IK via RNA interference results in mitotic arrest. We also demonstrate that IK undergoes dynamic translocation during interphase and mitosis. In particular, IK is primarily present in some interphase cells as nuclear foci/bodies which do not co-localize with nucleoli, PMA bodies and Cajal bodies. Pull-down analysis coupled with mass spectrometry reveals that IK is associated with DHX15, a putative ATP-dependent RNA helicase. Our results strongly suggest that IK may participate in pre-mRNA splicing and that it may be a useful biomarker for a new nuclear structure in the cell.
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Affiliation(s)
- Liyan Hu
- Department of Environmental Medicine, New York University Langone Medical Center, Tuxedo, NY, 10987, USA.
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18
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He C, Li Z, Chen P, Huang H, Hurst LD, Chen J. Young intragenic miRNAs are less coexpressed with host genes than old ones: implications of miRNA-host gene coevolution. Nucleic Acids Res 2012; 40:4002-12. [PMID: 22238379 PMCID: PMC3351155 DOI: 10.1093/nar/gkr1312] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
MicroRNAs (miRNAs) have emerged as key regulators of gene expression. Intragenic miRNAs account for ∼50% of mammalian miRNAs. Classic studies reported that they are usually coexpressed with host genes. Here, using genome-wide miRNA and gene expression profiles from five sample sets, we show that evolutionarily conserved (‘old’) intragenic miRNAs tend to be coexpressed with host genes, but non-conserved (‘young’) ones rarely do so. This result is robust: in all sample sets, the coexpression rate of young miRNAs is significantly lower than that of conserved ones even after controlling for abundance. As a result, although young miRNAs dominate in human genome, the majority of intragenic miRNAs that show coexpression with host genes are phylogenetically old ones. For younger miRNAs, extrapolation of their expression profiles from those of their host genes should be treated with caution. We propose a model to explain this phenomenon in which the majority of young miRNAs are unlikely to be coexpressed with host genes; however, for some fraction of young miRNAs coexpression with their host genes, initially imbued by chromatin level effects, is advantageous and these are the ones likely to embed into the system and evolve ever higher levels of coexpression, possibly by evolving piggybacking mechanisms.
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Affiliation(s)
- Chunjiang He
- Department of Medicine, University of Chicago, Chicago, IL 60637, USA
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Aksaas AK, Larsen AC, Rogne M, Rosendal K, Kvissel AK, Skålhegg BS. G-patch domain and KOW motifs-containing protein, GPKOW; a nuclear RNA-binding protein regulated by protein kinase A. J Mol Signal 2011; 6:10. [PMID: 21880142 PMCID: PMC3179746 DOI: 10.1186/1750-2187-6-10] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Accepted: 08/31/2011] [Indexed: 12/28/2022] Open
Abstract
Background Post-transcriptional processing of pre-mRNA takes place in several steps and requires involvement of a number of RNA-binding proteins. How pre-mRNA processing is regulated is in large enigmatic. The catalytic (C) subunit of protein kinase A (PKA) is a serine/threonine kinase, which regulates numerous cellular processes including pre-mRNA splicing. Despite that a significant fraction of the C subunit is found in splicing factor compartments in the nucleus, there are no indications of a direct interaction between RNA and PKA. Based on this we speculate if the specificity of the C subunit in regulating pre-mRNA splicing may be mediated indirectly through other nuclear proteins. Results Using yeast two-hybrid screening with the PKA C subunit Cbeta2 as bait, we identified the G-patch domain and KOW motifs-containing protein (GPKOW), also known as the T54 protein or MOS2 homolog, as an interaction partner for Cbeta2. We demonstrate that GPKOW, which contains one G-patch domain and two KOW motifs, is a nuclear RNA-binding protein conserved between species. GPKOW contains two sites that are phosphorylated by PKA in vitro. By RNA immunoprecipitation and site directed mutagenesis of the PKA phosphorylation sites we revealed that GPKOW binds RNA in vivo in a PKA sensitive fashion. Conclusion GPKOW is a RNA-binding protein that binds RNA in a PKA regulated fashion. Together with our previous results demonstrating that PKA regulates pre-mRNA splicing, our results suggest that PKA phosphorylation is involved in regulating RNA processing at several steps.
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Zhu S, Jiang Q, Wang G, Liu B, Teng M, Wang Y. Chromatin structure characteristics of pre-miRNA genomic sequences. BMC Genomics 2011; 12:329. [PMID: 21702984 PMCID: PMC3135579 DOI: 10.1186/1471-2164-12-329] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2010] [Accepted: 06/25/2011] [Indexed: 12/21/2022] Open
Abstract
Background MicroRNAs (miRNAs) are non-coding RNAs with important roles in regulating gene expression. Recent studies indicate that transcription and cleavage of miRNA are coupled, and that chromatin structure may influence miRNA transcription. However, little is known about the relationship between the chromatin structure and cleavage of pre-miRNA from pri-miRNA. Results By analysis of genome-wide nucleosome positioning data sets from human and Caenorhabditis elegans (C. elegans), we found an enrichment of positioned nucleosome on pre-miRNA genomic sequences, which is highly correlated with GC content within pre-miRNA. In addition, obvious enrichments of three histone modifications (H2BK5me1, H3K36me3 and H4K20me1) as well as RNA Polymerase II (RNAPII) were observed on pre-miRNA genomic sequences corresponding to the active-promoter miRNAs and expressed miRNAs. Conclusion Our results revealed the chromatin structure characteristics of pre-miRNA genomic sequences, and implied potential mechanisms that can recognize these characteristics, thus improving pre-miRNA cleavage.
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Affiliation(s)
- Shijia Zhu
- Center for Biomedical Informatics, School of Computer Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang 150001, China
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Tannukit S, Crabb TL, Hertel KJ, Wen X, Jans DA, Paine ML. Identification of a novel nuclear localization signal and speckle-targeting sequence of tuftelin-interacting protein 11, a splicing factor involved in spliceosome disassembly. Biochem Biophys Res Commun 2009; 390:1044-50. [PMID: 19857462 DOI: 10.1016/j.bbrc.2009.10.111] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2009] [Accepted: 10/21/2009] [Indexed: 11/18/2022]
Abstract
Tuftelin-interacting protein 11 (TFIP11) is a protein component of the spliceosome complex that promotes the release of the lariat-intron during late-stage splicing through a direct recruitment and interaction with DHX15/PRP43. Expression of TFIP11 is essential for cell and organismal survival. TFIP11 contains a G-patch domain, a signature motif of RNA-processing proteins that is responsible for TFIP11-DHX15 interactions. No other functional domains within TFIP11 have been described. TFIP11 is localized to distinct speckled regions within the cell nucleus, although excluded from the nucleolus. In this study sequential C-terminal deletions and mutational analyses have identified two novel protein elements in mouse TFIP11. The first domain covers amino acids 701-706 (VKDKFN) and is an atypical nuclear localization signal (NLS). The second domain is contained within amino acids 711-735 and defines TFIP11's distinct speckled nuclear localization. The identification of a novel TFIP11 nuclear speckle-targeting sequence (TFIP11-STS) suggests that this domain directly interacts with additional spliceosomal components. These data help define the mechanism of nuclear/nuclear speckle localization of the splicing factor TFIP11, with implications for it's function.
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Affiliation(s)
- Sissada Tannukit
- Center for Craniofacial Molecular Biology, University of Southern California, 2250 Alcazar Street, CSA Rm103, Los Angeles, CA 90033-1004, USA
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MicroRNA-biogenesis and Pre-mRNA splicing crosstalk. J Biomed Biotechnol 2009; 2009:594678. [PMID: 19606257 PMCID: PMC2709726 DOI: 10.1155/2009/594678] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Accepted: 05/18/2009] [Indexed: 12/21/2022] Open
Abstract
MicroRNAs (miRNAs) are often hosted in introns of protein-coding genes. Given that the same transcriptional unit can potentially give rise to both miRNA and mRNA transcripts raises the intriguing question of the level of interaction between these processes. Recent studies from transcription, pre-mRNA splicing, and miRNA-processing perspectives have investigated these relationships and yielded interesting, yet somewhat controversial findings. Here we discuss major studies in the field.
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