101
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Ne E, Palstra RJ, Mahmoudi T. Transcription: Insights From the HIV-1 Promoter. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2018; 335:191-243. [DOI: 10.1016/bs.ircmb.2017.07.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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102
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Gauthier MS, Cloutier P, Coulombe B. Role of the PAQosome in Regulating Arrangement of Protein Quaternary Structure in Health and Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1106:25-36. [PMID: 30484151 DOI: 10.1007/978-3-030-00737-9_3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The PAQosome, formerly known as the R2TP/PFDL complex, is an eleven-subunit cochaperone complex that assists HSP90 in the assembly of numerous large multisubunit protein complexes involved in essential cellular functions such as protein synthesis, ribosome biogenesis, transcription, splicing, and others. In this review, we discuss possible mechanisms of action and role of phosphorylation in the assembly of client complexes by the PAQosome as well as its potential role in cancer, ciliogenesis and ciliopathies.
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Affiliation(s)
| | | | - Benoit Coulombe
- Institut de Recherches Cliniques de Montréal, QC, Canada. .,Department of Biochemistry and Molecular Medicine, Université de Montréal, QC, Canada.
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103
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Ao M, Pan Z, Qian Y, Tang B, Feng Z, Fang H, Wu Z, Chen J, Xue Y, Fang M. Design, synthesis, and biological evaluation of AV6 derivatives as novel dual reactivators of latent HIV-1. RSC Adv 2018; 8:17279-17292. [PMID: 35539279 PMCID: PMC9080425 DOI: 10.1039/c8ra01216d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 04/24/2018] [Indexed: 01/31/2023] Open
Abstract
The “shock and kill” strategy might be a promising therapeutic approach for HIV/AIDS due to the existence of latent viral reservoirs. A major challenge of the “shock and kill” strategy arises from the general lack of clinically effective latency-reversing agents (LRAs). The 2-methylquinoline derivative, antiviral 6 (AV6) has been reported to induce latent HIV-1 expression and act synergistically with a HDAC inhibitor VA to reverse HIV latency. We report herein the design and identification of AV6 analogues which possess the zinc-binding group of HDAC inhibitors and have dual acting mechanism for the reactivation of HIV-1 from latency. Evaluation of compounds for the reactivation of HIV-1 latency identified two excellent active compounds 12c and 12d. Further bioassays revealed that these two compounds reactivated latent HIV-1 through dual mechanism, the inhibition of HDACs and NFAT-required for early HIV-1 gene expression. Additionally, it was found that 12c and 12d could reactivate HIV-1 transcription by releasing P-TEFb from the inactive complex 7SK snRNP. At last, molecular docking identified their orientation and binding interactions at the active site of HDAC2. This experimental data suggests that 12c and 12d can be served as effective HIV-1 LRAs which can be taken up for further studies. As dual-acting HIV LRAs, compounds 12c and 12d could activate latent HIV-1 via the NFAT-required mechanism and as histone deacetylase (HDAC) inhibitors.![]()
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104
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Muñoz-Hernández H, Pal M, Rodríguez CF, Prodromou C, Pearl LH, Llorca O. Advances on the Structure of the R2TP/Prefoldin-like Complex. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1106:73-83. [DOI: 10.1007/978-3-030-00737-9_5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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105
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Abstract
The 7SK RNA is a small nuclear RNA that is involved in the regulation of Pol-II transcription. It is very well conserved in vertebrates, but shows extensive variations in both sequence and structure across invertebrates. A systematic homology search extended the collection of 7SK genes in both Arthropods and Lophotrochozoa making use of the large number of recently published invertebrate genomes. The extended data set made it possible to infer complete consensus structures for invertebrate 7SK RNAs. These show that not only the well-conserved 5'- and 3'- domains but all the interior Stem A domain is universally conserved. In contrast, Stem B region exhibits substantial structural variation and does not adhere to a common structural model beyond phylum level.
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Affiliation(s)
- Ali M Yazbeck
- a Bioinformatics Group, Department of Computer Science , Leipzig University , Härtelstraße 16-18, Leipzig , Germany.,b Lebanese University, Doctoral School for Science and Technology, Rafic Hariri University Campus , Hadath , Lebanon
| | - Kifah R Tout
- b Lebanese University, Doctoral School for Science and Technology, Rafic Hariri University Campus , Hadath , Lebanon
| | - Peter F Stadler
- a Bioinformatics Group, Department of Computer Science , Leipzig University , Härtelstraße 16-18, Leipzig , Germany.,c Interdisciplinary Center for Bioinformatics, German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Competence Center for Scalable Data Services and Solutions, and Leipzig Research Center for Civilization Diseases , Leipzig University.,d Department of Diagnostics , Fraunhofer Institute for Cell Therapy and Immunology - IZI , Perlickstraße 1, D-04103 Leipzig , Germany.,e Max Planck Institute for Mathematics in the Sciences , Inselstraße 22, D-04103 Leipzig , Germany.,f Department of Theoretical Chemistry , University of Vienna , Währingerstraße 17, A-1090 Wien , Austria.,g Center for non-coding RNA in Technology and Health , University of Copenhagen , Grønnegårdsvej 3, DK-1870 Frederiksberg C , Denmark.,h Santa Fe Institute , 1399 Hyde Park Rd., Santa Fe , NM 87501 , USA
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106
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The PAQosome, an R2TP-Based Chaperone for Quaternary Structure Formation. Trends Biochem Sci 2017; 43:4-9. [PMID: 29203338 DOI: 10.1016/j.tibs.2017.11.001] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 10/31/2017] [Accepted: 11/01/2017] [Indexed: 01/19/2023]
Abstract
The Rvb1-Rvb2-Tah1-Pih1/prefoldin-like (R2TP/PFDL) complex is a unique chaperone that provides a platform for the assembly and maturation of many key multiprotein complexes in mammalian cells. Here, we propose to rename R2TP/PFDL as PAQosome (particle for arrangement of quaternary structure) to more accurately represent its unique function.
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107
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Pajares MÁ. PDRG1 at the interface between intermediary metabolism and oncogenesis. World J Biol Chem 2017; 8:175-186. [PMID: 29225734 PMCID: PMC5714802 DOI: 10.4331/wjbc.v8.i4.175] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 11/14/2017] [Accepted: 11/19/2017] [Indexed: 02/05/2023] Open
Abstract
PDRG1 is a small oncogenic protein of 133 residues. In normal human tissues, the p53 and DNA damage-regulated gene 1 (PDRG1) gene exhibits maximal expression in the testis and minimal levels in the liver. Increased expression has been detected in several tumor cells and in response to genotoxic stress. High-throughput studies identified the PDRG1 protein in a variety of macromolecular complexes involved in processes that are altered in cancer cells. For example, this oncogene has been found as part of the RNA polymerase II complex, the splicing machinery and nutrient sensing machinery, although its role in these complexes remains unclear. More recently, the PDRG1 protein was found as an interaction target for the catalytic subunits of methionine adenosyltransferases. These enzymes synthesize S-adenosylmethionine, the methyl donor for, among others, epigenetic methylations that occur on the DNA and histones. In fact, downregulation of S-adenosylmethionine synthesis is the first functional effect directly ascribed to PDRG1. The existence of global DNA hypomethylation, together with increased PDRG1 expression, in many tumor cells highlights the importance of this interaction as one of the putative underlying causes for cell transformation. Here, we will review the accumulated knowledge on this oncogene, emphasizing the numerous aspects that remain to be explored.
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Affiliation(s)
- María Ángeles Pajares
- Department of Chemical and Physical Biology, Centro de Investigaciones Biológicas (CSIC), Madrid 28040, Spain
- Instituto de Investigación Sanitaria La Paz (IdiPAZ), Madrid 28046, Spain
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108
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Brogie JE, Price DH. Reconstitution of a functional 7SK snRNP. Nucleic Acids Res 2017; 45:6864-6880. [PMID: 28431135 PMCID: PMC5499737 DOI: 10.1093/nar/gkx262] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 04/11/2017] [Indexed: 01/29/2023] Open
Abstract
The 7SK small nuclear ribonucleoprotein (snRNP) plays a central role in RNA polymerase II elongation control by regulating the availability of active P-TEFb. We optimized conditions for analyzing 7SK RNA by SHAPE and demonstrated a hysteretic effect of magnesium on 7SK folding dynamics including a 7SK GAUC motif switch. We also found evidence that the 5΄ end pairs alternatively with two different regions of 7SK giving rise to open and closed forms that dictate the state of the 7SK motif. We then used recombinant P-TEFb, HEXIM1, LARP7 and MEPCE to reconstruct a functional 7SK snRNP in vitro. Stably associated P-TEFb was highly inhibited, but could still be released and activated by HIV-1 Tat. Notably, P-TEFb association with both in vitro-reconstituted and cellular snRNPs led to similar changes in SHAPE reactivities, confirming that 7SK undergoes a P-TEFb-dependent structural change. We determined that the xRRM of LARP7 binds to the 3΄ stem loop of 7SK and inhibits the methyltransferase activity of MEPCE through a C-terminal MEPCE interaction domain (MID). Inhibition of MEPCE is dependent on the structure of the 3΄ stem loop and the closed form of 7SK RNA. This study provides important insights into intramolecular interactions within the 7SK snRNP.
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Affiliation(s)
- John E Brogie
- Biochemistry Department, University of Iowa, Iowa City, IA 52242, USA
| | - David H Price
- Biochemistry Department, University of Iowa, Iowa City, IA 52242, USA
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109
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Maraia RJ, Mattijssen S, Cruz-Gallardo I, Conte MR. The La and related RNA-binding proteins (LARPs): structures, functions, and evolving perspectives. WILEY INTERDISCIPLINARY REVIEWS. RNA 2017; 8:10.1002/wrna.1430. [PMID: 28782243 PMCID: PMC5647580 DOI: 10.1002/wrna.1430] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 05/12/2017] [Accepted: 05/15/2017] [Indexed: 01/02/2023]
Abstract
La was first identified as a polypeptide component of ribonucleic protein complexes targeted by antibodies in autoimmune patients and is now known to be a eukaryote cell-ubiquitous protein. Structure and function studies have shown that La binds to a common terminal motif, UUU-3'-OH, of nascent RNA polymerase III (RNAP III) transcripts and protects them from exonucleolytic decay. For precursor-tRNAs, the most diverse and abundant of these transcripts, La also functions as an RNA chaperone that helps to prevent their misfolding. Related to this, we review evidence that suggests that La and its link to RNAP III were significant in the great expansions of the tRNAomes that occurred in eukaryotes. Four families of La-related proteins (LARPs) emerged during eukaryotic evolution with specialized functions. We provide an overview of the high-resolution structural biology of La and LARPs. LARP7 family members most closely resemble La but function with a single RNAP III nuclear transcript, 7SK, or telomerase RNA. A cytoplasmic isoform of La protein as well as LARPs 6, 4, and 1 function in mRNA metabolism and translation in distinct but similar ways, sometimes with the poly(A)-binding protein, and in some cases by direct binding to poly(A)-RNA. New structures of LARP domains, some complexed with RNA, provide novel insights into the functional versatility of these proteins. We also consider LARPs in relation to ancestral La protein and potential retention of links to specific RNA-related pathways. One such link may be tRNA surveillance and codon usage by LARP-associated mRNAs. WIREs RNA 2017, 8:e1430. doi: 10.1002/wrna.1430 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Richard J. Maraia
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD USA
- Commissioned Corps, U.S. Public Health Service, Rockville, MD USA
| | - Sandy Mattijssen
- Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD USA
| | - Isabel Cruz-Gallardo
- Randall Division of Cell and Molecular Biophysics, King's College London, Guy's Campus, London, UK
| | - Maria R. Conte
- Randall Division of Cell and Molecular Biophysics, King's College London, Guy's Campus, London, UK
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110
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Lavallée-Adam M, Cloutier P, Coulombe B, Blanchette M. Functional 5' UTR motif discovery with LESMoN: Local Enrichment of Sequence Motifs in biological Networks. Nucleic Acids Res 2017; 45:10415-10427. [PMID: 28977652 PMCID: PMC5737372 DOI: 10.1093/nar/gkx751] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 08/17/2017] [Indexed: 01/09/2023] Open
Abstract
Biological networks are rich representations of the relationships between entities such as genes or proteins and have become increasingly complete thanks to various high-throughput network mapping experimental approaches. Here, we propose a method to use such networks to guide the search for functional sequence motifs. Specifically, we introduce Local Enrichment of Sequence Motifs in biological Networks (LESMoN), an enumerative motif discovery algorithm that identifies 5' untranslated region (UTR) sequence motifs whose associated proteins form unexpectedly dense clusters in a given biological network. When applied to the human protein-protein interaction network from BioGRID, LESMoN identifies several highly significant 5' UTR sequence motifs, including both previously known motifs and uncharacterized ones. The vast majority of these motifs are evolutionary conserved and the genes containing them are significantly enriched for various gene ontology terms suggesting new associations between 5' UTR motifs and a number of biological processes. We validate in vivo the role in protein expression regulation of three motifs identified by LESMoN.
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Affiliation(s)
- Mathieu Lavallée-Adam
- McGill Centre for Bioinformatics and School of Computer Science, McGill University, Montréal, Québec H3A 0E9, Canada.,Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Philippe Cloutier
- Translational Proteomics Laboratory, Institut de recherches cliniques de Montréal, Montréal, Québec H2W 1R7, Canada
| | - Benoit Coulombe
- Translational Proteomics Laboratory, Institut de recherches cliniques de Montréal, Montréal, Québec H2W 1R7, Canada.,Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Mathieu Blanchette
- McGill Centre for Bioinformatics and School of Computer Science, McGill University, Montréal, Québec H3A 0E9, Canada
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111
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Méndez-Hernández LE, Robledo-Rivera AY, Macías-Silva M, Calera MR, Sánchez-Olea R. Gpn3 is polyubiquitinated on lysine 216 and degraded by the proteasome in the cell nucleus in a Gpn1-inhibitable manner. FEBS Lett 2017; 591:3757-3770. [DOI: 10.1002/1873-3468.12883] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 10/04/2017] [Accepted: 10/05/2017] [Indexed: 11/09/2022]
Affiliation(s)
| | | | - Marina Macías-Silva
- Instituto de Fisiología Celular; Universidad Nacional Autónoma de México; México
| | - Mónica R. Calera
- Instituto de Física; Universidad Autónoma de San Luis Potosí; México
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112
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Warda AS, Kretschmer J, Hackert P, Lenz C, Urlaub H, Höbartner C, Sloan KE, Bohnsack MT. Human METTL16 is a N6-methyladenosine (m 6A) methyltransferase that targets pre-mRNAs and various non-coding RNAs. EMBO Rep 2017; 18:2004-2014. [PMID: 29051200 DOI: 10.15252/embr.201744940] [Citation(s) in RCA: 447] [Impact Index Per Article: 63.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 09/17/2017] [Accepted: 09/28/2017] [Indexed: 01/05/2023] Open
Abstract
N6-methyladenosine (m6A) is a highly dynamic RNA modification that has recently emerged as a key regulator of gene expression. While many m6A modifications are installed by the METTL3-METTL14 complex, others appear to be introduced independently, implying that additional human m6A methyltransferases remain to be identified. Using crosslinking and analysis of cDNA (CRAC), we reveal that the putative human m6A "writer" protein METTL16 binds to the U6 snRNA and other ncRNAs as well as numerous lncRNAs and pre-mRNAs. We demonstrate that METTL16 is responsible for N6-methylation of A43 of the U6 snRNA and identify the early U6 biogenesis factors La, LARP7 and the methylphosphate capping enzyme MEPCE as METTL16 interaction partners. Interestingly, A43 lies within an essential ACAGAGA box of U6 that base pairs with 5' splice sites of pre-mRNAs during splicing, suggesting that METTL16-mediated modification of this site plays an important role in splicing regulation. The identification of METTL16 as an active m6A methyltransferase in human cells expands our understanding of the mechanisms by which the m6A landscape is installed on cellular RNAs.
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Affiliation(s)
- Ahmed S Warda
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany
| | - Jens Kretschmer
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany
| | - Philipp Hackert
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany
| | - Christof Lenz
- Bioanalytical Mass Spectrometry Group, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany.,Department of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany.,Department of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Claudia Höbartner
- Institute for Organic and Biomolecular Chemistry, Georg-August-University, Göttingen, Germany.,Göttingen Center for Molecular Biosciences, Georg-August-University, Göttingen, Germany
| | - Katherine E Sloan
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany .,Göttingen Center for Molecular Biosciences, Georg-August-University, Göttingen, Germany
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113
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Recent progress in mass spectrometry proteomics for biomedical research. SCIENCE CHINA-LIFE SCIENCES 2017; 60:1093-1113. [DOI: 10.1007/s11427-017-9175-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 09/15/2017] [Indexed: 12/30/2022]
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114
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Ballestrero A, Bedognetti D, Ferraioli D, Franceschelli P, Labidi-Galy SI, Leo E, Murai J, Pommier Y, Tsantoulis P, Vellone VG, Zoppoli G. Report on the first SLFN11 monothematic workshop: from function to role as a biomarker in cancer. J Transl Med 2017; 15:199. [PMID: 28969705 PMCID: PMC5625715 DOI: 10.1186/s12967-017-1296-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 09/12/2017] [Indexed: 01/05/2023] Open
Abstract
SLFN11 is a recently discovered protein with a putative DNA/RNA helicase function. First identified in association with the maturation of thymocytes, SLFN11 was later causally associated, by two independent groups, with the resistance to DNA damaging agents such as topoisomerase I and II inhibitors, platinum compounds, and other alkylators, making it an attractive molecule for biomarker development. Later, SLFN11 was linked to antiviral response in human cells and interferon production, establishing a potential bond between immunity and chemotherapy. Recently, we demonstrated the potential role of SLN11 as a biomarker to predict sensitivity to the carboplatin/taxol combination in ovarian cancer. The present manuscript reports on the first international monothematic workshop on SLFN11. Several researchers from around the world, directly and actively involved in the discovery, functional characterization, and study of SLFN11 for its biomarker and medicinal properties gathered to share their views on the current knowledge advances concerning SLFN11. The aim of the manuscript is to summarize the authors’ interventions and the main take-home messages resulting from the workshop.
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Affiliation(s)
- Alberto Ballestrero
- Istituto di Ricovero e Cura a Carattere Scientifico, Policlinico San Martino IST-Istituto Nazionale Tumori, Genoa, Italy.,Università degli Studi di Genova, Viale Benedetto XV, 6, 16132, Genoa, Italy
| | - Davide Bedognetti
- Tumor Biology Immunology and Therapy Branch, Sidra Medical and Research Center, Doah, Qatar
| | - Domenico Ferraioli
- Università degli Studi di Genova, Viale Benedetto XV, 6, 16132, Genoa, Italy.,Centre de Lutte contre le Cancer Léon Bérard, Lyon, France
| | - Paola Franceschelli
- Università degli Studi di Genova, Viale Benedetto XV, 6, 16132, Genoa, Italy
| | | | - Elisabetta Leo
- Oncology, Innovative Medicine Early Development, AstraZeneca, Cambridge, UK
| | - Junko Murai
- Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Yves Pommier
- Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Petros Tsantoulis
- Department of Oncology, Hôpitaux Universitaires de Genève, Geneva, Switzerland
| | - Valerio Gaetano Vellone
- Istituto di Ricovero e Cura a Carattere Scientifico, Policlinico San Martino IST-Istituto Nazionale Tumori, Genoa, Italy.,Università degli Studi di Genova, Viale Benedetto XV, 6, 16132, Genoa, Italy
| | - Gabriele Zoppoli
- Istituto di Ricovero e Cura a Carattere Scientifico, Policlinico San Martino IST-Istituto Nazionale Tumori, Genoa, Italy. .,Università degli Studi di Genova, Viale Benedetto XV, 6, 16132, Genoa, Italy.
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115
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Martinez A, Yamashita S, Nagaike T, Sakaguchi Y, Suzuki T, Tomita K. Human BCDIN3D monomethylates cytoplasmic histidine transfer RNA. Nucleic Acids Res 2017; 45:5423-5436. [PMID: 28119416 PMCID: PMC5435960 DOI: 10.1093/nar/gkx051] [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: 11/12/2016] [Accepted: 01/19/2017] [Indexed: 11/13/2022] Open
Abstract
Human RNA methyltransferase BCDIN3D is overexpressed in breast cancer cells, and is related to the tumorigenic phenotype and poor prognosis of breast cancer. Here, we show that cytoplasmic tRNAHis is the primary target of BCDIN3D in human cells. Recombinant human BCDIN3D, expressed in Escherichia coli, monomethylates the 5΄-monophosphate of cytoplasmic tRNAHis efficiently in vitro. In BCDN3D-knockout cells, established by CRISPR/Cas9 editing, the methyl moiety at the 5΄-monophosphate of cytoplasmic tRNAHis is lost, and the exogenous expression of BCDIN3D in the knockout cells restores the modification in cytoplasmic tRNAHis. BCIDN3D recognizes the 5΄-guanosine nucleoside at position -1 (G-1) and the eight-nucleotide acceptor helix with the G-1-A73 mis-pair at the top of the acceptor stem of cytoplasmic tRNAHis, which are exceptional structural features among cytoplasmic tRNA species. While the monomethylation of the 5΄-monophosphate of cytoplasmic tRNAHis affects neither the overall aminoacylation process in vitro nor the steady-state level of cytoplasmic tRNAHisin vivo, it protects the cytoplasmic tRNAHis transcript from degradation in vitro. Thus, BCDIN3D acts as a cytoplasmic tRNAHis-specific 5΄-methylphosphate capping enzyme. The present results also suggest the possible involvement of the monomethylation of the 5΄-monophosphate of cytoplasmic tRNAHis and/or cytoplasmic tRNAHis itself in the tumorigenesis of breast cancer cells.
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Affiliation(s)
- Anna Martinez
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Seisuke Yamashita
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Takashi Nagaike
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Yuriko Sakaguchi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Tsutomu Suzuki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Kozo Tomita
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
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116
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A chalcone derivative reactivates latent HIV-1 transcription through activating P-TEFb and promoting Tat-SEC interaction on viral promoter. Sci Rep 2017; 7:10657. [PMID: 28878233 PMCID: PMC5587564 DOI: 10.1038/s41598-017-10728-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: 03/22/2017] [Accepted: 08/14/2017] [Indexed: 12/12/2022] Open
Abstract
The principal barrier to the eradication of HIV/AIDS is the existence of latent viral reservoirs. One strategy to overcome this barrier is to use latency-reversing agents (LRAs) to reactivate the latent proviruses, which can then be eliminated by effective anti-retroviral therapy. Although a number of LRAs have been found to reactivate latent HIV, they have not been used clinically due to high toxicity and poor efficacy. In this study, we report the identification of a chalcone analogue called Amt-87 that can significantly reactivate the transcription of latent HIV provirses and act synergistically with known LRAs such as prostratin and JQ1 to reverse latency. Amt-87 works by activating the human transcriptional elongation factor P-TEFb, a CDK9-cyclin T1 heterodimer that is part of the super elongation complex (SEC) used by the viral encoded Tat protein to activate HIV transcription. Amt-87 does so by promoting the phosphorylation of CDK9 at the T-loop, liberating P-TEFb from the inactive 7SK snRNP, and inducing the formation of the Tat-SEC complex at the viral promoter. Together, our data reveal chalcones as a promising category of compounds that should be further explored to identify effective LRAs for targeted reversal of HIV latency.
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117
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Mao YQ, Houry WA. The Role of Pontin and Reptin in Cellular Physiology and Cancer Etiology. Front Mol Biosci 2017; 4:58. [PMID: 28884116 PMCID: PMC5573869 DOI: 10.3389/fmolb.2017.00058] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 08/03/2017] [Indexed: 12/29/2022] Open
Abstract
Pontin (RUVBL1, TIP49, TIP49a, Rvb1) and Reptin (RUVBL2, TIP48, TIP49b, Rvb2) are highly conserved ATPases of the AAA+ (ATPases Associated with various cellular Activities) superfamily and are involved in various cellular processes that are important for oncogenesis. First identified as being upregulated in hepatocellular carcinoma and colorectal cancer, their overexpression has since been shown in multiple cancer types such as breast, lung, gastric, esophageal, pancreatic, kidney, bladder as well as lymphatic, and leukemic cancers. However, their exact functions are still quite unknown as they interact with many molecular complexes with vastly different downstream effectors. Within the nucleus, Pontin and Reptin participate in the TIP60 and INO80 complexes important for chromatin remodeling. Although not transcription factors themselves, Pontin and Reptin modulate the transcriptional activities of bona fide proto-oncogenes such as MYC and β-catenin. They associate with proteins involved in DNA damage repair such as PIKK complexes as well as with the core complex of Fanconi anemia pathway. They have also been shown to be important for cell cycle progression, being involved in assembly of telomerase, mitotic spindle, RNA polymerase II, and snoRNPs. When the two ATPases localize to the cytoplasm, they were reported to promote cancer cell invasion and metastasis. Due to their various roles in carcinogenesis, it is not surprising that Pontin and Reptin are proving to be important biomarkers for diagnosis and prognosis of various cancers. They are also current targets for the development of new therapeutic anticancer drugs.
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Affiliation(s)
- Yu-Qian Mao
- Department of Biochemistry, University of TorontoToronto, ON, Canada
| | - Walid A Houry
- Department of Biochemistry, University of TorontoToronto, ON, Canada.,Department of Chemistry, University of TorontoToronto, ON, Canada
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Martinez-Zapien D, Legrand P, McEwen AG, Proux F, Cragnolini T, Pasquali S, Dock-Bregeon AC. The crystal structure of the 5΄ functional domain of the transcription riboregulator 7SK. Nucleic Acids Res 2017; 45:3568-3579. [PMID: 28082395 PMCID: PMC5389472 DOI: 10.1093/nar/gkw1351] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 01/06/2017] [Indexed: 12/22/2022] Open
Abstract
In vertebrates, the 7SK RNA forms the scaffold of a complex, which regulates transcription pausing of RNA-polymerase II. By binding to the HEXIM protein, the complex comprising proteins LARP7 and MePCE captures the positive transcription elongation factor P-TEFb and prevents phosphorylation of pausing factors. The HEXIM-binding site embedded in the 5΄-hairpin of 7SK (HP1) encompasses a short signature sequence, a GAUC repeat framed by single-stranded uridines. The present crystal structure of HP1 shows a remarkably straight helical stack involving several unexpected triples formed at a central region. Surprisingly, two uridines of the signature sequence make triple interactions in the major groove of the (GAUC)2. The third uridine is turned outwards or inward, wedging between the other uridines, thus filling the major groove. A molecular dynamics simulation indicates that these two conformations of the signature sequence represent stable alternatives. Analyses of the interaction with the HEXIM protein confirm the importance of the triple interactions at the signature sequence. Altogether, the present structural analysis of 7SK HP1 highlights an original mechanism of swapping bases, which could represent a possible ‘7SK signature’ and provides new insight into the functional importance of the plasticity of RNA.
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Affiliation(s)
- Denise Martinez-Zapien
- Biotechnologie et signalisation cellulaire, CNRS UMR 7242, Ecole Supérieure de Biotechnologie de Strasbourg, F-67412 Illkirch, France
| | - Pierre Legrand
- Synchrotron SOLEIL, L'Orme des Merisiers, F-91190 Gif-sur-Yvette, France
| | - Alastair G McEwen
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Florence Proux
- Department of functional genomics, CNRS UMR 8197, Institut de Biologie de l΄Ecole Normale Supérieure F-75005 Paris, France.,Department of functional genomics, INSERM-U1024, Institut de Biologie de l΄Ecole Normale Supérieure F-75005 Paris, France
| | | | - Samuela Pasquali
- Laboratoire de Biochimie Théorique, IBPC, CNRS UPR 9080, Université Sorbonne Paris Cite, Paris Diderot, 75005 Paris, France
| | - Anne-Catherine Dock-Bregeon
- Department of functional genomics, CNRS UMR 8197, Institut de Biologie de l΄Ecole Normale Supérieure F-75005 Paris, France.,Department of functional genomics, INSERM-U1024, Institut de Biologie de l΄Ecole Normale Supérieure F-75005 Paris, France.,Sorbonne Universités UPMC, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff cedex, France.,CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff cedex, France
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119
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Massenet S, Bertrand E, Verheggen C. Assembly and trafficking of box C/D and H/ACA snoRNPs. RNA Biol 2017; 14:680-692. [PMID: 27715451 PMCID: PMC5519232 DOI: 10.1080/15476286.2016.1243646] [Citation(s) in RCA: 118] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 09/09/2016] [Accepted: 09/27/2016] [Indexed: 12/23/2022] Open
Abstract
Box C/D and box H/ACA snoRNAs are abundant non-coding RNAs that localize in the nucleolus and mostly function as guides for nucleotide modifications. While a large pool of snoRNAs modifies rRNAs, an increasing number of snoRNAs could also potentially target mRNAs. ScaRNAs belong to a family of specific RNAs that localize in Cajal bodies and that are structurally similar to snoRNAs. Most scaRNAs are involved in snRNA modification, while telomerase RNA, which contains H/ACA motifs, functions in telomeric DNA synthesis. In this review, we describe how box C/D and H/ACA snoRNAs are processed and assembled with core proteins to form functional RNP particles. Their biogenesis involve several transport factors that first direct pre-snoRNPs to Cajal bodies, where some processing steps are believed to take place, and then to nucleoli. Assembly of core proteins involves the HSP90/R2TP chaperone-cochaperone system for both box C/D and H/ACA RNAs, but also several factors specific for each family. These assembly factors chaperone unassembled core proteins, regulate the formation and disassembly of pre-snoRNP intermediates, and control the activity of immature particles. The AAA+ ATPase RUVBL1 and RUVBL2 belong to the R2TP co-chaperones and play essential roles in snoRNP biogenesis, as well as in the formation of other macro-molecular complexes. Despite intensive research, their mechanisms of action are still incompletely understood.
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Affiliation(s)
- Séverine Massenet
- Ingénierie Moléculaire et Physiopathologie Articulaire, UMR 7365 CNRS, 9 Avenue de la forêt de Haye, 54505 Vandoeuvre-les-Nancy Cedex, France, Université de Lorraine, Campus Biologie –Santé, CS 50184, 54505 Vandoeuvre-les-Nancy Cedex, France
| | - Edouard Bertrand
- Institut de Génétique Moléculaire de Montpellier, UMR 5535 CNRS, 1919 route de Mende, 34293 Montpellier cedex 5, France, Université de Montpellier, 163 rue Auguste Broussonnet, 34090 Montpellier, France
| | - Céline Verheggen
- Institut de Génétique Moléculaire de Montpellier, UMR 5535 CNRS, 1919 route de Mende, 34293 Montpellier cedex 5, France, Université de Montpellier, 163 rue Auguste Broussonnet, 34090 Montpellier, France
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120
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Cloutier P, Poitras C, Durand M, Hekmat O, Fiola-Masson É, Bouchard A, Faubert D, Chabot B, Coulombe B. R2TP/Prefoldin-like component RUVBL1/RUVBL2 directly interacts with ZNHIT2 to regulate assembly of U5 small nuclear ribonucleoprotein. Nat Commun 2017; 8:15615. [PMID: 28561026 PMCID: PMC5460035 DOI: 10.1038/ncomms15615] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 04/12/2017] [Indexed: 01/11/2023] Open
Abstract
The R2TP/Prefoldin-like (R2TP/PFDL) complex has emerged as a cochaperone complex involved in the assembly of a number of critical protein complexes including snoRNPs, nuclear RNA polymerases and PIKK-containing complexes. Here we report on the use of multiple target affinity purification coupled to mass spectrometry to identify two additional complexes that interact with R2TP/PFDL: the TSC1–TSC2 complex and the U5 small nuclear ribonucleoprotein (snRNP). The interaction between R2TP/PFDL and the U5 snRNP is mostly mediated by the previously uncharacterized factor ZNHIT2. A more general function for the zinc-finger HIT domain in binding RUVBL2 is exposed. Disruption of ZNHIT2 and RUVBL2 expression impacts the protein composition of the U5 snRNP suggesting a function for these proteins in promoting the assembly of the ribonucleoprotein. A possible implication of R2TP/PFDL as a major effector of stress-, energy- and nutrient-sensing pathways that regulate anabolic processes through the regulation of its chaperoning activity is discussed. The R2TP/Prefoldin-like cochaperone complex is involved in the assembly of a number of protein complexes. Here the authors provide evidence that RUVBL1/RUVBL2, subunits of that cochaperone complex, directly interact with ZNHIT2 to regulate assembly of U5 small ribonucleoprotein.
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Affiliation(s)
- Philippe Cloutier
- Translational Proteomics Laboratory, Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, Canada H2W 1R7
| | - Christian Poitras
- Translational Proteomics Laboratory, Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, Canada H2W 1R7
| | - Mathieu Durand
- Laboratory of Functional Genomics, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Quebec, Canada J1E 4K8
| | - Omid Hekmat
- Translational Proteomics Laboratory, Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, Canada H2W 1R7
| | - Émilie Fiola-Masson
- Translational Proteomics Laboratory, Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, Canada H2W 1R7
| | - Annie Bouchard
- Translational Proteomics Laboratory, Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, Canada H2W 1R7
| | - Denis Faubert
- Translational Proteomics Laboratory, Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, Canada H2W 1R7
| | - Benoit Chabot
- Laboratory of Functional Genomics, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Quebec, Canada J1E 4K8.,Département de Microbiologie et d'Infectiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Quebec, Canada J1E 4K8
| | - Benoit Coulombe
- Translational Proteomics Laboratory, Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, Canada H2W 1R7.,Département de Biochimie, Université de Montréal, Montreal, Quebec, Canada H3T 1J4
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121
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Elagib KE, Lu CH, Mosoyan G, Khalil S, Zasadzińska E, Foltz DR, Balogh P, Gru AA, Fuchs DA, Rimsza LM, Verhoeyen E, Sansó M, Fisher RP, Iancu-Rubin C, Goldfarb AN. Neonatal expression of RNA-binding protein IGF2BP3 regulates the human fetal-adult megakaryocyte transition. J Clin Invest 2017; 127:2365-2377. [PMID: 28481226 DOI: 10.1172/jci88936] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 03/16/2017] [Indexed: 12/31/2022] Open
Abstract
Hematopoietic transitions that accompany fetal development, such as erythroid globin chain switching, play important roles in normal physiology and disease development. In the megakaryocyte lineage, human fetal progenitors do not execute the adult morphogenesis program of enlargement, polyploidization, and proplatelet formation. Although these defects decline with gestational stage, they remain sufficiently severe at birth to predispose newborns to thrombocytopenia. These defects may also contribute to inferior platelet recovery after cord blood stem cell transplantation and may underlie inefficient platelet production by megakaryocytes derived from pluripotent stem cells. In this study, comparison of neonatal versus adult human progenitors has identified a blockade in the specialized positive transcription elongation factor b (P-TEFb) activation mechanism that is known to drive adult megakaryocyte morphogenesis. This blockade resulted from neonatal-specific expression of an oncofetal RNA-binding protein, IGF2BP3, which prevented the destabilization of the nuclear RNA 7SK, a process normally associated with adult megakaryocytic P-TEFb activation. Knockdown of IGF2BP3 sufficed to confer both phenotypic and molecular features of adult-type cells on neonatal megakaryocytes. Pharmacologic inhibition of IGF2BP3 expression via bromodomain and extraterminal domain (BET) inhibition also elicited adult features in neonatal megakaryocytes. These results identify IGF2BP3 as a human ontogenic master switch that restricts megakaryocyte development by modulating a lineage-specific P-TEFb activation mechanism, revealing potential strategies toward enhancing platelet production.
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Affiliation(s)
- Kamaleldin E Elagib
- Department of Pathology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Chih-Huan Lu
- Department of Pathology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Goar Mosoyan
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Shadi Khalil
- Department of Pathology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Ewelina Zasadzińska
- Department of Biochemistry and Molecular Genetics, University of Virginia, School of Medicine, Charlottesville, Virginia, USA
| | - Daniel R Foltz
- Department of Biochemistry and Molecular Genetics, University of Virginia, School of Medicine, Charlottesville, Virginia, USA.,Department of Biochemistry and Molecular Genetics, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Peter Balogh
- Department of Pathology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Alejandro A Gru
- Department of Pathology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Deborah A Fuchs
- Department of Pathology, University of Arizona College of Medicine, Tucson, Arizona, USA
| | - Lisa M Rimsza
- Department of Laboratory Medicine and Pathology, Mayo Clinic Arizona, Scottsdale, Arizona, USA
| | - Els Verhoeyen
- Centre International de Recherche en Infectiologie (CIRI), Team EVIR, Inserm, U1111, Ecole Normale Supériere de Lyon, Université Lyon 1, CNRS, UMR5308, Lyon, France.,Inserm U1065, Centre Méditerranéen de Médecine Moléculaire, Nice, France
| | - Miriam Sansó
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Robert P Fisher
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Camelia Iancu-Rubin
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Adam N Goldfarb
- Department of Pathology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
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122
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Kropp J, Carrillo JA, Namous H, Daniels A, Salih SM, Song J, Khatib H. Male fertility status is associated with DNA methylation signatures in sperm and transcriptomic profiles of bovine preimplantation embryos. BMC Genomics 2017; 18:280. [PMID: 28381255 PMCID: PMC5382486 DOI: 10.1186/s12864-017-3673-y] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 03/31/2017] [Indexed: 11/12/2022] Open
Abstract
Background Infertility in dairy cattle is a concern where reduced fertilization rates and high embryonic loss are contributing factors. Studies of the paternal contribution to reproductive performance are limited. However, recent discoveries have shown that, in addition to DNA, sperm delivers transcription factors and epigenetic components that are required for fertilization and proper embryonic development. Hence, characterization of the paternal contribution at the time of fertilization is warranted. We hypothesized that sire fertility is associated with differences in DNA methylation patterns in sperm and that the embryonic transcriptomic profiles are influenced by the fertility status of the bull. Embryos were generated in vitro by fertilization with either a high or low fertility Holstein bull. Blastocysts derived from each high and low fertility bulls were evaluated for morphology, development, and transcriptomic analysis using RNA-Sequencing. Additionally, DNA methylation signatures of sperm from high and low fertility sires were characterized by performing whole-genome DNA methylation binding domain sequencing. Results Embryo morphology and developmental capacity did not differ between embryos generated from either a high or low fertility bull. However, RNA-Sequencing revealed 98 genes to be differentially expressed at a false discovery rate < 1%. A total of 65 genes were upregulated in high fertility bull derived embryos, and 33 genes were upregulated in low fertility derived embryos. Expression of the genes CYCS, EEA1, SLC16A7, MEPCE, and TFB2M was validated in three new pairs of biological replicates of embryos. The role of the differentially expressed gene TFB2M in embryonic development was further assessed through expression knockdown at the zygotic stage, which resulted in decreased development to the blastocyst stage. Assessment of the epigenetic signature of spermatozoa between high and low fertility bulls revealed 76 differentially methylated regions. Conclusions Despite similar morphology and development to the blastocyst stage, preimplantation embryos derived from high and low fertility bulls displayed significant transcriptomic differences. The relationship between the paternal contribution and the embryonic transcriptome is unclear, although differences in methylated regions were identified which could influence the reprogramming of the early embryo. Further characterization of paternal factors delivered to the oocyte could lead to the identification of biomarkers for better selection of sires to improve reproductive efficiency. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3673-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jenna Kropp
- Department of Animal Sciences, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - José A Carrillo
- Department of Animal and Avian Sciences, University of Maryland, College Park, MD, 20742, USA
| | - Hadjer Namous
- Department of Animal Sciences, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Alyssa Daniels
- Department of Animal Sciences, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Sana M Salih
- Department of Obstetrics and Gynecology, University of Wisconsin-Madison, Madison, WI, 53792, USA.,Present address: Department of Obstetrics and Gynecology, West Virginia University, Morgantown, WV, 26508, USA
| | - Jiuzhou Song
- Department of Animal and Avian Sciences, University of Maryland, College Park, MD, 20742, USA
| | - Hasan Khatib
- Department of Animal Sciences, University of Wisconsin-Madison, Madison, WI, 53706, USA.
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123
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Tawamie H, Martianov I, Wohlfahrt N, Buchert R, Mengus G, Uebe S, Janiri L, Hirsch FW, Schumacher J, Ferrazzi F, Sticht H, Reis A, Davidson I, Colombo R, Abou Jamra R. Hypomorphic Pathogenic Variants in TAF13 Are Associated with Autosomal-Recessive Intellectual Disability and Microcephaly. Am J Hum Genet 2017; 100:555-561. [PMID: 28257693 DOI: 10.1016/j.ajhg.2017.01.032] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 01/25/2017] [Indexed: 10/20/2022] Open
Abstract
In two independent consanguineous families each with two children affected by mild intellectual disability and microcephaly, we identified two homozygous missense variants (c.119T>A [p.Met40Lys] and c.92T>A [p.Leu31His]) in TATA-box-binding-protein-associated factor 13 (TAF13). Molecular modeling suggested a pathogenic effect of both variants through disruption of the interaction between TAF13 and TAF11. These two proteins form a histone-like heterodimer that is essential for their recruitment into the general RNA polymerase II transcription factor IID (TFIID) complex. Co-immunoprecipitation in HeLa cells transfected with plasmids encoding TAF11 and TAF13 revealed that both variants indeed impaired formation of the TAF13-TAF11 heterodimer, thus confirming the protein modeling analysis. To further understand the functional role of TAF13, we performed RNA sequencing of neuroblastoma cell lines upon TAF13 knockdown. The transcriptional profile showed significant deregulation of gene expression patterns with an emphasis on genes related to neuronal and skeletal functions and those containing E-box motives in their promoters. Here, we expand the spectrum of TAF-associated phenotypes and highlight the importance of TAF13 in neuronal functions.
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124
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Egloff S, Vitali P, Tellier M, Raffel R, Murphy S, Kiss T. The 7SK snRNP associates with the little elongation complex to promote snRNA gene expression. EMBO J 2017; 36:934-948. [PMID: 28254838 DOI: 10.15252/embj.201695740] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 01/26/2017] [Accepted: 01/27/2017] [Indexed: 11/09/2022] Open
Abstract
The 7SK small nuclear RNP (snRNP), composed of the 7SK small nuclear RNA (snRNA), MePCE, and Larp7, regulates the mRNA elongation capacity of RNA polymerase II (RNAPII) through controlling the nuclear activity of positive transcription elongation factor b (P-TEFb). Here, we demonstrate that the human 7SK snRNP also functions as a canonical transcription factor that, in collaboration with the little elongation complex (LEC) comprising ELL, Ice1, Ice2, and ZC3H8, promotes transcription of RNAPII-specific spliceosomal snRNA and small nucleolar RNA (snoRNA) genes. The 7SK snRNA specifically associates with a fraction of RNAPII hyperphosphorylated at Ser5 and Ser7, which is a hallmark of RNAPII engaged in snRNA synthesis. Chromatin immunoprecipitation (ChIP) and chromatin isolation by RNA purification (ChIRP) experiments revealed enrichments for all components of the 7SK snRNP on RNAPII-specific sn/snoRNA genes. Depletion of 7SK snRNA or Larp7 disrupts LEC integrity, inhibits RNAPII recruitment to RNAPII-specific sn/snoRNA genes, and reduces nascent snRNA and snoRNA synthesis. Thus, through controlling both mRNA elongation and sn/snoRNA synthesis, the 7SK snRNP is a key regulator of nuclear RNA production by RNAPII.
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Affiliation(s)
- Sylvain Egloff
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), CNRS, UPS, Université de Toulouse, Toulouse Cedex 9, France
| | - Patrice Vitali
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), CNRS, UPS, Université de Toulouse, Toulouse Cedex 9, France
| | - Michael Tellier
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Raoul Raffel
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), CNRS, UPS, Université de Toulouse, Toulouse Cedex 9, France
| | - Shona Murphy
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Tamás Kiss
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative (CBI), CNRS, UPS, Université de Toulouse, Toulouse Cedex 9, France .,Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
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125
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Muñoz A, Mangano S, González-García MP, Contreras R, Sauer M, De Rybel B, Weijers D, Sánchez-Serrano JJ, Sanmartín M, Rojo E. RIMA-Dependent Nuclear Accumulation of IYO Triggers Auxin-Irreversible Cell Differentiation in Arabidopsis. THE PLANT CELL 2017; 29:575-588. [PMID: 28223441 PMCID: PMC5385956 DOI: 10.1105/tpc.16.00791] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 12/28/2016] [Accepted: 02/14/2017] [Indexed: 05/09/2023]
Abstract
The transcriptional regulator MINIYO (IYO) is essential and rate-limiting for initiating cell differentiation in Arabidopsis thaliana Moreover, IYO moves from the cytosol into the nucleus in cells at the meristem periphery, possibly triggering their differentiation. However, the genetic mechanisms controlling IYO nuclear accumulation were unknown, and the evidence that increased nuclear IYO levels trigger differentiation remained correlative. Searching for IYO interactors, we identified RPAP2 IYO Mate (RIMA), a homolog of yeast and human proteins linked to nuclear import of selective cargo. Knockdown of RIMA causes delayed onset of cell differentiation, phenocopying the effects of IYO knockdown at the transcriptomic and developmental levels. Moreover, differentiation is completely blocked when IYO and RIMA activities are simultaneously reduced and is synergistically accelerated when IYO and RIMA are concurrently overexpressed, confirming their functional interaction. Indeed, RIMA knockdown reduces the nuclear levels of IYO and prevents its prodifferentiation activity, supporting the conclusion that RIMA-dependent nuclear IYO accumulation triggers cell differentiation in Arabidopsis. Importantly, by analyzing the effect of the IYO/RIMA pathway on xylem pole pericycle cells, we provide compelling evidence reinforcing the view that the capacity for de novo organogenesis and regeneration from mature plant tissues can reside in stem cell reservoirs.
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Affiliation(s)
- Alfonso Muñoz
- Centro Nacional de Biotecnología-CSIC, Cantoblanco, E-28049 Madrid, Spain
| | - Silvina Mangano
- Centro Nacional de Biotecnología-CSIC, Cantoblanco, E-28049 Madrid, Spain
| | | | - Ramón Contreras
- Centro Nacional de Biotecnología-CSIC, Cantoblanco, E-28049 Madrid, Spain
| | - Michael Sauer
- Centro Nacional de Biotecnología-CSIC, Cantoblanco, E-28049 Madrid, Spain
| | - Bert De Rybel
- Laboratory of Biochemistry, Wageningen University, 6703 HA Wageningen, The Netherlands
| | - Dolf Weijers
- Laboratory of Biochemistry, Wageningen University, 6703 HA Wageningen, The Netherlands
| | | | - Maite Sanmartín
- Centro Nacional de Biotecnología-CSIC, Cantoblanco, E-28049 Madrid, Spain
| | - Enrique Rojo
- Centro Nacional de Biotecnología-CSIC, Cantoblanco, E-28049 Madrid, Spain
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Guerrero-Serrano G, Castanedo L, Cristóbal-Mondragón GR, Montalvo-Arredondo J, Riego-Ruíz L, DeLuna A, De Las Peñas A, Castaño I, Calera MR, Sánchez-Olea R. Npa3/ScGpn1 carboxy-terminal tail is dispensable for cell viability and RNA polymerase II nuclear targeting but critical for microtubule stability and function. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1864:451-462. [PMID: 27965115 DOI: 10.1016/j.bbamcr.2016.12.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 12/03/2016] [Accepted: 12/09/2016] [Indexed: 10/20/2022]
Abstract
Genetic deletion of the essential GTPase Gpn1 or replacement of the endogenous gene by partial loss of function mutants in yeast is associated with multiple cellular phenotypes, including in all cases a marked cytoplasmic retention of RNA polymerase II (RNAPII). Global inhibition of RNAPII-mediated transcription due to malfunction of Gpn1 precludes the identification and study of other cellular function(s) for this GTPase. In contrast to the single Gpn protein present in Archaea, eukaryotic Gpn1 possesses an extension of approximately 100 amino acids at the C-terminal end of the GTPase domain. To determine the importance of this C-terminal extension in Saccharomyces cerevisiae Gpn1, we generated yeast strains expressing either C-terminal truncated (gpn1ΔC) or full-length ScGpn1. We found that ScGpn1ΔC was retained in the cell nucleus, an event physiologically relevant as gpn1ΔC cells contained a higher nuclear fraction of the RNAPII CTD phosphatase Rtr1. gpn1ΔC cells displayed an increased size, a delay in mitosis exit, and an increased sensitivity to the microtubule polymerization inhibitor benomyl at the cell proliferation level and two cellular events that depend on microtubule function: RNAPII nuclear targeting and vacuole integrity. These phenotypes were not caused by inhibition of RNAPII, as in gpn1ΔC cells RNAPII nuclear targeting and transcriptional activity were unaffected. These data, combined with our description here of a genetic interaction between GPN1 and BIK1, a microtubule plus-end tracking protein with a mitotic function, strongly suggest that the ScGpn1 C-terminal tail plays a critical role in microtubule dynamics and mitotic progression in an RNAPII-independent manner.
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Affiliation(s)
- Gehenna Guerrero-Serrano
- Instituto de Física, Universidad Autónoma de San Luis Potosí, Manuel Nava 6, Zona Univesitaria, C.P. 78290, San Luis Potosí, San Luis Potosí, Mexico
| | - Leonardo Castanedo
- Instituto de Física, Universidad Autónoma de San Luis Potosí, Manuel Nava 6, Zona Univesitaria, C.P. 78290, San Luis Potosí, San Luis Potosí, Mexico
| | - Gema R Cristóbal-Mondragón
- Instituto de Física, Universidad Autónoma de San Luis Potosí, Manuel Nava 6, Zona Univesitaria, C.P. 78290, San Luis Potosí, San Luis Potosí, Mexico
| | - Javier Montalvo-Arredondo
- IPICYT, División de Biología Molecular, Camino a la Presa San José 2055, C.P. 78216, San Luis Potosí, San Luis Potosí, Mexico
| | - Lina Riego-Ruíz
- IPICYT, División de Biología Molecular, Camino a la Presa San José 2055, C.P. 78216, San Luis Potosí, San Luis Potosí, Mexico
| | - Alexander DeLuna
- LANGEBIO: Laboratorio Nacional de Genomica para la Biodiversidad, Km 9.6 Libramiento Norte Carretera León, C.P. 36821 Irapuato, Guanajuato, Mexico
| | - Alejandro De Las Peñas
- IPICYT, División de Biología Molecular, Camino a la Presa San José 2055, C.P. 78216, San Luis Potosí, San Luis Potosí, Mexico
| | - Irene Castaño
- IPICYT, División de Biología Molecular, Camino a la Presa San José 2055, C.P. 78216, San Luis Potosí, San Luis Potosí, Mexico
| | - Mónica R Calera
- Instituto de Física, Universidad Autónoma de San Luis Potosí, Manuel Nava 6, Zona Univesitaria, C.P. 78290, San Luis Potosí, San Luis Potosí, Mexico.
| | - Roberto Sánchez-Olea
- Instituto de Física, Universidad Autónoma de San Luis Potosí, Manuel Nava 6, Zona Univesitaria, C.P. 78290, San Luis Potosí, San Luis Potosí, Mexico.
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Bourbigot S, Dock-Bregeon AC, Eberling P, Coutant J, Kieffer B, Lebars I. Solution structure of the 5'-terminal hairpin of the 7SK small nuclear RNA. RNA (NEW YORK, N.Y.) 2016; 22:1844-1858. [PMID: 27852926 PMCID: PMC5113205 DOI: 10.1261/rna.056523.116] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 09/10/2016] [Indexed: 05/10/2023]
Abstract
The small nuclear 7SK RNA regulates RNA polymerase II (RNA Pol II) transcription, by sequestering and inhibiting the positive transcription elongation factor b (P-TEFb). P-TEFb is stored in the 7SK ribonucleoprotein (RNP) that contains the three nuclear proteins Hexim1, LaRP7, and MePCE. P-TEFb interacts with the protein Hexim1 and the 7SK RNA. Once P-TEFb is released from the 7SK RNP, it activates transcription by phosphorylating the C-terminal domain of RNA Pol II. P-TEFb also plays a crucial role in the replication of the human immunodeficiency virus HIV-1, through its recruitment by the viral transactivator Tat. Previous work demonstrated that the protein Tat promotes the release of P-TEFb from the 7SK RNP through direct binding to the 7SK RNA. Hexim1 and Tat proteins both comprise conserved and similar arginine-rich motifs that were identified to bind the 7SK RNA at a repeated GAUC site located at the top of the 5'-terminal hairpin (HPI). Here, we report the solution structure of this region as determined by nuclear magnetic resonance, to identify HPI structural features recognized by Hexim1 and Tat. The HPI solution structure displays an elongated shape featuring four helical segments interrupted by one internal loop and three bulges with distinct folds. In particular, the repeated GAUC motif adopts a pre-organized geometry. Our results suggest that the binding of Hexim1 and Tat to the 7SK RNA could originate from a conformational selection of this motif, highlighting how RNA local structure could lead to an adaptive recognition of their partners.
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Affiliation(s)
- Sarah Bourbigot
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR 7104, INSERM U964, Université de Strasbourg, 67404 Illkirch Cedex, France
| | - Anne-Catherine Dock-Bregeon
- Department of Functional Genomics, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), CNRS UMR 8197, INSERM U1024, 75005 Paris, France
| | - Pascal Eberling
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR 7104, INSERM U964, Université de Strasbourg, 67404 Illkirch Cedex, France
| | - Jérôme Coutant
- Bruker BioSpin SAS, BP 10002, 67166 Wissembourg Cedex, France
| | - Bruno Kieffer
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR 7104, INSERM U964, Université de Strasbourg, 67404 Illkirch Cedex, France
| | - Isabelle Lebars
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR 7104, INSERM U964, Université de Strasbourg, 67404 Illkirch Cedex, France
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Herranz N, Dave N, Millanes-Romero A, Pascual-Reguant L, Morey L, Díaz VM, Lórenz-Fonfría V, Gutierrez-Gallego R, Jerónimo C, Iturbide A, Di Croce L, García de Herreros A, Peiró S. Lysyl oxidase-like 2 (LOXL2) oxidizes trimethylated lysine 4 in histone H3. FEBS J 2016; 283:4263-4273. [PMID: 27735137 DOI: 10.1111/febs.13922] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 10/10/2016] [Indexed: 12/15/2022]
Abstract
Methylation of histone H3 lysine 4 is linked to active transcription and can be removed by LSD1 or the JmjC domain-containing proteins by amino-oxidation or hydroxylation, respectively. Here we describe that its deamination can be catalyzed by lysyl oxidase-like 2 protein (LOXL2), presenting an unconventional chemical mechanism for H3K4 modification. Infrared spectroscopy and mass spectrometry analyses demonstrated that recombinant LOXL2 specifically deaminates trimethylated H3K4. Moreover, by regulating H3K4me3 deamination, LOXL2 activity is linked with the transcriptional control of the CDH1 gene. These results reveal the existence of further H3 modification as well as a novel mechanism for H3K4me3 demethylation. DATABASE The GEO accession number for the data referred to this paper is GSE35600.
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Affiliation(s)
- Nicolás Herranz
- Programa de Recerca en Càncer, Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), Barcelona, Spain
| | - Natàlia Dave
- Programa de Recerca en Càncer, Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), Barcelona, Spain
| | - Alba Millanes-Romero
- Programa de Recerca en Càncer, Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), Barcelona, Spain
| | - Laura Pascual-Reguant
- Programa de Recerca en Càncer, Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), Barcelona, Spain
| | - Lluis Morey
- Centre de Regulació Genòmica (CRG), Barcelona, Spain
| | - Víctor M Díaz
- Programa de Recerca en Càncer, Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), Barcelona, Spain.,Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
| | - Víctor Lórenz-Fonfría
- Unitat de Biofísica, Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | | | | | - Ane Iturbide
- Programa de Recerca en Càncer, Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), Barcelona, Spain
| | - Luciano Di Croce
- Centre de Regulació Genòmica (CRG), Barcelona, Spain.,Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain.,Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
| | - Antonio García de Herreros
- Programa de Recerca en Càncer, Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), Barcelona, Spain.,Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
| | - Sandra Peiró
- Programa de Recerca en Càncer, Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), Barcelona, Spain
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129
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An evolutionary conserved Hexim1 peptide binds to the Cdk9 catalytic site to inhibit P-TEFb. Proc Natl Acad Sci U S A 2016; 113:12721-12726. [PMID: 27791144 DOI: 10.1073/pnas.1612331113] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The positive transcription elongation factor (P-TEFb) is required for the transcription of most genes by RNA polymerase II. Hexim proteins associated with 7SK RNA bind to P-TEFb and reversibly inhibit its activity. P-TEFb comprises the Cdk9 cyclin-dependent kinase and a cyclin T. Hexim proteins have been shown to bind the cyclin T subunit of P-TEFb. How this binding leads to inhibition of the kinase activity of Cdk9 has remained elusive, however. Using a photoreactive amino acid incorporated into proteins, we show that in live cells, cell extracts, and in vitro reconstituted complexes, Hexim1 cross-links and thus contacts Cdk9. Notably, replacement of a phenylalanine, F208, belonging to an evolutionary conserved Hexim1 peptide (202PYNTTQFLM210) known as the "PYNT" sequence, cross-links a peptide within the activation segment that controls access to the Cdk9 catalytic cleft. Reciprocally, Hexim1 is cross-linked by a photoreactive amino acid replacing Cdk9 W193, a tryptophan within this activation segment. These findings provide evidence of a direct interaction between Cdk9 and its inhibitor, Hexim1. Based on similarities with Cdk2 3D structure, the Cdk9 peptide cross-linked by Hexim1 corresponds to the substrate binding-site. Accordingly, the Hexim1 PYNT sequence is proposed to interfere with substrate binding to Cdk9 and thereby to inhibit its kinase activity.
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130
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7SK small nuclear RNA transcription level down-regulates in human tumors and stem cells. Med Oncol 2016; 33:128. [PMID: 27752877 DOI: 10.1007/s12032-016-0841-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 10/05/2016] [Indexed: 01/18/2023]
Abstract
The small nuclear noncoding RNA (snRNA) 7SK is a highly conserved noncoding RNA of 331 nucleotides in animals, which is present in a nuclear ribonucleoprotein complex with proteins such as methylphosphate capping enzyme (MePCE), hexamethylene bisacetamide-inducible proteins 1 and 2 (HEXIM1 and HEXIM2) and La-related protein 7 (Larp7). Regulating the activity of the positive transcription elongation factor b (P-TEFb) is the key function of 7SK noncoding RNA. Recently, we have shown that 7SK snRNA over-expression reduces human embryonic kidney 293T cell line viability. Here, we attempt to monitor the expression level of 7SK snRNA in different human cell lines and cancer tissues. Examination of 7SK transcription either in cell lines or in different malignant tissues including blood (CML), breast and colon showed that 7SK expression significantly down-regulated in cancer. Similar to human cancer tissues and cell lines, 7SK transcriptional level decreased in stem cells in comparison with differentiated cell types. In this regard, over-expression of 7SK snRNA might be a powerful tool for blocking cancer progression by controlling the activity of P-TEFb.
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131
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Stegeman R, Spreacker PJ, Swanson SK, Stephenson R, Florens L, Washburn MP, Weake VM. The Spliceosomal Protein SF3B5 is a Novel Component of Drosophila SAGA that Functions in Gene Expression Independent of Splicing. J Mol Biol 2016; 428:3632-49. [PMID: 27185460 PMCID: PMC5011000 DOI: 10.1016/j.jmb.2016.05.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 04/19/2016] [Accepted: 05/08/2016] [Indexed: 12/16/2022]
Abstract
The interaction between splicing factors and the transcriptional machinery provides an intriguing link between the coupled processes of transcription and splicing. Here, we show that the two components of the SF3B complex, SF3B3 and SF3B5, that form part of the U2 small nuclear ribonucleoprotein particle (snRNP) are also subunits of the Spt-Ada-Gcn5 acetyltransferase (SAGA) transcriptional coactivator complex in Drosophila melanogaster. Whereas SF3B3 had previously been identified as a human SAGA subunit, SF3B5 had not been identified as a component of SAGA in any species. We show that SF3B3 and SF3B5 bind to SAGA independent of RNA and interact with multiple SAGA subunits including Sgf29 and Spt7 in a yeast two-hybrid assay. Through analysis of sf3b5 mutant flies, we show that SF3B5 is necessary for proper development and cell viability but not for histone acetylation. Although SF3B5 does not appear to function in SAGA's histone-modifying activities, SF3B5 is still required for expression of a subset of SAGA-regulated genes independent of splicing. Thus, our data support an independent function of SF3B5 in SAGA's transcription coactivator activity that is separate from its role in splicing.
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Affiliation(s)
- Rachel Stegeman
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Peyton J Spreacker
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Selene K Swanson
- Stowers Institute for Medical Research, 1000 E. 50th St., Kansas City, MO 64110, USA
| | - Robert Stephenson
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Laurence Florens
- Stowers Institute for Medical Research, 1000 E. 50th St., Kansas City, MO 64110, USA
| | - Michael P Washburn
- Stowers Institute for Medical Research, 1000 E. 50th St., Kansas City, MO 64110, USA; Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA
| | - Vikki M Weake
- Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA; Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA.
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132
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Tan JL, Fogley RD, Flynn RA, Ablain J, Yang S, Saint-André V, Fan ZP, Do BT, Laga AC, Fujinaga K, Santoriello C, Greer CB, Kim YJ, Clohessy JG, Bothmer A, Pandell N, Avagyan S, Brogie JE, van Rooijen E, Hagedorn EJ, Shyh-Chang N, White RM, Price DH, Pandolfi PP, Peterlin BM, Zhou Y, Kim TH, Asara JM, Chang HY, Young RA, Zon LI. Stress from Nucleotide Depletion Activates the Transcriptional Regulator HEXIM1 to Suppress Melanoma. Mol Cell 2016; 62:34-46. [PMID: 27058786 DOI: 10.1016/j.molcel.2016.03.013] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 02/02/2016] [Accepted: 03/10/2016] [Indexed: 12/29/2022]
Abstract
Studying cancer metabolism gives insight into tumorigenic survival mechanisms and susceptibilities. In melanoma, we identify HEXIM1, a transcription elongation regulator, as a melanoma tumor suppressor that responds to nucleotide stress. HEXIM1 expression is low in melanoma. Its overexpression in a zebrafish melanoma model suppresses cancer formation, while its inactivation accelerates tumor onset in vivo. Knockdown of HEXIM1 rescues zebrafish neural crest defects and human melanoma proliferation defects that arise from nucleotide depletion. Under nucleotide stress, HEXIM1 is induced to form an inhibitory complex with P-TEFb, the kinase that initiates transcription elongation, to inhibit elongation at tumorigenic genes. The resulting alteration in gene expression also causes anti-tumorigenic RNAs to bind to and be stabilized by HEXIM1. HEXIM1 plays an important role in inhibiting cancer cell-specific gene transcription while also facilitating anti-cancer gene expression. Our study reveals an important role for HEXIM1 in coupling nucleotide metabolism with transcriptional regulation in melanoma.
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Affiliation(s)
- Justin L Tan
- Howard Hughes Medical Institute, Stem Cell Program and Division of Pediatric Hematology/Oncology, Boston Children's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA; Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Cambridge, MA 02138, USA
| | - Rachel D Fogley
- Howard Hughes Medical Institute, Stem Cell Program and Division of Pediatric Hematology/Oncology, Boston Children's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA; Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Cambridge, MA 02138, USA
| | - Ryan A Flynn
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Julien Ablain
- Howard Hughes Medical Institute, Stem Cell Program and Division of Pediatric Hematology/Oncology, Boston Children's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA; Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Cambridge, MA 02138, USA
| | - Song Yang
- Howard Hughes Medical Institute, Stem Cell Program and Division of Pediatric Hematology/Oncology, Boston Children's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA; Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Cambridge, MA 02138, USA
| | - Violaine Saint-André
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Zi Peng Fan
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Brian T Do
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Alvaro C Laga
- Department of Pathology, Brigham & Women's Hospital, Boston, MA 02215, USA
| | - Koh Fujinaga
- Departments of Medicine, Microbiology, and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Cristina Santoriello
- Howard Hughes Medical Institute, Stem Cell Program and Division of Pediatric Hematology/Oncology, Boston Children's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA; Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Cambridge, MA 02138, USA
| | - Celeste B Greer
- Department of Pharmacology, School of Medicine, Yale University, New Haven, CT 06520, USA
| | - Yoon Jung Kim
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX 75080, USA
| | - John G Clohessy
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, and Department of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA; Preclinical Murine Pharmacogenetics Facility, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Anne Bothmer
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, and Department of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Nicole Pandell
- Preclinical Murine Pharmacogenetics Facility, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Serine Avagyan
- Howard Hughes Medical Institute, Stem Cell Program and Division of Pediatric Hematology/Oncology, Boston Children's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA; Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Cambridge, MA 02138, USA
| | - John E Brogie
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
| | - Ellen van Rooijen
- Howard Hughes Medical Institute, Stem Cell Program and Division of Pediatric Hematology/Oncology, Boston Children's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA; Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Cambridge, MA 02138, USA
| | - Elliott J Hagedorn
- Howard Hughes Medical Institute, Stem Cell Program and Division of Pediatric Hematology/Oncology, Boston Children's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA; Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Cambridge, MA 02138, USA
| | - Ng Shyh-Chang
- Genome Institute of Singapore, 60 Biopolis Street, Singapore 138672, Singapore
| | - Richard M White
- Memorial Sloan Kettering Cancer Center and Weill Cornell Medical College, New York, NY 10065, USA
| | - David H Price
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
| | - Pier Paolo Pandolfi
- Cancer Research Institute, Beth Israel Deaconess Cancer Center, and Department of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - B Matija Peterlin
- Departments of Medicine, Microbiology, and Immunology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Yi Zhou
- Howard Hughes Medical Institute, Stem Cell Program and Division of Pediatric Hematology/Oncology, Boston Children's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA; Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Cambridge, MA 02138, USA
| | - Tae Hoon Kim
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX 75080, USA
| | - John M Asara
- Division of Signal Transduction, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Howard Y Chang
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Richard A Young
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Leonard I Zon
- Howard Hughes Medical Institute, Stem Cell Program and Division of Pediatric Hematology/Oncology, Boston Children's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA; Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Cambridge, MA 02138, USA.
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Pérez C, Pérez-Zúñiga FJ, Garrido F, Reytor E, Portillo F, Pajares MA. The Oncogene PDRG1 Is an Interaction Target of Methionine Adenosyltransferases. PLoS One 2016; 11:e0161672. [PMID: 27548429 PMCID: PMC4993455 DOI: 10.1371/journal.pone.0161672] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 06/03/2016] [Indexed: 12/15/2022] Open
Abstract
Methionine adenosyltransferases MAT I and MAT III (encoded by Mat1a) catalyze S-adenosylmethionine synthesis in normal liver. Major hepatic diseases concur with reduced levels of this essential methyl donor, which are primarily due to an expression switch from Mat1a towards Mat2a. Additional changes in the association state and even in subcellular localization of these isoenzymes are also detected. All these alterations result in a reduced content of the moderate (MAT I) and high Vmax (MAT III) isoenzymes, whereas the low Vmax (MAT II) isoenzyme increases and nuclear accumulation of MAT I is observed. These changes derive in a reduced availability of cytoplasmic S-adenosylmethionine, together with an effort to meet its needs in the nucleus of damaged cells, rendering enhanced levels of certain epigenetic modifications. In this context, the putative role of protein-protein interactions in the control of S-adenosylmethionine synthesis has been scarcely studied. Using yeast two hybrid and a rat liver library we identified PDRG1 as an interaction target for MATα1 (catalytic subunit of MAT I and MAT III), further confirmation being obtained by immunoprecipitation and pull-down assays. Nuclear MATα interacts physically and functionally with the PDRG1 oncogene, resulting in reduced DNA methylation levels. Increased Pdrg1 expression is detected in acute liver injury and hepatoma cells, together with decreased Mat1a expression and nuclear accumulation of MATα1. Silencing of Pdrg1 expression in hepatoma cells alters their steady-state expression profile on microarrays, downregulating genes associated with tumor progression according to GO pathway analysis. Altogether, the results unveil the role of PDRG1 in the control of the nuclear methylation status through methionine adenosyltransferase binding and its putative collaboration in the progression of hepatic diseases.
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Affiliation(s)
- Claudia Pérez
- Instituto de Investigaciones Biomédicas Alberto Sols (CSIC-UAM), Arturo Duperier 4, 28029 Madrid, Spain
| | - Francisco J. Pérez-Zúñiga
- Instituto de Investigaciones Biomédicas Alberto Sols (CSIC-UAM), Arturo Duperier 4, 28029 Madrid, Spain
| | - Francisco Garrido
- Instituto de Investigaciones Biomédicas Alberto Sols (CSIC-UAM), Arturo Duperier 4, 28029 Madrid, Spain
| | - Edel Reytor
- Instituto de Investigaciones Biomédicas Alberto Sols (CSIC-UAM), Arturo Duperier 4, 28029 Madrid, Spain
| | - Francisco Portillo
- Instituto de Investigaciones Biomédicas Alberto Sols (CSIC-UAM), Arturo Duperier 4, 28029 Madrid, Spain
- Instituto de Investigación Sanitaria La Paz (IdiPAZ), Paseo de la Castellana 261, 28046 Madrid, Spain
- Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de Madrid, Arzobispo Morcillo 4, 28029 Madrid, Spain
| | - María A. Pajares
- Instituto de Investigaciones Biomédicas Alberto Sols (CSIC-UAM), Arturo Duperier 4, 28029 Madrid, Spain
- Instituto de Investigación Sanitaria La Paz (IdiPAZ), Paseo de la Castellana 261, 28046 Madrid, Spain
- * E-mail:
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C Quaresma AJ, Bugai A, Barboric M. Cracking the control of RNA polymerase II elongation by 7SK snRNP and P-TEFb. Nucleic Acids Res 2016; 44:7527-39. [PMID: 27369380 PMCID: PMC5027500 DOI: 10.1093/nar/gkw585] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 06/17/2016] [Indexed: 01/01/2023] Open
Abstract
Release of RNA polymerase II (Pol II) from promoter-proximal pausing has emerged as a critical step regulating gene expression in multicellular organisms. The transition of Pol II into productive elongation requires the kinase activity of positive transcription elongation factor b (P-TEFb), which is itself under a stringent control by the inhibitory 7SK small nuclear ribonucleoprotein (7SK snRNP) complex. Here, we provide an overview on stimulating Pol II pause release by P-TEFb and on sequestering P-TEFb into 7SK snRNP. Furthermore, we highlight mechanisms that govern anchoring of 7SK snRNP to chromatin as well as means that release P-TEFb from the inhibitory complex, and propose a unifying model of P-TEFb activation on chromatin. Collectively, these studies shine a spotlight on the central role of RNA binding proteins (RBPs) in directing the inhibition and activation of P-TEFb, providing a compelling paradigm for controlling Pol II transcription with a non-coding RNA.
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Affiliation(s)
- Alexandre J C Quaresma
- Medicum, Department of Biochemistry and Developmental Biology, University of Helsinki, Helsinki FIN-00014, Finland
| | - Andrii Bugai
- Medicum, Department of Biochemistry and Developmental Biology, University of Helsinki, Helsinki FIN-00014, Finland
| | - Matjaz Barboric
- Medicum, Department of Biochemistry and Developmental Biology, University of Helsinki, Helsinki FIN-00014, Finland
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135
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Bragantini B, Tiotiu D, Rothé B, Saliou JM, Marty H, Cianférani S, Charpentier B, Quinternet M, Manival X. Functional and Structural Insights of the Zinc-Finger HIT protein family members Involved in Box C/D snoRNP Biogenesis. J Mol Biol 2016; 428:2488-2506. [DOI: 10.1016/j.jmb.2016.04.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 04/20/2016] [Accepted: 04/23/2016] [Indexed: 11/29/2022]
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136
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Sansó M, Levin RS, Lipp JJ, Wang VYF, Greifenberg AK, Quezada EM, Ali A, Ghosh A, Larochelle S, Rana TM, Geyer M, Tong L, Shokat KM, Fisher RP. P-TEFb regulation of transcription termination factor Xrn2 revealed by a chemical genetic screen for Cdk9 substrates. Genes Dev 2016; 30:117-31. [PMID: 26728557 PMCID: PMC4701974 DOI: 10.1101/gad.269589.115] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Sansó et al. identified ∼100 putative substrates of human positive transcription elongation factor b (P-TEFb), which were enriched for proteins implicated in transcription and RNA catabolism. Among the RNA processing factors phosphorylated by Cdk9 was the 5′-to-3′ “torpedo” exoribonuclease Xrn2, required in transcription termination by Pol II. The transcription cycle of RNA polymerase II (Pol II) is regulated at discrete transition points by cyclin-dependent kinases (CDKs). Positive transcription elongation factor b (P-TEFb), a complex of Cdk9 and cyclin T1, promotes release of paused Pol II into elongation, but the precise mechanisms and targets of Cdk9 action remain largely unknown. Here, by a chemical genetic strategy, we identified ∼100 putative substrates of human P-TEFb, which were enriched for proteins implicated in transcription and RNA catabolism. Among the RNA processing factors phosphorylated by Cdk9 was the 5′-to-3′ “torpedo” exoribonuclease Xrn2, required in transcription termination by Pol II, which we validated as a bona fide P-TEFb substrate in vivo and in vitro. Phosphorylation by Cdk9 or phosphomimetic substitution of its target residue, Thr439, enhanced enzymatic activity of Xrn2 on synthetic substrates in vitro. Conversely, inhibition or depletion of Cdk9 or mutation of Xrn2-Thr439 to a nonphosphorylatable Ala residue caused phenotypes consistent with inefficient termination in human cells: impaired Xrn2 chromatin localization and increased readthrough transcription of endogenous genes. Therefore, in addition to its role in elongation, P-TEFb regulates termination by promoting chromatin recruitment and activation of a cotranscriptional RNA processing enzyme, Xrn2.
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Affiliation(s)
- Miriam Sansó
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Rebecca S Levin
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, California 94143, USA; Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, California 94143, USA
| | - Jesse J Lipp
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, California 94143, USA; Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, California 94143, USA
| | - Vivien Ya-Fan Wang
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
| | - Ann Katrin Greifenberg
- Department of Structural Immunology, Institute of Innate Immunity, University of Bonn, 53127 Bonn, Germany
| | - Elizabeth M Quezada
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Akbar Ali
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Animesh Ghosh
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Stéphane Larochelle
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Tariq M Rana
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA; Department of Pediatrics, University of California at San Diego School of Medicine, La Jolla, California 92093, USA
| | - Matthias Geyer
- Department of Pediatrics, University of California at San Diego School of Medicine, La Jolla, California 92093, USA
| | - Liang Tong
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
| | - Kevan M Shokat
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, California 94143, USA; Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, California 94143, USA
| | - Robert P Fisher
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
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137
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McNamara RP, Bacon CW, D'Orso I. Transcription elongation control by the 7SK snRNP complex: Releasing the pause. Cell Cycle 2016; 15:2115-2123. [PMID: 27152730 DOI: 10.1080/15384101.2016.1181241] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The ability for the eukaryotic cell to transcriptionally respond to various stimuli is critical for the overall homeostasis of the cell, and in turn, the organism. The human RNA polymerase II complex (Pol II), which is responsible for the transcription of protein-encoding genes and non-coding RNAs, is paused at promoter-proximal regions to ensure their rapid activation. In response to stimulation, Pol II pause release is facilitated by the action of positive transcription elongation factors such as the P-TEFb kinase. However, the majority of P-TEFb is held in a catalytically inactivate state, assembled into the 7SK small nuclear ribonucleoprotein (snRNP) complex, and must be dislodged to become catalytically active. In this review, we discuss mechanisms of 7SK snRNP recruitment to promoter-proximal regions and P-TEFb disassembly from the inhibitory snRNP to regulate 'on site' kinase activation and Pol II pause release.
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Affiliation(s)
- Ryan P McNamara
- a Department of Microbiology , The University of Texas Southwestern Medical Center , Dallas , TX , USA
| | - Curtis W Bacon
- a Department of Microbiology , The University of Texas Southwestern Medical Center , Dallas , TX , USA
| | - Iván D'Orso
- a Department of Microbiology , The University of Texas Southwestern Medical Center , Dallas , TX , USA
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138
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Abstract
RNA polymerase II (Pol II) pausing at promoter-proximal regions is a highly regulated step in the transcription cycle. Pause release is facilitated by the P-TEFb kinase, which phosphorylates Pol II and negative elongation factors. Recent studies suggest that P-TEFb (as part of the inhibitory 7SK snRNP) is recruited to promoter-proximal regions through interaction with KAP1/TRIM28/TIF1β to facilitate 'on-site' kinase activation and transcription elongation. Here, I discuss features of this model and future challenges to further hone our understanding of transcriptional regulation including Pol II pausing and pause release.
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Affiliation(s)
- Iván D'Orso
- a Department of Microbiology , The University of Texas Southwestern Medical Center , Dallas , TX , USA
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139
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Zhou M, Li Q, Wang R. Current Experimental Methods for Characterizing Protein-Protein Interactions. ChemMedChem 2016; 11:738-56. [PMID: 26864455 PMCID: PMC7162211 DOI: 10.1002/cmdc.201500495] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 01/08/2016] [Indexed: 12/14/2022]
Abstract
Protein molecules often interact with other partner protein molecules in order to execute their vital functions in living organisms. Characterization of protein-protein interactions thus plays a central role in understanding the molecular mechanism of relevant protein molecules, elucidating the cellular processes and pathways relevant to health or disease for drug discovery, and charting large-scale interaction networks in systems biology research. A whole spectrum of methods, based on biophysical, biochemical, or genetic principles, have been developed to detect the time, space, and functional relevance of protein-protein interactions at various degrees of affinity and specificity. This article presents an overview of these experimental methods, outlining the principles, strengths and limitations, and recent developments of each type of method.
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Affiliation(s)
- Mi Zhou
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China
| | - Qing Li
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China
| | - Renxiao Wang
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China.
- State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Avenida Wai Long, Macau, 999078, People's Republic of China.
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140
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Zhou M, Li Q, Wang R. Current Experimental Methods for Characterizing Protein-Protein Interactions. ChemMedChem 2016. [PMID: 26864455 DOI: 10.1002/cmdc.201500495.] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Protein molecules often interact with other partner protein molecules in order to execute their vital functions in living organisms. Characterization of protein-protein interactions thus plays a central role in understanding the molecular mechanism of relevant protein molecules, elucidating the cellular processes and pathways relevant to health or disease for drug discovery, and charting large-scale interaction networks in systems biology research. A whole spectrum of methods, based on biophysical, biochemical, or genetic principles, have been developed to detect the time, space, and functional relevance of protein-protein interactions at various degrees of affinity and specificity. This article presents an overview of these experimental methods, outlining the principles, strengths and limitations, and recent developments of each type of method.
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Affiliation(s)
- Mi Zhou
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China
| | - Qing Li
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China
| | - Renxiao Wang
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China. .,State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Avenida Wai Long, Macau, 999078, People's Republic of China.
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141
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Abstract
RNA methyltransferases (RNMTs) play important roles in RNA stability, splicing, and epigenetic mechanisms. They constitute a promising target class that is underexplored by the medicinal chemistry community. Information of relevance to drug design can be extracted from the rich structural coverage of human RNMTs. In this work, the structural chemistry of this protein family is analyzed in depth. Unlike most methyltransferases, RNMTs generally feature a substrate-binding site that is largely open on the cofactor-binding pocket, favoring the design of bisubstrate inhibitors. Substrate purine or pyrimidines are often sandwiched between hydrophobic walls that can accommodate planar ring systems. When the substrate base is laying on a shallow surface, a 5' flanking base is sometimes anchored in a druggable cavity. The cofactor-binding site is structurally more diverse than in protein methyltransferases and more druggable in SPOUT than in Rossman-fold enzymes. Finally, conformational plasticity observed both at the substrate and cofactor binding sites may be a challenge for structure-based drug design. The landscape drawn here may inform ongoing efforts toward the discovery of the first human RNMT inhibitors.
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Affiliation(s)
- Matthieu Schapira
- Structural
Genomics Consortium, University of Toronto, Toronto, Ontario M5G 1L7, Canada
- Department
of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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142
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Irani S, Yogesha SD, Mayfield J, Zhang M, Zhang Y, Matthews WL, Nie G, Prescott NA, Zhang YJ. Structure of Saccharomyces cerevisiae Rtr1 reveals an active site for an atypical phosphatase. Sci Signal 2016; 9:ra24. [PMID: 26933063 DOI: 10.1126/scisignal.aad4805] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Changes in the phosphorylation status of the carboxyl-terminal domain (CTD) of RNA polymerase II (RNAPII) correlate with the process of eukaryotic transcription. The yeast protein regulator of transcription 1 (Rtr1) and the human homolog RNAPII-associated protein 2 (RPAP2) may function as CTD phosphatases; however, crystal structures of Kluyveromyces lactis Rtr1 lack a consensus active site. We identified a phosphoryl transfer domain in Saccharomyces cerevisiae Rtr1 by obtaining and characterizing a 2.6 Å resolution crystal structure. We identified a putative substrate-binding pocket in a deep groove between the zinc finger domain and a pair of helices that contained a trapped sulfate ion. Because sulfate mimics the chemistry of a phosphate group, this structural data suggested that this groove represents the phosphoryl transfer active site. Mutagenesis of the residues lining this groove disrupted catalytic activity of the enzyme assayed in vitro with a fluorescent chemical substrate, and expression of the mutated Rtr1 failed to rescue growth of yeast lacking Rtr1. Characterization of the phosphatase activity of RPAP2 and a mutant of the conserved putative catalytic site in the same chemical assay indicated a conserved reaction mechanism. Our data indicated that the structure of the phosphoryl transfer domain and reaction mechanism for the phosphoryl transfer activity of Rtr1 is distinct from those of other phosphatase families.
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Affiliation(s)
- Seema Irani
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - S D Yogesha
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Joshua Mayfield
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Mengmeng Zhang
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Yong Zhang
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Wendy L Matthews
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Grace Nie
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Nicholas A Prescott
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Yan Jessie Zhang
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA.,Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA
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143
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Whitmill A, Timani KA, Liu Y, He JJ. Tip110: Physical properties, primary structure, and biological functions. Life Sci 2016; 149:79-95. [PMID: 26896687 DOI: 10.1016/j.lfs.2016.02.062] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Revised: 02/11/2016] [Accepted: 02/15/2016] [Indexed: 12/11/2022]
Abstract
HIV-1 Tat-interacting protein of 110kDa (Tip110), also referred to as squamous cell carcinoma antigen recognized by T cells 3 (Sart3), p110 or p110(nrb), was initially identified as a cDNA clone (KIAA0156) without annotated functions. Over the past twenty years, several functions have been attributed to this protein. The proposed biological functions include roles for Tip110 in pre-mRNA splicing, gene transcription, stem cell biology, and development. Dysregulation of Tip110 is also a contributing factor in the development of cancer and other human diseases. It is clear that our understanding of this protein is rapidly evolving. In this review, we aimed to provide a summary of all the existing literature on this gene/protein and its proposed biological functions.
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Affiliation(s)
- Amanda Whitmill
- Department of Cell Biology and Immunology, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX 76107, United States
| | - Khalid Amine Timani
- Department of Cell Biology and Immunology, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX 76107, United States
| | - Ying Liu
- Department of Cell Biology and Immunology, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX 76107, United States
| | - Johnny J He
- Department of Cell Biology and Immunology, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX 76107, United States.
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144
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hCLE/C14orf166, a cellular protein required for viral replication, is incorporated into influenza virus particles. Sci Rep 2016; 6:20744. [PMID: 26864902 PMCID: PMC4749964 DOI: 10.1038/srep20744] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 01/07/2016] [Indexed: 02/08/2023] Open
Abstract
The influenza A virus polymerase associates with a number of cellular transcription-related factors, including the RNA polymerase II (RNAP II). We previously described that the cellular protein hCLE/C14orf166 interacts with and stimulates influenza virus polymerase as well as RNAP II activities. Here we show that, despite the considerable cellular shut-off observed in infected cells, which includes RNAP II degradation, hCLE protein levels increase throughout infection in a virus replication-dependent manner. Human and avian influenza viruses of various subtypes increase hCLE levels, but other RNA or DNA viruses do not. hCLE colocalises and interacts with viral ribonucleoproteins (vRNP) in the nucleus, as well as in the cytoplasm late in infection. Furthermore, biochemical analysis of purified virus particles and immunoelectron microscopy of infected cells show hCLE in virions, in close association with viral vRNP. These findings indicate that hCLE, a cellular protein important for viral replication, is one of the very few examples of transcription factors that are incorporated into particles of an RNA-containing virus.
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145
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Gudipaty SA, D’Orso I. Functional interplay between PPM1G and the transcription elongation machinery. RNA & DISEASE 2016; 3:e1215. [PMID: 27088130 PMCID: PMC4830430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Transcription elongation is a critical regulatory step in the gene expression cycle. One key regulator of the switch between transcription initiation and elongation is the P-TEFb kinase, which phosphorylates RNA polymerase II (Pol II) and several negative elongation factors to relieve the elongation block at paused promoters to facilitate productive elongation. Here, we highlight recent findings signifying the role of the PPM1G/PP2Cγ phosphatase in activating and maintaining the active transcription elongation state by regulating the availability of P-TEFb and blocking its assembly into the catalytic inactive 7SK small nuclear ribonucleoprotein (snRNP) complex.
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Affiliation(s)
| | - Iván D’Orso
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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146
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Xu L, Kong R, Zhu J, Sun H, Chang S. Unraveling the conformational determinants of LARP7 and 7SK small nuclear RNA by theoretical approaches. MOLECULAR BIOSYSTEMS 2016; 12:2613-21. [DOI: 10.1039/c6mb00252h] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
LARP7, a member of the La-related proteins (LARPs), shares a conserved La module comprising the La-motif (LAM) and the RNA-recognition motif (RRM1), binding exclusively to the non-coding RNA 7SK.
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Affiliation(s)
- Lei Xu
- Institute of Bioinformatics and Medical Engineering
- School of Electrical and Information Engineering
- Jiangsu University of Technology
- Changzhou 213001
- China
| | - Ren Kong
- Institute of Bioinformatics and Medical Engineering
- School of Electrical and Information Engineering
- Jiangsu University of Technology
- Changzhou 213001
- China
| | - Jingyu Zhu
- College of Pharmaceutical Sciences
- Zhejiang University
- Hangzhou
- China
| | - Huiyong Sun
- College of Pharmaceutical Sciences
- Zhejiang University
- Hangzhou
- China
| | - Shan Chang
- Institute of Bioinformatics and Medical Engineering
- School of Electrical and Information Engineering
- Jiangsu University of Technology
- Changzhou 213001
- China
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147
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Structure of GPN-Loop GTPase Npa3 and Implications for RNA Polymerase II Assembly. Mol Cell Biol 2015; 36:820-31. [PMID: 26711263 DOI: 10.1128/mcb.01009-15] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 12/21/2015] [Indexed: 11/20/2022] Open
Abstract
Biogenesis of the 12-subunit RNA polymerase II (Pol II) transcription complex requires so-called GPN-loop GTPases, but the function of these enzymes is unknown. Here we report the first crystal structure of a eukaryotic GPN-loop GTPase, the Saccharomyces cerevisiae enzyme Npa3 (a homolog of human GPN1, also called RPAP4, XAB1, and MBDin), and analyze its catalytic mechanism. The enzyme was trapped in a GDP-bound closed conformation and in a novel GTP analog-bound open conformation displaying a conserved hydrophobic pocket distant from the active site. We show that Npa3 has chaperone activity and interacts with hydrophobic peptide regions of Pol II subunits that form interfaces in the assembled Pol II complex. Biochemical results are consistent with a model that the hydrophobic pocket binds peptides and that this can allosterically stimulate GTPase activity and subsequent peptide release. These results suggest that GPN-loop GTPases are assembly chaperones for Pol II and other protein complexes.
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148
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KAP1 Recruitment of the 7SK snRNP Complex to Promoters Enables Transcription Elongation by RNA Polymerase II. Mol Cell 2015; 61:39-53. [PMID: 26725010 DOI: 10.1016/j.molcel.2015.11.004] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 09/29/2015] [Accepted: 11/03/2015] [Indexed: 01/08/2023]
Abstract
The transition from transcription initiation to elongation at promoters of primary response genes (PRGs) in metazoan cells is controlled by inducible transcription factors, which utilize P-TEFb to phosphorylate RNA polymerase II (Pol II) in response to stimuli. Prior to stimulation, a fraction of P-TEFb is recruited to promoter-proximal regions in a catalytically inactive state bound to the 7SK small nuclear ribonucleoprotein (snRNP) complex. However, it remains unclear how and why the 7SK snRNP is assembled at these sites. Here we report that the transcriptional regulator KAP1 continuously tethers the 7SK snRNP to PRG promoters to facilitate P-TEFb recruitment and productive elongation in response to stimulation. Remarkably, besides PRGs, genome-wide studies revealed that KAP1 and 7SK snRNP co-occupy most promoter-proximal regions containing paused Pol II. Collectively, we provide evidence of an unprecedented mechanism controlling 7SK snRNP delivery to promoter-proximal regions to facilitate "on-site" P-TEFb activation and Pol II elongation.
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149
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Giguère SSB, Guise AJ, Jean Beltran PM, Joshi PM, Greco TM, Quach OL, Kong J, Cristea IM. The Proteomic Profile of Deleted in Breast Cancer 1 (DBC1) Interactions Points to a Multifaceted Regulation of Gene Expression. Mol Cell Proteomics 2015; 15:791-809. [PMID: 26657080 DOI: 10.1074/mcp.m115.054619] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Indexed: 01/01/2023] Open
Abstract
Deleted in breast cancer 1 (DBC1) has emerged as an important regulator of multiple cellular processes, ranging from gene expression to cell cycle progression. DBC1 has been linked to tumorigenesis both as an inhibitor of histone deacetylases, HDAC3 and sirtuin 1, and as a transcriptional cofactor for nuclear hormone receptors. However, despite mounting interest in DBC1, relatively little is known about the range of its interacting partners and the scope of its functions. Here, we carried out a functional proteomics-based investigation of DBC1 interactions in two relevant cell types, T cells and kidney cells. Microscopy, molecular biology, biochemistry, and mass spectrometry studies allowed us to assess DBC1 mRNA and protein levels, localization, phosphorylation status, and protein interaction networks. The comparison of DBC1 interactions in these cell types revealed conserved regulatory roles for DBC1 in gene expression, chromatin organization and modification, and cell cycle progression. Interestingly, we observe previously unrecognized DBC1 interactions with proteins encoded by cancer-associated genes. Among these interactions are five components of the SWI/SNF complex, the most frequently mutated chromatin remodeling complex in human cancers. Additionally, we identified a DBC1 interaction with TBL1XR1, a component of the NCoR complex, which we validated by reciprocal isolation. Strikingly, we discovered that DBC1 associates with proteins that regulate the circadian cycle, including DDX5, DHX9, and SFPQ. We validated this interaction by colocalization and reciprocal isolation. Functional assessment of this association demonstrated that DBC1 protein levels are important for regulating CLOCK and BMAL1 protein oscillations in synchronized T cells. Our results suggest that DBC1 is integral to the maintenance of the circadian molecular clock. Furthermore, the identified interactions provide a valuable resource for the exploration of pathways involved in DBC1-associated tumorigenesis.
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Affiliation(s)
- Sophie S B Giguère
- From the ‡Department of Molecular Biology, Princeton University, Princeton, New Jersey, 08544
| | - Amanda J Guise
- From the ‡Department of Molecular Biology, Princeton University, Princeton, New Jersey, 08544
| | - Pierre M Jean Beltran
- From the ‡Department of Molecular Biology, Princeton University, Princeton, New Jersey, 08544
| | - Preeti M Joshi
- From the ‡Department of Molecular Biology, Princeton University, Princeton, New Jersey, 08544
| | - Todd M Greco
- From the ‡Department of Molecular Biology, Princeton University, Princeton, New Jersey, 08544
| | - Olivia L Quach
- From the ‡Department of Molecular Biology, Princeton University, Princeton, New Jersey, 08544
| | - Jeffery Kong
- From the ‡Department of Molecular Biology, Princeton University, Princeton, New Jersey, 08544
| | - Ileana M Cristea
- From the ‡Department of Molecular Biology, Princeton University, Princeton, New Jersey, 08544
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150
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Role of Ostm1 Cytosolic Complex with Kinesin 5B in Intracellular Dispersion and Trafficking. Mol Cell Biol 2015; 36:507-21. [PMID: 26598607 DOI: 10.1128/mcb.00656-15] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 11/17/2015] [Indexed: 01/05/2023] Open
Abstract
In humans and in mice, mutations in the Ostm1 gene cause the most severe form of osteopetrosis, a major bone disease, and neuronal degeneration, both of which are associated with early death. To gain insight into Ostm1 function, we first investigated by sequence and biochemical analysis an immature 34-kDa type I transmembrane Ostm1 protein with a unique cytosolic tail. Mature Ostm1 is posttranslationally processed and highly N-glycosylated and has an apparent mass of ∼60 kDa. Analysis the subcellular localization of Ostm1 showed that it is within the endoplasmic reticulum, trans-Golgi network, and endosomes/lysosomes. By a wide protein screen under physiologic conditions, several novel cytosolic Ostm1 partners were identified and validated, for which a direct interaction with the kinesin 5B heavy chains was demonstrated. These results determined that Ostm1 is part of a cytosolic scaffolding multiprotein complex, imparting an adaptor function to Ostm1. Moreover, we uncovered a role for the Ostm1/KIF5B complex in intracellular trafficking and dispersion of cargos from the endoplasmic reticulum to late endosomal/lysosomal subcellular compartments. These Ostm1 molecular and cellular functions could elucidate all of the pathophysiologic mechanisms underlying the wide phenotypic spectrum of Ostm1-deficient mice.
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