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Roehrig AE, Klupsch K, Oses-Prieto JA, Chaib S, Henderson S, Emmett W, Young LC, Surinova S, Blees A, Pfeiffer A, Tijani M, Brunk F, Hartig N, Muñoz-Alegre M, Hergovich A, Jennings BH, Burlingame AL, Rodriguez-Viciana P. Cell-cell adhesion regulates Merlin/NF2 interaction with the PAF complex. PLoS One 2021; 16:e0254697. [PMID: 34424918 PMCID: PMC8382200 DOI: 10.1371/journal.pone.0254697] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 07/01/2021] [Indexed: 12/14/2022] Open
Abstract
The PAF complex (PAFC) coordinates transcription elongation and mRNA processing and its CDC73/parafibromin subunit functions as a tumour suppressor. The NF2/Merlin tumour suppressor functions both at the cell cortex and nucleus and is a key mediator of contact inhibition but the molecular mechanisms remain unclear. In this study we have used affinity proteomics to identify novel Merlin interacting proteins and show that Merlin forms a complex with multiple proteins involved in RNA processing including the PAFC and the CHD1 chromatin remodeller. Tumour-derived inactivating mutations in both Merlin and the CDC73 PAFC subunit mutually disrupt their interaction and growth suppression by Merlin requires CDC73. Merlin interacts with the PAFC in a cell density-dependent manner and we identify a role for FAT cadherins in regulating the Merlin-PAFC interaction. Our results suggest that in addition to its function within the Hippo pathway, Merlin is part of a tumour suppressor network regulated by cell-cell adhesion which coordinates post-initiation steps of the transcription cycle of genes mediating contact inhibition.
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Affiliation(s)
- Anne E. Roehrig
- UCL Cancer Institute, University College London, London, United Kingdom
| | - Kristina Klupsch
- UCL Cancer Institute, University College London, London, United Kingdom
| | - Juan A. Oses-Prieto
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California, United States of America
| | - Selim Chaib
- UCL Cancer Institute, University College London, London, United Kingdom
| | - Stephen Henderson
- UCL Cancer Institute, University College London, London, United Kingdom
| | - Warren Emmett
- University College London Genetics Institute, London, United Kingdom
| | - Lucy C. Young
- UCL Cancer Institute, University College London, London, United Kingdom
| | - Silvia Surinova
- UCL Cancer Institute, University College London, London, United Kingdom
| | - Andreas Blees
- UCL Cancer Institute, University College London, London, United Kingdom
| | - Anett Pfeiffer
- UCL Cancer Institute, University College London, London, United Kingdom
| | - Maha Tijani
- UCL Cancer Institute, University College London, London, United Kingdom
| | - Fabian Brunk
- UCL Cancer Institute, University College London, London, United Kingdom
| | - Nicole Hartig
- UCL Cancer Institute, University College London, London, United Kingdom
| | | | | | | | - Alma L. Burlingame
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California, United States of America
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Shukla A, Ramirez NGP, D’Orso I. HIV-1 Proviral Transcription and Latency in the New Era. Viruses 2020; 12:v12050555. [PMID: 32443452 PMCID: PMC7291205 DOI: 10.3390/v12050555] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 05/06/2020] [Accepted: 05/12/2020] [Indexed: 12/11/2022] Open
Abstract
Three decades of extensive work in the HIV field have revealed key viral and host cell factors controlling proviral transcription. Various models of transcriptional regulation have emerged based on the collective information from in vitro assays and work in both immortalized and primary cell-based models. Here, we provide a recount of the past and current literature, highlight key regulatory aspects, and further describe potential limitations of previous studies. We particularly delve into critical steps of HIV gene expression including the role of the integration site, nucleosome positioning and epigenomics, and the transition from initiation to pausing and pause release. We also discuss open questions in the field concerning the generality of previous regulatory models to the control of HIV transcription in patients under suppressive therapy, including the role of the heterogeneous integration landscape, clonal expansion, and bottlenecks to eradicate viral persistence. Finally, we propose that building upon previous discoveries and improved or yet-to-be discovered technologies will unravel molecular mechanisms of latency establishment and reactivation in a “new era”.
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SUN2 Modulates HIV-1 Infection and Latency through Association with Lamin A/C To Maintain the Repressive Chromatin. mBio 2018; 9:mBio.02408-17. [PMID: 29717016 PMCID: PMC5930302 DOI: 10.1128/mbio.02408-17] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The postintegrational latency of HIV-1 is characterized by reversible silencing of long terminal repeat (LTR)-driven transcription of the HIV genome. It is known that the formation of repressive chromatin at the 5′-LTR of HIV-1 proviral DNA impedes viral transcription by blocking the recruitment of positive transcription factors. How the repressive chromatin is formed and modulated during HIV-1 infection remains elusive. Elucidation of which chromatin reassembly factor mediates the reorganization of chromatin is likely to facilitate the understanding of the host’s modulation of HIV-1 transcription and latency. Here we revealed that “Sad1 and UNC84 domain containing 2” (SUN2), an inner nuclear membrane protein, maintained the repressive chromatin and inhibited HIV LTR-driven transcription of proviral DNA through an association with lamin A/C. Specifically, lamin A/C tethered SUN2 to the nucleosomes 1 and 2 of the HIV-1 5′-LTR to block the initiation and elongation of HIV-1 transcription. SUN2 knockdown converted chromatin to an active form and thus enhanced the phosphorylation of RNA polymerase II and its recruitment to the 5′-LTR HIV-1 proviral DNA, leading to reactivation of HIV-1 from latency. Conversely, the exogenous factors such as tumor necrosis factor alpha (TNF-α) induced reactivation, and the replication of HIV-1 led to the disassociation between SUN2 and lamin A/C, suggesting that disruption of the association between SUN2 and lamin A/C to convert the repressive chromatin to the active form might be a prerequisite for the initiation of HIV-1 transcription and replication. Together, our findings indicate that SUN2 is a novel chromatin reassembly factor that helps to maintain chromatin in a repressive state and consequently inhibits HIV-1 transcription. Despite the successful use of scores of antiretroviral drugs, HIV latency poses a major impediment to virus eradication. Elucidation of the mechanism of latency facilitates the discovery of new therapeutic strategies. It has been known that the formation of repressive chromatin at the 5′-LTR of HIV-1 proviral DNA impedes viral transcription and maintains viral latency, but how the repressive chromatin is formed and modulated during HIV-1 infection remains elusive. In this study, we performed in-depth virological and cell biological studies and discovered that an inner nuclear membrane protein, SUN2, is a novel chromatin reassembly factor that maintains repressive chromatin and thus modulates HIV-1 transcription and latency: therefore, targeting SUN2 may lead to new strategies for HIV cure.
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Multiple Inhibitory Factors Act in the Late Phase of HIV-1 Replication: a Systematic Review of the Literature. Microbiol Mol Biol Rev 2018; 82:82/1/e00051-17. [PMID: 29321222 DOI: 10.1128/mmbr.00051-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The use of lentiviral vectors for therapeutic purposes has shown promising results in clinical trials. The ability to produce a clinical-grade vector at high yields remains a critical issue. One possible obstacle could be cellular factors known to inhibit human immunodeficiency virus (HIV). To date, five HIV restriction factors have been identified, although it is likely that more factors are involved in the complex HIV-cell interaction. Inhibitory factors that have an adverse effect but do not abolish virus production are much less well described. Therefore, a gap exists in the knowledge of inhibitory factors acting late in the HIV life cycle (from transcription to infection of a new cell), which are relevant to the lentiviral vector production process. The objective was to review the HIV literature to identify cellular factors previously implicated as inhibitors of the late stages of lentivirus production. A search for publications was conducted on MEDLINE via the PubMed interface, using the keyword sequence "HIV restriction factor" or "HIV restriction" or "inhibit HIV" or "repress HIV" or "restrict HIV" or "suppress HIV" or "block HIV," with a publication date up to 31 December 2016. Cited papers from the identified records were investigated, and additional database searches were performed. A total of 260 candidate inhibitory factors were identified. These factors have been identified in the literature as having a negative impact on HIV replication. This study identified hundreds of candidate inhibitory factors for which the impact of modulating their expression in lentiviral vector production could be beneficial.
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5
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Gómez-Herreros F, Margaritis T, Rodríguez-Galán O, Pelechano V, Begley V, Millán-Zambrano G, Morillo-Huesca M, Muñoz-Centeno MC, Pérez-Ortín JE, de la Cruz J, Holstege FCP, Chávez S. The ribosome assembly gene network is controlled by the feedback regulation of transcription elongation. Nucleic Acids Res 2017. [PMID: 28637236 PMCID: PMC5737610 DOI: 10.1093/nar/gkx529] [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] [Indexed: 12/20/2022] Open
Abstract
Ribosome assembly requires the concerted expression of hundreds of genes, which are transcribed by all three nuclear RNA polymerases. Transcription elongation involves dynamic interactions between RNA polymerases and chromatin. We performed a synthetic lethal screening in Saccharomyces cerevisiae with a conditional allele of SPT6, which encodes one of the factors that facilitates this process. Some of these synthetic mutants corresponded to factors that facilitate pre-rRNA processing and ribosome biogenesis. We found that the in vivo depletion of one of these factors, Arb1, activated transcription elongation in the set of genes involved directly in ribosome assembly. Under these depletion conditions, Spt6 was physically targeted to the up-regulated genes, where it helped maintain their chromatin integrity and the synthesis of properly stable mRNAs. The mRNA profiles of a large set of ribosome biogenesis mutants confirmed the existence of a feedback regulatory network among ribosome assembly genes. The transcriptional response in this network depended on both the specific malfunction and the role of the regulated gene. In accordance with our screening, Spt6 positively contributed to the optimal operation of this global network. On the whole, this work uncovers a feedback control of ribosome biogenesis by fine-tuning transcription elongation in ribosome assembly factor-coding genes.
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Affiliation(s)
- Fernando Gómez-Herreros
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Virgen del Rocío-CSIC-Universidad de Sevilla, and Departamento de Genética, Universidad de Sevilla, 41013 Seville, Spain
| | - Thanasis Margaritis
- Molecular Cancer Research, University Medical Center Utrecht, & Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
| | - Olga Rodríguez-Galán
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Virgen del Rocío-CSIC-Universidad de Sevilla, and Departamento de Genética, Universidad de Sevilla, 41013 Seville, Spain
| | - Vicent Pelechano
- Departamento de Bioquímica y Biología Molecular and ERI Biotecmed. Facultad de Biológicas, Universitat de València. Burjassot, Spain.,SciLifeLab, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 171 65 Solna, Sweden
| | - Victoria Begley
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Virgen del Rocío-CSIC-Universidad de Sevilla, and Departamento de Genética, Universidad de Sevilla, 41013 Seville, Spain
| | - Gonzalo Millán-Zambrano
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Virgen del Rocío-CSIC-Universidad de Sevilla, and Departamento de Genética, Universidad de Sevilla, 41013 Seville, Spain
| | - Macarena Morillo-Huesca
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Virgen del Rocío-CSIC-Universidad de Sevilla, and Departamento de Genética, Universidad de Sevilla, 41013 Seville, Spain
| | - Mari Cruz Muñoz-Centeno
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Virgen del Rocío-CSIC-Universidad de Sevilla, and Departamento de Genética, Universidad de Sevilla, 41013 Seville, Spain
| | - José E Pérez-Ortín
- Departamento de Bioquímica y Biología Molecular and ERI Biotecmed. Facultad de Biológicas, Universitat de València. Burjassot, Spain
| | - Jesús de la Cruz
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Virgen del Rocío-CSIC-Universidad de Sevilla, and Departamento de Genética, Universidad de Sevilla, 41013 Seville, Spain
| | - Frank C P Holstege
- Molecular Cancer Research, University Medical Center Utrecht, & Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands
| | - Sebastián Chávez
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Virgen del Rocío-CSIC-Universidad de Sevilla, and Departamento de Genética, Universidad de Sevilla, 41013 Seville, Spain
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6
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The Multifaceted Contributions of Chromatin to HIV-1 Integration, Transcription, and Latency. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 328:197-252. [PMID: 28069134 DOI: 10.1016/bs.ircmb.2016.08.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The capacity of the human immunodeficiency virus (HIV-1) to establish latent infections constitutes a major barrier to the development of a cure for HIV-1. In latent infection, replication competent HIV-1 provirus is integrated within the host genome but remains silent, masking the infected cells from the activity of the host immune response. Despite the progress in elucidating the molecular players that regulate HIV-1 gene expression, the mechanisms driving the establishment and maintenance of latency are still not fully understood. Transcription from the HIV-1 genome occurs in the context of chromatin and is subjected to the same regulatory mechanisms that drive cellular gene expression. Much like in eukaryotic genes, the nucleosomal landscape of the HIV-1 promoter and its position within genomic chromatin are determinants of its transcriptional activity. Understanding the multilayered chromatin-mediated mechanisms that underpin HIV-1 integration and expression is of utmost importance for the development of therapeutic strategies aimed at reducing the pool of latently infected cells. In this review, we discuss the impact of chromatin structure on viral integration, transcriptional regulation and latency, and the host factors that influence HIV-1 replication by regulating chromatin organization. Finally, we describe therapeutic strategies under development to target the chromatin-HIV-1 interplay.
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7
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Gérard A, Ségéral E, Naughtin M, Abdouni A, Charmeteau B, Cheynier R, Rain JC, Emiliani S. The integrase cofactor LEDGF/p75 associates with Iws1 and Spt6 for postintegration silencing of HIV-1 gene expression in latently infected cells. Cell Host Microbe 2015; 17:107-17. [PMID: 25590759 DOI: 10.1016/j.chom.2014.12.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 10/13/2014] [Accepted: 11/14/2014] [Indexed: 12/11/2022]
Abstract
The persistence of a latent reservoir containing transcriptionally silent, but replication-competent, integrated provirus is a serious challenge to HIV eradication. HIV integration is under the control of LEDGF/p75, the cellular cofactor of viral integrase. Investigating possible postintegration roles for LEDGF/p75, we find that LEDGF/p75 represses HIV expression in latently infected cells. LEDGF/p75 associated with two proteins involved in the control of gene expression and chromatin structure, Spt6 and Iws1, to form a stable complex. Iws1 plays a role in the establishment of latent infection, whereas Spt6 functions to recruit Iws1 and LEDGF/p75 to the silenced provirus and maintains histone occupancy at the HIV promoter. In latently infected cells, depletion of the complex results in reactivation of HIV expression Altogether, our results indicate that a complex containing LEDGF/p75, Iws1, and Spt6 participates in regulating postintegration steps of HIV latency.
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Affiliation(s)
- Annabelle Gérard
- Inserm, U1016, Institut Cochin, 75014 Paris, France; CNRS, UMR8104, 75014 Paris, France; Université Paris Descartes, 75014 Paris, France.
| | - Emmanuel Ségéral
- Inserm, U1016, Institut Cochin, 75014 Paris, France; CNRS, UMR8104, 75014 Paris, France; Université Paris Descartes, 75014 Paris, France
| | - Monica Naughtin
- Inserm, U1016, Institut Cochin, 75014 Paris, France; CNRS, UMR8104, 75014 Paris, France; Université Paris Descartes, 75014 Paris, France
| | - Ahmed Abdouni
- Inserm, U1016, Institut Cochin, 75014 Paris, France; CNRS, UMR8104, 75014 Paris, France; Université Paris Descartes, 75014 Paris, France
| | - Bénédicte Charmeteau
- Inserm, U1016, Institut Cochin, 75014 Paris, France; CNRS, UMR8104, 75014 Paris, France; Université Paris Descartes, 75014 Paris, France
| | - Rémi Cheynier
- Inserm, U1016, Institut Cochin, 75014 Paris, France; CNRS, UMR8104, 75014 Paris, France; Université Paris Descartes, 75014 Paris, France
| | | | - Stéphane Emiliani
- Inserm, U1016, Institut Cochin, 75014 Paris, France; CNRS, UMR8104, 75014 Paris, France; Université Paris Descartes, 75014 Paris, France.
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8
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Gal C, Moore KM, Paszkiewicz K, Kent NA, Whitehall SK. The impact of the HIRA histone chaperone upon global nucleosome architecture. Cell Cycle 2015; 14:123-34. [PMID: 25602522 PMCID: PMC4614360 DOI: 10.4161/15384101.2014.967123] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
HIRA is an evolutionarily conserved histone chaperone that mediates
replication-independent nucleosome assembly and is important for a variety of processes
such as cell cycle progression, development, and senescence. Here we have used a chromatin
sequencing approach to determine the genome-wide contribution of HIRA to nucleosome
organization in Schizosaccharomyces pombe. Cells lacking HIRA experience
a global reduction in nucleosome occupancy at gene sequences, consistent with the proposed
role for HIRA in chromatin reassembly behind elongating RNA polymerase II. In addition, we
find that at its target promoters, HIRA commonly maintains the full occupancy of the
−1 nucleosome. HIRA does not affect global chromatin structure at replication
origins or in rDNA repeats but is required for nucleosome occupancy in silent regions of
the genome. Nucleosome organization associated with the heterochromatic
(dg-dh) repeats located at the centromere is perturbed by loss of HIRA
function and furthermore HIRA is required for normal nucleosome occupancy at Tf2 LTR
retrotransposons. Overall, our data indicate that HIRA plays an important role in
maintaining nucleosome architecture at both euchromatic and heterochromatic loci.
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Affiliation(s)
- Csenge Gal
- a Institute for Cell & Molecular Biosciences ; Newcastle University ; Newcastle upon Tyne , UK
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9
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A genetic screen and transcript profiling reveal a shared regulatory program for Drosophila linker histone H1 and chromatin remodeler CHD1. G3-GENES GENOMES GENETICS 2015; 5:677-87. [PMID: 25628309 PMCID: PMC4390582 DOI: 10.1534/g3.115.016709] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Chromatin structure and activity can be modified through ATP-dependent repositioning of nucleosomes and posttranslational modifications of core histone tails within nucleosome core particles and by deposition of linker histones into the oligonucleosome fiber. The linker histone H1 is essential in metazoans. It has a profound effect on organization of chromatin into higher-order structures and on recruitment of histone-modifying enzymes to chromatin. Here, we describe a genetic screen for modifiers of the lethal phenotype caused by depletion of H1 in Drosophila melanogaster. We identify 41 mis-expression alleles that enhance and 20 that suppress the effect of His1 depletion in vivo. Most of them are important for chromosome organization, transcriptional regulation, and cell signaling. Specifically, the reduced viability of H1-depleted animals is strongly suppressed by ubiquitous mis-expression of the ATP-dependent chromatin remodeling enzyme CHD1. Comparison of transcript profiles in H1-depleted and Chd1 null mutant larvae revealed that H1 and CHD1 have common transcriptional regulatory programs in vivo. H1 and CHD1 share roles in repression of numerous developmentally regulated and extracellular stimulus-responsive transcripts, including immunity-related and stress response-related genes. Thus, linker histone H1 participates in various regulatory programs in chromatin to alter gene expression.
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10
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Rodgers MJ, Banks DJ, Bradley KA, Young JA. CHD1 and CHD2 are positive regulators of HIV-1 gene expression. Virol J 2014; 11:180. [PMID: 25297984 PMCID: PMC4283154 DOI: 10.1186/1743-422x-11-180] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 09/24/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Retroviruses encode a very limited number of proteins and therefore must exploit a wide variety of host proteins for completion of their lifecycle. METHODS We performed an insertional mutagenesis screen to identify novel cellular regulators of retroviral replication. RESULTS This approach identified the ATP-dependent chromatin remodeler, chromodomain helicase DNA-binding protein 2 (CHD2), as well as the highly related CHD1 protein, as positive regulators of both MLV and HIV-1 replication in rodent and human cells. RNAi knockdown of either CHD2 or the related CHD1 protein, in human cells resulted in a block to infection by HIV-1, specifically at the level of transcription. CONCLUSIONS These results demonstrate that CHD1 and CHD2 can act as positive regulators of HIV-1 gene expression.
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Affiliation(s)
| | | | | | - John At Young
- The Nomis Center for Immunobiology and Microbial Pathogenesis, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
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11
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Millán-Zambrano G, Rodríguez-Gil A, Peñate X, de Miguel-Jiménez L, Morillo-Huesca M, Krogan N, Chávez S. The prefoldin complex regulates chromatin dynamics during transcription elongation. PLoS Genet 2013; 9:e1003776. [PMID: 24068951 PMCID: PMC3777993 DOI: 10.1371/journal.pgen.1003776] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 07/23/2013] [Indexed: 12/13/2022] Open
Abstract
Transcriptional elongation requires the concerted action of several factors that allow RNA polymerase II to advance through chromatin in a highly processive manner. In order to identify novel elongation factors, we performed systematic yeast genetic screening based on the GLAM (Gene Length-dependent Accumulation of mRNA) assay, which is used to detect defects in the expression of long transcription units. Apart from well-known transcription elongation factors, we identified mutants in the prefoldin complex subunits, which were among those that caused the most dramatic phenotype. We found that prefoldin, so far involved in the cytoplasmic co-translational assembly of protein complexes, is also present in the nucleus and that a subset of its subunits are recruited to chromatin in a transcription-dependent manner. Prefoldin influences RNA polymerase II the elongation rate in vivo and plays an especially important role in the transcription elongation of long genes and those whose promoter regions contain a canonical TATA box. Finally, we found a specific functional link between prefoldin and histone dynamics after nucleosome remodeling, which is consistent with the extensive network of genetic interactions between this factor and the machinery regulating chromatin function. This study establishes the involvement of prefoldin in transcription elongation, and supports a role for this complex in cotranscriptional histone eviction. Transcription is the biological process that allows genes to be copied into RNA; the molecule that can be read by the cell in order to fabricate its structural components, proteins. Transcription is carried out by RNA polymerases, but these molecular machines need auxiliary factors to guide them through the genome and to help them during the RNA synthesis process. We searched for novel auxiliary factors using a genetic procedure and found a set of potential novel transcriptional players. Among them, we encountered a highly unexpected result: a factor, called prefoldin, so far exclusively involved in the folding of proteins during their fabrication. We confirmed that prefoldin binds transcribed genes and plays an important role during gene transcription. We also further investigated this transcriptional role and found that prefoldin is important for unpacking genes, thus facilitating the advance of the RNA polymerases along them.
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Affiliation(s)
- Gonzalo Millán-Zambrano
- Departmento de Genética, Universidad de Sevilla, and Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
| | - Alfonso Rodríguez-Gil
- Departmento de Genética, Universidad de Sevilla, and Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
| | - Xenia Peñate
- Departmento de Genética, Universidad de Sevilla, and Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
| | - Lola de Miguel-Jiménez
- Departmento de Genética, Universidad de Sevilla, and Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
| | - Macarena Morillo-Huesca
- Departmento de Genética, Universidad de Sevilla, and Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
| | - Nevan Krogan
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, California, United States of America
| | - Sebastián Chávez
- Departmento de Genética, Universidad de Sevilla, and Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
- * E-mail:
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12
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Nakamura M, Basavarajaiah P, Rousset E, Beraud C, Latreille D, Henaoui IS, Lassot I, Mari B, Kiernan R. Spt6 levels are modulated by PAAF1 and proteasome to regulate the HIV-1 LTR. Retrovirology 2012; 9:13. [PMID: 22316138 PMCID: PMC3305501 DOI: 10.1186/1742-4690-9-13] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Accepted: 02/08/2012] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Tat-mediated activation of the HIV-1 promoter depends upon a proteasome-associated factor, PAAF1, which dissociates 26S proteasome to produce 19S RP that is essential for transcriptional elongation. The effect of PAAF1 on proteasome activity could also potentially shield certain factors from proteolysis, which may be implicated in the transcriptional co-activator activity of PAAF1 towards the LTR. RESULTS Here, we show that Spt6 is targeted by proteasome in the absence of PAAF1. PAAF1 interacts with the N-terminus of Spt6, suggesting that PAAF1 protects Spt6 from proteolysis. Depletion of either PAAF1 or Spt6 reduced histone occupancy at the HIV-1 promoter, and induced the synthesis of aberrant transcripts. Ectopic Spt6 expression or treatment with proteasome inhibitor partially rescued the transcription defect associated with loss of PAAF1. Transcriptional profiling followed by ChIP identified a subset of cellular genes that are regulated in a similar fashion to HIV-1 by Spt6 and/or PAAF1, including many that are involved in cancer, such as BRCA1 and BARD1. CONCLUSION These results show that intracellular levels of Spt6 are fine-tuned by PAAF1 and proteasome, which is required for HIV-1 transcription and extends to cellular genes implicated in cancer.
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Affiliation(s)
- Mirai Nakamura
- Laboratoire de Régulation des Gènes, Institut de Génétique Humaine, CNRS UPR1142, Montpellier, France
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13
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A matter of packaging: influence of nucleosome positioning on heterologous gene expression. Methods Mol Biol 2012; 824:51-64. [PMID: 22160893 DOI: 10.1007/978-1-61779-433-9_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The organization of DNA into the various levels of chromatin compaction is the main obstacle that restricts the access of transcriptional machinery to genes. Genome-wide chromatin analyses have shown that there are common chromatin organization patterns for most genes but have also revealed important differences in nucleosome positioning throughout the genome. Such chromatin heterogeneity is one of the reasons why recombinant gene expression is highly dependent on integration sites. Different solutions have been tested for this problem, including artificial targeting of chromatin-modifying factors or the addition of DNA elements, which efficiently counteract the influence of the chromatin environment.An influence of the chromatin configuration of the recombinant gene itself on its transcriptional behavior has also been established. This view is especially important for heterologous genes since the general parameters of chromatin organization change from one species to another. The chromatin organization of bacterial DNA proves particularly dramatic when introduced into eukaryotes. The nucleosome positioning of recombinant genes is the result of the interaction between the machinery of the hosting cell and the sequences of both the recombinant genes and the promoter regions. We discuss the key aspects of this phenomenon from the heterologous gene expression perspective.
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Rafati H, Parra M, Hakre S, Moshkin Y, Verdin E, Mahmoudi T. Repressive LTR nucleosome positioning by the BAF complex is required for HIV latency. PLoS Biol 2011; 9:e1001206. [PMID: 22140357 PMCID: PMC3226458 DOI: 10.1371/journal.pbio.1001206] [Citation(s) in RCA: 134] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Accepted: 10/18/2011] [Indexed: 12/30/2022] Open
Abstract
Persistence of a reservoir of latently infected memory T cells provides a barrier to HIV eradication in treated patients. Several reports have implicated the involvement of SWI/SNF chromatin remodeling complexes in restricting early steps in HIV infection, in coupling the processes of integration and remodeling, and in promoter/LTR transcription activation and repression. However, the mechanism behind the seemingly contradictory involvement of SWI/SNF in the HIV life cycle remains unclear. Here we addressed the role of SWI/SNF in regulation of the latent HIV LTR before and after transcriptional activation. We determined the predicted nucleosome affinity of the LTR sequence and found a striking reverse correlation when compared to the strictly positioned in vivo LTR nucleosomal structure; sequences encompassing the DNase hypersensitive regions displayed the highest nucleosome affinity, while the strictly positioned nucleosomes displayed lower affinity for nucleosome formation. To examine the mechanism behind this reverse correlation, we used a combinatorial approach to determine DNA accessibility, histone occupancy, and the unique recruitment and requirement of BAF and PBAF, two functionally distinct subclasses of SWI/SNF at the LTR of HIV-infected cells before and after activation. We find that establishment and maintenance of HIV latency requires BAF, which removes a preferred nucleosome from DHS1 to position the repressive nucleosome-1 over energetically sub-optimal sequences. Depletion of BAF resulted in de-repression of HIV latency concomitant with a dramatic alteration in the LTR nucleosome profile as determined by high resolution MNase nucleosomal mapping. Upon activation, BAF was lost from the HIV promoter, while PBAF was selectively recruited by acetylated Tat to facilitate LTR transcription. Thus BAF and PBAF, recruited during different stages of the HIV life cycle, display opposing function on the HIV promoter. Our data point to the ATP-dependent BRG1 component of BAF as a putative therapeutic target to deplete the latent reservoir in patients. The SWI/SNF BAF chromatin remodeling complex generates a repressive nucleosome structure at the HIV LTR conducive to establishment and maintenance of HIV latency, while PBAF augments HIV transcription. Despite the effectiveness of antiretroviral medication, the HIV virus persists in resting memory T cells of infected patients in a latent state, providing the main impediment to eradication of the virus. In this article, we examined the molecular mechanism responsible for the establishment and maintenance of HIV latency and its re-activation, and uncovered the role played in this process by the SWI/SNF class of chromatin remodeling complexes, which use energy from ATP to alter the structure of chromatin. We show that two distinct sub-classes of SWI/SNF, BAF and PBAF, play functionally opposing roles in distinct steps of the HIV promoter (or long terminal repeat, LTR) transcription cycle. The PBAF complex augments transcription of the LTR by the viral transactivator Tat. In contrast, the distinct BAF complex generates a chromatin structure at the LTR that is energetically unfavorable with respect to the intrinsic histone-DNA sequence preferences. Specifically, we find that BAF positions a repressive nucleosome immediately downstream of the HIV transcription start site, abrogating transcription, and in this way contributes to the establishment and maintenance of HIV latency. Our data describe a novel molecular mechanism for the establishment and maintenance of HIV latency, and we identify the catalytic subunit of BAF, the enzyme BRG1, as a putative molecular target to deplete the latent reservoir in infected patients.
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Affiliation(s)
- Haleh Rafati
- Department of Biochemistry, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Maribel Parra
- Gladstone Institute of Virology and Immunology, University of California–San Francisco, San Francisco, California, United States of America
| | - Shweta Hakre
- Gladstone Institute of Virology and Immunology, University of California–San Francisco, San Francisco, California, United States of America
| | - Yuri Moshkin
- Department of Biochemistry, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Eric Verdin
- Gladstone Institute of Virology and Immunology, University of California–San Francisco, San Francisco, California, United States of America
- * E-mail: (EV); (TM)
| | - Tokameh Mahmoudi
- Department of Biochemistry, Erasmus University Medical Center, Rotterdam, The Netherlands
- Gladstone Institute of Virology and Immunology, University of California–San Francisco, San Francisco, California, United States of America
- * E-mail: (EV); (TM)
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Close D, Johnson SJ, Sdano MA, McDonald SM, Robinson H, Formosa T, Hill CP. Crystal structures of the S. cerevisiae Spt6 core and C-terminal tandem SH2 domain. J Mol Biol 2011; 408:697-713. [PMID: 21419780 PMCID: PMC3086336 DOI: 10.1016/j.jmb.2011.03.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Revised: 02/24/2011] [Accepted: 03/01/2011] [Indexed: 01/07/2023]
Abstract
The conserved and essential eukaryotic protein Spt6 functions in transcription elongation, chromatin maintenance, and RNA processing. Spt6 has three characterized functions. It is a histone chaperone capable of reassembling nucleosomes, a central component of transcription elongation complexes, and is required for recruitment of RNA processing factors to elongating RNA polymerase II (RNAPII). Here, we report multiple crystal structures of the 168-kDa Spt6 protein from Saccharomyces cerevisiae that together represent essentially all of the ordered sequence. Our two structures of the ∼900-residue core region reveal a series of putative nucleic acid and protein-protein interaction domains that fold into an elongated form that resembles the bacterial protein Tex. The similarity to a bacterial transcription factor suggests that the core domain performs nucleosome-independent activities, and as with Tex, we find that Spt6 binds DNA. Unlike Tex, however, the Spt6 S1 domain does not contribute to this activity. Crystal structures of the Spt6 C-terminal region reveal a tandem SH2 domain structure composed of two closely associated SH2 folds. One of these SH2 folds is cryptic, while the other shares striking structural similarity with metazoan SH2 domains and possesses structural features associated with the ability to bind phosphorylated substrates including phosphotyrosine. Binding studies with phosphopeptides that mimic the RNAPII C-terminal domain revealed affinities typical of other RNAPII C-terminal domain-binding proteins but did not indicate a specific interaction. Overall, these findings provide a structural foundation for understanding how Spt6 encodes several distinct functions within a single polypeptide chain.
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Affiliation(s)
- Devin Close
- Department of Biochemistry, University of Utah, Salt Lake City, Utah 84112-5650
| | - Sean J Johnson
- Department of Chemistry & Biochemistry, Utah State University, Logan, Utah 84322-0300
| | - Matthew A Sdano
- Department of Biochemistry, University of Utah, Salt Lake City, Utah 84112-5650
| | - Seth M McDonald
- Department of Biochemistry, University of Utah, Salt Lake City, Utah 84112-5650
| | - Howard Robinson
- Department of Biology, Brookhaven National Laboratory, Upton, NY 11973
| | - Tim Formosa
- Department of Biochemistry, University of Utah, Salt Lake City, Utah 84112-5650
| | - Christopher P Hill
- Department of Biochemistry, University of Utah, Salt Lake City, Utah 84112-5650
- Corresponding author:
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Chromatin reassembly factors are involved in transcriptional interference promoting HIV latency. J Virol 2011; 85:3187-202. [PMID: 21270164 DOI: 10.1128/jvi.01920-10] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The establishment of a stable reservoir of latently infected cells allows HIV to persist in the host. Usually, HIV infection of T cells results in integration of the viral genome, with a preference for regions in the human genome containing active genes, viral expression, and production of new viruses. However, in rare cases T cells become latently infected, and this is presumed to be due to a combination of two factors: integrated viruses are not efficiently transcribed and infected T cells revert to a resting memory state. HIV latency has been associated with provirus integration in regions of constitutive heterochromatin, gene deserts, or very highly expressed genes. We have investigated the transcriptional consequences of latent HIV integration into cellular genes and the involvement of chromatin reassembly factors (CRFs) in the transcriptional interference that a host gene exerts on the integrated cryptic HIV promoter. Chimeric transcripts containing sequences from the host gene and HIV can be detected, having been initiated at promoters of either the cell or the virus. Reactivation of HIV downregulates host gene expression. Cryptic promoters might remain inactive due to the repressive chromatin configuration established by CRFs during transcription elongation. Depletion of CRFs such as Spt6, Chd1, and FACT, or the histone chaperones ASF1a and HIRA, promoted HIV reactivation, concomitantly with chromatin relaxation and a decrease in general RNA polymerase activity. Overall, our results indicate that CRFs play a role in maintaining HIV latency by transcriptional interference when the provirus is integrated into an intron of a highly active gene.
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McDonald SM, Close D, Xin H, Formosa T, Hill CP. Structure and biological importance of the Spn1-Spt6 interaction, and its regulatory role in nucleosome binding. Mol Cell 2010; 40:725-35. [PMID: 21094070 PMCID: PMC3017428 DOI: 10.1016/j.molcel.2010.11.014] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Revised: 08/11/2010] [Accepted: 09/21/2010] [Indexed: 01/07/2023]
Abstract
Eukaryotic transcription and mRNA processing depend upon the coordinated interactions of many proteins, including Spn1 and Spt6, which are conserved across eukaryotes, are essential for viability, and associate with each other in some of their biologically important contexts. Here we report crystal structures of the Spn1 core alone and in complex with the binding determinant of Spt6. Mutating interface residues greatly diminishes binding in vitro and causes strong phenotypes in vivo, including a defect in maintaining repressive chromatin. Overexpression of Spn1 partially suppresses the defects caused by an spt6 mutation affecting the Spn1 interface, indicating that the Spn1-Spt6 interaction is important for managing chromatin. Spt6 binds nucleosomes directly in vitro, and this interaction is blocked by Spn1, providing further mechanistic insight into the function of the interaction. These data thereby reveal the structural and biochemical bases of molecular interactions that function in the maintenance of chromatin structure.
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Macías D, Oya R, Saniger L, Martín F, Luque F. A lentiviral vector that activates latent human immunodeficiency virus-1 proviruses by the overexpression of tat and that kills the infected cells. Hum Gene Ther 2010; 20:1259-68. [PMID: 19604078 DOI: 10.1089/hum.2009.059] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Despite the efficient HIV-1 replication blockage achieved with current highly active antiretroviral therapy (HAART) therapies, HIV-1 persists in the body and survives in a latent state that can last for the entire life of the patient. A long-lived reservoir of latently infected CD4(+) memory T cells represents the most important sanctuary for the virus and the greatest obstacle for viral eradication. In this work, we present an initial step toward a gene therapy approach aimed at the activation of latent provirus to induce the death of latently infected T cells. Latent HIV-1 infection is characterized by the failure of viral gene expression as a consequence of uninitiated or aborted transcription. We have constructed an HIV-1-based lentiviral vector (p5p53RTAT3) that expresses the viral trans-activating protein Tat in a drug-regulated manner and p53 in a Rev-dependent manner. We have demonstrated that the Tat-expressed protein from p5p53RTAT3 vector reactivates latent HIV-1 proviruses in J1.1 and ACH-2 cell lines and promotes p53-induced apoptosis in the presence of Rev. Our system was able to trigger the trans-activation of the provirus 5' long terminal repeat (LTR), stimulate the expression of the Rev protein from a tat-defective provirus, and provoke apoptosis selectively in the cells transfected with a tat-defective HIV-1 provirus in contrast to those with no HIV-1 provirus. However, the Rev-dependent p53 killing of latently infected cells was not effective enough for complete elimination of the awakened HIV-1 viruses. In summary, we have developed a vector system that is efficient in activating latent HIV-1 proviruses but that needs further improvement to kill infected cells.
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Affiliation(s)
- David Macías
- Departamento de Biología Experimental, Universidad de Jaén, Jaén, Spain.
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Interaction of the papillomavirus E8--E2C protein with the cellular CHD6 protein contributes to transcriptional repression. J Virol 2010; 84:9505-15. [PMID: 20631145 DOI: 10.1128/jvi.00678-10] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Expression of the E6 and E7 oncogenes of high-risk human papillomaviruses (HPV) is controlled by cellular transcription factors and by viral E2 and E8--E2C proteins, which are both derived from the HPV E2 gene. Both proteins bind to and repress the HPV E6/E7 promoter. Promoter inhibition has been suggested to be due to binding site competition with cellular transcription factors and to interactions of different cellular transcription modulators with the different amino termini of E2 and E8--E2C. We have now identified the cellular chromodomain helicase DNA binding domain 6 protein (CHD6) as a novel interactor with HPV31 E8--E2C by using yeast two-hybrid screening. Pull-down and coimmunoprecipitation assays indicate that CHD6 interacts with the HPV31 E8--E2C protein via the E2C domain. This interaction is conserved, as it occurs also with the E8--E2C proteins expressed by HPV16 and -18 and with the HPV31 E2 protein. Both RNA knockdown experiments and mutational analyses of the E2C domain suggest that binding of CHD6 to E8--E2C contributes to the transcriptional repression of the HPV E6/E7 oncogene promoter. We provide evidence that CHD6 is also involved in transcriptional repression but not activation by E2. Taken together our results indicate that the E2C domain not only mediates specific DNA binding but also has an additional role in transcriptional repression by recruitment of the CHD6 protein. This suggests that repression of the E6/E7 promoter by E2 and E8--E2C involves multiple interactions with host cell proteins through different protein domains.
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Morillo-Huesca M, Maya D, Muñoz-Centeno MC, Singh RK, Oreal V, Reddy GU, Liang D, Géli V, Gunjan A, Chávez S. FACT prevents the accumulation of free histones evicted from transcribed chromatin and a subsequent cell cycle delay in G1. PLoS Genet 2010; 6:e1000964. [PMID: 20502685 PMCID: PMC2873916 DOI: 10.1371/journal.pgen.1000964] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2009] [Accepted: 04/20/2010] [Indexed: 11/18/2022] Open
Abstract
The FACT complex participates in chromatin assembly and disassembly during transcription elongation. The yeast mutants affected in the SPT16 gene, which encodes one of the FACT subunits, alter the expression of G1 cyclins and exhibit defects in the G1/S transition. Here we show that the dysfunction of chromatin reassembly factors, like FACT or Spt6, down-regulates the expression of the gene encoding the cyclin that modulates the G1 length (CLN3) in START by specifically triggering the repression of its promoter. The G1 delay undergone by spt16 mutants is not mediated by the DNA–damage checkpoint, although the mutation of RAD53, which is otherwise involved in histone degradation, enhances the cell-cycle defects of spt16-197. We reveal how FACT dysfunction triggers an accumulation of free histones evicted from transcribed chromatin. This accumulation is enhanced in a rad53 background and leads to a delay in G1. Consistently, we show that the overexpression of histones in wild-type cells down-regulates CLN3 in START and causes a delay in G1. Our work shows that chromatin reassembly factors are essential players in controlling the free histones potentially released from transcribed chromatin and describes a new cell cycle phenomenon that allows cells to respond to excess histones before starting DNA replication. Lengthy genomic DNA is packed in a highly organized nucleoprotein structure called chromatin, whose basic subunit is the nucleosome which is formed by DNA wrapped around an octamer of proteins called histones. Nucleosomes need to be disassembled to allow DNA transcription by RNA polymerases. An essential factor for the disassembly/reassembly process during DNA transcription is the FACT complex. We investigated a phenotype of yeast FACT mutants, a delay in a specific step of the cell cycle division process immediately prior to starting DNA replication. The dysfunction caused by the FACT mutation causes a downregulation of a gene, CLN3, which controls the length of that specific step of the cell cycle. FACT dysfunction also increases the level of the free histones released from chromatin during transcription, and the phenotype of the Spt16 mutant is enhanced by a second mutation affecting a protein that regulates DNA repair and excess histone degradation. Moreover, we show that the overexpression of histones causes a cell cycle delay before DNA replication in wild-type cells. Our results point out a so-far unknown connection between chromatin dynamics and the regulation of the cell cycle.
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Affiliation(s)
| | - Douglas Maya
- Departamento de Genética, Universidad de Sevilla, Seville, Spain
| | | | - Rakesh Kumar Singh
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, United States of America
| | - Vincent Oreal
- Laboratoire d'Instabilité Génétique et Cancérogenèse, Institut de Biologie Struturale et Microbiologie, Centre National de la Recherche Scientifique, Marseille, France
| | - Gajjalaiahvari Ugander Reddy
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, United States of America
| | - Dun Liang
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, United States of America
| | - Vincent Géli
- Laboratoire d'Instabilité Génétique et Cancérogenèse, Institut de Biologie Struturale et Microbiologie, Centre National de la Recherche Scientifique, Marseille, France
| | - Akash Gunjan
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida, United States of America
| | - Sebastián Chávez
- Departamento de Genética, Universidad de Sevilla, Seville, Spain
- * E-mail: (SC); (MCM-C)
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HIV interactions with monocytes and dendritic cells: viral latency and reservoirs. Retrovirology 2009; 6:51. [PMID: 19486514 PMCID: PMC2697150 DOI: 10.1186/1742-4690-6-51] [Citation(s) in RCA: 168] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Accepted: 06/01/2009] [Indexed: 11/10/2022] Open
Abstract
HIV is a devastating human pathogen that causes serious immunological diseases in humans around the world. The virus is able to remain latent in an infected host for many years, allowing for the long-term survival of the virus and inevitably prolonging the infection process. The location and mechanisms of HIV latency are under investigation and remain important topics in the study of viral pathogenesis. Given that HIV is a blood-borne pathogen, a number of cell types have been proposed to be the sites of latency, including resting memory CD4+ T cells, peripheral blood monocytes, dendritic cells and macrophages in the lymph nodes, and haematopoietic stem cells in the bone marrow. This review updates the latest advances in the study of HIV interactions with monocytes and dendritic cells, and highlights the potential role of these cells as viral reservoirs and the effects of the HIV-host-cell interactions on viral pathogenesis.
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