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Grandgenett DP, Engelman AN. Brief Histories of Retroviral Integration Research and Associated International Conferences. Viruses 2024; 16:604. [PMID: 38675945 PMCID: PMC11054761 DOI: 10.3390/v16040604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 04/05/2024] [Accepted: 04/10/2024] [Indexed: 04/28/2024] Open
Abstract
The field of retroviral integration research has a long history that started with the provirus hypothesis and subsequent discoveries of the retroviral reverse transcriptase and integrase enzymes. Because both enzymes are essential for retroviral replication, they became valued targets in the effort to discover effective compounds to inhibit HIV-1 replication. In 2007, the first integrase strand transfer inhibitor was licensed for clinical use, and subsequently approved second-generation integrase inhibitors are now commonly co-formulated with reverse transcriptase inhibitors to treat people living with HIV. International meetings specifically focused on integrase and retroviral integration research first convened in 1995, and this paper is part of the Viruses Special Issue on the 7th International Conference on Retroviral Integration, which was held in Boulder Colorado in the summer of 2023. Herein, we overview key historical developments in the field, especially as they pertain to the development of the strand transfer inhibitor drug class. Starting from the mid-1990s, research advancements are presented through the lens of the international conferences. Our overview highlights the impact that regularly scheduled, subject-specific international meetings can have on community-building and, as a result, on field-specific collaborations and scientific advancements.
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Affiliation(s)
- Duane P. Grandgenett
- Department of Molecular Microbiology and Immunology, School of Medicine, Saint Louis University, St. Louis, MO 63104, USA
| | - Alan N. Engelman
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Department of Medicine, Harvard Medical School, Boston, MA 02115, USA
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2
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Munasinghe M, Springer N, Brandvain Y. Critical role of insertion preference for invasion trajectory of transposons. Evolution 2023; 77:2173-2185. [PMID: 37519088 DOI: 10.1093/evolut/qpad128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/01/2023] [Accepted: 07/24/2023] [Indexed: 08/01/2023]
Abstract
It is unclear how mobile DNA sequences (transposable elements, hereafter TEs) invade eukaryotic genomes and reach stable copy numbers, as transposition can decrease host fitness. This challenge is particularly stark early in the invasion of a TE family at which point hosts may lack the specialized machinery to repress the spread of these TEs. One possibility (in addition to the evolution of host regulation of TEs) is that TE families may evolve to preferentially insert into chromosomal regions that are less likely to impact host fitness. This may allow the mean TE copy number to grow while minimizing the risk for host population extinction. To test this, we constructed simulations to explore how the transposition probability and insertion preference of a TE family influence the evolution of mean TE copy number and host population size, allowing for extinction. We find that the effect of a TE family's insertion preference depends on a host's ability to regulate this TE family. Without host repression, a neutral insertion preference increases the frequency of and decreases the time to population extinction. With host repression, a preference for neutral insertions minimizes the cumulative deleterious load, increases population fitness, and, ultimately, avoids triggering an extinction vortex.
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Affiliation(s)
- Manisha Munasinghe
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN, United States
| | - Nathan Springer
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN, United States
| | - Yaniv Brandvain
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN, United States
- Department of Ecology, Evolution and Behavior, University of Minnesota, St. Paul, MN, United States
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3
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Chakrabarty P, Sen R, Sengupta S. From parasites to partners: exploring the intricacies of host-transposon dynamics and coevolution. Funct Integr Genomics 2023; 23:278. [PMID: 37610667 DOI: 10.1007/s10142-023-01206-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 08/01/2023] [Accepted: 08/07/2023] [Indexed: 08/24/2023]
Abstract
Transposable elements, often referred to as "jumping genes," have long been recognized as genomic parasites due to their ability to integrate and disrupt normal gene function and induce extensive genomic alterations, thereby compromising the host's fitness. To counteract this, the host has evolved a plethora of mechanisms to suppress the activity of the transposons. Recent research has unveiled the host-transposon relationships to be nuanced and complex phenomena, resulting in the coevolution of both entities. Transposition increases the mutational rate in the host genome, often triggering physiological pathways such as immune and stress responses. Current gene transfer technologies utilizing transposable elements have potential drawbacks, including off-target integration, induction of mutations, and modifications of cellular machinery, which makes an in-depth understanding of the host-transposon relationship imperative. This review highlights the dynamic interplay between the host and transposable elements, encompassing various factors and components of the cellular machinery. We provide a comprehensive discussion of the strategies employed by transposable elements for their propagation, as well as the mechanisms utilized by the host to mitigate their parasitic effects. Additionally, we present an overview of recent research identifying host proteins that act as facilitators or inhibitors of transposition. We further discuss the evolutionary outcomes resulting from the genetic interactions between the host and the transposable elements. Finally, we pose open questions in this field and suggest potential avenues for future research.
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Affiliation(s)
- Prayas Chakrabarty
- Department of Life Sciences, Presidency University Kolkata, 86/1 College Street, Kolkata, 700073, India
| | - Raneet Sen
- Department of Life Sciences, Presidency University Kolkata, 86/1 College Street, Kolkata, 700073, India
- Institute of Bioorganic Chemistry, Department of RNA Metabolism, Polish Academy of Sciences, Poznan, Poland
| | - Sugopa Sengupta
- Department of Life Sciences, Presidency University Kolkata, 86/1 College Street, Kolkata, 700073, India.
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Beckwith SL, Nomberg EJ, Newman AC, Taylor JV, Guerrero-Ferreira RC, Garfinkel DJ. An interchangeable prion-like domain is required for Ty1 retrotransposition. Proc Natl Acad Sci U S A 2023; 120:e2303358120. [PMID: 37459521 PMCID: PMC10372613 DOI: 10.1073/pnas.2303358120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 06/12/2023] [Indexed: 07/20/2023] Open
Abstract
Retrotransposons and retroviruses shape genome evolution and can negatively impact genome function. Saccharomyces cerevisiae and its close relatives harbor several families of LTR-retrotransposons, the most abundant being Ty1 in several laboratory strains. The cytosolic foci that nucleate Ty1 virus-like particle (VLP) assembly are not well understood. These foci, termed retrosomes or T-bodies, contain Ty1 Gag and likely Gag-Pol and the Ty1 mRNA destined for reverse transcription. Here, we report an intrinsically disordered N-terminal prion-like domain (PrLD) within Gag that is required for transposition. This domain contains amino acid composition similar to known yeast prions and is sufficient to nucleate prionogenesis in an established cell-based prion reporter system. Deleting the Ty1 PrLD results in dramatic VLP assembly and retrotransposition defects but does not affect Gag protein level. Ty1 Gag chimeras in which the PrLD is replaced with other sequences, including yeast and mammalian prionogenic domains, display a range of retrotransposition phenotypes from wild type to null. We examine these chimeras throughout the Ty1 replication cycle and find that some support retrosome formation, VLP assembly, and retrotransposition, including the yeast Sup35 prion and the mouse PrP prion. Our interchangeable Ty1 system provides a useful, genetically tractable in vivo platform for studying PrLDs, complete with a suite of robust and sensitive assays. Our work also invites study into the prevalence of PrLDs in additional mobile elements.
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Affiliation(s)
- Sean L. Beckwith
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA30602
| | - Emily J. Nomberg
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA30602
| | - Abigail C. Newman
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA30602
| | - Jeannette V. Taylor
- Robert P. Apkarian Integrated Electron Microscopy Core at Emory University, Atlanta, GA30322
| | | | - David J. Garfinkel
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA30602
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Chen J, Basting PJ, Han S, Garfinkel DJ, Bergman CM. Reproducible evaluation of transposable element detectors with McClintock 2 guides accurate inference of Ty insertion patterns in yeast. Mob DNA 2023; 14:8. [PMID: 37452430 PMCID: PMC10347736 DOI: 10.1186/s13100-023-00296-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 06/09/2023] [Indexed: 07/18/2023] Open
Abstract
BACKGROUND Many computational methods have been developed to detect non-reference transposable element (TE) insertions using short-read whole genome sequencing data. The diversity and complexity of such methods often present challenges to new users seeking to reproducibly install, execute, or evaluate multiple TE insertion detectors. RESULTS We previously developed the McClintock meta-pipeline to facilitate the installation, execution, and evaluation of six first-generation short-read TE detectors. Here, we report a completely re-implemented version of McClintock written in Python using Snakemake and Conda that improves its installation, error handling, speed, stability, and extensibility. McClintock 2 now includes 12 short-read TE detectors, auxiliary pre-processing and analysis modules, interactive HTML reports, and a simulation framework to reproducibly evaluate the accuracy of component TE detectors. When applied to the model microbial eukaryote Saccharomyces cerevisiae, we find substantial variation in the ability of McClintock 2 components to identify the precise locations of non-reference TE insertions, with RelocaTE2 showing the highest recall and precision in simulated data. We find that RelocaTE2, TEMP, TEMP2 and TEBreak provide consistent estimates of [Formula: see text]50 non-reference TE insertions per strain and that Ty2 has the highest number of non-reference TE insertions in a species-wide panel of [Formula: see text]1000 yeast genomes. Finally, we show that best-in-class predictors for yeast applied to resequencing data have sufficient resolution to reveal a dyad pattern of integration in nucleosome-bound regions upstream of yeast tRNA genes for Ty1, Ty2, and Ty4, allowing us to extend knowledge about fine-scale target preferences revealed previously for experimentally-induced Ty1 insertions to spontaneous insertions for other copia-superfamily retrotransposons in yeast. CONCLUSION McClintock ( https://github.com/bergmanlab/mcclintock/ ) provides a user-friendly pipeline for the identification of TEs in short-read WGS data using multiple TE detectors, which should benefit researchers studying TE insertion variation in a wide range of different organisms. Application of the improved McClintock system to simulated and empirical yeast genome data reveals best-in-class methods and novel biological insights for one of the most widely-studied model eukaryotes and provides a paradigm for evaluating and selecting non-reference TE detectors in other species.
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Affiliation(s)
- Jingxuan Chen
- Institute of Bioinformatics, University of Georgia, Athens, GA USA
| | | | - Shunhua Han
- Institute of Bioinformatics, University of Georgia, Athens, GA USA
| | - David J. Garfinkel
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA USA
| | - Casey M. Bergman
- Institute of Bioinformatics, University of Georgia, Athens, GA USA
- Department of Genetics, University of Georgia, Athens, GA USA
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Nguyen PQ, Huecas S, Asif-Laidin A, Plaza-Pegueroles A, Capuzzi B, Palmic N, Conesa C, Acker J, Reguera J, Lesage P, Fernández-Tornero C. Structural basis of Ty1 integrase tethering to RNA polymerase III for targeted retrotransposon integration. Nat Commun 2023; 14:1729. [PMID: 36977686 PMCID: PMC10050235 DOI: 10.1038/s41467-023-37109-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 03/02/2023] [Indexed: 03/30/2023] Open
Abstract
The yeast Ty1 retrotransposon integrates upstream of genes transcribed by RNA polymerase III (Pol III). Specificity of integration is mediated by an interaction between the Ty1 integrase (IN1) and Pol III, currently uncharacterized at the atomic level. We report cryo-EM structures of Pol III in complex with IN1, revealing a 16-residue segment at the IN1 C-terminus that contacts Pol III subunits AC40 and AC19, an interaction that we validate by in vivo mutational analysis. Binding to IN1 associates with allosteric changes in Pol III that may affect its transcriptional activity. The C-terminal domain of subunit C11, involved in RNA cleavage, inserts into the Pol III funnel pore, providing evidence for a two-metal mechanism during RNA cleavage. Additionally, ordering next to C11 of an N-terminal portion from subunit C53 may explain the connection between these subunits during termination and reinitiation. Deletion of the C53 N-terminal region leads to reduced chromatin association of Pol III and IN1, and a major fall in Ty1 integration events. Our data support a model in which IN1 binding induces a Pol III configuration that may favor its retention on chromatin, thereby improving the likelihood of Ty1 integration.
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Affiliation(s)
- Phong Quoc Nguyen
- Centro de Investigaciones Biológicas Margarita Salas, CSIC, 28040, Madrid, Spain
- Aix-Marseille Université, CNRS, AFMB UMR 7257, 13288, Marseille, France
| | - Sonia Huecas
- Centro de Investigaciones Biológicas Margarita Salas, CSIC, 28040, Madrid, Spain
| | - Amna Asif-Laidin
- Université Paris Cité, IRSL, Inserm, U944, CNRS, UMR7212, 75010, Paris, France
| | | | - Beatrice Capuzzi
- Université Paris Cité, IRSL, Inserm, U944, CNRS, UMR7212, 75010, Paris, France
| | - Noé Palmic
- Université Paris Cité, IRSL, Inserm, U944, CNRS, UMR7212, 75010, Paris, France
| | - Christine Conesa
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Joël Acker
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Juan Reguera
- Aix-Marseille Université, CNRS, AFMB UMR 7257, 13288, Marseille, France
- INSERM, AFMB UMR7257, 13288, Marseille, France
| | - Pascale Lesage
- Université Paris Cité, IRSL, Inserm, U944, CNRS, UMR7212, 75010, Paris, France.
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Beckwith SL, Nomberg EJ, Newman AC, Taylor JV, Guerrero RC, Garfinkel DJ. An interchangeable prion-like domain is required for Ty1 retrotransposition. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.27.530227. [PMID: 36909481 PMCID: PMC10002725 DOI: 10.1101/2023.02.27.530227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
Retrotransposons and retroviruses shape genome evolution and can negatively impact genome function. Saccharomyces cerevisiae and its close relatives harbor several families of LTR-retrotransposons, the most abundant being Ty1 in several laboratory strains. The cytosolic foci that nucleate Ty1 virus-like particle (VLP) assembly are not well-understood. These foci, termed retrosomes or T-bodies, contain Ty1 Gag and likely Gag-Pol and the Ty1 mRNA destined for reverse transcription. Here, we report a novel intrinsically disordered N-terminal pr ion-like d omain (PrLD) within Gag that is required for transposition. This domain contains amino-acid composition similar to known yeast prions and is sufficient to nucleate prionogenesis in an established cell-based prion reporter system. Deleting the Ty1 PrLD results in dramatic VLP assembly and retrotransposition defects but does not affect Gag protein level. Ty1 Gag chimeras in which the PrLD is replaced with other sequences, including yeast and mammalian prionogenic domains, display a range of retrotransposition phenotypes from wildtype to null. We examine these chimeras throughout the Ty1 replication cycle and find that some support retrosome formation, VLP assembly, and retrotransposition, including the yeast Sup35 prion and the mouse PrP prion. Our interchangeable Ty1 system provides a useful, genetically tractable in vivo platform for studying PrLDs, complete with a suite of robust and sensitive assays, and host modulators developed to study Ty1 retromobility. Our work invites study into the prevalence of PrLDs in additional mobile elements. Significance Retrovirus-like retrotransposons help shape the genome evolution of their hosts and replicate within cytoplasmic particles. How their building blocks associate and assemble within the cell is poorly understood. Here, we report a novel pr ion-like d omain (PrLD) in the budding yeast retrotransposon Ty1 Gag protein that builds virus-like particles. The PrLD has similar sequence properties to prions and disordered protein domains that can drive the formation of assemblies that range from liquid to solid. We demonstrate that the Ty1 PrLD can function as a prion and that certain prion sequences can replace the PrLD and support Ty1 transposition. This interchangeable system is an effective platform to study additional disordered sequences in living cells.
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Affiliation(s)
- Sean L. Beckwith
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Emily J. Nomberg
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Abigail C. Newman
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Jeannette V. Taylor
- Robert P. Apkarian Integrated Electron Microscopy Core at Emory University, Atlanta, GA, 30322, USA
| | - Ricardo C. Guerrero
- Robert P. Apkarian Integrated Electron Microscopy Core at Emory University, Atlanta, GA, 30322, USA
| | - David J. Garfinkel
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
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8
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Chen J, Basting PJ, Han S, Garfinkel DJ, Bergman CM. Reproducible evaluation of short-read transposable element detectors and species-wide data mining of insertion patterns in yeast. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.13.528343. [PMID: 36824955 PMCID: PMC9948991 DOI: 10.1101/2023.02.13.528343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Background Many computational methods have been developed to detect non-reference transposable element (TE) insertions using short-read whole genome sequencing data. The diversity and complexity of such methods often present challenges to new users seeking to reproducibly install, execute or evaluate multiple TE insertion detectors. Results We previously developed the McClintock meta-pipeline to facilitate the installation, execution, and evaluation of six first-generation short-read TE detectors. Here, we report a completely re-implemented version of McClintock written in Python using Snakemake and Conda that improves its installation, error handling, speed, stability, and extensibility. McClintock 2 now includes 12 short-read TE detectors, auxiliary pre-processing and analysis modules, interactive HTML reports, and a simulation framework to reproducibly evaluate the accuracy of component TE detectors. When applied to the model microbial eukaryote Saccharomyces cerevisiae , we find substantial variation in the ability of McClintock 2 components to identify the precise locations of non-reference TE insertions, with RelocaTE2 showing the highest recall and precision in simulated data. We find that RelocaTE2, TEMP, TEMP2 and TEBreak provide a consistent and biologically meaningful view of non-reference TE insertions in a species-wide panel of ∼ 1000 yeast genomes, as evaluated by coverage-based abundance estimates and expected patterns of tRNA promoter targeting. Finally, we show that best-in-class predictors for yeast have sufficient resolution to reveal a dyad pattern of integration in nucleosome-bound regions upstream of yeast tRNA genes for Ty1, Ty2, and Ty4, allowing us to extend knowledge aboutfine-scale target preferences first revealed experimentally for Ty1 to natural insertions and related copia -superfamily retrotransposons in yeast. Conclusion McClintock ( https://github.com/bergmanlab/mcclintock/ ) provides a user-friendly pipeline for the identification of TEs in short-read WGS data using multiple TE detectors, which should benefit researchers studying TE insertion variation in a wide range of different organisms. Application of the improved McClintock system to simulated and empirical yeast genome data reveals best-in-class methods and novel biological insights for one of the most widely-studied model eukaryotes and provides a paradigm for evaluating and selecting non-reference TE detectors for other species.
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Barkova A, Adhya I, Conesa C, Asif-Laidin A, Bonnet A, Rabut E, Chagneau C, Lesage P, Acker J. A proteomic screen of Ty1 integrase partners identifies the protein kinase CK2 as a regulator of Ty1 retrotransposition. Mob DNA 2022; 13:26. [PMCID: PMC9673352 DOI: 10.1186/s13100-022-00284-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 10/13/2022] [Indexed: 11/19/2022] Open
Abstract
Abstract
Background
Transposable elements are ubiquitous and play a fundamental role in shaping genomes during evolution. Since excessive transposition can be mutagenic, mechanisms exist in the cells to keep these mobile elements under control. Although many cellular factors regulating the mobility of the retrovirus-like transposon Ty1 in Saccharomyces cerevisiae have been identified in genetic screens, only very few of them interact physically with Ty1 integrase (IN).
Results
Here, we perform a proteomic screen to establish Ty1 IN interactome. Among the 265 potential interacting partners, we focus our study on the conserved CK2 kinase. We confirm the interaction between IN and CK2, demonstrate that IN is a substrate of CK2 in vitro and identify the modified residues. We find that Ty1 IN is phosphorylated in vivo and that these modifications are dependent in part on CK2. No significant change in Ty1 retromobility could be observed when we introduce phospho-ablative mutations that prevent IN phosphorylation by CK2 in vitro. However, the absence of CK2 holoenzyme results in a strong stimulation of Ty1 retrotransposition, characterized by an increase in Ty1 mRNA and protein levels and a high accumulation of cDNA.
Conclusion
Our study shows that Ty1 IN is phosphorylated, as observed for retroviral INs and highlights an important role of CK2 in the regulation of Ty1 retrotransposition. In addition, the proteomic approach enabled the identification of many new Ty1 IN interacting partners, whose potential role in the control of Ty1 mobility will be interesting to study.
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Winans S, Yu HJ, de Los Santos K, Wang GZ, KewalRamani VN, Goff SP. A point mutation in HIV-1 integrase redirects proviral integration into centromeric repeats. Nat Commun 2022; 13:1474. [PMID: 35304442 PMCID: PMC8933506 DOI: 10.1038/s41467-022-29097-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 02/24/2022] [Indexed: 11/25/2022] Open
Abstract
Retroviruses utilize the viral integrase (IN) protein to integrate a DNA copy of their genome into host chromosomal DNA. HIV-1 integration sites are highly biased towards actively transcribed genes, likely mediated by binding of the IN protein to specific host factors, particularly LEDGF, located at these gene regions. We here report a substantial redirection of integration site distribution induced by a single point mutation in HIV-1 IN. Viruses carrying the K258R IN mutation exhibit a high frequency of integrations into centromeric alpha satellite repeat sequences, as assessed by deep sequencing, a more than 10-fold increase over wild-type. Quantitative PCR and in situ immunofluorescence assays confirm this bias of the K258R mutant virus for integration into centromeric DNA. Immunoprecipitation studies identify host factors binding to IN that may account for the observed bias for integration into centromeres. Centromeric integration events are known to be enriched in the latent reservoir of infected memory T cells, as well as in elite controllers who limit viral replication without intervention. The K258R point mutation in HIV-1 IN is also present in databases of latent proviruses found in patients, and may reflect an unappreciated aspect of the establishment of viral latency. HIV-1 integration sites are biased towards actively transcribed genes, likely mediated by binding of the viral integrase (IN) protein to host factors. Here, Winans et al. show that the K258R point mutation in IN eredirects viral DNA integration to the centromeres of host chromosomes, which may affect HIV latency.
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Affiliation(s)
- Shelby Winans
- Department of Biochemistry and Molecular Biophysics, Columbia University Medical Center, New York, NY, USA.,Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY, USA.,Howard Hughes Medical Institute, Columbia University, New York, NY, USA
| | - Hyun Jae Yu
- Basic Science Program, Leidos Biomedical Research, Frederick National Laboratory, Frederick, MD, USA
| | - Kenia de Los Santos
- Department of Biochemistry and Molecular Biophysics, Columbia University Medical Center, New York, NY, USA.,Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY, USA.,Howard Hughes Medical Institute, Columbia University, New York, NY, USA
| | - Gary Z Wang
- Department of Pathology, Columbia University Medical Center, New York, NY, USA
| | - Vineet N KewalRamani
- Basic Research Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA
| | - Stephen P Goff
- Department of Biochemistry and Molecular Biophysics, Columbia University Medical Center, New York, NY, USA. .,Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY, USA. .,Howard Hughes Medical Institute, Columbia University, New York, NY, USA.
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Böttcher R, Schmidts I, Nitschko V, Duric P, Förstemann K. RNA polymerase II is recruited to DNA double-strand breaks for dilncRNA transcription in Drosophila. RNA Biol 2021; 19:68-77. [PMID: 34965182 PMCID: PMC8786327 DOI: 10.1080/15476286.2021.2014694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
DNA double-strand breaks are among the most toxic lesions that can occur in a genome and their faithful repair is thus of great importance. Recent findings have uncovered local transcription that initiates at the break and forms a non-coding transcript, called damage-induced long non-coding RNA (dilncRNA), which helps to coordinate the DNA transactions necessary for repair. We provide nascent RNA sequencing-based evidence that RNA polymerase II transcribes the dilncRNA in Drosophila and that this is more efficient for DNA breaks in an intron-containing gene, consistent with the higher damage-induced siRNA levels downstream of an intron. The spliceosome thus stimulates recruitment of RNA polymerase II to the break, rather than merely promoting the annealing of sense and antisense RNA to form the siRNA precursor. In contrast, RNA polymerase III nascent RNA libraries did not contain reads corresponding to the cleaved loci and selective inhibition of RNA polymerase III did not reduce the yield of damage-induced siRNAs. Finally, the damage-induced siRNA density was unchanged downstream of a T8 sequence, which terminates RNA polymerase III transcription. We thus found no evidence for a participation of RNA polymerase III in dilncRNA transcription in cultured Drosophila cells.
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Affiliation(s)
- Romy Böttcher
- Department. Of Biochemistry and Gene Center, Ludwig-Maximilians-Universität München, München, Germany
| | - Ines Schmidts
- Department. Of Biochemistry and Gene Center, Ludwig-Maximilians-Universität München, München, Germany
| | - Volker Nitschko
- Department. Of Biochemistry and Gene Center, Ludwig-Maximilians-Universität München, München, Germany
| | - Petar Duric
- Department. Of Biochemistry and Gene Center, Ludwig-Maximilians-Universität München, München, Germany
| | - Klaus Förstemann
- Department. Of Biochemistry and Gene Center, Ludwig-Maximilians-Universität München, München, Germany
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12
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Abascal-Palacios G, Jochem L, Pla-Prats C, Beuron F, Vannini A. Structural basis of Ty3 retrotransposon integration at RNA Polymerase III-transcribed genes. Nat Commun 2021; 12:6992. [PMID: 34848735 PMCID: PMC8632968 DOI: 10.1038/s41467-021-27338-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 11/15/2021] [Indexed: 12/29/2022] Open
Abstract
Retrotransposons are endogenous elements that have the ability to mobilise their DNA between different locations in the host genome. The Ty3 retrotransposon integrates with an exquisite specificity in a narrow window upstream of RNA Polymerase (Pol) III-transcribed genes, representing a paradigm for harmless targeted integration. Here we present the cryo-EM reconstruction at 4.0 Å of an active Ty3 strand transfer complex bound to TFIIIB transcription factor and a tRNA gene. The structure unravels the molecular mechanisms underlying Ty3 targeting specificity at Pol III-transcribed genes and sheds light into the architecture of retrotransposon machinery during integration. Ty3 intasome contacts a region of TBP, a subunit of TFIIIB, which is blocked by NC2 transcription regulator in RNA Pol II-transcribed genes. A newly-identified chromodomain on Ty3 integrase interacts with TFIIIB and the tRNA gene, defining with extreme precision the integration site position.
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Affiliation(s)
| | - Laura Jochem
- Division of Structural Biology, The Institute of Cancer Research, London, SW7 3RP, UK
| | - Carlos Pla-Prats
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Fabienne Beuron
- Division of Structural Biology, The Institute of Cancer Research, London, SW7 3RP, UK
| | - Alessandro Vannini
- Division of Structural Biology, The Institute of Cancer Research, London, SW7 3RP, UK.
- Human Technopole, 20157, Milan, Italy.
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13
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Bonnet A, Chaput C, Palmic N, Palancade B, Lesage P. A nuclear pore sub-complex restricts the propagation of Ty retrotransposons by limiting their transcription. PLoS Genet 2021; 17:e1009889. [PMID: 34723966 PMCID: PMC8585004 DOI: 10.1371/journal.pgen.1009889] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 11/11/2021] [Accepted: 10/18/2021] [Indexed: 11/19/2022] Open
Abstract
Beyond their canonical function in nucleocytoplasmic exchanges, nuclear pore complexes (NPCs) regulate the expression of protein-coding genes. Here, we have implemented transcriptomic and molecular methods to specifically address the impact of the NPC on retroelements, which are present in multiple copies in genomes. We report a novel function for the Nup84 complex, a core NPC building block, in specifically restricting the transcription of LTR-retrotransposons in yeast. Nup84 complex-dependent repression impacts both Copia and Gypsy Ty LTR-retrotransposons, all over the S. cerevisiae genome. Mechanistically, the Nup84 complex restricts the transcription of Ty1, the most active yeast retrotransposon, through the tethering of the SUMO-deconjugating enzyme Ulp1 to NPCs. Strikingly, the modest accumulation of Ty1 RNAs caused by Nup84 complex loss-of-function is sufficient to trigger an important increase of Ty1 cDNA levels, resulting in massive Ty1 retrotransposition. Altogether, our study expands our understanding of the complex interactions between retrotransposons and the NPC, and highlights the importance for the cells to keep retrotransposons under tight transcriptional control.
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Affiliation(s)
- Amandine Bonnet
- Université de Paris, Institut de Recherche Saint-Louis, INSERM U944, CNRS UMR 7212, Paris, France
- Université de Paris, CNRS, Institut Jacques Monod, Paris, France
| | - Carole Chaput
- Université de Paris, Institut de Recherche Saint-Louis, INSERM U944, CNRS UMR 7212, Paris, France
| | - Noé Palmic
- Université de Paris, Institut de Recherche Saint-Louis, INSERM U944, CNRS UMR 7212, Paris, France
| | - Benoit Palancade
- Université de Paris, CNRS, Institut Jacques Monod, Paris, France
| | - Pascale Lesage
- Université de Paris, Institut de Recherche Saint-Louis, INSERM U944, CNRS UMR 7212, Paris, France
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14
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Nguyen PQ, Conesa C, Rabut E, Bragagnolo G, Gouzerh C, Fernández-Tornero C, Lesage P, Reguera J, Acker J. Ty1 integrase is composed of an active N-terminal domain and a large disordered C-terminal module dispensable for its activity in vitro. J Biol Chem 2021; 297:101093. [PMID: 34416236 PMCID: PMC8487063 DOI: 10.1016/j.jbc.2021.101093] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 08/05/2021] [Accepted: 08/16/2021] [Indexed: 11/16/2022] Open
Abstract
Long-terminal repeat (LTR) retrotransposons are genetic elements that, like retroviruses, replicate by reverse transcription of an RNA intermediate into a complementary DNA (cDNA) that is next integrated into the host genome by their own integrase. The Ty1 LTR retrotransposon has proven to be a reliable working model to investigate retroelement integration site preference. However, the low yield of recombinant Ty1 integrase production reported so far has been a major obstacle for structural studies. Here we analyze the biophysical and biochemical properties of a stable and functional recombinant Ty1 integrase highly expressed in E.coli. The recombinant protein is monomeric and has an elongated shape harboring the three-domain structure common to all retroviral integrases at the N-terminal half, an extra folded region, and a large intrinsically disordered region at the C-terminal half. Recombinant Ty1 integrase efficiently catalyzes concerted integration in vitro, and the N-terminal domain displays similar activity. These studies that will facilitate structural analyses may allow elucidating the molecular mechanisms governing Ty1 specific integration into safe places in the genome.
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Affiliation(s)
| | - Christine Conesa
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Elise Rabut
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
| | | | - Célia Gouzerh
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France
| | | | - Pascale Lesage
- INSERM U944, CNRS UMR 7212, Genomes and Cell Biology of Disease Unit, Institut de Recherche Saint-Louis, Université de Paris, Hôpital Saint-Louis, Paris, France
| | - Juan Reguera
- Aix-Marseille Université, CNRS, AFMB UMR 7257, Marseille, France; INSERM, AFMB UMR7257, Marseille, France.
| | - Joël Acker
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France.
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15
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Andrzejewska A, Zawadzka M, Gumna J, Garfinkel DJ, Pachulska-Wieczorek K. In vivo structure of the Ty1 retrotransposon RNA genome. Nucleic Acids Res 2021; 49:2878-2893. [PMID: 33621339 PMCID: PMC7969010 DOI: 10.1093/nar/gkab090] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/28/2021] [Accepted: 02/02/2021] [Indexed: 12/25/2022] Open
Abstract
Long terminal repeat (LTR)-retrotransposons constitute a significant part of eukaryotic genomes and influence their function and evolution. Like other RNA viruses, LTR-retrotransposons efficiently utilize their RNA genome to interact with host cell machinery during replication. Here, we provide the first genome-wide RNA secondary structure model for a LTR-retrotransposon in living cells. Using SHAPE probing, we explore the secondary structure of the yeast Ty1 retrotransposon RNA genome in its native in vivo state and under defined in vitro conditions. Comparative analyses reveal the strong impact of the cellular environment on folding of Ty1 RNA. In vivo, Ty1 genome RNA is significantly less structured and more dynamic but retains specific well-structured regions harboring functional cis-acting sequences. Ribosomes participate in the unfolding and remodeling of Ty1 RNA, and inhibition of translation initiation stabilizes Ty1 RNA structure. Together, our findings support the dual role of Ty1 genomic RNA as a template for protein synthesis and reverse transcription. This study also contributes to understanding how a complex multifunctional RNA genome folds in vivo, and strengthens the need for studying RNA structure in its natural cellular context.
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Affiliation(s)
- Angelika Andrzejewska
- Department of Structure and Function of Retrotransposons, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Małgorzata Zawadzka
- Department of Structure and Function of Retrotransposons, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Julita Gumna
- Department of Structure and Function of Retrotransposons, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - David J Garfinkel
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Katarzyna Pachulska-Wieczorek
- Department of Structure and Function of Retrotransposons, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
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16
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Bonnet A, Lesage P. Light and shadow on the mechanisms of integration site selection in yeast Ty retrotransposon families. Curr Genet 2021; 67:347-357. [PMID: 33590295 DOI: 10.1007/s00294-021-01154-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/04/2021] [Accepted: 01/07/2021] [Indexed: 12/21/2022]
Abstract
Transposable elements are ubiquitous in genomes. Their successful expansion depends in part on their sites of integration in their host genome. In Saccharomyces cerevisiae, evolution has selected various strategies to target the five Ty LTR-retrotransposon families into gene-poor regions in a genome, where coding sequences occupy 70% of the DNA. The integration of Ty1/Ty2/Ty4 and Ty3 occurs upstream and at the transcription start site of the genes transcribed by RNA polymerase III, respectively. Ty5 has completely different integration site preferences, targeting heterochromatin regions. Here, we review the history that led to the identification of the cellular tethering factors that play a major role in anchoring Ty retrotransposons to their preferred sites. We also question the involvement of additional factors in the fine-tuning of the integration site selection, with several studies converging towards an importance of the structure and organization of the chromatin.
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Affiliation(s)
- Amandine Bonnet
- INSERM U944, CNRS UMR 7212, Genomes and Cell Biology of Disease Unit, Institut de Recherche Saint-Louis, Université de Paris, Hôpital Saint-Louis, Paris, France
| | - Pascale Lesage
- INSERM U944, CNRS UMR 7212, Genomes and Cell Biology of Disease Unit, Institut de Recherche Saint-Louis, Université de Paris, Hôpital Saint-Louis, Paris, France.
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17
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Asif‐Laidin A, Conesa C, Bonnet A, Grison C, Adhya I, Menouni R, Fayol H, Palmic N, Acker J, Lesage P. A small targeting domain in Ty1 integrase is sufficient to direct retrotransposon integration upstream of tRNA genes. EMBO J 2020; 39:e104337. [PMID: 32677087 PMCID: PMC7459421 DOI: 10.15252/embj.2019104337] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 06/09/2020] [Accepted: 06/18/2020] [Indexed: 12/25/2022] Open
Abstract
Integration of transposable elements into the genome is mutagenic. Mechanisms targeting integrations into relatively safe locations, hence minimizing deleterious consequences for cell fitness, have emerged during evolution. In budding yeast, integration of the Ty1 LTR retrotransposon upstream of RNA polymerase III (Pol III)-transcribed genes requires interaction between Ty1 integrase (IN1) and AC40, a subunit common to Pol I and Pol III. Here, we identify the Ty1 targeting domain of IN1 that ensures (i) IN1 binding to Pol I and Pol III through AC40, (ii) IN1 genome-wide recruitment to Pol I- and Pol III-transcribed genes, and (iii) Ty1 integration only at Pol III-transcribed genes, while IN1 recruitment by AC40 is insufficient to target Ty1 integration into Pol I-transcribed genes. Swapping the targeting domains between Ty5 and Ty1 integrases causes Ty5 integration at Pol III-transcribed genes, indicating that the targeting domain of IN1 alone confers Ty1 integration site specificity.
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Affiliation(s)
- Amna Asif‐Laidin
- INSERM U944, CNRS UMR 7212Genomes& Cell Biology of Disease UnitInstitut de Recherche Saint‐LouisHôpital Saint‐LouisUniversité de ParisParisFrance
| | - Christine Conesa
- CEACNRSInstitute for Integrative Biology of the Cell (I2BC)Université Paris‐SaclayGif‐sur‐YvetteFrance
| | - Amandine Bonnet
- INSERM U944, CNRS UMR 7212Genomes& Cell Biology of Disease UnitInstitut de Recherche Saint‐LouisHôpital Saint‐LouisUniversité de ParisParisFrance
| | - Camille Grison
- INSERM U944, CNRS UMR 7212Genomes& Cell Biology of Disease UnitInstitut de Recherche Saint‐LouisHôpital Saint‐LouisUniversité de ParisParisFrance
| | - Indranil Adhya
- CEACNRSInstitute for Integrative Biology of the Cell (I2BC)Université Paris‐SaclayGif‐sur‐YvetteFrance
| | - Rachid Menouni
- INSERM U944, CNRS UMR 7212Genomes& Cell Biology of Disease UnitInstitut de Recherche Saint‐LouisHôpital Saint‐LouisUniversité de ParisParisFrance
| | - Hélène Fayol
- INSERM U944, CNRS UMR 7212Genomes& Cell Biology of Disease UnitInstitut de Recherche Saint‐LouisHôpital Saint‐LouisUniversité de ParisParisFrance
| | - Noé Palmic
- INSERM U944, CNRS UMR 7212Genomes& Cell Biology of Disease UnitInstitut de Recherche Saint‐LouisHôpital Saint‐LouisUniversité de ParisParisFrance
| | - Joël Acker
- CEACNRSInstitute for Integrative Biology of the Cell (I2BC)Université Paris‐SaclayGif‐sur‐YvetteFrance
| | - Pascale Lesage
- INSERM U944, CNRS UMR 7212Genomes& Cell Biology of Disease UnitInstitut de Recherche Saint‐LouisHôpital Saint‐LouisUniversité de ParisParisFrance
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