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Salinero AC, Emerson S, Cormier TC, Yin J, Morse RH, Curcio MJ. Reliance of Host-Encoded Regulators of Retromobility on Ty1 Promoter Activity or Architecture. Front Mol Biosci 2022; 9:896215. [PMID: 35847981 PMCID: PMC9283973 DOI: 10.3389/fmolb.2022.896215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 06/10/2022] [Indexed: 11/13/2022] Open
Abstract
The Ty1 retrotransposon family is maintained in a functional but dormant state by its host, Saccharomyces cerevisiae. Several hundred RHF and RTT genes encoding co-factors and restrictors of Ty1 retromobility, respectively, have been identified. Well-characterized examples include MED3 and MED15, encoding subunits of the Mediator transcriptional co-activator complex; control of retromobility by Med3 and Med15 requires the Ty1 promoter in the U3 region of the long terminal repeat. To characterize the U3-dependence of other Ty1 regulators, we screened a library of 188 known rhf and rtt mutants for altered retromobility of Ty1his3AI expressed from the strong, TATA-less TEF1 promoter or the weak, TATA-containing U3 promoter. Two classes of genes, each including both RHFs and RTTs, were identified. The first class comprising 82 genes that regulated Ty1his3AI retromobility independently of U3 is enriched for RHF genes that restrict the G1 phase of the cell cycle and those involved in transcriptional elongation and mRNA catabolism. The second class of 51 genes regulated retromobility of Ty1his3AI driven only from the U3 promoter. Nineteen U3-dependent regulators (U3DRs) also controlled retromobility of Ty1his3AI driven by the weak, TATA-less PSP2 promoter, suggesting reliance on the low activity of U3. Thirty-one U3DRs failed to modulate PPSP2-Ty1his3AI retromobility, suggesting dependence on the architecture of U3. To further investigate the U3-dependency of Ty1 regulators, we developed a novel fluorescence-based assay to monitor expression of p22-Gag, a restriction factor expressed from the internal Ty1i promoter. Many U3DRs had minimal effects on levels of Ty1 RNA, Ty1i RNA or p22-Gag. These findings uncover a role for the Ty1 promoter in integrating signals from diverse host factors to modulate Ty1 RNA biogenesis or fate.
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Affiliation(s)
- Alicia C. Salinero
- Laboratory of Molecular Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, United States
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY, United States
| | - Simey Emerson
- Laboratory of Molecular Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, United States
| | - Tayla C. Cormier
- Laboratory of Molecular Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, United States
| | - John Yin
- Laboratory of Molecular Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, United States
| | - Randall H. Morse
- Laboratory of Molecular Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, United States
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY, United States
| | - M. Joan Curcio
- Laboratory of Molecular Genetics, Wadsworth Center, New York State Department of Health, Albany, NY, United States
- Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY, United States
- *Correspondence: M. Joan Curcio,
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2
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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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3
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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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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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5
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Maxwell PH. Diverse transposable element landscapes in pathogenic and nonpathogenic yeast models: the value of a comparative perspective. Mob DNA 2020; 11:16. [PMID: 32336995 PMCID: PMC7175516 DOI: 10.1186/s13100-020-00215-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 04/16/2020] [Indexed: 12/14/2022] Open
Abstract
Genomics and other large-scale analyses have drawn increasing attention to the potential impacts of transposable elements (TEs) on their host genomes. However, it remains challenging to transition from identifying potential roles to clearly demonstrating the level of impact TEs have on genome evolution and possible functions that they contribute to their host organisms. I summarize TE content and distribution in four well-characterized yeast model systems in this review: the pathogens Candida albicans and Cryptococcus neoformans, and the nonpathogenic species Saccharomyces cerevisiae and Schizosaccharomyces pombe. I compare and contrast their TE landscapes to their lifecycles, genomic features, as well as the presence and nature of RNA interference pathways in each species to highlight the valuable diversity represented by these models for functional studies of TEs. I then review the regulation and impacts of the Ty1 and Ty3 retrotransposons from Saccharomyces cerevisiae and Tf1 and Tf2 retrotransposons from Schizosaccharomyces pombe to emphasize parallels and distinctions between these well-studied elements. I propose that further characterization of TEs in the pathogenic yeasts would enable this set of four yeast species to become an excellent set of models for comparative functional studies to address outstanding questions about TE-host relationships.
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6
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Kuhn TM, Pascual-Garcia P, Gozalo A, Little SC, Capelson M. Chromatin targeting of nuclear pore proteins induces chromatin decondensation. J Cell Biol 2019; 218:2945-2961. [PMID: 31366666 PMCID: PMC6719443 DOI: 10.1083/jcb.201807139] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 04/05/2019] [Accepted: 07/08/2019] [Indexed: 12/03/2022] Open
Abstract
Nuclear pore complexes have emerged in recent years as chromatin-binding nuclear scaffolds, able to influence target gene expression. However, how nucleoporins (Nups) exert this control remains poorly understood. Here we show that ectopically tethering Drosophila Nups, especially Sec13, to chromatin is sufficient to induce chromatin decondensation. This decondensation is mediated through chromatin-remodeling complex PBAP, as PBAP is both robustly recruited by Sec13 and required for Sec13-induced decondensation. This phenomenon is not correlated with localization of the target locus to the nuclear periphery, but is correlated with robust recruitment of Nup Elys. Furthermore, we identified a biochemical interaction between endogenous Sec13 and Elys with PBAP, and a role for endogenous Elys in global as well as gene-specific chromatin decompaction. Together, these findings reveal a functional role and mechanism for specific nuclear pore components in promoting an open chromatin state.
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Affiliation(s)
- Terra M Kuhn
- Department of Cell and Developmental Biology, Penn Institute of Epigenetics, University of Pennsylvania, Philadelphia, PA
| | - Pau Pascual-Garcia
- Department of Cell and Developmental Biology, Penn Institute of Epigenetics, University of Pennsylvania, Philadelphia, PA
| | - Alejandro Gozalo
- Department of Cell and Developmental Biology, Penn Institute of Epigenetics, University of Pennsylvania, Philadelphia, PA
| | - Shawn C Little
- Department of Cell and Developmental Biology, Penn Institute of Epigenetics, University of Pennsylvania, Philadelphia, PA
| | - Maya Capelson
- Department of Cell and Developmental Biology, Penn Institute of Epigenetics, University of Pennsylvania, Philadelphia, PA
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Patterson K, Shavarebi F, Magnan C, Chang I, Qi X, Baldi P, Bilanchone V, Sandmeyer SB. Local features determine Ty3 targeting frequency at RNA polymerase III transcription start sites. Genome Res 2019; 29:1298-1309. [PMID: 31249062 PMCID: PMC6673722 DOI: 10.1101/gr.240861.118] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 06/12/2019] [Indexed: 12/27/2022]
Abstract
Retroelement integration into host genomes affects chromosome structure and function. A goal of a considerable number of investigations is to elucidate features influencing insertion site selection. The Saccharomyces cerevisiae Ty3 retrotransposon inserts proximal to the transcription start sites (TSS) of genes transcribed by RNA polymerase III (RNAP3). In this study, differential patterns of insertion were profiled genome-wide using a random barcode-tagged Ty3. Saturation transposition showed that tRNA genes (tDNAs) are targeted at widely different frequencies even within isoacceptor families. Ectopic expression of Ty3 integrase (IN) showed that it localized to targets independent of other Ty3 proteins and cDNA. IN, RNAP3, and transcription factor Brf1 were enriched at tDNA targets with high frequencies of transposition. To examine potential effects of cis-acting DNA features on transposition, targeting was tested on high-copy plasmids with restricted amounts of 5′ flanking sequence plus tDNA. Relative activity of targets was reconstituted in these constructions. Weighting of genomic insertions according to frequency identified an A/T-rich sequence followed by C as the dominant site of strand transfer. This site lies immediately adjacent to the adenines previously implicated in the RNAP3 TSS motif (CAA). In silico DNA structural analysis upstream of this motif showed that targets with elevated DNA curvature coincide with reduced integration. We propose that integration mediated by the Ty3 intasome complex (IN and cDNA) is subject to inputs from a combination of host factor occupancy and insertion site architecture, and that this results in the wide range of Ty3 targeting frequencies.
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Affiliation(s)
- Kurt Patterson
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, Irvine, California 92697, USA
| | - Farbod Shavarebi
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, Irvine, California 92697, USA
| | - Christophe Magnan
- School of Information and Computer Sciences, University of California, Irvine, Irvine, California 92697, USA
| | - Ivan Chang
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, Irvine, California 92697, USA
| | - Xiaojie Qi
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, Irvine, California 92697, USA
| | - Pierre Baldi
- School of Information and Computer Sciences, University of California, Irvine, Irvine, California 92697, USA
| | - Virginia Bilanchone
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, Irvine, California 92697, USA
| | - Suzanne B Sandmeyer
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, Irvine, California 92697, USA
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8
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Cheung S, Manhas S, Measday V. Retrotransposon targeting to RNA polymerase III-transcribed genes. Mob DNA 2018; 9:14. [PMID: 29713390 PMCID: PMC5911963 DOI: 10.1186/s13100-018-0119-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 04/16/2018] [Indexed: 12/20/2022] Open
Abstract
Retrotransposons are genetic elements that are similar in structure and life cycle to retroviruses by replicating via an RNA intermediate and inserting into a host genome. The Saccharomyces cerevisiae (S. cerevisiae) Ty1-5 elements are long terminal repeat (LTR) retrotransposons that are members of the Ty1-copia (Pseudoviridae) or Ty3-gypsy (Metaviridae) families. Four of the five S. cerevisiae Ty elements are inserted into the genome upstream of RNA Polymerase (Pol) III-transcribed genes such as transfer RNA (tRNA) genes. This particular genomic locus provides a safe environment for Ty element insertion without disruption of the host genome and is a targeting strategy used by retrotransposons that insert into compact genomes of hosts such as S. cerevisiae and the social amoeba Dictyostelium. The mechanism by which Ty1 targeting is achieved has been recently solved due to the discovery of an interaction between Ty1 Integrase (IN) and RNA Pol III subunits. We describe the methods used to identify the Ty1-IN interaction with Pol III and the Ty1 targeting consequences if the interaction is perturbed. The details of Ty1 targeting are just beginning to emerge and many unexplored areas remain including consideration of the 3-dimensional shape of genome. We present a variety of other retrotransposon families that insert adjacent to Pol III-transcribed genes and the mechanism by which the host machinery has been hijacked to accomplish this targeting strategy. Finally, we discuss why retrotransposons selected Pol III-transcribed genes as a target during evolution and how retrotransposons have shaped genome architecture.
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Affiliation(s)
- Stephanie Cheung
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of British Columbia, Vancouver, BC V6T 1Z4 Canada
| | - Savrina Manhas
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of British Columbia, Vancouver, BC V6T 1Z4 Canada
| | - Vivien Measday
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of British Columbia, Vancouver, BC V6T 1Z4 Canada
- Department of Food Science, Wine Research Centre, Faculty of Land and Food Systems, University of British Columbia, Room 325-2205 East Mall, Vancouver, British Columbia V6T 1Z4 Canada
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