1
|
Ros-Pardo D, Gómez-Puertas P, Marcos-Alcalde Í. STAG2-RAD21 complex: A unidirectional DNA ratchet mechanism in loop extrusion. Int J Biol Macromol 2024; 276:133822. [PMID: 39002918 DOI: 10.1016/j.ijbiomac.2024.133822] [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: 02/05/2024] [Revised: 07/08/2024] [Accepted: 07/09/2024] [Indexed: 07/15/2024]
Abstract
DNA loop extrusion plays a key role in the regulation of gene expression and the structural arrangement of chromatin. Most existing mechanistic models of loop extrusion depend on some type of ratchet mechanism, which should permit the elongation of loops while preventing their collapse, by enabling DNA to move in only one direction. STAG2 is already known to exert a role as DNA anchor, but the available structural data suggest a possible role in unidirectional DNA motion. In this work, a computational simulation framework was constructed to evaluate whether STAG2 could enforce such unidirectional displacement of a DNA double helix. The results reveal that STAG2 V-shape allows DNA sliding in one direction, but blocks opposite DNA movement via a linear ratchet mechanism. Furthermore, these results suggest that RAD21 binding to STAG2 controls its flexibility by narrowing the opening of its V-shape, which otherwise remains widely open in absence of RAD21. Therefore, in the proposed model, in addition to its already described role as a DNA anchor, the STAG2-RAD21 complex would be part of a ratchet mechanism capable of exerting directional selectivity on DNA sliding during loop extrusion. The identification of the molecular basis of the ratchet mechanism of loop extrusion is a critical step in unraveling new insights into a broad spectrum of chromatin activities and their implications for the mechanisms of chromatin-related diseases.
Collapse
Affiliation(s)
- David Ros-Pardo
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, CL Nicolás Cabrera, 1, 28049 Madrid, Spain
| | - Paulino Gómez-Puertas
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, CL Nicolás Cabrera, 1, 28049 Madrid, Spain.
| | - Íñigo Marcos-Alcalde
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, CL Nicolás Cabrera, 1, 28049 Madrid, Spain
| |
Collapse
|
2
|
Labudina AA, Meier M, Gimenez G, Tatarakis D, Ketharnathan S, Mackie B, Schilling TF, Antony J, Horsfield JA. Cohesin composition and dosage independently affect early development in zebrafish. Development 2024; 151:dev202593. [PMID: 38975838 DOI: 10.1242/dev.202593] [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: 12/07/2023] [Accepted: 06/27/2024] [Indexed: 07/09/2024]
Abstract
Cohesin, a chromatin-associated protein complex with four core subunits (Smc1a, Smc3, Rad21 and either Stag1 or 2), has a central role in cell proliferation and gene expression in metazoans. Human developmental disorders termed 'cohesinopathies' are characterized by germline variants of cohesin or its regulators that do not entirely eliminate cohesin function. However, it is not clear whether mutations in individual cohesin subunits have independent developmental consequences. Here, we show that zebrafish rad21 or stag2b mutants independently influence embryonic tailbud development. Both mutants have altered mesoderm induction, but only homozygous or heterozygous rad21 mutation affects cell cycle gene expression. stag2b mutants have narrower notochords and reduced Wnt signaling in neuromesodermal progenitors as revealed by single-cell RNA sequencing. Stimulation of Wnt signaling rescues transcription and morphology in stag2b, but not rad21, mutants. Our results suggest that mutations altering the quantity versus composition of cohesin have independent developmental consequences, with implications for the understanding and management of cohesinopathies.
Collapse
Affiliation(s)
- Anastasia A Labudina
- Department of Pathology, Dunedin School of Medicine, University of Otago, P.O. Box 913, Dunedin 9016, New Zealand
| | - Michael Meier
- Department of Pathology, Dunedin School of Medicine, University of Otago, P.O. Box 913, Dunedin 9016, New Zealand
| | - Gregory Gimenez
- Department of Pathology, Dunedin School of Medicine, University of Otago, P.O. Box 913, Dunedin 9016, New Zealand
| | - David Tatarakis
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA 92697-2300, USA
| | - Sarada Ketharnathan
- Department of Pathology, Dunedin School of Medicine, University of Otago, P.O. Box 913, Dunedin 9016, New Zealand
| | - Bridget Mackie
- Department of Pathology, Dunedin School of Medicine, University of Otago, P.O. Box 913, Dunedin 9016, New Zealand
| | - Thomas F Schilling
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA 92697-2300, USA
| | - Jisha Antony
- Department of Pathology, Dunedin School of Medicine, University of Otago, P.O. Box 913, Dunedin 9016, New Zealand
| | - Julia A Horsfield
- Department of Pathology, Dunedin School of Medicine, University of Otago, P.O. Box 913, Dunedin 9016, New Zealand
| |
Collapse
|
3
|
Xu W, Kim JS, Yang T, Ya A, Sadzewicz L, Tallon L, Harris BT, Sarkaria J, Jin F, Waldman T. STAG2 mutations regulate 3D genome organization, chromatin loops, and Polycomb signaling in glioblastoma multiforme. J Biol Chem 2024; 300:107341. [PMID: 38705393 PMCID: PMC11157269 DOI: 10.1016/j.jbc.2024.107341] [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: 02/14/2024] [Revised: 04/18/2024] [Accepted: 04/25/2024] [Indexed: 05/07/2024] Open
Abstract
Inactivating mutations of genes encoding the cohesin complex are common in a wide range of human cancers. STAG2 is the most commonly mutated subunit. Here we report the impact of stable correction of endogenous, naturally occurring STAG2 mutations on gene expression, 3D genome organization, chromatin loops, and Polycomb signaling in glioblastoma multiforme (GBM). In two GBM cell lines, correction of their STAG2 mutations significantly altered the expression of ∼10% of all expressed genes. Virtually all the most highly regulated genes were negatively regulated by STAG2 (i.e., expressed higher in STAG2-mutant cells), and one of them-HEPH-was regulated by STAG2 in uncultured GBM tumors as well. While STAG2 correction had little effect on large-scale features of 3D genome organization (A/B compartments, TADs), STAG2 correction did alter thousands of individual chromatin loops, some of which controlled the expression of adjacent genes. Loops specific to STAG2-mutant cells, which were regulated by STAG1-containing cohesin complexes, were very large, supporting prior findings that STAG1-containing cohesin complexes have greater loop extrusion processivity than STAG2-containing cohesin complexes and suggesting that long loops may be a general feature of STAG2-mutant cancers. Finally, STAG2 mutation activated Polycomb activity leading to increased H3K27me3 marks, identifying Polycomb signaling as a potential target for therapeutic intervention in STAG2-mutant GBM tumors. Together, these findings illuminate the landscape of STAG2-regulated genes, A/B compartments, chromatin loops, and pathways in GBM, providing important clues into the largely still unknown mechanism of STAG2 tumor suppression.
Collapse
Affiliation(s)
- Wanying Xu
- Department of Genetics and Genome Sciences, Case Comprehensive Cancer Center, Case Western Reserve School of Medicine, Cleveland, Ohio, USA; The Biomedical Sciences Training Program, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Jung-Sik Kim
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University School of Medicine, Washington, District of Columbia, USA
| | - Tianyi Yang
- Department of Genetics and Genome Sciences, Case Comprehensive Cancer Center, Case Western Reserve School of Medicine, Cleveland, Ohio, USA; The Biomedical Sciences Training Program, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Alvin Ya
- MD/PhD Program, Georgetown University School of Medicine, Washington, District of Columbia, USA; Tumor Biology Training Program, Georgetown University School of Medicine, Washington, District of Columbia, USA
| | - Lisa Sadzewicz
- Institute for Genome Sciences, University of Maryland, Baltimore, Maryland, USA
| | - Luke Tallon
- Institute for Genome Sciences, University of Maryland, Baltimore, Maryland, USA
| | - Brent T Harris
- Departments of Neurology and Pathology, Georgetown University School of Medicine, Washington, District of Columbia, USA
| | - Jann Sarkaria
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota, USA
| | - Fulai Jin
- Department of Genetics and Genome Sciences, Case Comprehensive Cancer Center, Case Western Reserve School of Medicine, Cleveland, Ohio, USA; Department of Computer and Data Sciences, Department of Population and Quantitative Health Sciences, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio, USA.
| | - Todd Waldman
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University School of Medicine, Washington, District of Columbia, USA.
| |
Collapse
|
4
|
Theofilatos D, Ho T, Waitt G, Äijö T, Schiapparelli LM, Soderblom EJ, Tsagaratou A. Deciphering the TET3 interactome in primary thymic developing T cells. iScience 2024; 27:109782. [PMID: 38711449 PMCID: PMC11070343 DOI: 10.1016/j.isci.2024.109782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 03/04/2024] [Accepted: 04/15/2024] [Indexed: 05/08/2024] Open
Abstract
Ten-eleven translocation (TET) proteins are DNA dioxygenases that mediate active DNA demethylation. TET3 is the most highly expressed TET protein in thymic developing T cells. TET3, either independently or in cooperation with TET1 or TET2, has been implicated in T cell lineage specification by regulating DNA demethylation. However, TET-deficient mice exhibit complex phenotypes, suggesting that TET3 exerts multifaceted roles, potentially by interacting with other proteins. We performed liquid chromatography with tandem mass spectrometry in primary developing T cells to identify TET3 interacting partners in endogenous, in vivo conditions. We discover TET3 interacting partners. Our data establish that TET3 participates in a plethora of fundamental biological processes, such as transcriptional regulation, RNA polymerase elongation, splicing, DNA repair, and DNA replication. This resource brings in the spotlight emerging functions of TET3 and sets the stage for systematic studies to dissect the precise mechanistic contributions of TET3 in shaping T cell biology.
Collapse
Affiliation(s)
- Dimitris Theofilatos
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Tricia Ho
- Duke Proteomics and Metabolomics Core Facility, Duke Center for Genomic and Computational Biology, Duke University, Durham, NC, USA
| | - Greg Waitt
- Duke Proteomics and Metabolomics Core Facility, Duke Center for Genomic and Computational Biology, Duke University, Durham, NC, USA
| | - Tarmo Äijö
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | | - Erik J. Soderblom
- Duke Proteomics and Metabolomics Core Facility, Duke Center for Genomic and Computational Biology, Duke University, Durham, NC, USA
- Department of Cell Biology, Duke University, Durham, NC, USA
| | - Ageliki Tsagaratou
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| |
Collapse
|
5
|
Gouveia Roque C, Phatnani H, Hengst U. The broken Alzheimer's disease genome. CELL GENOMICS 2024; 4:100555. [PMID: 38697121 PMCID: PMC11099344 DOI: 10.1016/j.xgen.2024.100555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 02/25/2024] [Accepted: 04/07/2024] [Indexed: 05/04/2024]
Abstract
The complex pathobiology of late-onset Alzheimer's disease (AD) poses significant challenges to therapeutic and preventative interventions. Despite these difficulties, genomics and related disciplines are allowing fundamental mechanistic insights to emerge with clarity, particularly with the introduction of high-resolution sequencing technologies. After all, the disrupted processes at the interface between DNA and gene expression, which we call the broken AD genome, offer detailed quantitative evidence unrestrained by preconceived notions about the disease. In addition to highlighting biological pathways beyond the classical pathology hallmarks, these advances have revitalized drug discovery efforts and are driving improvements in clinical tools. We review genetic, epigenomic, and gene expression findings related to AD pathogenesis and explore how their integration enables a better understanding of the multicellular imbalances contributing to this heterogeneous condition. The frontiers opening on the back of these research milestones promise a future of AD care that is both more personalized and predictive.
Collapse
Affiliation(s)
- Cláudio Gouveia Roque
- Center for Genomics of Neurodegenerative Disease, New York Genome Center, New York, NY 10013, USA; The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
| | - Hemali Phatnani
- Center for Genomics of Neurodegenerative Disease, New York Genome Center, New York, NY 10013, USA; Department of Neurology, Center for Translational and Computational Neuroimmunology, Columbia University, New York, NY 10032, USA
| | - Ulrich Hengst
- The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA; Department of Pathology & Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
| |
Collapse
|
6
|
Munguia-Galaviz FJ, Gutierrez-Mercado YK, Miranda-Diaz AG, Portilla de Buen E, Flores-Soto ME, Echavarria R. Cardiac transcriptomic changes induced by early CKD in mice reveal novel pathways involved in the pathogenesis of Cardiorenal syndrome type 4. Heliyon 2024; 10:e27468. [PMID: 38509984 PMCID: PMC10950824 DOI: 10.1016/j.heliyon.2024.e27468] [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] [Received: 08/21/2023] [Revised: 12/26/2023] [Accepted: 02/29/2024] [Indexed: 03/22/2024] Open
Abstract
Background Cardiorenal syndrome (CRS) type 4 is prevalent among the chronic kidney disease (CKD) population, with many patients dying from cardiovascular complications. However, limited data regarding cardiac transcriptional changes induced early by CKD is available. Methods We used a murine unilateral ureteral obstruction (UUO) model to evaluate renal damage, cardiac remodeling, and transcriptional regulation at 21 days post-surgery through histological analysis, RT-qPCR, RNA-seq, and bioinformatics. Results UUO leads to significant kidney injury, low uremia, and pathological cardiac remodeling, evidenced by increased collagen deposition and smooth muscle alpha-actin 2 expression. RNA-seq analysis identified 76 differentially expressed genes (DEGs) in UUO hearts. Upregulated DEGs were significantly enriched in cell cycle and cell division pathways, immune responses, cardiac repair, inflammation, proliferation, oxidative stress, and apoptosis. Gene Set Enrichment Analysis further revealed mitochondrial oxidative bioenergetic pathways, autophagy, and peroxisomal pathways are downregulated in UUO hearts. Vimentin was also identified as an UUO-upregulated transcript. Conclusions Our results emphasize the relevance of extensive transcriptional changes, mitochondrial dysfunction, homeostasis deregulation, fatty-acid metabolism alterations, and vimentin upregulation in CRS type 4 development.
Collapse
Affiliation(s)
- Francisco Javier Munguia-Galaviz
- Departamento de Fisiologia, CUCS, Universidad de Guadalajara, Guadalajara 44340, Jalisco, Mexico
- Division de Ciencias de la Salud, CUSUR, Universidad de Guadalajara, Ciudad Guzman 49000, Jalisco, Mexico
| | | | | | - Eliseo Portilla de Buen
- Division de Investigacion Quirurgica, Centro de Investigacion Biomedica de Occidente, Instituto Mexicano del Seguro Social, Guadalajara 44340, Mexico
| | - Mario Eduardo Flores-Soto
- Division de Neurociencias, Centro de Investigacion Biomedica de Occidente, Instituto Mexicano del Seguro Social, Guadalajara 44340, Jalisco, Mexico
| | - Raquel Echavarria
- CONAHCYT-Centro de Investigacion Biomedica de Occidente, Instituto Mexicano del Seguro Social, Guadalajara 44340, Jalisco, Mexico
| |
Collapse
|
7
|
Pallotta MM, Di Nardo M, Musio A. Synthetic Lethality between Cohesin and WNT Signaling Pathways in Diverse Cancer Contexts. Cells 2024; 13:608. [PMID: 38607047 PMCID: PMC11011321 DOI: 10.3390/cells13070608] [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: 02/27/2024] [Revised: 03/25/2024] [Accepted: 03/29/2024] [Indexed: 04/13/2024] Open
Abstract
Cohesin is a highly conserved ring-shaped complex involved in topologically embracing chromatids, gene expression regulation, genome compartmentalization, and genome stability maintenance. Genomic analyses have detected mutations in the cohesin complex in a wide array of human tumors. These findings have led to increased interest in cohesin as a potential target in cancer therapy. Synthetic lethality has been suggested as an approach to exploit genetic differences in cancer cells to influence their selective killing. In this study, we show that mutations in ESCO1, NIPBL, PDS5B, RAD21, SMC1A, SMC3, STAG2, and WAPL genes are synthetically lethal with stimulation of WNT signaling obtained following LY2090314 treatment, a GSK3 inhibitor, in several cancer cell lines. Moreover, treatment led to the stabilization of β-catenin and affected the expression of c-MYC, probably due to the occupancy decrease in cohesin at the c-MYC promoter. Finally, LY2090314 caused gene expression dysregulation mainly involving pathways related to transcription regulation, cell proliferation, and chromatin remodeling. For the first time, our work provides the underlying molecular basis for synthetic lethality due to cohesin mutations and suggests that targeting the WNT may be a promising therapeutic approach for tumors carrying mutated cohesin.
Collapse
Affiliation(s)
| | | | - Antonio Musio
- Institute for Biomedical Technologies (ITB), National Research Council (CNR), 56124 Pisa, Italy; (M.M.P.); (M.D.N.)
| |
Collapse
|
8
|
Kong IY, Giulino-Roth L. Targeting latent viral infection in EBV-associated lymphomas. Front Immunol 2024; 15:1342455. [PMID: 38464537 PMCID: PMC10920267 DOI: 10.3389/fimmu.2024.1342455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 02/05/2024] [Indexed: 03/12/2024] Open
Abstract
Epstein-Barr virus (EBV) contributes to the development of a significant subset of human lymphomas. As a herpes virus, EBV can transition between a lytic state which is required to establish infection and a latent state where a limited number of viral antigens are expressed which allows infected cells to escape immune surveillance. Three broad latency programs have been described which are defined by the expression of viral proteins RNA, with latency I being the most restrictive expressing only EBV nuclear antigen 1 (EBNA1) and EBV-encoded small RNAs (EBERs) and latency III expressing the full panel of latent viral genes including the latent membrane proteins 1 and 2 (LMP1/2), and EBNA 2, 3, and leader protein (LP) which induce a robust T-cell response. The therapeutic use of EBV-specific T-cells has advanced the treatment of EBV-associated lymphoma, however this approach is only effective against EBV-associated lymphomas that express the latency II or III program. Latency I tumors such as Burkitt lymphoma (BL) and a subset of diffuse large B-cell lymphomas (DLBCL) evade the host immune response to EBV and are resistant to EBV-specific T-cell therapies. Thus, strategies for inducing a switch from the latency I to the latency II or III program in EBV+ tumors are being investigated as mechanisms to sensitize tumors to T-cell mediated killing. Here, we review what is known about the establishment and regulation of latency in EBV infected B-cells, the role of EBV-specific T-cells in lymphoma, and strategies to convert latency I tumors to latency II/III.
Collapse
|
9
|
Di Nardo M, Astigiano S, Baldari S, Pallotta MM, Porta G, Pigozzi S, Antonini A, Emionite L, Frattini A, Valli R, Toietta G, Soddu S, Musio A. The synergism of SMC1A cohesin gene silencing and bevacizumab against colorectal cancer. J Exp Clin Cancer Res 2024; 43:49. [PMID: 38365745 PMCID: PMC10870497 DOI: 10.1186/s13046-024-02976-2] [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: 01/02/2024] [Accepted: 02/07/2024] [Indexed: 02/18/2024] Open
Abstract
BACKGROUND SMC1A is a subunit of the cohesin complex that participates in many DNA- and chromosome-related biological processes. Previous studies have established that SMC1A is involved in cancer development and in particular, is overexpressed in chromosomally unstable human colorectal cancer (CRC). This study aimed to investigate whether SMC1A could serve as a therapeutic target for CRC. METHODS At first, we studied the effects of either SMC1A overexpression or knockdown in vitro. Next, the outcome of SMC1A knocking down (alone or in combination with bevacizumab, a monoclonal antibody against vascular endothelial growth factor) was analyzed in vivo. RESULTS We found that SMC1A knockdown affects cell proliferation and reduces the ability to grow in anchorage-independent manner. Next, we demonstrated that the silencing of SMC1A and the combo treatment were effective in increasing overall survival in a xenograft mouse model. Functional analyses indicated that both treatments lead to atypical mitotic figures and gene expression dysregulation. Differentially expressed genes were implicated in several pathways including gene transcription regulation, cellular proliferation, and other transformation-associated processes. CONCLUSIONS These results indicate that SMC1A silencing, in combination with bevacizumab, can represent a promising therapeutic strategy for human CRC.
Collapse
Affiliation(s)
- Maddalena Di Nardo
- Istituto di Tecnologie Biomediche (ITB), Consiglio Nazionale delle Ricerche (CNR), Via Moruzzi, Pisa, 1 56124, Italy
| | | | - Silvia Baldari
- Dipartimento Ricerca e Tecnologie Avanzate, IRCCS Istituto Nazionale Tumori Regina Elena, Rome, Italy
| | - Maria Michela Pallotta
- Istituto di Tecnologie Biomediche (ITB), Consiglio Nazionale delle Ricerche (CNR), Via Moruzzi, Pisa, 1 56124, Italy
| | - Giovanni Porta
- Dipartimento di Medicina e Chirurgia, Sezione di Biologia Generale e Genetica Medica, Università degli Studi dell'Insubria, Varese, Italy
| | - Simona Pigozzi
- IRCCS Ospedale Policlinico San Martino, Genoa, Italy
- Dipartimento di Scienze Chirurgiche e Diagnostiche Integrate, Università degli Studi di Genova, Genoa, Italy
| | - Annalisa Antonini
- Dipartimento Ricerca e Tecnologie Avanzate, IRCCS Istituto Nazionale Tumori Regina Elena, Rome, Italy
| | | | - Annalisa Frattini
- Dipartimento di Medicina e Chirurgia, Sezione di Biologia Generale e Genetica Medica, Università degli Studi dell'Insubria, Varese, Italy
- Istituto di Ricerca Genetica e Biomedica (IRGB), Consiglio Nazionale delle Ricerche (CNR), Milan, Italy
| | - Roberto Valli
- Dipartimento di Medicina e Chirurgia, Sezione di Biologia Generale e Genetica Medica, Università degli Studi dell'Insubria, Varese, Italy
| | - Gabriele Toietta
- Dipartimento Ricerca e Tecnologie Avanzate, IRCCS Istituto Nazionale Tumori Regina Elena, Rome, Italy
| | - Silvia Soddu
- Dipartimento Ricerca e Tecnologie Avanzate, IRCCS Istituto Nazionale Tumori Regina Elena, Rome, Italy
| | - Antonio Musio
- Istituto di Tecnologie Biomediche (ITB), Consiglio Nazionale delle Ricerche (CNR), Via Moruzzi, Pisa, 1 56124, Italy.
| |
Collapse
|
10
|
Li X, Levine M. What are tethering elements? Curr Opin Genet Dev 2024; 84:102151. [PMID: 38237456 DOI: 10.1016/j.gde.2023.102151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 12/19/2023] [Accepted: 12/19/2023] [Indexed: 02/12/2024]
Abstract
High-resolution Micro-C maps identified a specialized class of regulatory DNAs termed 'tethering elements' (TEs) in Drosophila. These 300-500-bp elements facilitate specific long-range genomic associations or loops. The POZ-containing transcription factor GAF (GAGA-associated factor) contributes to loop formation. Tether-tether interactions accelerate Hox gene activation by distal enhancers, and coordinate transcription of duplicated genes (paralogs) through promoter-promoter associations. Some TEs engage in ultra-long-range enhancer-promoter and promoter-promoter interactions (meta-loops) in the Drosophila brain. We discuss the basis for tether-tether specificity and speculate on the occurrence of similar elements in vertebrate genomes.
Collapse
Affiliation(s)
- Xiao Li
- Lewis-Sigler Institute, Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA. https://twitter.com/@XiaoLi5525
| | - Michael Levine
- Lewis-Sigler Institute, Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA.
| |
Collapse
|
11
|
Ros-Pardo D, Gómez-Puertas P, Marcos-Alcalde Í. STAG2: Computational Analysis of Missense Variants Involved in Disease. Int J Mol Sci 2024; 25:1280. [PMID: 38279279 PMCID: PMC10816197 DOI: 10.3390/ijms25021280] [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: 12/20/2023] [Revised: 01/16/2024] [Accepted: 01/18/2024] [Indexed: 01/28/2024] Open
Abstract
The human STAG2 protein is an essential component of the cohesin complex involved in cellular processes of gene expression, DNA repair, and genomic integrity. Somatic mutations in the STAG2 sequence have been associated with various types of cancer, while congenital variants have been linked to developmental disorders such as Mullegama-Klein-Martinez syndrome, X-linked holoprosencephaly-13, and Cornelia de Lange syndrome. In the cohesin complex, the direct interaction of STAG2 with DNA and with NIPBL, RAD21, and CTCF proteins has been described. The function of STAG2 within the complex is still unknown, but it is related to its DNA binding capacity and is modulated by its binding to the other three proteins. Every missense variant described for STAG2 is located in regions involved in one of these interactions. In the present work, we model the structure of 12 missense variants described for STAG2, as well as two other variants of NIPBl and two of RAD21 located at STAG2 interaction zone, and then analyze their behavior through molecular dynamic simulations, comparing them with the same simulation of the wild-type protein. This will allow the effects of variants to be rationalized at the atomic level and provide clues as to how STAG2 functions in the cohesin complex.
Collapse
Affiliation(s)
| | - Paulino Gómez-Puertas
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid (CSIC-UAM), C/Nicolás Cabrera, 1, 28049 Madrid, Spain; (D.R.-P.); (Í.M.-A.)
| | | |
Collapse
|
12
|
Yu R, Roseman S, Siegenfeld AP, Nguyen SC, Joyce EF, Liau BB, Krantz ID, Alexander KA, Berger SL. CTCF/cohesin organize the ground state of chromatin-nuclear speckle association. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.22.550178. [PMID: 37961560 PMCID: PMC10634669 DOI: 10.1101/2023.07.22.550178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
The interchromatin space in the cell nucleus contains various membrane-less nuclear bodies. Recent findings indicate that nuclear speckles, comprising a distinct nuclear body, exhibit interactions with certain chromatin regions in a ground state. Key questions are how this ground state of chromatin-nuclear speckle association is established and what are the gene regulatory roles of this layer of nuclear organization. We report here that chromatin structural factors CTCF and cohesin are required for full ground state association between DNA and nuclear speckles. Disruption of ground state DNA-speckle contacts via either CTCF depletion or cohesin depletion had minor effects on basal level expression of speckle-associated genes, however we show strong negative effects on stimulus-dependent induction of speckle-associated genes. We identified a putative speckle targeting motif (STM) within cohesin subunit RAD21 and demonstrated that the STM is required for chromatin-nuclear speckle association. In contrast to reduction of CTCF or RAD21, depletion of the cohesin releasing factor WAPL stabilized cohesin on chromatin and DNA-speckle contacts, resulting in enhanced inducibility of speckle-associated genes. In addition, we observed disruption of chromatin-nuclear speckle association in patient derived cells with Cornelia de Lange syndrome (CdLS), a congenital neurodevelopmental diagnosis involving defective cohesin pathways, thus revealing nuclear speckles as an avenue for therapeutic inquiry. In summary, our findings reveal a mechanism to establish the ground organizational state of chromatin-speckle association, to promote gene inducibility, and with relevance to human disease.
Collapse
|
13
|
Ding X, Gong X, Fan Y, Cao J, Zhao J, Zhang Y, Wang X, Meng K. DNA double-strand break genetic variants in patients with premature ovarian insufficiency. J Ovarian Res 2023; 16:135. [PMID: 37430352 DOI: 10.1186/s13048-023-01221-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Accepted: 06/20/2023] [Indexed: 07/12/2023] Open
Abstract
Premature ovarian insufficiency (POI) is a clinically heterogeneous disease that may seriously affect the physical and mental health of women of reproductive age. POI primarily manifests as ovarian function decline and endocrine disorders in women prior to age 40 and is an established cause of female infertility. It is crucial to elucidate the causative factors of POI, not only to expand the understanding of ovarian physiology, but also to provide genetic counselling and fertility guidance to affected patients. Factors leading to POI are multifaceted with genetic factors accounting for 7% to 30%. In recent years, an increasing number of DNA damage-repair-related genes have been linked with the occurrence of POI. Among them, DNA double-strand breaks (DSBs), one of the most damaging to DNA, and its main repair methods including homologous recombination (HR) and non-homologous end joining (NHEJ) are of particular interest. Numerous genes are known to be involved in the regulation of programmed DSB formation and damage repair. The abnormal expression of several genes have been shown to trigger defects in the overall repair pathway and induce POI and other diseases. This review summarises the DSB-related genes that may contribute to the development of POI and their potential regulatory mechanisms, which will help to further establish role of DSB in the pathogenesis of POI and provide theoretical guidance for the study of the pathogenesis and clinical treatment of this disease.
Collapse
Affiliation(s)
- Xuechun Ding
- Collaborative Innovation Center for Birth Defect Research and Transformation of Shandong Province, Jining Medical University, Jining, China
- College of Second Clinical Medical, Jining Medical University, Jining, China
| | - Xiaowei Gong
- Collaborative Innovation Center for Birth Defect Research and Transformation of Shandong Province, Jining Medical University, Jining, China
- College of Second Clinical Medical, Jining Medical University, Jining, China
| | - Yingying Fan
- Affiliated Hospital of Jining Medical University, Jining, China
| | - Jinghe Cao
- Affiliated Hospital of Jining Medical University, Jining, China
| | - Jingyu Zhao
- Collaborative Innovation Center for Birth Defect Research and Transformation of Shandong Province, Jining Medical University, Jining, China
- College of Second Clinical Medical, Jining Medical University, Jining, China
| | - Yixin Zhang
- Collaborative Innovation Center for Birth Defect Research and Transformation of Shandong Province, Jining Medical University, Jining, China
- College of Second Clinical Medical, Jining Medical University, Jining, China
| | - Xiaomei Wang
- College of Basic Medicine, Jining Medical University, Jining, China.
| | - Kai Meng
- Collaborative Innovation Center for Birth Defect Research and Transformation of Shandong Province, Jining Medical University, Jining, China.
- Lin He's Academician Workstation of New Medicine and Clinical Translation, Jining Medical University, Jining, China.
| |
Collapse
|
14
|
Biswas U, Deb Mallik T, Pschirer J, Lesche M, Sameith K, Jessberger R. Cohesin SMC1β promotes closed chromatin and controls TERRA expression at spermatocyte telomeres. Life Sci Alliance 2023; 6:e202201798. [PMID: 37160312 PMCID: PMC10172765 DOI: 10.26508/lsa.202201798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 04/26/2023] [Accepted: 04/26/2023] [Indexed: 05/11/2023] Open
Abstract
Previous data showed that meiotic cohesin SMC1β protects spermatocyte telomeres from damage. The underlying reason, however, remained unknown as the expressions of telomerase and shelterin components were normal in Smc1β -/- spermatocytes. Here. we report that SMC1β restricts expression of the long noncoding RNA TERRA (telomeric repeat containing RNA) in spermatocytes. In somatic cell lines increased TERRA was reported to cause telomere damage through altering telomere chromatin structure. In Smc1β -/- spermatocytes, we observed strongly increased levels of TERRA which accumulate on damaged chromosomal ends, where enhanced R-loop formation was found. This suggested a more open chromatin configuration near telomeres in Smc1β -/- spermatocytes, which was confirmed by ATAC-seq. Telomere-distal regions were not affected by the absence of SMC1β but RNA-seq revealed increased transcriptional activity in telomere-proximal regions. Thus, SMC1β promotes closed chromatin specifically near telomeres and limits TERRA expression in spermatocytes.
Collapse
Affiliation(s)
- Uddipta Biswas
- Institute of Physiological Chemistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Tanaya Deb Mallik
- Institute of Physiological Chemistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Johannes Pschirer
- Institute of Physiological Chemistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Matthias Lesche
- Center for Molecular and Cellular Bioengineering, Genome Center Technology Platform, Dresden, Germany
| | - Katrin Sameith
- Center for Molecular and Cellular Bioengineering, Genome Center Technology Platform, Dresden, Germany
| | - Rolf Jessberger
- Institute of Physiological Chemistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| |
Collapse
|
15
|
Kabirova E, Nurislamov A, Shadskiy A, Smirnov A, Popov A, Salnikov P, Battulin N, Fishman V. Function and Evolution of the Loop Extrusion Machinery in Animals. Int J Mol Sci 2023; 24:5017. [PMID: 36902449 PMCID: PMC10003631 DOI: 10.3390/ijms24055017] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 02/25/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023] Open
Abstract
Structural maintenance of chromosomes (SMC) complexes are essential proteins found in genomes of all cellular organisms. Essential functions of these proteins, such as mitotic chromosome formation and sister chromatid cohesion, were discovered a long time ago. Recent advances in chromatin biology showed that SMC proteins are involved in many other genomic processes, acting as active motors extruding DNA, which leads to the formation of chromatin loops. Some loops formed by SMC proteins are highly cell type and developmental stage specific, such as SMC-mediated DNA loops required for VDJ recombination in B-cell progenitors, or dosage compensation in Caenorhabditis elegans and X-chromosome inactivation in mice. In this review, we focus on the extrusion-based mechanisms that are common for multiple cell types and species. We will first describe an anatomy of SMC complexes and their accessory proteins. Next, we provide biochemical details of the extrusion process. We follow this by the sections describing the role of SMC complexes in gene regulation, DNA repair, and chromatin topology.
Collapse
Affiliation(s)
- Evelyn Kabirova
- Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Artem Nurislamov
- Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Artem Shadskiy
- Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Alexander Smirnov
- Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Andrey Popov
- Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Pavel Salnikov
- Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Nariman Battulin
- Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Veniamin Fishman
- Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
- Artificial Intelligence Research Institute (AIRI), 121108 Moscow, Russia
| |
Collapse
|
16
|
Attou A, Zülske T, Wedemann G. Cohesin and CTCF complexes mediate contacts in chromatin loops depending on nucleosome positions. Biophys J 2022; 121:4788-4799. [PMID: 36325618 PMCID: PMC9811664 DOI: 10.1016/j.bpj.2022.10.044] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 09/12/2022] [Accepted: 10/28/2022] [Indexed: 11/06/2022] Open
Abstract
The spatial organization of the eukaryotic genome plays an important role in regulating transcriptional activity. In the nucleus, chromatin forms loops that assemble into fundamental units called topologically associating domains that facilitate or inhibit long-range contacts. These loops are formed and held together by the ring-shaped cohesin protein complex, and this can involve binding of CCCTC-binding factor (CTCF). High-resolution conformation capture experiments provide the frequency at which two DNA fragments physically associate in three-dimensional space. However, technical limitations of this approach, such as low throughput, low resolution, or noise in contact maps, make data interpretation and identification of chromatin intraloop contacts, e.g., between distal regulatory elements and their target genes, challenging. Herein, an existing coarse-grained model of chromatin at single-nucleosome resolution was extended by integrating potentials describing CTCF and cohesin. We performed replica-exchange Monte Carlo simulations with regularly spaced nucleosomes and experimentally determined nucleosome positions in the presence of cohesin-CTCF, as well as depleted systems as controls. In fully extruded loops caused by the presence of cohesin and CTCF, the number of contacts within the formed loops was increased. The number and types of these contacts were impacted by the nucleosome distribution and loop size. Microloops were observed within cohesin-mediated loops due to thermal fluctuations without additional influence of other factors, and the number, size, and shape of microloops were determined by nucleosome distribution and loop size. Nucleosome positions directly affect the spatial structure and contact probability within a loop, with presumed consequences for transcriptional activity.
Collapse
Affiliation(s)
- Aymen Attou
- Competence Center Bioinformatics, Institute for Applied Computer Science, Hochschule Stralsund, Stralsund, Germany
| | - Tilo Zülske
- Competence Center Bioinformatics, Institute for Applied Computer Science, Hochschule Stralsund, Stralsund, Germany
| | - Gero Wedemann
- Competence Center Bioinformatics, Institute for Applied Computer Science, Hochschule Stralsund, Stralsund, Germany.
| |
Collapse
|
17
|
Cheng J, Xu L, Bergér V, Bruckmann A, Yang C, Schubert V, Grasser KD, Schnittger A, Zheng B, Jiang H. H3K9 demethylases IBM1 and JMJ27 are required for male meiosis in Arabidopsis thaliana. THE NEW PHYTOLOGIST 2022; 235:2252-2269. [PMID: 35638341 DOI: 10.1111/nph.18286] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
Abstract
Dimethylation of histone H3 lysine 9 (H3K9me2), a crucial modification for heterochromatin formation and transcriptional silencing, is essential for proper meiotic prophase progression in mammals. We analyzed meiotic defects and generated genome-wide profiles of H3K9me2 and transcriptomes for the mutants of H3K9 demethylases. Moreover, we also identified proteins interacting with H3K9 demethylases. H3K9me2 is usually found at transposable elements and repetitive sequences but is absent from the bodies of protein-coding genes. In this study, we show that the Arabidopsis thaliana H3K9 demethylases IBM1 and JMJ27 cooperatively regulate crossover formation and chromosome segregation. They protect thousands of protein-coding genes from ectopic H3K9me2, including genes essential for meiotic prophase progression. In addition to removing H3K9me2, IBM1 and JMJ27 interact with the Precocious Dissociation of Sisters 5 (PDS5) cohesin complex cofactors. The pds5 mutant shared similar transcriptional alterations with ibm1 jmj27, including meiosis-essential genes, yet without affecting H3K9me2 levels. Hence, PDS5s, together with IBM1 and JMJ27, regulate male meiosis and gene expression independently of H3K9 demethylation. These findings uncover a novel role of H3K9me2 removal in meiosis and a new function of H3K9 demethylases and cohesin cofactors in meiotic transcriptional regulation.
Collapse
Affiliation(s)
- Jinping Cheng
- Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, 06466, Germany
| | - Linhao Xu
- Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, 06466, Germany
| | - Valentin Bergér
- Cell Biology & Plant Biochemistry, Biochemistry Center, University of Regensburg, Regensburg, 93053, Germany
| | - Astrid Bruckmann
- Department of Biochemistry, Regensburg Center for Biochemistry, University of Regensburg, Regensburg, 93053, Germany
| | - Chao Yang
- Department of Developmental Biology, University of Hamburg, Hamburg, 20146, Germany
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Veit Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, 06466, Germany
| | - Klaus D Grasser
- Cell Biology & Plant Biochemistry, Biochemistry Center, University of Regensburg, Regensburg, 93053, Germany
| | - Arp Schnittger
- Department of Developmental Biology, University of Hamburg, Hamburg, 20146, Germany
| | - Binglian Zheng
- State Key Laboratory of Genetic Engineering, Ministry of Education Key Laboratory of Biodiversity Sciences and Ecological Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Hua Jiang
- Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, 06466, Germany
| |
Collapse
|
18
|
Buskirk S, Skibbens RV. G1-Cyclin2 (Cln2) promotes chromosome hypercondensation in eco1/ctf7 rad61 null cells during hyperthermic stress in Saccharomyces cerevisiae. G3 (BETHESDA, MD.) 2022; 12:6613937. [PMID: 35736360 PMCID: PMC9339302 DOI: 10.1093/g3journal/jkac157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 06/13/2022] [Indexed: 11/16/2022]
Abstract
Eco1/Ctf7 is a highly conserved acetyltransferase that activates cohesin complexes and is critical for sister chromatid cohesion, chromosome condensation, DNA damage repair, nucleolar integrity, and gene transcription. Mutations in the human homolog of ECO1 (ESCO2/EFO2), or in genes that encode cohesin subunits, result in severe developmental abnormalities and intellectual disabilities referred to as Roberts syndrome and Cornelia de Lange syndrome, respectively. In yeast, deletion of ECO1 results in cell inviability. Codeletion of RAD61 (WAPL in humans), however, produces viable yeast cells. These eco1 rad61 double mutants, however, exhibit a severe temperature-sensitive growth defect, suggesting that Eco1 or cohesins respond to hyperthermic stress through a mechanism that occurs independent of Rad61. Here, we report that deletion of the G1 cyclin CLN2 rescues the temperature-sensitive lethality otherwise exhibited by eco1 rad61 mutant cells, such that the triple mutant cells exhibit robust growth over a broad range of temperatures. While Cln1, Cln2, and Cln3 are functionally redundant G1 cyclins, neither CLN1 nor CLN3 deletions rescue the temperature-sensitive growth defects otherwise exhibited by eco1 rad61 double mutants. We further provide evidence that CLN2 deletion rescues hyperthermic growth defects independent of START and impacts the state of chromosome condensation. These findings reveal novel roles for Cln2 that are unique among the G1 cyclin family and appear critical for cohesin regulation during hyperthermic stress.
Collapse
Affiliation(s)
- Sean Buskirk
- Department of Biology, West Chester University, West Chester, PA 19383, USA
| | - Robert V Skibbens
- Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015, USA
| |
Collapse
|