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Chaudhri A, Lizee G, Hwu P, Rai K. Chromatin Remodelers Are Regulators of the Tumor Immune Microenvironment. Cancer Res 2024; 84:965-976. [PMID: 38266066 DOI: 10.1158/0008-5472.can-23-2244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 11/24/2023] [Accepted: 01/17/2024] [Indexed: 01/26/2024]
Abstract
Immune checkpoint inhibitors show remarkable responses in a wide range of cancers, yet patients develop adaptive resistance. This necessitates the identification of alternate therapies that synergize with immunotherapies. Epigenetic modifiers are potent mediators of tumor-intrinsic mechanisms and have been shown to regulate immune response genes, making them prime targets for therapeutic combinations with immune checkpoint inhibitors. Some success has been observed in early clinical studies that combined immunotherapy with agents targeting DNA methylation and histone modification; however, less is known about chromatin remodeler-targeted therapies. Here, we provide a discussion on the regulation of tumor immunogenicity by the chromatin remodeling SWI/SNF complex through multiple mechanisms associated with immunotherapy response that broadly include IFN signaling, DNA damage, mismatch repair, regulation of oncogenic programs, and polycomb-repressive complex antagonism. Context-dependent targeting of SWI/SNF subunits can elicit opportunities for synthetic lethality and reduce T-cell exhaustion. In summary, alongside the significance of SWI/SNF subunits in predicting immunotherapy outcomes, their ability to modulate the tumor immune landscape offers opportunities for therapeutic intervention.
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Affiliation(s)
- Apoorvi Chaudhri
- Department of Melanoma Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
- Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer Center, Houston, Texas
- Department of Medical Oncology, Dana Farber Cancer Institute, Boston, Massachusetts
| | - Gregory Lizee
- Department of Melanoma Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
- Department of Immunology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | | | - Kunal Rai
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas
- MDACC Epigenomics Therapy Initiative, The University of Texas MD Anderson Cancer Center, Houston, Texas
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2
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Xiao K, Liu L, He R, Rollins JA, Li A, Zhang G, He X, Wang R, Liu J, Zhang X, Zhang Y, Pan H. The Snf5-Hsf1 transcription module synergistically regulates stress responses and pathogenicity by maintaining ROS homeostasis in Sclerotinia sclerotiorum. THE NEW PHYTOLOGIST 2024; 241:1794-1812. [PMID: 38135652 DOI: 10.1111/nph.19484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 11/12/2023] [Indexed: 12/24/2023]
Abstract
The SWI/SNF complex is guided to the promoters of designated genes by its co-operator to activate transcription in a timely and appropriate manner to govern development, pathogenesis, and stress responses in fungi. Nevertheless, knowledge of the complexes and their co-operator in phytopathogenic fungi is still fragmented. We demonstrate that the heat shock transcription factor SsHsf1 guides the SWI/SNF complex to promoters of heat shock protein (hsp) genes and antioxidant enzyme genes using biochemistry and pharmacology. This is accomplished through direct interaction with the complex subunit SsSnf5 under heat shock and oxidative stress. This results in the activation of their transcription and mediates histone displacement to maintain reactive oxygen species (ROS) homeostasis. Genetic results demonstrate that the transcription module formed by SsSnf5 and SsHsf1 is responsible for regulating morphogenesis, stress tolerance, and pathogenicity in Sclerotinia sclerotiorum, especially by directly activating the transcription of hsp genes and antioxidant enzyme genes counteracting plant-derived ROS. Furthermore, we show that stress-induced phosphorylation of SsSnf5 is necessary for the formation of the transcription module. This study establishes that the SWI/SNF complex and its co-operator cooperatively regulate the transcription of hsp genes and antioxidant enzyme genes to respond to host and environmental stress in the devastating phytopathogenic fungi.
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Affiliation(s)
- Kunqin Xiao
- College of Plant Sciences, Jilin University, Changchun, 130062, China
| | - Ling Liu
- College of Plant Sciences, Jilin University, Changchun, 130062, China
| | - Ruonan He
- College of Plant Sciences, Jilin University, Changchun, 130062, China
| | - Jeffrey A Rollins
- Department of Plant Pathology, University of Florida, Gainesville, FL, 32611, USA
| | - Anmo Li
- College of Plant Sciences, Jilin University, Changchun, 130062, China
| | - Guiping Zhang
- College of Plant Sciences, Jilin University, Changchun, 130062, China
| | - Xiaoyue He
- College of Plant Sciences, Jilin University, Changchun, 130062, China
| | - Rui Wang
- College of Plant Sciences, Jilin University, Changchun, 130062, China
| | - Jinliang Liu
- College of Plant Sciences, Jilin University, Changchun, 130062, China
| | - Xianghui Zhang
- College of Plant Sciences, Jilin University, Changchun, 130062, China
| | - Yanhua Zhang
- College of Plant Sciences, Jilin University, Changchun, 130062, China
| | - Hongyu Pan
- College of Plant Sciences, Jilin University, Changchun, 130062, China
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3
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Affiliation(s)
- Kangjing Chen
- MOE Key Laboratory of Protein Science, Tsinghua University, Beijing, P.R. China,School of Life Sciences, Tsinghua University, Beijing, P.R. China
| | - Junjie Yuan
- MOE Key Laboratory of Protein Science, Tsinghua University, Beijing, P.R. China,School of Life Sciences, Tsinghua University, Beijing, P.R. China,Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, Beijing, Beijing, China
| | - Youyang Sia
- MOE Key Laboratory of Protein Science, Tsinghua University, Beijing, P.R. China,School of Life Sciences, Tsinghua University, Beijing, P.R. China
| | - Zhucheng Chen
- MOE Key Laboratory of Protein Science, Tsinghua University, Beijing, P.R. China,School of Life Sciences, Tsinghua University, Beijing, P.R. China,Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, Beijing, Beijing, China,CONTACT Zhucheng Chen MOE Key Laboratory of Protein Science, Tsinghua University, Beijing100084, P.R. China
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4
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Church MC, Price A, Li H, Workman JL. The Swi-Snf chromatin remodeling complex mediates gene repression through metabolic control. Nucleic Acids Res 2023; 51:10278-10291. [PMID: 37650639 PMCID: PMC10602859 DOI: 10.1093/nar/gkad711] [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: 01/11/2023] [Revised: 08/02/2023] [Accepted: 08/16/2023] [Indexed: 09/01/2023] Open
Abstract
In eukaryotes, ATP-dependent chromatin remodelers regulate gene expression in response to nutritional and metabolic stimuli. However, altered transcription of metabolic genes may have significant indirect consequences which are currently poorly understood. In this study, we use genetic and molecular approaches to uncover a role for the remodeler Swi-Snf as a critical regulator of metabolism. We find that snfΔ mutants display a cysteine-deficient phenotype, despite growth in nutrient-rich media. This correlates with widespread perturbations in sulfur metabolic gene transcription, including global redistribution of the sulfur-sensing transcription factor Met4. Our findings show how a chromatin remodeler can have a significant impact on a whole metabolic pathway by directly regulating an important gene subset and demonstrate an emerging role for chromatin remodeling complexes as decisive factors in metabolic control.
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Affiliation(s)
- Michael C Church
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Andrew Price
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Hua Li
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Jerry L Workman
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
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5
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Kuwahara Y, Iehara T, Matsumoto A, Okuda T. Recent insights into the SWI/SNF complex and the molecular mechanism of hSNF5 deficiency in rhabdoid tumors. Cancer Med 2023; 12:16323-16336. [PMID: 37317642 PMCID: PMC10469780 DOI: 10.1002/cam4.6255] [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: 10/11/2022] [Revised: 05/04/2023] [Accepted: 06/05/2023] [Indexed: 06/16/2023] Open
Abstract
Genetic information encoded by DNA is packaged in the nucleus using the chromatin structure. The accessibility of transcriptional elements in DNA is controlled by the dynamic structural changes of chromatin for the appropriate regulation of gene transcription. Chromatin structure is regulated by two general mechanisms, one is histone modification and the other is chromatin remodeling in an ATP-dependent manner. Switch/sucrose nonfermentable (SWI/SNF) complexes utilize the energy from ATP hydrolysis to mobilize nucleosomes and remodel the chromatin structure, contributing to conformational changes in chromatin. Recently, the inactivation of encoding genes for subunits of the SWI/SNF complexes has been documented in a series of human cancers, accounting for up to almost 20% of all human cancers. For example, human SNF5 (hSNF5), the gene that encodes a subunit of the SWI/SNF complexes, is the sole mutation target that drives malignant rhabdoid tumors (MRT). Despite remarkably simple genomes, the MRT has highly malignant characteristics. As a key to understanding MRT tumorigenesis, it is necessary to fully examine the mechanism of chromatin remodeling by the SWI/SNF complexes. Herein, we review the current understanding of chromatin remodeling by focusing on SWI/SNF complexes. In addition, we describe the molecular mechanisms and influences of hSNF5 deficiency in rhabdoid tumors and the prospects for developing new therapeutic targets to overcome the epigenetic drive of cancer that is caused by abnormal chromatin remodeling.
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Affiliation(s)
- Yasumichi Kuwahara
- Department of Biochemistry and Molecular Biology, Graduate School of Medical ScienceKyoto Prefectural University of MedicineKyotoJapan
| | - Tomoko Iehara
- Department of Pediatrics, Graduate School of Medical ScienceKyoto Prefectural University of MedicineKyotoJapan
| | - Akifumi Matsumoto
- Department of Ophthalmology, Graduate School of Medical ScienceKyoto Prefectural University of MedicineKyotoJapan
| | - Tsukasa Okuda
- Department of Biochemistry and Molecular Biology, Graduate School of Medical ScienceKyoto Prefectural University of MedicineKyotoJapan
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6
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Fu W, Yu Y, Shu J, Yu Z, Zhong Y, Zhu T, Zhang Z, Liang Z, Cui Y, Chen C, Li C. Organization, genomic targeting, and assembly of three distinct SWI/SNF chromatin remodeling complexes in Arabidopsis. THE PLANT CELL 2023; 35:2464-2483. [PMID: 37062961 PMCID: PMC10291025 DOI: 10.1093/plcell/koad111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 03/21/2023] [Accepted: 03/26/2023] [Indexed: 06/19/2023]
Abstract
Switch defective/sucrose nonfermentable (SWI/SNF) complexes are evolutionarily conserved multisubunit machines that play vital roles in chromatin architecture regulation for modulating gene expression via sliding or ejection of nucleosomes in eukaryotes. In plants, perturbations of SWI/SNF subunits often result in severe developmental disorders. However, the subunit composition, pathways of assembly, and genomic targeting of the plant SWI/SNF complexes are poorly understood. Here, we report the organization, genomic targeting, and assembly of 3 distinct SWI/SNF complexes in Arabidopsis thaliana: BRAHMA-Associated SWI/SNF complexes (BAS), SPLAYED-Associated SWI/SNF complexes (SAS), and MINUSCULE-Associated SWI/SNF complexes (MAS). We show that BAS complexes are equivalent to human ncBAF, whereas SAS and MAS complexes evolve in multiple subunits unique to plants, suggesting plant-specific functional evolution of SWI/SNF complexes. We further show overlapping and specific genomic targeting of the 3 plant SWI/SNF complexes on chromatin and reveal that SAS complexes are necessary for the correct genomic localization of the BAS complexes. Finally, we define the role of the core module subunit in the assembly of plant SWI/SNF complexes and highlight that ATPase module subunit is required for global complex stability and the interaction of core module subunits in Arabidopsis SAS and BAS complexes. Together, our work highlights the divergence of SWI/SNF chromatin remodelers during eukaryote evolution and provides a comprehensive landscape for understanding plant SWI/SNF complex organization, assembly, genomic targeting, and function.
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Affiliation(s)
- Wei Fu
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Yaoguang Yu
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Jie Shu
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong 510650, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Zewang Yu
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Yixiong Zhong
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Tao Zhu
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Zhihao Zhang
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Zhenwei Liang
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Yuhai Cui
- London Research and Development Centre, Agriculture and Agri-Food Canada, London, Ontario, Canada N5V 4T3
| | - Chen Chen
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong 510650, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Chenlong Li
- State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
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7
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Singh A, Modak SB, Chaturvedi MM, Purohit JS. SWI/SNF Chromatin Remodelers: Structural, Functional and Mechanistic Implications. Cell Biochem Biophys 2023:10.1007/s12013-023-01140-5. [PMID: 37119511 DOI: 10.1007/s12013-023-01140-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Accepted: 04/19/2023] [Indexed: 05/01/2023]
Abstract
The nuclear events of a eukaryotic cell, such as replication, transcription, recombination and repair etc. require the transition of the compactly arranged chromatin into an uncompacted state and vice-versa. This is mediated by post-translational modification of the histones, exchange of histone variants and ATP-dependent chromatin remodeling. The SWI/SNF chromatin remodeling complexes are one of the most well characterized families of chromatin remodelers. In addition to their role in modulating chromatin, they have also been assigned roles in cancer and health-related anomalies such as developmental, neurocognitive, and intellectual disabilities. Owing to their vital cellular and medical connotations, developing an understanding of the structural and functional aspects of the complex becomes imperative. However, due to the intricate nature of higher-order chromatin as well as compositional heterogeneity of the SWI/SNF complex, intra-species isoforms and inter-species homologs, this often becomes challenging. To this end, the present review attempts to present an amalgamated perspective on the discovery, structure, function, and regulation of the SWI/SNF complex.
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Affiliation(s)
- Abhilasha Singh
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | | | - Madan M Chaturvedi
- Department of Zoology, University of Delhi, Delhi, 110007, India
- SGT University, Gurugram (Delhi-NCR), Haryana, 122505, India
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8
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Sanz AB, García R, Pavón-Vergés M, Rodríguez-Peña JM, Arroyo J. Control of Gene Expression via the Yeast CWI Pathway. Int J Mol Sci 2022; 23:ijms23031791. [PMID: 35163713 PMCID: PMC8836261 DOI: 10.3390/ijms23031791] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/27/2022] [Accepted: 02/01/2022] [Indexed: 12/18/2022] Open
Abstract
Living cells exposed to stressful environmental situations can elicit cellular responses that guarantee maximal cell survival. Most of these responses are mediated by mitogen-activated protein kinase (MAPK) cascades, which are highly conserved from yeast to humans. Cell wall damage conditions in the yeast Saccharomyces cerevisiae elicit rescue mechanisms mainly associated with reprogramming specific transcriptional responses via the cell wall integrity (CWI) pathway. Regulation of gene expression by this pathway is coordinated by the MAPK Slt2/Mpk1, mainly via Rlm1 and, to a lesser extent, through SBF (Swi4/Swi6) transcription factors. In this review, we summarize the molecular mechanisms controlling gene expression upon cell wall stress and the role of chromatin structure in these processes. Some of these mechanisms are also discussed in the context of other stresses governed by different yeast MAPK pathways. Slt2 regulates both transcriptional initiation and elongation by interacting with chromatin at the promoter and coding regions of CWI-responsive genes but using different mechanisms for Rlm1- and SBF-dependent genes. Since MAPK pathways are very well conserved in eukaryotic cells and are essential for controlling cellular physiology, improving our knowledge regarding how they regulate gene expression could impact the future identification of novel targets for therapeutic intervention.
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9
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Jian Y, Shim WB, Ma Z. Multiple functions of SWI/SNF chromatin remodeling complex in plant-pathogen interactions. STRESS BIOLOGY 2021; 1:18. [PMID: 37676626 PMCID: PMC10442046 DOI: 10.1007/s44154-021-00019-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Accepted: 11/22/2021] [Indexed: 09/08/2023]
Abstract
The SWI/SNF chromatin remodeling complex utilizes the energy of ATP hydrolysis to facilitate chromatin access and plays essential roles in DNA-based events. Studies in animals, plants and fungi have uncovered sophisticated regulatory mechanisms of this complex that govern development and various stress responses. In this review, we summarize the composition of SWI/SNF complex in eukaryotes and discuss multiple functions of the SWI/SNF complex in regulating gene transcription, mRNA splicing, and DNA damage response. Our review further highlights the importance of SWI/SNF complex in regulating plant immunity responses and fungal pathogenesis. Finally, the potentials in exploiting chromatin remodeling for management of crop disease are presented.
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Affiliation(s)
- Yunqing Jian
- State Key Laboratory of Rice Biology, and Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Won-Bo Shim
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, USA
| | - Zhonghua Ma
- State Key Laboratory of Rice Biology, and Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, Hangzhou, China.
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10
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Kumar S. SWI/SNF (BAF) complexes: From framework to a functional role in endothelial mechanotransduction. CURRENT TOPICS IN MEMBRANES 2021; 87:171-198. [PMID: 34696885 DOI: 10.1016/bs.ctm.2021.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/14/2023]
Abstract
Endothelial cells (ECs) are constantly subjected to an array of mechanical cues, especially shear stress, due to their luminal placement in the blood vessels. Blood flow can regulate various aspects of endothelial biology and pathophysiology by regulating the endothelial processes at the transcriptomic, proteomic, miRNomic, metabolomics, and epigenomic levels. ECs sense, respond, and adapt to altered blood flow patterns and shear profiles by specialized mechanisms of mechanosensing and mechanotransduction, resulting in qualitative and quantitative differences in their gene expression. Chromatin-regulatory proteins can regulate transcriptional activation by modifying the organization of nucleosomes at promoters, enhancers, silencers, insulators, and locus control regions. Recent research efforts have illustrated that SWI/SNF (SWItch/Sucrose Non-Fermentable) or BRG1/BRM-associated factor (BAF) complex regulates DNA accessibility and chromatin structure. Since the discovery, the gene-regulatory mechanisms of the BAF complex associated with chromatin remodeling have been intensively studied to investigate its role in diverse disease phenotypes. Thus far, it is evident that (1) the SWI/SNF complex broadly regulates the activity of transcriptional enhancers to control lineage-specific differentiation and (2) mutations in the BAF complex proteins lead to developmental disorders and cancers. It is unclear if blood flow can modulate the activity of SWI/SNF complex to regulate EC differentiation and reprogramming. This review emphasizes the integrative role of SWI/SNF complex from a structural and functional standpoint with a special reference to cardiovascular diseases (CVDs). The review also highlights how regulation of this complex by blood flow can lead to the discovery of new therapeutic interventions for the treatment of endothelial dysfunction in vascular diseases.
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Affiliation(s)
- Sandeep Kumar
- Wallace H. Coulter Department of Biomedical Engineering at Emory University and Georgia Institute of Technology, Atlanta, GA, United States.
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11
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Klim J, Zielenkiewicz U, Skoneczny M, Skoneczna A, Kurlandzka A, Kaczanowski S. Genetic interaction network has a very limited impact on the evolutionary trajectories in continuous culture-grown populations of yeast. BMC Ecol Evol 2021; 21:99. [PMID: 34039270 PMCID: PMC8157726 DOI: 10.1186/s12862-021-01830-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 05/19/2021] [Indexed: 11/30/2022] Open
Abstract
Background The impact of genetic interaction networks on evolution is a fundamental issue. Previous studies have demonstrated that the topology of the network is determined by the properties of the cellular machinery. Functionally related genes frequently interact with one another, and they establish modules, e.g., modules of protein complexes and biochemical pathways. In this study, we experimentally tested the hypothesis that compensatory evolutionary modifications, such as mutations and transcriptional changes, occur frequently in genes from perturbed modules of interacting genes. Results Using Saccharomyces cerevisiae haploid deletion mutants as a model, we investigated two modules lacking COG7 or NUP133, which are evolutionarily conserved genes with many interactions. We performed laboratory evolution experiments with these strains in two genetic backgrounds (with or without additional deletion of MSH2), subjecting them to continuous culture in a non-limiting minimal medium. Next, the evolved yeast populations were characterized through whole-genome sequencing and transcriptome analyses. No obvious compensatory changes resulting from inactivation of genes already included in modules were identified. The supposedly compensatory inactivation of genes in the evolved strains was only rarely observed to be in accordance with the established fitness effect of the genetic interaction network. In fact, a substantial majority of the gene inactivations were predicted to be neutral in the experimental conditions used to determine the interaction network. Similarly, transcriptome changes during continuous culture mostly signified adaptation to growth conditions rather than compensation of the absence of the COG7, NUP133 or MSH2 genes. However, we noticed that for genes whose inactivation was deleterious an upregulation of transcription was more common than downregulation. Conclusions Our findings demonstrate that the genetic interactions and the modular structure of the network described by others have very limited effects on the evolutionary trajectory following gene deletion of module elements in our experimental conditions and has no significant impact on short-term compensatory evolution. However, we observed likely compensatory evolution in functionally related (albeit non-interacting) genes. Supplementary Information The online version contains supplementary material available at 10.1186/s12862-021-01830-9.
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Affiliation(s)
- Joanna Klim
- Department of Microbial Biochemistry, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106, Warsaw, Poland
| | - Urszula Zielenkiewicz
- Department of Microbial Biochemistry, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106, Warsaw, Poland
| | - Marek Skoneczny
- Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106, Warsaw, Poland
| | - Adrianna Skoneczna
- Laboratory of Mutagenesis and DNA Repair, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106, Warsaw, Poland
| | - Anna Kurlandzka
- Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106, Warsaw, Poland
| | - Szymon Kaczanowski
- Department of Bioinformatics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106, Warsaw, Poland.
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12
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Innis SM, Cabot B. GBAF, a small BAF sub-complex with big implications: a systematic review. Epigenetics Chromatin 2020; 13:48. [PMID: 33143733 PMCID: PMC7607862 DOI: 10.1186/s13072-020-00370-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 10/23/2020] [Indexed: 12/01/2022] Open
Abstract
ATP-dependent chromatin remodeling by histone-modifying enzymes and chromatin remodeling complexes is crucial for maintaining chromatin organization and facilitating gene transcription. In the SWI/SNF family of ATP-dependent chromatin remodelers, distinct complexes such as BAF, PBAF, GBAF, esBAF and npBAF/nBAF are of particular interest regarding their implications in cellular differentiation and development, as well as in various diseases. The recently identified BAF subcomplex GBAF is no exception to this, and information is emerging linking this complex and its components to crucial events in mammalian development. Furthermore, given the essential nature of many of its subunits in maintaining effective chromatin remodeling function, it comes as no surprise that aberrant expression of GBAF complex components is associated with disease development, including neurodevelopmental disorders and numerous malignancies. It becomes clear that building upon our knowledge of GBAF and BAF complex function will be essential for advancements in both mammalian reproductive applications and the development of more effective therapeutic interventions and strategies. Here, we review the roles of the SWI/SNF chromatin remodeling subcomplex GBAF and its subunits in mammalian development and disease.
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Affiliation(s)
- Sarah M Innis
- Department of Animal Sciences, Purdue University, West Lafayette, IN, USA
| | - Birgit Cabot
- Department of Animal Sciences, Purdue University, West Lafayette, IN, USA.
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13
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The mechanisms of action of chromatin remodelers and implications in development and disease. Biochem Pharmacol 2020; 180:114200. [DOI: 10.1016/j.bcp.2020.114200] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/09/2020] [Accepted: 08/12/2020] [Indexed: 02/06/2023]
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14
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Abstract
ATP-dependent chromatin remodelling enzymes are molecular machines that act to reconfigure the structure of nucleosomes. Until recently, little was known about the structure of these enzymes. Recent progress has revealed that their interaction with chromatin is dominated by ATPase domains that contact DNA at favoured locations on the nucleosome surface. Contacts with histones are limited but play important roles in modulating activity. The ATPase domains do not act in isolation but are flanked by diverse accessory domains and subunits. New structures indicate how these subunits are arranged in multi-subunit complexes providing a framework from which to understand how a common motor is applied to distinct functions.
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Affiliation(s)
- Ramasubramian Sundaramoorthy
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, Dundee, DD1 5EH, UK
| | - Tom Owen-Hughes
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, Dundee, DD1 5EH, UK
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15
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Wang C, Guo Z, Zhan X, Yang F, Wu M, Zhang X. Structure of the yeast Swi/Snf complex in a nucleosome free state. Nat Commun 2020; 11:3398. [PMID: 32636384 PMCID: PMC7340788 DOI: 10.1038/s41467-020-17229-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 06/15/2020] [Indexed: 11/09/2022] Open
Abstract
SWI/SNF remodelers play a key role in regulating chromatin architecture and gene expression. Here, we report the cryo-EM structure of the Saccharomyces cerevisiae Swi/Snf complex in a nucleosome-free state. The structure consists of a stable triangular base module and a flexible Arp module. The conserved subunits Swi1 and Swi3 form the backbone of the complex and closely interact with other components. Snf6, which is specific for yeast Swi/Snf complex, stabilizes the binding of the ATPase-containing subunit Snf2 to the base module. Comparison of the yeast Swi/Snf and RSC complexes reveals conserved structural features that govern the assembly and function of these two subfamilies of chromatin remodelers. Our findings complement those from recent structures of the yeast and human chromatin remodelers and provide further insights into the assembly and function of the SWI/SNF remodelers.
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Affiliation(s)
- Chengcheng Wang
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, 310024, Hangzhou, Zhejiang Province, China. .,School of Life Sciences, Westlake University, 18 Shilongshan Road, 310024, Hangzhou, Zhejiang Province, China.
| | - Zhouyan Guo
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, 310024, Hangzhou, Zhejiang Province, China.,School of Life Sciences, Westlake University, 18 Shilongshan Road, 310024, Hangzhou, Zhejiang Province, China.,College of Life Sciences, Zhejiang University, 310058, Hangzhou, China
| | - Xiechao Zhan
- Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, 100084, Beijing, China
| | - Fenghua Yang
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, 310024, Hangzhou, Zhejiang Province, China.,School of Life Sciences, Westlake University, 18 Shilongshan Road, 310024, Hangzhou, Zhejiang Province, China
| | - Mingxuan Wu
- School of Science, Westlake University, 18 Shilongshan Road, 310024, Hangzhou, Zhejiang Province, China.,Institute of Natural Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, 310024, Hangzhou, Zhejiang Province, China
| | - Xiaofeng Zhang
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, 18 Shilongshan Road, 310024, Hangzhou, Zhejiang Province, China. .,School of Life Sciences, Westlake University, 18 Shilongshan Road, 310024, Hangzhou, Zhejiang Province, China.
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16
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Zhou H, Chen G, Dong C, Zhao X, Shen Z, Chen F, Liu B, Long J. Snf5 and Swi3 subcomplex formation is required for SWI/SNF complex function in yeast. Biochem Biophys Res Commun 2020; 526:934-940. [PMID: 32284172 DOI: 10.1016/j.bbrc.2020.03.169] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 03/29/2020] [Indexed: 01/18/2023]
Abstract
The SWI/SNF chromatin remodeling complex, which alters nucleosome positions by either evicting histones or sliding nucleosomes on DNA, is highly conserved from yeast to humans, and 20% of all human cancers have mutations in various subunits of the SWI/SNF complex. Here, we reported the crystal structure of the yeast Snf5-Swi3 subcomplex at a resolution of 2.65 Å. Our results showed that the Snf5-Swi3 subcomplex assembles into a heterotrimer with one Snf5 molecule bound to two distinct Swi3 molecules. In addition, we demonstrated that Snf5-Swi3 subcomplex formation is required for SWI/SNF function in yeast. These findings shed light on the important role of the Snf5-Swi3 subcomplex in the assembly and functional integrity of the SWI/SNF complex.
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Affiliation(s)
- Hao Zhou
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin, 300071, China.
| | - Guidong Chen
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin, 300071, China
| | - Chunming Dong
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin, 300457, China
| | - Xiaozhou Zhao
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin, 300071, China
| | - Zhongtian Shen
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin, 300071, China
| | - Feilong Chen
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin, 300071, China
| | - Beibei Liu
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin, 300071, China
| | - Jiafu Long
- State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin, 300071, China.
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17
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Accumulation of unacetylatable Snf2p at the INO1 promoter is detrimental to remodeler recycling supply for CUP1 induction. PLoS One 2020; 15:e0230572. [PMID: 32210477 PMCID: PMC7094851 DOI: 10.1371/journal.pone.0230572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 03/03/2020] [Indexed: 11/19/2022] Open
Abstract
Chromatin structure plays a decisive role in gene regulation through the actions of transcriptional activators, coactivators, and epigenetic machinery. These trans-acting factors contribute to gene expression through their interactions with chromatin structure. In yeast INO1 activation, transcriptional activators and coactivators have been defined through intense study but the mechanistic links within these trans-acting factors and their functional implications are not yet fully understood. In this study, we examined the crosstalk within transcriptional coactivators with regard to the implications of Snf2p acetylation during INO1 activation. Through various biochemical analysis, we demonstrated that both Snf2p and Ino80p chromatin remodelers accumulate at the INO1 promoter in the absence of Snf2p acetylation during induction. Furthermore, nucleosome density and histone acetylation patterns remained unaffected by Snf2p acetylation status. We also showed that cells experience increased sensitivity to copper toxicity when remodelers accumulate at the INO1 promoter due to the decreased CUP1 expression. Therefore, our data provide evidence for crosstalk within transcriptional co-activators during INO1 activation. In light of these findings, we propose a model in which acetylation-driven chromatin remodeler recycling allows for efficient regulation of genes that are dependent upon limited co-activators.
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18
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He S, Wu Z, Tian Y, Yu Z, Yu J, Wang X, Li J, Liu B, Xu Y. Structure of nucleosome-bound human BAF complex. Science 2020; 367:875-881. [PMID: 32001526 DOI: 10.1126/science.aaz9761] [Citation(s) in RCA: 157] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 01/10/2020] [Accepted: 01/22/2020] [Indexed: 12/14/2022]
Abstract
Mammalian SWI/SNF family chromatin remodelers, BRG1/BRM-associated factor (BAF) and polybromo-associated BAF (PBAF), regulate chromatin structure and transcription, and their mutations are linked to cancers. The 3.7-angstrom-resolution cryo-electron microscopy structure of human BAF bound to the nucleosome reveals that the nucleosome is sandwiched by the base and the adenosine triphosphatase (ATPase) modules, which are bridged by the actin-related protein (ARP) module. The ATPase motor is positioned proximal to nucleosomal DNA and, upon ATP hydrolysis, engages with and pumps DNA along the nucleosome. The C-terminal α helix of SMARCB1, enriched in positively charged residues frequently mutated in cancers, mediates interactions with an acidic patch of the nucleosome. AT-rich interactive domain-containing protein 1A (ARID1A) and the SWI/SNF complex subunit SMARCC serve as a structural core and scaffold in the base module organization, respectively. Our study provides structural insights into subunit organization and nucleosome recognition of human BAF complex.
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Affiliation(s)
- Shuang He
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China.,The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, China, Department of Systems Biology for Medicine, School of Basic Medical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Zihan Wu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China.,The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, China, Department of Systems Biology for Medicine, School of Basic Medical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Yuan Tian
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China.,The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, China, Department of Systems Biology for Medicine, School of Basic Medical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Zishuo Yu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China.,The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, China, Department of Systems Biology for Medicine, School of Basic Medical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Jiali Yu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China.,The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, China, Department of Systems Biology for Medicine, School of Basic Medical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Xinxin Wang
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China.,The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, China, Department of Systems Biology for Medicine, School of Basic Medical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Jie Li
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Bijun Liu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Yanhui Xu
- Fudan University Shanghai Cancer Center, Institutes of Biomedical Sciences, State Key Laboratory of Genetic Engineering, and Shanghai Key Laboratory of Medical Epigenetics, Shanghai Medical College of Fudan University, Shanghai 200032, China. .,The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, China, Department of Systems Biology for Medicine, School of Basic Medical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China.,Human Phenome Institute, Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200433, China.,CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China
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19
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Patel AB, Moore CM, Greber BJ, Luo J, Zukin SA, Ranish J, Nogales E. Architecture of the chromatin remodeler RSC and insights into its nucleosome engagement. eLife 2019; 8:e54449. [PMID: 31886770 PMCID: PMC6959994 DOI: 10.7554/elife.54449] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 12/23/2019] [Indexed: 12/21/2022] Open
Abstract
Eukaryotic DNA is packaged into nucleosome arrays, which are repositioned by chromatin remodeling complexes to control DNA accessibility. The Saccharomyces cerevisiae RSC (Remodeling the Structure of Chromatin) complex, a member of the SWI/SNF chromatin remodeler family, plays critical roles in genome maintenance, transcription, and DNA repair. Here, we report cryo-electron microscopy (cryo-EM) and crosslinking mass spectrometry (CLMS) studies of yeast RSC complex and show that RSC is composed of a rigid tripartite core and two flexible lobes. The core structure is scaffolded by an asymmetric Rsc8 dimer and built with the evolutionarily conserved subunits Sfh1, Rsc6, Rsc9 and Sth1. The flexible ATPase lobe, composed of helicase subunit Sth1, Arp7, Arp9 and Rtt102, is anchored to this core by the N-terminus of Sth1. Our cryo-EM analysis of RSC bound to a nucleosome core particle shows that in addition to the expected nucleosome-Sth1 interactions, RSC engages histones and nucleosomal DNA through one arm of the core structure, composed of the Rsc8 SWIRM domains, Sfh1 and Npl6. Our findings provide structural insights into the conserved assembly process for all members of the SWI/SNF family of remodelers, and illustrate how RSC selects, engages, and remodels nucleosomes.
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Affiliation(s)
- Avinash B Patel
- Biophysics Graduate GroupUniversity of California, BerkeleyBerkeleyUnited States
- Molecular Biophysics and Integrative Bio-Imaging DivisionLawrence Berkeley National LaboratoryBerkeleyUnited States
| | - Camille M Moore
- Molecular and Cell Biology DepartmentUniversity of California, BerkeleyBerkeleyUnited States
| | - Basil J Greber
- Molecular Biophysics and Integrative Bio-Imaging DivisionLawrence Berkeley National LaboratoryBerkeleyUnited States
- California Institute for Quantitative Biology (QB3)University of California, BerkeleyBerkeleyUnited States
| | - Jie Luo
- The Institute for Systems BiologySeattleUnited States
| | - Stefan A Zukin
- Chemistry DepartmentUniversity of California, BerkeleyBerkeleyUnited States
| | - Jeff Ranish
- The Institute for Systems BiologySeattleUnited States
| | - Eva Nogales
- Molecular Biophysics and Integrative Bio-Imaging DivisionLawrence Berkeley National LaboratoryBerkeleyUnited States
- Molecular and Cell Biology DepartmentUniversity of California, BerkeleyBerkeleyUnited States
- California Institute for Quantitative Biology (QB3)University of California, BerkeleyBerkeleyUnited States
- Howard Hughes Medical Institute, University of California, BerkeleyBerkeleyUnited States
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20
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Generation of Remosomes by the SWI/SNF Chromatin Remodeler Family. Sci Rep 2019; 9:14212. [PMID: 31578361 PMCID: PMC6775096 DOI: 10.1038/s41598-019-50572-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 09/04/2019] [Indexed: 12/11/2022] Open
Abstract
Chromatin remodelers are complexes able to both alter histone-DNA interactions and to mobilize nucleosomes. The mechanism of their action and the conformation of remodeled nucleosomes remain a matter of debates. In this work we compared the type and structure of the products of nucleosome remodeling by SWI/SNF and ACF complexes using high-resolution microscopy combined with novel biochemical approaches. We find that SWI/SNF generates a multitude of nucleosome-like metastable particles termed "remosomes". Restriction enzyme accessibility assay, DNase I footprinting and AFM experiments reveal perturbed histone-DNA interactions within these particles. Electron cryo-microscopy shows that remosomes adopt a variety of different structures with variable irregular DNA path, similar to those described upon RSC remodeling. Remosome DNA accessibility to restriction enzymes is also markedly increased. We suggest that the generation of remosomes is a common feature of the SWI/SNF family remodelers. In contrast, the ACF remodeler, belonging to ISWI family, only produces repositioned nucleosomes and no evidence for particles associated with extra DNA, or perturbed DNA paths was found. The remosome generation by the SWI/SNF type of remodelers may represent a novel mechanism involved in processes where nucleosomal DNA accessibility is required, such as DNA repair or transcription regulation.
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21
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Zhang Z, Wang X, Xin J, Ding Z, Liu S, Fang Q, Yang N, Xu RM, Cai G. Architecture of SWI/SNF chromatin remodeling complex. Protein Cell 2019; 9:1045-1049. [PMID: 29546678 PMCID: PMC6251806 DOI: 10.1007/s13238-018-0524-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Affiliation(s)
- Zhihui Zhang
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China
| | - Xuejuan Wang
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China. .,CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Hefei, 230026, China.
| | - Jiyu Xin
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China
| | - Zhenrui Ding
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China
| | - Sheng Liu
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China
| | - Qianglin Fang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Na Yang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Rui-Min Xu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Gang Cai
- Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China. .,CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Hefei, 230026, China.
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22
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Nucleosome remodelling: structural insights into ATP-dependent remodelling enzymes. Essays Biochem 2019; 63:45-58. [PMID: 30967479 DOI: 10.1042/ebc20180059] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 03/19/2019] [Accepted: 03/20/2019] [Indexed: 12/22/2022]
Abstract
ATP-dependent chromatin remodelling enzymes play a fundamental role in determining how nucleosomes are organised, and render DNA sequences accessible to interacting proteins, thereby enabling precise regulation of eukaryotic genes. Remodelers conserved from yeast to humans are classified into four families based on the domains and motifs present in their ATPase subunits. Insights into overall assembly and the mode of interaction to the nucleosome by these different families of remodelers remained limited due to the complexity of obtaining structural information on these challenging samples. Electron microscopy and single-particle methods have made advancement and uncovered vital structural information on the number of remodelling complexes. In this article, we highlight some of the recent structural work that advanced our understanding on the mechanisms and biological functions of these ATP-dependent remodelling machines.
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23
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Alfert A, Moreno N, Kerl K. The BAF complex in development and disease. Epigenetics Chromatin 2019; 12:19. [PMID: 30898143 PMCID: PMC6427853 DOI: 10.1186/s13072-019-0264-y] [Citation(s) in RCA: 138] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 03/13/2019] [Indexed: 01/16/2023] Open
Abstract
The ATP-dependent chromatin remodelling complex BAF (= mammalian SWI/SNF complex) is crucial for the regulation of gene expression and differentiation. In the course of evolution from yeast to mammals, the BAF complex evolved an immense complexity with a high number of subunits encoded by gene families. In this way, tissue-specific BAF function and regulation of development begin with the combinatorial assembly of distinct BAF complexes such as esBAF, npBAF and nBAF. Furthermore, whole-genome sequencing reveals the tremendous role BAF complex mutations have in both neurodevelopmental disorders and human malignancies. Therefore, gaining a more elaborate insight into how BAF complex assembly influences its function and which role distinct subunits play, will hopefully give rise to a better understanding of disease pathogenesis and ultimately to new treatments for many human diseases.
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Affiliation(s)
- Amelie Alfert
- Department of Paediatric Haematology and Oncology, University Children’s Hospital Muenster, Domagkstraße 24, 48149 Muenster, Germany
| | - Natalia Moreno
- Department of Paediatric Haematology and Oncology, University Children’s Hospital Muenster, Domagkstraße 24, 48149 Muenster, Germany
| | - Kornelius Kerl
- Department of Paediatric Haematology and Oncology, University Children’s Hospital Muenster, Domagkstraße 24, 48149 Muenster, Germany
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24
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RNA Sequencing Reveals Specific TranscriptomicSignatures Distinguishing Effects of the [ SWI⁺] Prion and SWI1 Deletion in Yeast Saccharomyces cerevisiae. Genes (Basel) 2019; 10:genes10030212. [PMID: 30871095 PMCID: PMC6471900 DOI: 10.3390/genes10030212] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Revised: 03/01/2019] [Accepted: 03/08/2019] [Indexed: 01/02/2023] Open
Abstract
Prions are infectious, self-perpetuating protein conformers. In mammals, pathological aggregation of the prion protein causes incurable neurodegenerative disorders, while in yeast Saccharomyces cerevisiae, prion formation may be neutral or even beneficial. According to the prevailing contemporary point of view, prion formation is considered to be a functional inactivation of the corresponding protein whose conformational state shifts from the functional monomeric one to the infectious aggregated one. The Swi1 protein forms the [SWI+] prion and belongs to the nucleosome remodeler complex SWI/SNF controlling the expression of a significant part of the yeast genome. In this work, we performed RNA sequencing of isogenic S. cerevisiae strains grown on the media containing galactose as the sole carbon source. These strains bore the [SWI+] prion or had its structural gene SWI1 deleted. The comparative analysis showed that [SWI+] affects genome expression significantly weaker as compared to the SWI1 deletion. Moreover, in contrast to [SWI+], the SWI1 deletion causes the general inhibition of translation-related genes expression and chromosome I disomy. At the same time, the [SWI+] prion exhibits a specific pattern of modulation of the metabolic pathways and some biological processes and functions, as well as the expression of several genes. Thus, the [SWI+] prion only partially corresponds to the loss-of-function of SWI1 and demonstrates several gain-of-function traits.
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25
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Farrell AW, Halliday GM, Lyons JG. Brahma deficiency in keratinocytes promotes UV carcinogenesis by accelerating the escape from cell cycle arrest and the formation of DNA photolesions. J Dermatol Sci 2018; 92:254-263. [PMID: 30522882 DOI: 10.1016/j.jdermsci.2018.11.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 11/06/2018] [Accepted: 11/19/2018] [Indexed: 01/18/2023]
Abstract
BACKGROUND Ultraviolet radiation (UVR) is the principal cause of keratinocyte skin cancers. Previous work found that levels of the chromatin remodelling protein, Brahma (Brm), are diminished during the progression from actinic keratoses to cutaneous squamous cell carcinomas in humans, and its loss in UV-irradiated mouse skin causes epidermal hyperplasia and increased tumour incidence. METHODS The skins of mice and mouse and human keratinocytes deficient in Brm were exposed to UVR and evaluated for cell cycle progression and DNA damage response. OBJECTIVE To identify the mechanisms by which loss of Brm contributes to UVR-induced skin carcinogenesis. RESULTS In both mouse keratinocytes and HaCaT cells, Brm deficiency led to an increased cell population growth following UVR exposure compared to cells with normal levels of Brm. Cell cycle analysis using a novel assay showed that Brm-deficient keratinocytes entered cell cycle arrest normally, but escaped from cell cycle arrest faster, enabling them to begin proliferating earlier. In mouse keratinocytes, Brm primarily affected accumulation in G0/G1-phase, whereas in HaCaT cells, which lack normal p53, accumulation in G2/M-phase was affected. Brm-deficient keratinocytes in mouse skin and human cell cultures also had higher levels of UVR-induced cyclobutane pyrimidine dimer photolesions. These effects occurred without any compensatory increase in DNA repair or cell death to remove photolesions or the cells that harbor them from the keratinocyte population. CONCLUSION The loss of Brm in keratinocytes exposed to UVR enables them to resume proliferation while harboring DNA photolesions, leading to an increased fixation of mutations and, consequently, increased carcinogenesis.
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Affiliation(s)
- Andrew W Farrell
- Dermatology, Central Clinical School, and Bosch Institute, University of Sydney, Sydney, NSW, Australia
| | - Gary M Halliday
- Dermatology, Central Clinical School, and Bosch Institute, University of Sydney, Sydney, NSW, Australia
| | - J Guy Lyons
- Dermatology, Central Clinical School, and Bosch Institute, University of Sydney, Sydney, NSW, Australia; Centenary Institute, Cancer Services, Royal Prince Alfred Hospital, Dermatology, Bosch Institute, University of Sydney, Camperdown, NSW 2050, Australia.
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26
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Li M, Zhai Y, Bai J, Wang S, Gao H, Li C, Gui S, Du J, Zhang Y. SNF5 as a prognostic factor in skull base chordoma. J Neurooncol 2017; 137:139-146. [PMID: 29222701 DOI: 10.1007/s11060-017-2706-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 12/03/2017] [Indexed: 11/29/2022]
Abstract
The current study aimed to characterize SNF5 expression and investigate the relationship between SNF5 and clinicopathological features in skull base chordoma. 48 patients diagnosed with skull base chordoma were enrolled in this study. Tissue microarray and immunohistochemistry were performed to evaluate the expression of SNF5 in skull base chordoma. Kaplan-Meier survival analysis was used to assess survival. Multivariable Cox regression analysis was used to identify risk factors affecting patient survival. The H-scores for cytoplasmic SNF5 ranged from 124.47 to 254.52. Low expression of SNF5 was correlated with shorter overall survival (OS) (p = 0.021). Patients with age > 55 years old had shorter progression free survival (PFS) and OS times than patients whose age ≤ 55 years old (p = 0.005 and 0.003, respectively). The gross total resection group showed longer PFS than the non-gross total resection group (p = 0.024). Females showed shorter PFS times than males (p = 0.033). Multivariable Cox regression analysis showed that age, extent of resection and sex were independent prognostic factors for PFS (p = 0.010, 0.013 and 0.042, respectively). Age was an independent prognostic factor for OS (p = 0.010). Our study indicate that low expression of SNF5 is associated with poor prognosis in skull base chordoma.
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Affiliation(s)
- Mingxuan Li
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
| | - Yixuan Zhai
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
| | - Jiwei Bai
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Shuai Wang
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
| | - Hua Gao
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
| | - Chuzhong Li
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
| | - Songbai Gui
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Jiang Du
- Department of Neuropathology, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
| | - Yazhuo Zhang
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China. .,Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China. .,Beijing Institute for Brain Disorders Brain Tumor Center, Beijing, China. .,China National Clinical Research Center for Neurological Diseases, Beijing, China.
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27
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The SWI/SNF subunit Bcl7a contributes to motor coordination and Purkinje cell function. Sci Rep 2017; 7:17055. [PMID: 29213114 PMCID: PMC5719005 DOI: 10.1038/s41598-017-17284-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 11/23/2017] [Indexed: 12/19/2022] Open
Abstract
Chromatin remodelers have emerged as prominent regulators of epigenetic processes and potential drivers of various human pathologies. The multi-subunit chromatin-remodeling SWI/SNF complex determines gene expression programs and, consequently, contributes to the differentiation, maturation and plasticity of neurons. Here, we investigate the elusive biological function of Bcl7a and Bcl7b, two newly identified subunits of the SWI/SNF complex that are highly expressed throughout the brain. We generated ubiquitous and neuron-specific Bcl7a and Bcl7b single and double knockout mice. We provide evidence that Bcl7b is dispensable for animal survival as well as behavioral plasticity. Conversely, ubiquitous Bcl7a knockout results in perinatal lethality, while genetic deletion of Bcl7a in postmitotic neurons elicits motor abnormalities and affects dendritic branching of Purkinje cells, with no obvious synergistic relationship with Bcl7b. Collectively, our findings reveal novel insights into the cellular processes linked to BCL7-containing SWI/SNF complexes and their unrecognized roles in the brain.
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28
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Abstract
Skeletal muscle regeneration is an efficient stem cell-based repair system that ensures healthy musculature. For this repair system to function continuously throughout life, muscle stem cells must contribute to the process of myofiber repair as well as repopulation of the stem cell niche. The decision made by the muscle stem cells to commit to the muscle repair or to remain a stem cell depends upon patterns of gene expression, a process regulated at the epigenetic level. Indeed, it is well accepted that dynamic changes in epigenetic landscapes to control DNA accessibility and expression is a critical component during myogenesis for the effective repair of damaged muscle. Changes in the epigenetic landscape are governed by various posttranslational histone tail modifications, nucleosome repositioning, and DNA methylation events which collectively allow the control of changes in transcription networks during transitions of satellite cells from a dormant quiescent state toward terminal differentiation. This chapter focuses upon the specific epigenetic changes that occur during muscle stem cell-mediated regeneration to ensure myofiber repair and continuity of the stem cell compartment. Furthermore, we explore open questions in the field that are expected to be important areas of exploration as we move toward a more thorough understanding of the epigenetic mechanism regulating muscle regeneration.
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Affiliation(s)
- Daniel C L Robinson
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada; University of Ottawa, Ottawa, ON, Canada
| | - Francis J Dilworth
- Sprott Centre for Stem Cell Research, Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada; University of Ottawa, Ottawa, ON, Canada.
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29
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Willhoft O, McCormack EA, Aramayo RJ, Bythell-Douglas R, Ocloo L, Zhang X, Wigley DB. Crosstalk within a functional INO80 complex dimer regulates nucleosome sliding. eLife 2017; 6. [PMID: 28585918 PMCID: PMC5472440 DOI: 10.7554/elife.25782] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 06/03/2017] [Indexed: 01/17/2023] Open
Abstract
Several chromatin remodellers have the ability to space nucleosomes on DNA. For ISWI remodellers, this involves an interplay between H4 histone tails, the AutoN and NegC motifs of the motor domains that together regulate ATPase activity and sense the length of DNA flanking the nucleosome. By contrast, the INO80 complex also spaces nucleosomes but is not regulated by H4 tails and lacks the AutoN and NegC motifs. Instead nucleosome sliding requires cooperativity between two INO80 complexes that monitor DNA length simultaneously on either side of the nucleosome during sliding. The C-terminal domain of the human Ino80 subunit (Ino80CTD) binds cooperatively to DNA and dimerisation of these domains provides crosstalk between complexes. ATPase activity, rather than being regulated, instead gradually becomes uncoupled as nucleosome sliding reaches an end point and this is controlled by the Ino80CTD. A single active ATPase motor within the dimer is sufficient for sliding. DOI:http://dx.doi.org/10.7554/eLife.25782.001
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Affiliation(s)
- Oliver Willhoft
- Department of Medicine, Section of Structural Biology, Imperial College London, London, United Kingdom
| | - Elizabeth A McCormack
- Department of Medicine, Section of Structural Biology, Imperial College London, London, United Kingdom
| | - Ricardo J Aramayo
- Department of Medicine, Section of Structural Biology, Imperial College London, London, United Kingdom
| | - Rohan Bythell-Douglas
- Department of Medicine, Section of Structural Biology, Imperial College London, London, United Kingdom
| | - Lorraine Ocloo
- Department of Medicine, Section of Structural Biology, Imperial College London, London, United Kingdom
| | - Xiaodong Zhang
- Department of Medicine, Section of Structural Biology, Imperial College London, London, United Kingdom
| | - Dale B Wigley
- Department of Medicine, Section of Structural Biology, Imperial College London, London, United Kingdom
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30
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Clapier CR, Iwasa J, Cairns BR, Peterson CL. Mechanisms of action and regulation of ATP-dependent chromatin-remodelling complexes. Nat Rev Mol Cell Biol 2017; 18:407-422. [PMID: 28512350 DOI: 10.1038/nrm.2017.26] [Citation(s) in RCA: 673] [Impact Index Per Article: 96.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cells utilize diverse ATP-dependent nucleosome-remodelling complexes to carry out histone sliding, ejection or the incorporation of histone variants, suggesting that different mechanisms of action are used by the various chromatin-remodelling complex subfamilies. However, all chromatin-remodelling complex subfamilies contain an ATPase-translocase 'motor' that translocates DNA from a common location within the nucleosome. In this Review, we discuss (and illustrate with animations) an alternative, unifying mechanism of chromatin remodelling, which is based on the regulation of DNA translocation. We propose the 'hourglass' model of remodeller function, in which each remodeller subfamily utilizes diverse specialized proteins and protein domains to assist in nucleosome targeting or to differentially detect nucleosome epitopes. These modules converge to regulate a common DNA translocation mechanism, to inform the conserved ATPase 'motor' on whether and how to apply DNA translocation, which together achieve the various outcomes of chromatin remodelling: nucleosome assembly, chromatin access and nucleosome editing.
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Affiliation(s)
- Cedric R Clapier
- Howard Hughes Medical Institute and Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah 84112, USA
| | - Janet Iwasa
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, Utah 84112, USA
| | - Bradley R Cairns
- Howard Hughes Medical Institute and Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, Utah 84112, USA
| | - Craig L Peterson
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
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31
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Dutta A, Sardiu M, Gogol M, Gilmore J, Zhang D, Florens L, Abmayr SM, Washburn MP, Workman JL. Composition and Function of Mutant Swi/Snf Complexes. Cell Rep 2017; 18:2124-2134. [PMID: 28249159 PMCID: PMC5837817 DOI: 10.1016/j.celrep.2017.01.058] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 12/09/2016] [Accepted: 01/23/2017] [Indexed: 12/15/2022] Open
Abstract
The 12-subunit Swi/Snf chromatin remodeling complex is conserved from yeast to humans. It functions to alter nucleosome positions by either sliding nucleosomes on DNA or evicting histones. Interestingly, 20% of all human cancers carry mutations in subunits of the Swi/Snf complex. Many of these mutations cause protein instability and loss, resulting in partial Swi/Snf complexes. Although several studies have shown that histone acetylation and activator-dependent recruitment of Swi/Snf regulate its function, it is less well understood how subunits regulate stability and function of the complex. Using functional proteomic and genomic approaches, we have assembled the network architecture of yeast Swi/Snf. In addition, we find that subunits of the Swi/Snf complex regulate occupancy of the catalytic subunit Snf2, thereby modulating gene transcription. Our findings have direct bearing on how cancer-causing mutations in orthologous subunits of human Swi/Snf may lead to aberrant regulation of gene expression by this complex.
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Affiliation(s)
- Arnob Dutta
- Department of Cell and Molecular Biology, University of Rhode Island, 120 Flagg Road, Kingston, RI 02881, USA.
| | - Mihaela Sardiu
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Madelaine Gogol
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Joshua Gilmore
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Daoyong Zhang
- Institute of Cancer Biological Therapy, Xuzhou Medical University, Jiangsu 221002, China
| | - Laurence Florens
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Susan M Abmayr
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA; Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Michael P Washburn
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA; Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Jerry L Workman
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA.
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32
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Adkins NL, Swygert SG, Kaur P, Niu H, Grigoryev SA, Sung P, Wang H, Peterson CL. Nucleosome-like, Single-stranded DNA (ssDNA)-Histone Octamer Complexes and the Implication for DNA Double Strand Break Repair. J Biol Chem 2017; 292:5271-5281. [PMID: 28202543 DOI: 10.1074/jbc.m117.776369] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 02/13/2017] [Indexed: 11/06/2022] Open
Abstract
Repair of DNA double strand breaks (DSBs) is key for maintenance of genome integrity. When DSBs are repaired by homologous recombination, DNA ends can undergo extensive processing, producing long stretches of single-stranded DNA (ssDNA). In vivo, DSB processing occurs in the context of chromatin, and studies indicate that histones may remain associated with processed DSBs. Here we demonstrate that histones are not evicted from ssDNA after in vitro chromatin resection. In addition, we reconstitute histone-ssDNA complexes (termed ssNucs) with ssDNA and recombinant histones and analyze these particles by a combination of native gel electrophoresis, sedimentation velocity, electron microscopy, and a recently developed electrostatic force microscopy technique, DREEM (dual-resonance frequency-enhanced electrostatic force microscopy). The reconstituted ssNucs are homogenous and relatively stable, and DREEM reveals ssDNA wrapping around histones. We also find that histone octamers are easily transferred in trans from ssNucs to either double-stranded DNA or ssDNA. Furthermore, the Fun30 remodeling enzyme, which has been implicated in DNA repair, binds ssNucs preferentially over nucleosomes, and ssNucs are effective at activating Fun30 ATPase activity. Our results indicate that ssNucs may be a hallmark of processes that generate ssDNA, and that posttranslational modification of ssNucs may generate novel signaling platforms involved in genome stability.
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Affiliation(s)
- Nicholas L Adkins
- From the Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Sarah G Swygert
- From the Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Parminder Kaur
- the Department of Physics.,Center for Human Health and the Environment, North Carolina State University, Raleigh, North Carolina 27695
| | - Hengyao Niu
- the Department Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut 06520, and
| | - Sergei A Grigoryev
- the Department of Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033
| | - Patrick Sung
- the Department Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut 06520, and
| | - Hong Wang
- the Department of Physics.,Center for Human Health and the Environment, North Carolina State University, Raleigh, North Carolina 27695
| | - Craig L Peterson
- From the Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605,
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33
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Volokh OI, Derkacheva NI, Studitsky VM, Sokolova OS. Structural studies of chromatin remodeling factors. Mol Biol 2016. [DOI: 10.1134/s0026893316060212] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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34
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Krietenstein N, Wal M, Watanabe S, Park B, Peterson CL, Pugh BF, Korber P. Genomic Nucleosome Organization Reconstituted with Pure Proteins. Cell 2016; 167:709-721.e12. [PMID: 27768892 DOI: 10.1016/j.cell.2016.09.045] [Citation(s) in RCA: 170] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 07/04/2016] [Accepted: 09/22/2016] [Indexed: 12/20/2022]
Abstract
Chromatin remodelers regulate genes by organizing nucleosomes around promoters, but their individual contributions are obfuscated by the complex in vivo milieu of factor redundancy and indirect effects. Genome-wide reconstitution of promoter nucleosome organization with purified proteins resolves this problem and is therefore a critical goal. Here, we reconstitute four stages of nucleosome architecture using purified components: yeast genomic DNA, histones, sequence-specific Abf1/Reb1, and remodelers RSC, ISW2, INO80, and ISW1a. We identify direct, specific, and sufficient contributions that in vivo observations validate. First, RSC clears promoters by translating poly(dA:dT) into directional nucleosome removal. Second, partial redundancy is recapitulated where INO80 alone, or ISW2 at Abf1/Reb1sites, positions +1 nucleosomes. Third, INO80 and ISW2 each align downstream nucleosomal arrays. Fourth, ISW1a tightens the spacing to canonical repeat lengths. Such a minimal set of rules and proteins establishes core mechanisms by which promoter chromatin architecture arises through a blend of redundancy and specialization.
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Affiliation(s)
- Nils Krietenstein
- Molecular Biology Division, Biomedical Center, LMU Munich, 82152 Planegg-Martinsried near Munich, Germany
| | - Megha Wal
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Shinya Watanabe
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Bongsoo Park
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Craig L Peterson
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - B Franklin Pugh
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA.
| | - Philipp Korber
- Molecular Biology Division, Biomedical Center, LMU Munich, 82152 Planegg-Martinsried near Munich, Germany.
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35
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Wagner S, Herrmannová A, Šikrová D, Valášek LS. Human eIF3b and eIF3a serve as the nucleation core for the assembly of eIF3 into two interconnected modules: the yeast-like core and the octamer. Nucleic Acids Res 2016; 44:10772-10788. [PMID: 27924037 PMCID: PMC5159561 DOI: 10.1093/nar/gkw972] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 10/07/2016] [Accepted: 10/11/2016] [Indexed: 12/05/2022] Open
Abstract
The 12-subunit mammalian eIF3 is the largest and most complex translation initiation factor and has been implicated in numerous steps of translation initiation, termination and ribosomal recycling. Imbalanced eIF3 expression levels are observed in various types of cancer and developmental disorders, but the consequences of altered eIF3 subunit expression on its overall structure and composition, and on translation in general, remain unclear. We present the first complete in vivo study monitoring the effects of RNAi knockdown of each subunit of human eIF3 on its function, subunit balance and integrity. We show that the eIF3b and octameric eIF3a subunits serve as the nucleation core around which other subunits assemble in an ordered way into two interconnected modules: the yeast-like core and the octamer, respectively. In the absence of eIF3b neither module forms in vivo, whereas eIF3d knock-down results in severe proliferation defects with no impact on eIF3 integrity. Disrupting the octamer produces an array of subcomplexes with potential roles in translational regulation. This study, outlining the mechanism of eIF3 assembly and illustrating how imbalanced expression of eIF3 subunits impacts the factor's overall expression profile, thus provides a comprehensive guide to the human eIF3 complex and to the relationship between eIF3 misregulation and cancer.
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Affiliation(s)
- Susan Wagner
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, Videnska 1083, Prague, 142 20, the Czech Republic
| | - Anna Herrmannová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, Videnska 1083, Prague, 142 20, the Czech Republic
| | - Darina Šikrová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, Videnska 1083, Prague, 142 20, the Czech Republic
| | - Leoš Shivaya Valášek
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, Videnska 1083, Prague, 142 20, the Czech Republic
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36
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Poynter ST, Kadoch C. Polycomb and trithorax opposition in development and disease. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2016; 5:659-688. [PMID: 27581385 DOI: 10.1002/wdev.244] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 05/07/2016] [Accepted: 06/02/2016] [Indexed: 01/08/2023]
Abstract
Early discoveries in chromatin biology and epigenetics heralded new insights into organismal development. From these studies, two mediators of cellular differentiation were discovered: the Polycomb group (PcG) of transcriptional repressors, and the trithorax group (trxG) of transcriptional activators. These protein families, while opposed in function, work together to coordinate the appropriate cellular developmental programs that allow for both embryonic stem cell self-renewal and differentiation. Recently, both the PcG and trxG chromatin modulators have been observed to be deregulated in a wide spectrum diseases including developmental disorders and cancer. To understand the impact of these findings we outline the past, present, and future. WIREs Dev Biol 2016, 5:659-688. doi: 10.1002/wdev.244 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Steven T Poynter
- Chemical Biology Program, Harvard Medical School, Boston, MA, USA.,Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.,Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Cigall Kadoch
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, USA. .,Broad Institute of MIT and Harvard, Cambridge, MA, USA.
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37
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Hodges C, Kirkland JG, Crabtree GR. The Many Roles of BAF (mSWI/SNF) and PBAF Complexes in Cancer. Cold Spring Harb Perspect Med 2016; 6:cshperspect.a026930. [PMID: 27413115 DOI: 10.1101/cshperspect.a026930] [Citation(s) in RCA: 269] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
During the last decade, a host of epigenetic mechanisms were found to contribute to cancer and other human diseases. Several genomic studies have revealed that ∼20% of malignancies have alterations of the subunits of polymorphic BRG-/BRM-associated factor (BAF) and Polybromo-associated BAF (PBAF) complexes, making them among the most frequently mutated complexes in cancer. Recurrent mutations arise in genes encoding several BAF/PBAF subunits, including ARID1A, ARID2, PBRM1, SMARCA4, and SMARCB1 These subunits share some degree of conservation with subunits from related adenosine triphosphate (ATP)-dependent chromatin remodeling complexes in model organisms, in which a large body of work provides insight into their roles in cancer. Here, we review the roles of BAF- and PBAF-like complexes in these organisms, and relate these findings to recent discoveries in cancer epigenomics. We review several roles of BAF and PBAF complexes in cancer, including transcriptional regulation, DNA repair, and regulation of chromatin architecture and topology. More recent results highlight the need for new techniques to study these complexes.
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Affiliation(s)
- Courtney Hodges
- Departments of Pathology, Developmental Biology, and Genetics, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California 94305
| | - Jacob G Kirkland
- Departments of Pathology, Developmental Biology, and Genetics, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California 94305
| | - Gerald R Crabtree
- Departments of Pathology, Developmental Biology, and Genetics, Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, California 94305
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38
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The Swi3 protein plays a unique role in regulating respiration in eukaryotes. Biosci Rep 2016; 36:BSR20160083. [PMID: 27190130 PMCID: PMC5293592 DOI: 10.1042/bsr20160083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 05/17/2016] [Indexed: 01/08/2023] Open
Abstract
Recent experimental evidence increasingly shows that the dysregulation of cellular bioenergetics is associated with a wide array of common human diseases, including cancer, neurological diseases and diabetes. Respiration provides a vital source of cellular energy for most eukaryotic cells, particularly high energy demanding cells. However, the understanding of how respiration is globally regulated is very limited. Interestingly, recent evidence suggests that Swi3 is an important regulator of respiration genes in yeast. In this report, we performed an array of biochemical and genetic experiments and computational analysis to directly evaluate the function of Swi3 and its human homologues in regulating respiration. First, we showed, by computational analysis and measurements of oxygen consumption and promoter activities, that Swi3, not Swi2, regulates genes encoding functions involved in respiration and oxygen consumption. Biochemical analysis showed that the levels of mitochondrial respiratory chain complexes were substantially increased in Δswi3 cells, compared with the parent cells. Additionally, our data showed that Swi3 strongly affects haem/oxygen-dependent activation of respiration gene promoters whereas Swi2 affects only the basal, haem-independent activities of these promoters. We found that increased expression of aerobic expression genes is correlated with increased oxygen consumption and growth rates in Δswi3 cells in air. Furthermore, using computational analysis and RNAi knockdown, we showed that the mammalian Swi3 BAF155 and BAF170 regulate respiration in HeLa cells. Together, these experimental and computational data demonstrated that Swi3 and its mammalian homologues are key regulators in regulating respiration.
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39
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Mazina MY, Vorobyeva NE. The role of ATP-dependent chromatin remodeling complexes in regulation of genetic processes. RUSS J GENET+ 2016. [DOI: 10.1134/s1022795416050082] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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40
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Low JKK, Webb SR, Silva APG, Saathoff H, Ryan DP, Torrado M, Brofelth M, Parker BL, Shepherd NE, Mackay JP. CHD4 Is a Peripheral Component of the Nucleosome Remodeling and Deacetylase Complex. J Biol Chem 2016; 291:15853-66. [PMID: 27235397 DOI: 10.1074/jbc.m115.707018] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Indexed: 01/08/2023] Open
Abstract
Chromatin remodeling enzymes act to dynamically regulate gene accessibility. In many cases, these enzymes function as large multicomponent complexes that in general comprise a central ATP-dependent Snf2 family helicase that is decorated with a variable number of regulatory subunits. The nucleosome remodeling and deacetylase (NuRD) complex, which is essential for normal development in higher organisms, is one such macromolecular machine. The NuRD complex comprises ∼10 subunits, including the histone deacetylases 1 and 2 (HDAC1 and HDAC2), and is defined by the presence of a CHD family remodeling enzyme, most commonly CHD4 (chromodomain helicase DNA-binding protein 4). The existing paradigm holds that CHD4 acts as the central hub upon which the complex is built. We show here that this paradigm does not, in fact, hold and that CHD4 is a peripheral component of the NuRD complex. A complex lacking CHD4 that has HDAC activity can exist as a stable species. The addition of recombinant CHD4 to this nucleosome deacetylase complex reconstitutes a NuRD complex with nucleosome remodeling activity. These data contribute to our understanding of the architecture of the NuRD complex.
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Affiliation(s)
- Jason K K Low
- From the School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales 2006, Australia and
| | - Sarah R Webb
- From the School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales 2006, Australia and
| | - Ana P G Silva
- From the School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales 2006, Australia and
| | - Hinnerk Saathoff
- From the School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales 2006, Australia and
| | - Daniel P Ryan
- the Department of Genome Sciences, John Curtin School of Medical Research, Australian National University, Acton, Australian Capital Territory 2601, Australia
| | - Mario Torrado
- From the School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales 2006, Australia and
| | - Mattias Brofelth
- From the School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales 2006, Australia and
| | - Benjamin L Parker
- From the School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales 2006, Australia and
| | - Nicholas E Shepherd
- From the School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales 2006, Australia and
| | - Joel P Mackay
- From the School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales 2006, Australia and
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41
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Structural analyses of the chromatin remodelling enzymes INO80-C and SWR-C. Nat Commun 2015; 6:7108. [PMID: 25964121 PMCID: PMC4431590 DOI: 10.1038/ncomms8108] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 04/01/2015] [Indexed: 01/11/2023] Open
Abstract
INO80-C and SWR-C are conserved members of a subfamily of ATP-dependent chromatin remodeling enzymes that function in transcription and genome-maintenance pathways. A crucial role for these enzymes is to control chromosomal distribution of the H2A.Z histone variant. Here we use electron microscopy (EM) and two-dimensional (2D) class averaging to demonstrate that these remodeling enzymes have similar overall architectures. Each enzyme is characterized by a dynamic ‘tail’ domain and a compact ‘head’ that contains Rvb1/Rvb2 subunits organized as hexameric rings. EM class averages and mass spectrometry support the existence of single heterohexameric rings in both SWR-C and INO80-C. EM studies define the position of the Arp8/Arp4/Act1 module within INO80-C, and we find that this module enhances nucleosome binding affinity but is largely dispensable for remodeling activities. In contrast, the Ies6/Arp5 module is essential for INO80-C remodeling, and furthermore this module controls conformational changes that may couple nucleosome binding to remodeling.
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42
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Tosi A, Haas C, Herzog F, Gilmozzi A, Berninghausen O, Ungewickell C, Gerhold CB, Lakomek K, Aebersold R, Beckmann R, Hopfner KP. Structure and subunit topology of the INO80 chromatin remodeler and its nucleosome complex. Cell 2013; 154:1207-19. [PMID: 24034245 DOI: 10.1016/j.cell.2013.08.016] [Citation(s) in RCA: 174] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 06/05/2013] [Accepted: 08/12/2013] [Indexed: 11/16/2022]
Abstract
INO80/SWR1 family chromatin remodelers are complexes composed of >15 subunits and molecular masses exceeding 1 MDa. Their important role in transcription and genome maintenance is exchanging the histone variants H2A and H2A.Z. We report the architecture of S. cerevisiae INO80 using an integrative approach of electron microscopy, crosslinking and mass spectrometry. INO80 has an embryo-shaped head-neck-body-foot architecture and shows dynamic open and closed conformations. We can assign an Rvb1/Rvb2 heterododecamer to the head in close contact with the Ino80 Snf2 domain, Ies2, and the Arp5 module at the neck. The high-affinity nucleosome-binding Nhp10 module localizes to the body, whereas the module that contains actin, Arp4, and Arp8 maps to the foot. Structural and biochemical analyses indicate that the nucleosome is bound at the concave surface near the neck, flanked by the Rvb1/2 and Arp8 modules. Our analysis establishes a structural and functional framework for this family of large remodelers.
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Affiliation(s)
- Alessandro Tosi
- Department of Biochemistry, Ludwig-Maximilian University, 81377 Munich, Germany; Gene Center, Ludwig-Maximilian University, 81377 Munich, Germany
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Nucleosome free regions in yeast promoters result from competitive binding of transcription factors that interact with chromatin modifiers. PLoS Comput Biol 2013; 9:e1003181. [PMID: 23990766 PMCID: PMC3749953 DOI: 10.1371/journal.pcbi.1003181] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 07/04/2013] [Indexed: 11/19/2022] Open
Abstract
Because DNA packaging in nucleosomes modulates its accessibility to transcription factors (TFs), unraveling the causal determinants of nucleosome positioning is of great importance to understanding gene regulation. Although there is evidence that intrinsic sequence specificity contributes to nucleosome positioning, the extent to which other factors contribute to nucleosome positioning is currently highly debated. Here we obtained both in vivo and in vitro reference maps of positions that are either consistently covered or free of nucleosomes across multiple experimental data-sets in Saccharomyces cerevisiae. We then systematically quantified the contribution of TF binding to nucleosome positiong using a rigorous statistical mechanics model in which TFs compete with nucleosomes for binding DNA. Our results reconcile previous seemingly conflicting results on the determinants of nucleosome positioning and provide a quantitative explanation for the difference between in vivo and in vitro positioning. On a genome-wide scale, nucleosome positioning is dominated by the phasing of nucleosome arrays over gene bodies, and their positioning is mainly determined by the intrinsic sequence preferences of nucleosomes. In contrast, larger nucleosome free regions in promoters, which likely have a much more significant impact on gene expression, are determined mainly by TF binding. Interestingly, of the 158 yeast TFs included in our modeling, we find that only 10–20 significantly contribute to inducing nucleosome-free regions, and these TFs are highly enriched for having direct interations with chromatin remodelers. Together our results imply that nucleosome free regions in yeast promoters results from the binding of a specific class of TFs that recruit chromatin remodelers. The DNA of all eukaryotic organisms is packaged into nucleosomes, which cover roughly of the genome. As nucleosome positioning profoundly affects DNA accessibility to other DNA binding proteins such as transcription factors (TFs), it plays an important role in transcription regulation. However, to what extent nucleosome positioning is guided by intrinsic DNA sequence preferences of nucleosomes, and to what extent other DNA binding factors play a role, is currently highly debated. Here we use a rigorous biophysical model to systematically study the relative contributions of intrinsic sequence preferences and competitive binding of TFs to nucleosome positioning in yeast. We find that, on the one hand, the phasing of the many small spacers within dense nucleosome arrays that cover gene bodies are mainly determined by intrinsic sequence preferences. On the other hand, larger nucleosome free regions (NFRs) in promoters are explained predominantly by TF binding. Strikingly, we find that only 10–20 TFs make a significant contribution to explaining NFRs, and these TFs are highly enriched for directly interacting with chromatin modifiers. Thus, the picture that emerges is that binding by a specific class of TFs recruits chromatin modifiers which mediate local nucleosome expulsion.
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Oike T, Ogiwara H, Nakano T, Yokota J, Kohno T. Inactivating Mutations in SWI/SNF Chromatin Remodeling Genes in Human Cancer. Jpn J Clin Oncol 2013; 43:849-55. [DOI: 10.1093/jjco/hyt101] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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45
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Adkins NL, Niu H, Sung P, Peterson CL. Nucleosome dynamics regulates DNA processing. Nat Struct Mol Biol 2013; 20:836-42. [PMID: 23728291 PMCID: PMC3711194 DOI: 10.1038/nsmb.2585] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 04/12/2013] [Indexed: 11/18/2022]
Abstract
The repair of DNA double strand breaks (DSBs) is critical for the maintenance of genome integrity. The first step in DSB repair by homologous recombination is processing of the ends by one of two resection pathways, exemplified by Saccharomyces cerevisiae Exo1 and Sgs1–Dna2. Here we report in vitro and in vivo studies that characterize the impact of chromatin on each resection pathway. We find that efficient resection by the Sgs1-Dna2 -dependent machinery requires a nucleosome-free gap adjacent to the DSB. Resection by Exo1 is blocked by nucleosomes, and processing activity can be partially restored by removal of the H2A-H2B dimers. Our study also supports a role for the dynamic incorporation of the H2A.Z histone variant in Exo1 processing, and it further suggests that the two resection pathways require distinct chromatin remodeling events in order to navigate chromatin structure.
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Affiliation(s)
- Nicholas L Adkins
- University of Massachusetts Medical School, Worcester, Massachusetts, USA
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46
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Interactions between the nucleosome histone core and Arp8 in the INO80 chromatin remodeling complex. Proc Natl Acad Sci U S A 2012; 109:20883-8. [PMID: 23213201 DOI: 10.1073/pnas.1214735109] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Actin-related protein Arp8 is a component of the INO80 chromatin remodeling complex. Yeast Arp8 (yArp8) comprises two domains: a 25-KDa N-terminal domain, found only in yeast, and a 75-KDa C-terminal domain (yArp8CTD) that contains the actin fold and is conserved across other species. The crystal structure shows that yArp8CTD contains three insertions within the actin core. Using a combination of biochemistry and EM, we show that Arp8 forms a complex with nucleosomes, and that the principal interactions are via the H3 and H4 histones, mediated through one of the yArp8 insertions. We show that recombinant yArp8 exists in monomeric and dimeric states, but the dimer is the biologically relevant form required for stable interactions with histones that exploits the twofold symmetry of the nucleosome core. Taken together, these data provide unique insight into the stoichiometry, architecture, and molecular interactions between components of the INO80 remodeling complex and nucleosomes, providing a first step toward building up the structure of the complex.
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47
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Euskirchen G, Auerbach RK, Snyder M. SWI/SNF chromatin-remodeling factors: multiscale analyses and diverse functions. J Biol Chem 2012; 287:30897-905. [PMID: 22952240 PMCID: PMC3438922 DOI: 10.1074/jbc.r111.309302] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Chromatin-remodeling enzymes play essential roles in many biological processes, including gene expression, DNA replication and repair, and cell division. Although one such complex, SWI/SNF, has been extensively studied, new discoveries are still being made. Here, we review SWI/SNF biochemistry; highlight recent genomic and proteomic advances; and address the role of SWI/SNF in human diseases, including cancer and viral infections. These studies have greatly increased our understanding of complex nuclear processes.
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Affiliation(s)
- Ghia Euskirchen
- Department of Genetics, Stanford University School of Medicine, Stanford, California 94305-5120, USA
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48
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Dastidar RG, Hooda J, Shah A, Cao TM, Henke RM, Zhang L. The nuclear localization of SWI/SNF proteins is subjected to oxygen regulation. Cell Biosci 2012; 2:30. [PMID: 22932476 PMCID: PMC3489556 DOI: 10.1186/2045-3701-2-30] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 08/17/2012] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Hypoxia is associated with many disease conditions in humans, such as cancer, stroke and traumatic injuries. Hypoxia elicits broad molecular and cellular changes in diverse eukaryotes. Our recent studies suggest that one likely mechanism mediating such broad changes is through changes in the cellular localization of important regulatory proteins. Particularly, we have found that over 120 nuclear proteins with important functions ranging from transcriptional regulation to RNA processing exhibit altered cellular locations under hypoxia. In this report, we describe further experiments to identify and evaluate the role of nuclear protein relocalization in mediating hypoxia responses in yeast. RESULTS To identify regulatory proteins that play a causal role in mediating hypoxia responses, we characterized the time courses of relocalization of hypoxia-altered nuclear proteins in response to hypoxia and reoxygenation. We found that 17 nuclear proteins relocalized in a significantly shorter time period in response to both hypoxia and reoxygenation. Particularly, several components of the SWI/SNF complex were fast responders, and analysis of gene expression data show that many targets of the SWI/SNF proteins are oxygen regulated. Furthermore, confocal fluorescent live cell imaging showed that over 95% of hypoxia-altered SWI/SNF proteins accumulated in the cytosol in hypoxic cells, while over 95% of the proteins were nuclear in normoxic cells, as expected. CONCLUSIONS SWI/SNF proteins relocalize in response to hypoxia and reoxygenation in a quick manner, and their relocalization likely accounts for, in part or in whole, oxygen regulation of many SWI/SNF target genes.
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Affiliation(s)
- Ranita Ghosh Dastidar
- Department of Molecular and Cell Biology, Center for Systems Biology, University of Texas at Dallas, Mail Stop RL11 800 W Campbell Road, Richardson, TX, 75080, USA
| | - Jagmohan Hooda
- Department of Molecular and Cell Biology, Center for Systems Biology, University of Texas at Dallas, Mail Stop RL11 800 W Campbell Road, Richardson, TX, 75080, USA
| | - Ajit Shah
- Department of Molecular and Cell Biology, Center for Systems Biology, University of Texas at Dallas, Mail Stop RL11 800 W Campbell Road, Richardson, TX, 75080, USA
| | - Thai M Cao
- Department of Molecular and Cell Biology, Center for Systems Biology, University of Texas at Dallas, Mail Stop RL11 800 W Campbell Road, Richardson, TX, 75080, USA
| | - Robert Michael Henke
- Department of Molecular and Cell Biology, Center for Systems Biology, University of Texas at Dallas, Mail Stop RL11 800 W Campbell Road, Richardson, TX, 75080, USA
| | - Li Zhang
- Department of Molecular and Cell Biology, Center for Systems Biology, University of Texas at Dallas, Mail Stop RL11 800 W Campbell Road, Richardson, TX, 75080, USA
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Willis MS, Homeister JW, Rosson GB, Annayev Y, Holley D, Holly SP, Madden VJ, Godfrey V, Parise LV, Bultman SJ. Functional redundancy of SWI/SNF catalytic subunits in maintaining vascular endothelial cells in the adult heart. Circ Res 2012; 111:e111-22. [PMID: 22740088 DOI: 10.1161/circresaha.112.265587] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
RATIONALE Mating type switching/sucrose non-fermenting (SWI/SNF) chromatin-remodeling complexes utilize either BRG1 or BRM as a catalytic subunit to alter nucleosome position and regulate gene expression. BRG1 is required for vascular endothelial cell (VEC) development and embryonic survival, whereas BRM is dispensable. OBJECTIVE To circumvent embryonic lethality and study Brg1 function in adult tissues, we used conditional gene targeting. To evaluate possible Brg1-Brm redundancy, we analyzed Brg1 mutant mice on wild-type and Brm-deficient backgrounds. METHODS AND RESULTS The inducible Mx1-Cre driver was used to mutate Brg1 in adult mice. These conditional-null mutants exhibited a tissue-specific phenotype and unanticipated functional compensation between Brg1 and Brm. Brg1 single mutants were healthy and had a normal lifespan, whereas Brg1/Brm double mutants exhibited cardiovascular defects and died within 1 month. BRG1 and BRM were required for the viability of VECs but not other cell types where both genes were also knocked out. The VEC phenotype was most evident in the heart, particularly in the microvasculature of the outer myocardium, and was recapitulated in primary cells ex vivo. VEC death resulted in vascular leakage, cardiac hemorrhage, secondary death of cardiomyocytes due to ischemia, and ventricular dissections. CONCLUSIONS BRG1-catalyzed SWI/SNF complexes are particularly important in cardiovascular tissues. However, in contrast to embryonic development, in which Brm does not compensate, Brg1 is required in adult VECs only when Brm is also mutated. These results demonstrate for the first time that Brm functionally compensates for Brg1 in vivo and that there are significant changes in the relative importance of BRG1- and BRM-catalyzed SWI/SNF complexes during the development of an essential cell lineage.
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Affiliation(s)
- Monte S Willis
- 120 Mason Farm Rd, Genetic Medicine Bldg, Room 5060, Chapel Hill, NC 27516-7264, USA
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He L, Liu H, Tang L. SWI/SNF chromatin remodeling complex: a new cofactor in reprogramming. Stem Cell Rev Rep 2012; 8:128-36. [PMID: 21655945 DOI: 10.1007/s12015-011-9285-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Induced pluripotent stem (iPS) cells can be derived from somatic cells. Four key factors are required in this process including Oct4, Sox2, Klf4 and c-Myc. Ectopic expression of these four factors in somatic cells leads to reprogramming. Recent studies show that the SWItch/Sucrose NonFermentable (SWI/SNF) chromatin remodeling complex plays critical roles in reprogramming of somatic cells and maintaining the pluripotency of stem cells. The possible mechanism is that SWI/SNF enhances the binding activity of reprogramming factors to pluripotent gene promoters and thus increases the reprogramming efficiency. Here, we review these recent advances and discuss how SWI/SNF plays a role in reprogramming. Understanding this mechanism will be helpful to find out the detail of reprogramming, which may provide a new therapy in medical science by generating patient-specific pluripotent stem cells.
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Affiliation(s)
- Ling He
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, 400044, China
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