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Saha D, Animireddy S, Bartholomew B. The SWI/SNF ATP-dependent chromatin remodeling complex in cell lineage priming and early development. Biochem Soc Trans 2024; 52:603-616. [PMID: 38572912 PMCID: PMC11088921 DOI: 10.1042/bst20230416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 03/22/2024] [Accepted: 03/26/2024] [Indexed: 04/05/2024]
Abstract
ATP dependent chromatin remodelers have pivotal roles in transcription, DNA replication and repair, and maintaining genome integrity. SWI/SNF remodelers were first discovered in yeast genetic screens for factors involved in mating type switching or for using alternative energy sources therefore termed SWI/SNF complex (short for SWItch/Sucrose NonFermentable). The SWI/SNF complexes utilize energy from ATP hydrolysis to disrupt histone-DNA interactions and shift, eject, or reposition nucleosomes making the underlying DNA more accessible to specific transcription factors and other regulatory proteins. In development, SWI/SNF orchestrates the precise activation and repression of genes at different stages, safe guards the formation of specific cell lineages and tissues. Dysregulation of SWI/SNF have been implicated in diseases such as cancer, where they can drive uncontrolled cell proliferation and tumor metastasis. Additionally, SWI/SNF defects are associated with neurodevelopmental disorders, leading to disruption of neural development and function. This review offers insights into recent developments regarding the roles of the SWI/SNF complex in pluripotency and cell lineage primining and the approaches that have helped delineate its importance. Understanding these molecular mechanisms is crucial for unraveling the intricate processes governing embryonic stem cell biology and developmental transitions and may potentially apply to human diseases linked to mutations in the SWI/SNF complex.
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Affiliation(s)
- Dhurjhoti Saha
- Department of Epigenetics and Molecular Carcinogenesis, Center for Cancer Epigenetics, University of Texas MD Anderson Cancer Center, Houston, TX 77054, U.S.A
| | - Srinivas Animireddy
- Department of Epigenetics and Molecular Carcinogenesis, Center for Cancer Epigenetics, University of Texas MD Anderson Cancer Center, Houston, TX 77054, U.S.A
| | - Blaine Bartholomew
- Department of Epigenetics and Molecular Carcinogenesis, Center for Cancer Epigenetics, University of Texas MD Anderson Cancer Center, Houston, TX 77054, U.S.A
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2
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Chio US, Palovcak E, Smith AAA, Autzen H, Muñoz EN, Yu Z, Wang F, Agard DA, Armache JP, Narlikar GJ, Cheng Y. Functionalized graphene-oxide grids enable high-resolution cryo-EM structures of the SNF2h-nucleosome complex without crosslinking. Nat Commun 2024; 15:2225. [PMID: 38472177 PMCID: PMC10933330 DOI: 10.1038/s41467-024-46178-y] [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: 05/19/2023] [Accepted: 02/15/2024] [Indexed: 03/14/2024] Open
Abstract
Single-particle cryo-EM is widely used to determine enzyme-nucleosome complex structures. However, cryo-EM sample preparation remains challenging and inconsistent due to complex denaturation at the air-water interface (AWI). Here, to address this issue, we develop graphene-oxide-coated EM grids functionalized with either single-stranded DNA (ssDNA) or thiol-poly(acrylic acid-co-styrene) (TAASTY) co-polymer. These grids protect complexes between the chromatin remodeler SNF2h and nucleosomes from the AWI and facilitate collection of high-quality micrographs of intact SNF2h-nucleosome complexes in the absence of crosslinking. The data yields maps ranging from 2.3 to 3 Å in resolution. 3D variability analysis reveals nucleotide-state linked conformational changes in SNF2h bound to a nucleosome. In addition, the analysis provides structural evidence for asymmetric coordination between two SNF2h protomers acting on the same nucleosome. We envision these grids will enable similar detailed structural analyses for other enzyme-nucleosome complexes and possibly other protein-nucleic acid complexes in general.
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Affiliation(s)
- Un Seng Chio
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - Eugene Palovcak
- Biophysics Graduate Program, University of California San Francisco, San Francisco, CA, USA
| | - Anton A A Smith
- Department of Materials Science & Engineering, Stanford University, Stanford, CA, USA
- Department of Health Technology, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Henriette Autzen
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
- Linderstrom-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, København, Denmark
| | - Elise N Muñoz
- Tetrad Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Zanlin Yu
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - Feng Wang
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - David A Agard
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - Jean-Paul Armache
- Department of Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA.
| | - Geeta J Narlikar
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA.
| | - Yifan Cheng
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA.
- Howard Hughes Medical Institute, University of California San Francisco, San Francisco, CA, USA.
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3
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Bacic L, Gaullier G, Mohapatra J, Mao G, Brackmann K, Panfilov M, Liszczak G, Sabantsev A, Deindl S. Asymmetric nucleosome PARylation at DNA breaks mediates directional nucleosome sliding by ALC1. Nat Commun 2024; 15:1000. [PMID: 38307862 PMCID: PMC10837151 DOI: 10.1038/s41467-024-45237-8] [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: 03/09/2023] [Accepted: 01/16/2024] [Indexed: 02/04/2024] Open
Abstract
The chromatin remodeler ALC1 is activated by DNA damage-induced poly(ADP-ribose) deposited by PARP1/PARP2 and their co-factor HPF1. ALC1 has emerged as a cancer drug target, but how it is recruited to ADP-ribosylated nucleosomes to affect their positioning near DNA breaks is unknown. Here we find that PARP1/HPF1 preferentially initiates ADP-ribosylation on the histone H2B tail closest to the DNA break. To dissect the consequences of such asymmetry, we generate nucleosomes with a defined ADP-ribosylated H2B tail on one side only. The cryo-electron microscopy structure of ALC1 bound to such an asymmetric nucleosome indicates preferential engagement on one side. Using single-molecule FRET, we demonstrate that this asymmetric recruitment gives rise to directed sliding away from the DNA linker closest to the ADP-ribosylation site. Our data suggest a mechanism by which ALC1 slides nucleosomes away from a DNA break to render it more accessible to repair factors.
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Affiliation(s)
- Luka Bacic
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, 75124, Uppsala, Sweden
| | - Guillaume Gaullier
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, 75124, Uppsala, Sweden
- Department of Chemistry - Ångström, Uppsala University, 75120, Uppsala, Sweden
| | - Jugal Mohapatra
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390, USA
| | - Guanzhong Mao
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, 75124, Uppsala, Sweden
| | - Klaus Brackmann
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, 75124, Uppsala, Sweden
| | - Mikhail Panfilov
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, 75124, Uppsala, Sweden
| | - Glen Liszczak
- Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390, USA
| | - Anton Sabantsev
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, 75124, Uppsala, Sweden.
| | - Sebastian Deindl
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, 75124, Uppsala, Sweden.
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4
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Bartholomew B, Shukla S, Ngubo M, Paul S, Persinger J, Brahma S. New insights into the mechanism and DNA-sequence specificity of INO80 chromatin remodeling. RESEARCH SQUARE 2023:rs.3.rs-3443329. [PMID: 37961512 PMCID: PMC10635376 DOI: 10.21203/rs.3.rs-3443329/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
The INO80 complex stood out in a large family of ATP-dependent chromatin remodelers because of its ATPase domain binding and translocating on DNA at the edge of nucleosomes, rather than at two helical turns from the center of DNA that is wrapped around nucleosomes. This unique property of INO80 was thought to account for its singular role in nucleosome placement at gene promoters in a DNA-sequence dependent manner that is crucial for transcription regulation. Now, we uncover INO80 functions differently than previously thought with its ATPase domain translocating on DNA close to the center of nucleosomes, like other remodelers. Our discovery also reveals the physical properties of the first ~36 bp of DNA on the entry side of nucleosomes is the main determinant for the DNA specificity of INO80 rather than the properties of the extranucleosomal DNA. The DNA sequence sensitive step of INO80 is after DNA is displaced from the histone octamer on the entry side of nucleosomes and 20 bp of DNA are moved out the exit side. We find the ATPase domain and Arp5 subunit of INO80 are likely involved in INO80's DNA specificity and the mechanism of INO80 remodeling is substantially different than originally proposed.
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5
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Sokolova V, Lee G, Mullins A, Mody P, Watanabe S, Tan D. DNA-translocation-independent role of INO80 remodeler in DNA damage repairs. J Biol Chem 2023; 299:105245. [PMID: 37696438 PMCID: PMC10570696 DOI: 10.1016/j.jbc.2023.105245] [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: 06/12/2023] [Revised: 08/22/2023] [Accepted: 09/04/2023] [Indexed: 09/13/2023] Open
Abstract
Chromatin remodelers utilize ATP hydrolysis to reposition histone octamers on DNA, facilitating transcription by promoting histone displacements. Although their actions on chromatin with damaged DNA are assumed to be similar, the precise mechanisms by which they modulate damaged nucleosomes and their specific roles in DNA damage response (DDR) remain unclear. INO80-C, a versatile chromatin remodeler, plays a crucial role in the efficient repair of various types of damage. In this study, we have demonstrated that both abasic sites and UV-irradiation damage abolish the DNA translocation activity of INO80-C. Additionally, we have identified compromised ATP hydrolysis within the Ino80 catalytic subunit as the primary cause of the inhibition of DNA translocation, while its binding to damaged nucleosomes remains unaffected. Moreover, we have uncovered a novel function of INO80-C that operates independently of its DNA translocation activity, namely, its facilitation of apurinic/apyrimidinic (AP) site cleavage by the AP-endonuclease 1 (APE1). Our findings provide valuable insights into the role of the INO80-C chromatin remodeler in DDR, thereby advancing our understanding of chromatin remodeling during DNA damage repairs.
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Affiliation(s)
- Vladyslava Sokolova
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Gahyun Lee
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Amber Mullins
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Preesha Mody
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Shinya Watanabe
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Dongyan Tan
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA.
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6
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Wu H, Muñoz EN, Hsieh LJ, Chio US, Gourdet MA, Narlikar GJ, Cheng Y. Reorientation of INO80 on hexasomes reveals basis for mechanistic versatility. Science 2023; 381:319-324. [PMID: 37384669 PMCID: PMC10480058 DOI: 10.1126/science.adf4197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 06/17/2023] [Indexed: 07/01/2023]
Abstract
Unlike other chromatin remodelers, INO80 preferentially mobilizes hexasomes, which can form during transcription. Why INO80 prefers hexasomes over nucleosomes remains unclear. Here, we report structures of Saccharomyces cerevisiae INO80 bound to a hexasome or a nucleosome. INO80 binds the two substrates in substantially different orientations. On a hexasome, INO80 places its ATPase subunit, Ino80, at superhelical location -2 (SHL -2), in contrast to SHL -6 and SHL -7, as previously seen on nucleosomes. Our results suggest that INO80 action on hexasomes resembles action by other remodelers on nucleosomes such that Ino80 is maximally active near SHL -2. The SHL -2 position also plays a critical role for nucleosome remodeling by INO80. Overall, the mechanistic adaptations used by INO80 for preferential hexasome sliding imply that subnucleosomal particles play considerable regulatory roles.
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Affiliation(s)
- Hao Wu
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94158, USA
| | - Elise N. Muñoz
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94158, USA
- Tetrad Graduate Program, University of California San Francisco, San Francisco, CA 94158, USA
| | - Laura J. Hsieh
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94158, USA
| | - Un Seng Chio
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94158, USA
| | - Muryam A. Gourdet
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94158, USA
- Tetrad Graduate Program, University of California San Francisco, San Francisco, CA 94158, USA
| | - Geeta J. Narlikar
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94158, USA
| | - Yifan Cheng
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94158, USA
- Howard Hughes Medical Institute, University of California San Francisco, San Francisco, CA 94158, USA
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7
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Chio US, Palovcak E, Autzen AAA, Autzen HE, Muñoz EN, Yu Z, Wang F, Agard DA, Armache JP, Narlikar GJ, Cheng Y. Functionalized graphene-oxide grids enable high-resolution cryo-EM structures of the SNF2h-nucleosome complex without crosslinking. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.20.545796. [PMID: 37546986 PMCID: PMC10402172 DOI: 10.1101/2023.06.20.545796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Single-particle cryo-EM is widely used to determine enzyme-nucleosome complex structures. However, cryo-EM sample preparation remains challenging and inconsistent due to complex denaturation at the air-water interface (AWI). To address this issue, we developed graphene-oxide-coated EM grids functionalized with either single-stranded DNA (ssDNA) or thiol-poly(acrylic acid-co-styrene) (TAASTY) co-polymer. These grids protect complexes between the chromatin remodeler SNF2h and nucleosomes from the AWI and facilitated collection of high-quality micrographs of intact SNF2h-nucleosome complexes in the absence of crosslinking. The data yields maps ranging from 2.3 to 3 Å in resolution. 3D variability analysis reveals nucleotide-state linked conformational changes in SNF2h bound to a nucleosome. In addition, the analysis provides structural evidence for asymmetric coordination between two SNF2h protomers acting on the same nucleosome. We envision these grids will enable similar detailed structural analyses for other enzyme-nucleosome complexes and possibly other protein-nucleic acid complexes in general.
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Affiliation(s)
- Un Seng Chio
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - Eugene Palovcak
- Biophysics Graduate Program, University of California San Francisco, San Francisco, CA, USA
| | - Anton A. A. Autzen
- Department of Materials Science & Engineering, Stanford University, Stanford, CA, USA
- Current: Department of Health Technology, Technical University of Denmark
| | - Henriette E. Autzen
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
- Linderstrom-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Denmark
| | - Elise N. Muñoz
- Tetrad Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Zanlin Yu
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - Feng Wang
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - David A. Agard
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - Jean-Paul Armache
- Department of Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA
| | - Geeta J. Narlikar
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - Yifan Cheng
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California San Francisco, San Francisco, CA, USA
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8
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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: 3] [Impact Index Per Article: 3.0] [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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Bhat JA, Balliano AJ, Hayes JJ. Histone protein surface accessibility dictates direction of RSC-dependent nucleosome mobilization. Nucleic Acids Res 2022; 50:10376-10384. [PMID: 36161493 PMCID: PMC9561379 DOI: 10.1093/nar/gkac790] [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: 06/14/2022] [Revised: 08/23/2022] [Accepted: 09/21/2022] [Indexed: 11/21/2022] Open
Abstract
Chromatin remodeling enzymes use energy derived from ATP hydrolysis to mobilize nucleosomes and alter their structure to facilitate DNA access. The Remodels the Structure of Chromatin (RSC) complex has been extensively studied, yet aspects of how this complex functionally interacts with nucleosomes remain unclear. We introduce a steric mapping approach to determine how RSC activity depends on interaction with specific surfaces within the nucleosome. We find that blocking SHL + 4.5/–4.5 via streptavidin binding to the H2A N-terminal tail domains results in inhibition of RSC nucleosome mobilization. However, restriction enzyme assays indicate that remodeling-dependent exposure of an internal DNA site near the nucleosome dyad is not affected. In contrast, occlusion of both protein faces of the nucleosome by streptavidin attachment near the acidic patch completely blocks both remodeling-dependent nucleosome mobilization and internal DNA site exposure. However, we observed partial inhibition when only one protein surface is occluded, consistent with abrogation of one of two productive RSC binding orientations. Our results indicate that nucleosome mobilization requires RSC access to the trailing but not the leading protein surface, and reveals a mechanism by which RSC and related complexes may drive unidirectional movement of nucleosomes to regulate cis-acting DNA sequences in vivo.
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Affiliation(s)
- Javeed Ahmad Bhat
- Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Angela J Balliano
- Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Jeffrey J Hayes
- Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, NY 14642, USA
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10
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Partitioned usage of chromatin remodelers by nucleosome-displacing factors. Cell Rep 2022; 40:111250. [PMID: 36001970 PMCID: PMC9422437 DOI: 10.1016/j.celrep.2022.111250] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 06/29/2022] [Accepted: 08/01/2022] [Indexed: 11/22/2022] Open
Abstract
Nucleosome-displacing-factors (NDFs) in yeast, similar to pioneer factors in higher eukaryotes, can open closed chromatin and generate nucleosome-depleted regions (NDRs). NDRs in yeast are also affected by ATP-dependent chromatin remodelers (CRs). However, how NDFs and CRs coordinate in nucleosome invasion and NDR formation is still unclear. Here, we design a high-throughput method to systematically study the interplay between NDFs and CRs. By combining an integrated synthetic oligonucleotide library with DNA methyltransferase-based, single-molecule nucleosome mapping, we measure the impact of CRs on NDRs generated by individual NDFs. We find that CRs are dispensable for nucleosome invasion by NDFs, and they function downstream of NDF binding to modulate the NDR length. A few CRs show high specificity toward certain NDFs; however, in most cases, CRs are recruited in a factor-nonspecific and NDR length-dependent manner. Overall, our study provides a framework to investigate how NDFs and CRs cooperate to regulate chromatin opening. Chromatin accessibility in yeast is regulated by nucleosome-displacing-factors (NDFs) and chromatin remodelers (CRs). Chen et al. show that NDFs first invade into nucleosomes and then recruit CRs to modulate the NDR length. NDF-specific and NDR length-dependent recruitment of CRs allow partitioned usage of CRs by NDFs.
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11
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Wang N, Qin Y, Du F, Wang X, Song C. Prevalence of SWI/SNF genomic alterations in cancer and association with the response to immune checkpoint inhibitors: A systematic review and meta-analysis. Gene X 2022; 834:146638. [PMID: 35680019 DOI: 10.1016/j.gene.2022.146638] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 06/02/2022] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND The association between SWI/SNF genomic alterations and responses to immune checkpoint inhibitors (ICIs) remains conflicting. This meta-analysis was performed to systematically assess the impact of SWI/SNF genomic alterations on response to ICIs in cancer. METHODS Relevant studies were searched in multiple databases updated to April 29, 2021. Outcomes of interest included prevalence of SWI/SNF alterations, overall survival (OS), progression-free survival (PFS) and time to treatment failure (TTF). For survival data, the hazard ratio (HR) was adopted, and the effect size was described as 95% confidence intervals (CI). RESULTS 15 studies involving 10,849 patients were included, with the overall frequency of 18.5% in SWI/SNF alterations. Across different cancer types, the mutational frequency of PBRM1 (32.0%) was the highest, followed by ARID1A (18.1%), SMARCA4 (15.6%), SMARCA2 (10.3%), ARID2 (8.1%), SMARCC2 (6.4%) and SMARCB1 (5.0%). Overall analysis showed that SWI/SNF alterations were not associated with improved OS (HR: 0.822, 95 %CI: 0.583-1.158, p = 0.262), PFS (HR: 0.608, 95 %CI: 0.434-1.067, p = 0.094) and TTF (HR: 0.923, 95 %CI: 0.757-1.125, p = 0.427) in patients treated with ICIs. In subgroup analysis, PBRM1 mutations were observed to be linked with improved OS (HR: 0.650, 95 %CI: 0.440-0.960, p = 0.030), PFS (HR: 0.539, 95 %CI: 0.314-0.926, p = 0.025) and TTF (HR: 0.490, 95 %CI: 0.271-0.885, p = 0.018) in RCC patients receiving ICIs. CONCLUSIONS The overall prevalence of SWI/SNF alterations was 18.5% across different cancer types. Except for PBRM1 mutations in RCC, SWI/SNF alterations may be uncorrelated with improved clinical outcomes in cancer.
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Affiliation(s)
- Nanya Wang
- Cancer Center, The First Hospital of Jilin University, Changchun 130021, China.
| | - Yong Qin
- State Key Laboratory of Translational Medicine and Innovative Drug Development, Jiangsu Simcere Diagnostics Co., Ltd, Nanjing 210042, China
| | - Furong Du
- State Key Laboratory of Translational Medicine and Innovative Drug Development, Jiangsu Simcere Diagnostics Co., Ltd, Nanjing 210042, China; Department of Medicine, Nanjing Simcere Medical Laboratory Science Co., Ltd., Nanjing 210042, China
| | - Xiaoxuan Wang
- State Key Laboratory of Translational Medicine and Innovative Drug Development, Jiangsu Simcere Diagnostics Co., Ltd, Nanjing 210042, China; Department of Medicine, Nanjing Simcere Medical Laboratory Science Co., Ltd., Nanjing 210042, China
| | - Chao Song
- State Key Laboratory of Translational Medicine and Innovative Drug Development, Jiangsu Simcere Diagnostics Co., Ltd, Nanjing 210042, China; Department of Medicine, Nanjing Simcere Medical Laboratory Science Co., Ltd., Nanjing 210042, China
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12
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Cooper GW, Hong AL. SMARCB1-Deficient Cancers: Novel Molecular Insights and Therapeutic Vulnerabilities. Cancers (Basel) 2022; 14:cancers14153645. [PMID: 35892904 PMCID: PMC9332782 DOI: 10.3390/cancers14153645] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 07/20/2022] [Accepted: 07/20/2022] [Indexed: 12/27/2022] Open
Abstract
Simple Summary Loss of SMARCB1 has been identified as the sole mutation in a number of rare pediatric and adult cancers, most of which have a poor prognosis despite intensive therapies including surgery, radiation, and chemotherapy. Thus, a more robust understanding of the mechanisms driving this set of cancers is vital to improving patient treatment and outcomes. This review outlines recent advances made in our understanding of the function of SMARCB1 and how these advances have been used to discover putative therapeutic vulnerabilities. Abstract SMARCB1 is a critical component of the BAF complex that is responsible for global chromatin remodeling. Loss of SMARCB1 has been implicated in the initiation of cancers such as malignant rhabdoid tumor (MRT), atypical teratoid rhabdoid tumor (ATRT), and, more recently, renal medullary carcinoma (RMC). These SMARCB1-deficient tumors have remarkably stable genomes, offering unique insights into the epigenetic mechanisms in cancer biology. Given the lack of druggable targets and the high mortality associated with SMARCB1-deficient tumors, a significant research effort has been directed toward understanding the mechanisms of tumor transformation and proliferation. Accumulating evidence suggests that tumorigenicity arises from aberrant enhancer and promoter regulation followed by dysfunctional transcriptional control. In this review, we outline key mechanisms by which loss of SMARCB1 may lead to tumor formation and cover how these mechanisms have been used for the design of targeted therapy.
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Affiliation(s)
- Garrett W. Cooper
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA;
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA
| | - Andrew L. Hong
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA;
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA
- Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA 30322, USA
- Correspondence:
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13
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A novel SNF2 ATPase complex in Trypanosoma brucei with a role in H2A.Z-mediated chromatin remodelling. PLoS Pathog 2022; 18:e1010514. [PMID: 35675371 PMCID: PMC9236257 DOI: 10.1371/journal.ppat.1010514] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/27/2022] [Accepted: 04/08/2022] [Indexed: 11/25/2022] Open
Abstract
A cascade of histone acetylation events with subsequent incorporation of a histone H2A variant plays an essential part in transcription regulation in various model organisms. A key player in this cascade is the chromatin remodelling complex SWR1, which replaces the canonical histone H2A with its variant H2A.Z. Transcriptional regulation of polycistronic transcription units in the unicellular parasite Trypanosoma brucei has been shown to be highly dependent on acetylation of H2A.Z, which is mediated by the histone-acetyltransferase HAT2. The chromatin remodelling complex which mediates H2A.Z incorporation is not known and an SWR1 orthologue in trypanosomes has not yet been reported. In this study, we identified and characterised an SWR1-like remodeller complex in T. brucei that is responsible for Pol II-dependent transcriptional regulation. Bioinformatic analysis of potential SNF2 DEAD/Box helicases, the key component of SWR1 complexes, identified a 1211 amino acids-long protein that exhibits key structural characteristics of the SWR1 subfamily. Systematic protein-protein interaction analysis revealed the existence of a novel complex exhibiting key features of an SWR1-like chromatin remodeller. RNAi-mediated depletion of the ATPase subunit of this complex resulted in a significant reduction of H2A.Z incorporation at transcription start sites and a subsequent decrease of steady-state mRNA levels. Furthermore, depletion of SWR1 and RNA-polymerase II (Pol II) caused massive chromatin condensation. The potential function of several proteins associated with the SWR1-like complex and with HAT2, the key factor of H2A.Z incorporation, is discussed. Trypanosoma brucei is the causative agent of African trypanosomiasis (sleeping sickness) in humans and nagana in cattle. Its unusual genomic organisation featuring large polycistronic units requires a general mechanism of transcription initiation, because individual gene promoters are mostly absent. Despite the fact that the histone variant H2A.Z has previously been identified as a key player of transcription regulation, the complex responsible for correct H2A.Z incorporation at transcription start sites (TSS) remains elusive. In other eukaryotes, SWR1, a SNF2 ATPase-associated chromatin remodelling complex, is responsible for correct incorporation of this histone variant. This study identified a SWR1-like complex in T. brucei. Depletion of the SNF2 ATPase resulted in a reduction of H2A.Z incorporation at the TSS and decreased steady-state mRNA levels accompanied by chromatin condensation. In addition to the SWR1-like complex, we also identified a trypanosome-specific HAT2 complex that includes the histone acetyltransferases HAT2, a key player in the H2A.Z incorporation process. This complex has a trypanosome-specific composition that is different from the NuA4/TIP60 complex in Saccharomyces cerevisiae.
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14
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Reb1, Cbf1, and Pho4 bias histone sliding and deposition away from their binding sites. Mol Cell Biol 2021; 42:e0047221. [PMID: 34898278 DOI: 10.1128/mcb.00472-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In transcriptionally active genes, nucleosome positions in promoters are regulated by nucleosome displacing factors (NDFs) and chromatin remodeling enzymes. Depletion of NDFs or the RSC chromatin remodeler shrinks or abolishes the nucleosome depleted regions (NDRs) in promoters, which can suppress gene activation and result in cryptic transcription. Despite their vital cellular functions, how the action of chromatin remodelers may be directly affected by site-specific binding factors like NDFs is poorly understood. Here we demonstrate that two NDFs, Reb1 and Cbf1, can direct both Chd1 and RSC chromatin remodeling enzymes in vitro, stimulating repositioning of the histone core away from their binding sites. Interestingly, although the Pho4 transcription factor had a much weaker effect on nucleosome positioning, both NDFs and Pho4 were able to similarly redirect positioning of hexasomes. In chaperone-mediated nucleosome assembly assays, Reb1 but not Pho4 showed an ability to block deposition of the histone H3/H4 tetramer, but Reb1 did not block addition of the H2A/H2B dimer to hexasomes. Our in vitro results show that NDFs bias the action of remodelers to increase the length of the free DNA in the vicinity of their binding sites. These results suggest that NDFs could directly affect NDR architecture through chromatin remodelers.
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15
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Kang E, Kang M, Ju Y, Lee SJ, Lee YS, Woo DC, Sung YH, Baek IJ, Shim WH, Son WC, Choi IH, Seo EJ, Yoo HW, Han YM, Lee BH. Association between ARID2 and RAS-MAPK pathway in intellectual disability and short stature. J Med Genet 2021; 58:767-777. [PMID: 33051312 DOI: 10.1136/jmedgenet-2020-107111] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 08/03/2020] [Accepted: 08/26/2020] [Indexed: 12/29/2022]
Abstract
BACKGROUND ARID2 belongs to the Switch/sucrose non-fermenting complex, in which the genetic defects have been found in patients with dysmorphism, short stature and intellectual disability (ID). As the phenotypes of patients with ARID2 mutations partially overlap with those of RASopathy, this study evaluated the biochemical association between ARID2 and RAS-MAPK pathway. METHODS The phenotypes of 22 patients with either an ARID2 heterozygous mutation or haploinsufficiency were reviewed. Comprehensive molecular analyses were performed using somatic and induced pluripotent stem cells (iPSCs) of a patient with ARID2 haploinsufficiency as well as using the mouse model of Arid2 haploinsufficiency by CRISPR/Cas9 gene editing. RESULTS The phenotypic characteristics of ARID2 deficiency include RASopathy, Coffin-Lowy syndrome or Coffin-Siris syndrome or undefined syndromic ID. Transient ARID2 knockout HeLa cells using an shRNA increased ERK1 and ERK2 phosphorylation. Impaired neuronal differentiation with enhanced RAS-MAPK activity was observed in patient-iPSCs. In addition, Arid2 haploinsufficient mice exhibited reduced body size and learning/memory deficit. ARID2 haploinsufficiency was associated with reduced IFITM1 expression, which interacts with caveolin-1 (CAV-1) and inhibits ERK activation. DISCUSSION ARID2 haploinsufficiency is associated with enhanced RAS-MAPK activity, leading to reduced IFITM1 and CAV-1 expression, thereby increasing ERK activity. This altered interaction might lead to abnormal neuronal development and a short stature.
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Affiliation(s)
- Eungu Kang
- Department of Pediatrics, Korea University Ansan Hospital, Ansan, Gyeonggi-do, Republic of Korea
| | - Minji Kang
- Asan institute for Life Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Younghee Ju
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Sang-Joon Lee
- Asan institute for Life Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Yong-Seok Lee
- Department of Physiology, Biomedical Sciences, Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Dong-Cheol Woo
- Convergence Medicine Research Center, Asan Institute for Life Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Young Hoon Sung
- Convergence Medicine Research Center, Asan Institute for Life Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
- Department of Convergence Medicine, Bio-Medical Institute of Technology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - In-Jeoung Baek
- Convergence Medicine Research Center, Asan Institute for Life Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
- Department of Convergence Medicine, Bio-Medical Institute of Technology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Woo Hyun Shim
- Department of Medical Science, Asan Medical Institute of Convergence Science and Technology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
- Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Woo-Chan Son
- Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - In Hee Choi
- Medical Genetics Center, Asan Medical Center, Seoul, Republic of Korea
| | - Eul-Ju Seo
- Medical Genetics Center, Asan Medical Center, Seoul, Republic of Korea
- Department of Laboratory Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Han-Wook Yoo
- Medical Genetics Center, Asan Medical Center, Seoul, Republic of Korea
- Department of Pediatrics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Yong-Mahn Han
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Beom Hee Lee
- Medical Genetics Center, Asan Medical Center, Seoul, Republic of Korea
- Department of Pediatrics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
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16
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Lee Y, Choi Y, Seo GH, Kim GH, Keum C, Kim YM, Do HS, Choi J, Choi IH, Yoo HW, Lee BH. Phenotypic and molecular spectra of patients with switch/sucrose nonfermenting complex-related intellectual disability disorders in Korea. BMC Med Genomics 2021; 14:254. [PMID: 34706719 PMCID: PMC8555129 DOI: 10.1186/s12920-021-01104-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 10/19/2021] [Indexed: 02/04/2023] Open
Abstract
Background The switch/sucrose nonfermenting (SWI/SNF) complex is an adenosine triphosphate-dependent chromatin-remodeling complex associated with the regulation of DNA accessibility. Germline mutations in the components of the SWI/SNF complex are related to human developmental disorders, including the Coffin–Siris syndrome (CSS), Nicolaides–Baraitser syndrome (NCBRS), and nonsyndromic intellectual disability. These disorders are collectively referred to as SWI/SNF complex-related intellectual disability disorders (SSRIDDs). Methods Whole-exome sequencing was performed in 564 Korean patients with neurodevelopmental disorders. Twelve patients with SSRIDDs (2.1%) were identified and their medical records were retrospectively analyzed. Results ARID1B, found in eight patients, was the most frequently altered gene. Four patients harbored pathogenic variants in SMARCA4, SMARCB1, ARID2, and SMARCA2. Ten patients were diagnosed with CSS, and one patient without a typical phenotype was diagnosed with ARID1B-related nonsyndromic intellectual disability. Another patient harboring the SMARCA2 pathogenic variant was diagnosed with NCBRS. All pathogenic variants in ARID1B were truncating, whereas variants in SMARCA2, SMARCB1, and SMARCA4 were nontruncating (missense). Frequently observed phenotypes were thick eyebrows (10/12), hypertrichosis (8/12), coarse face (8/12), thick lips (8/12), and long eyelashes (8/12). Developmental delay was observed in all patients, and profound speech delay was also characteristic. Agenesis or hypoplasia of the corpus callosum was observed in half of the patients (6/12). Conclusions SSRIDDs have a broad disease spectrum, including NCBRS, CSS, and ARID1B-related nonsyndromic intellectual disability. Thus, SSRIDDs should be considered as a small but important cause of human developmental disorders.
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Affiliation(s)
- Yena Lee
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, Republic of Korea
| | - Yunha Choi
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, Republic of Korea
| | | | - Gu-Hwan Kim
- Medical Genetics Center, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | | | - Yoo-Mi Kim
- Department of Pediatrics, Chungnam National University Sejong Hospital, College of Medicine, Chungnam National University, Sejong, Republic of Korea
| | - Hyo-Sang Do
- Genome Research Center for Birth Defects and Genetic Diseases, Asan Institute for Life Sciences, Asan Medical Center, Seoul, Republic of Korea
| | - Jeongmin Choi
- Genome Research Center for Birth Defects and Genetic Diseases, Asan Institute for Life Sciences, Asan Medical Center, Seoul, Republic of Korea
| | - In Hee Choi
- Department of Genetic Counseling, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Han-Wook Yoo
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, Republic of Korea.,Medical Genetics Center, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Beom Hee Lee
- Department of Pediatrics, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, Republic of Korea. .,Medical Genetics Center, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Seoul, Republic of Korea.
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17
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Bacic L, Gaullier G, Sabantsev A, Lehmann LC, Brackmann K, Dimakou D, Halic M, Hewitt G, Boulton SJ, Deindl S. Structure and dynamics of the chromatin remodeler ALC1 bound to a PARylated nucleosome. eLife 2021; 10:e71420. [PMID: 34486521 PMCID: PMC8463071 DOI: 10.7554/elife.71420] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 09/05/2021] [Indexed: 12/21/2022] Open
Abstract
The chromatin remodeler ALC1 is recruited to and activated by DNA damage-induced poly(ADP-ribose) (PAR) chains deposited by PARP1/PARP2/HPF1 upon detection of DNA lesions. ALC1 has emerged as a candidate drug target for cancer therapy as its loss confers synthetic lethality in homologous recombination-deficient cells. However, structure-based drug design and molecular analysis of ALC1 have been hindered by the requirement for PARylation and the highly heterogeneous nature of this post-translational modification. Here, we reconstituted an ALC1 and PARylated nucleosome complex modified in vitro using PARP2 and HPF1. This complex was amenable to cryo-EM structure determination without cross-linking, which enabled visualization of several intermediate states of ALC1 from the recognition of the PARylated nucleosome to the tight binding and activation of the remodeler. Functional biochemical assays with PARylated nucleosomes highlight the importance of nucleosomal epitopes for productive remodeling and suggest that ALC1 preferentially slides nucleosomes away from DNA breaks.
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Affiliation(s)
- Luka Bacic
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala UniversityUppsalaSweden
| | - Guillaume Gaullier
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala UniversityUppsalaSweden
| | - Anton Sabantsev
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala UniversityUppsalaSweden
| | - Laura C Lehmann
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala UniversityUppsalaSweden
| | - Klaus Brackmann
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala UniversityUppsalaSweden
| | - Despoina Dimakou
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala UniversityUppsalaSweden
| | - Mario Halic
- Department of Structural Biology, St Jude Children's Research HospitalMemphisUnited States
| | | | | | - Sebastian Deindl
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala UniversityUppsalaSweden
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18
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Nodelman IM, Patel A, Levendosky RF, Bowman GD. Reconstitution and Purification of Nucleosomes with Recombinant Histones and Purified DNA. ACTA ACUST UNITED AC 2021; 133:e130. [PMID: 33305911 DOI: 10.1002/cpmb.130] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Nucleosomes are substrates for a broad range of factors, including those involved in transcription or chromosome maintenance/reorganization and enzymes that covalently modify histones. Given the heterogeneous nature of nucleosomes in vivo (i.e., varying histone composition, post-translational modifications, DNA sequence register), understanding the specificity and activities of chromatin-interacting factors has required in vitro studies using well-defined nucleosome substrates. Here, we provide detailed methods for large-scale PCR preparation of DNA, assembly of nucleosomes from purified DNA and histones, and purification of DNA and mononucleosomes. Such production of well-defined nucleosomes for biochemical and biophysical studies is key for studying numerous proteins and protein complexes that bind and/or alter nucleosomes and for revealing inherent characteristics of nucleosomes. © 2020 Wiley Periodicals LLC. Basic Protocol 1: Large-scale PCR amplification of DNA Basic Protocol 2: DNA and nucleosome purification using a Bio-Rad Mini Prep Cell/Prep Cell Basic Protocol 3: Nucleosome reconstitution via linear gradient salt dialysis.
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Affiliation(s)
- Ilana M Nodelman
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland
| | - Ashok Patel
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India
| | - Robert F Levendosky
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland.,Present address: Catalent Cell and Gene Therapy, Baltimore, Maryland
| | - Gregory D Bowman
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland
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19
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Casari E, Gobbini E, Gnugnoli M, Mangiagalli M, Clerici M, Longhese MP. Dpb4 promotes resection of DNA double-strand breaks and checkpoint activation by acting in two different protein complexes. Nat Commun 2021; 12:4750. [PMID: 34362907 PMCID: PMC8346560 DOI: 10.1038/s41467-021-25090-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 07/20/2021] [Indexed: 12/24/2022] Open
Abstract
Budding yeast Dpb4 (POLE3/CHRAC17 in mammals) is a highly conserved histone fold protein that is shared by two protein complexes: the chromatin remodeler ISW2/hCHRAC and the DNA polymerase ε (Pol ε) holoenzyme. In Saccharomyces cerevisiae, Dpb4 forms histone-like dimers with Dls1 in the ISW2 complex and with Dpb3 in the Pol ε complex. Here, we show that Dpb4 plays two functions in sensing and processing DNA double-strand breaks (DSBs). Dpb4 promotes histone removal and DSB resection by interacting with Dls1 to facilitate the association of the Isw2 ATPase to DSBs. Furthermore, it promotes checkpoint activation by interacting with Dpb3 to facilitate the association of the checkpoint protein Rad9 to DSBs. Persistence of both Isw2 and Rad9 at DSBs is enhanced by the A62S mutation that is located in the Dpb4 histone fold domain and increases Dpb4 association at DSBs. Thus, Dpb4 exerts two distinct functions at DSBs depending on its interactors. The histone folding protein Dpb4 forms histone-like dimers within the ISW2 complex and the Pol ε complex in S. cerevisiae. Here the authors reveal insights into two distinct functions that Dpb4 exerts at DSBs depending on its interactors.
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Affiliation(s)
- Erika Casari
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Milano, Italy
| | - Elisa Gobbini
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Milano, Italy
| | - Marco Gnugnoli
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Milano, Italy
| | - Marco Mangiagalli
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Milano, Italy
| | - Michela Clerici
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Milano, Italy
| | - Maria Pia Longhese
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Milano, Italy.
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20
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Structure and Function of Chromatin Remodelers. J Mol Biol 2021; 433:166929. [PMID: 33711345 PMCID: PMC8184634 DOI: 10.1016/j.jmb.2021.166929] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 02/27/2021] [Accepted: 03/04/2021] [Indexed: 12/25/2022]
Abstract
Chromatin remodelers act to regulate multiple cellular processes, such as transcription and DNA repair, by controlling access to genomic DNA. Four families of chromatin remodelers have been identified in yeast, each with non-redundant roles within the cell. There has been a recent surge in structural models of chromatin remodelers in complex with their nucleosomal substrate. These structural studies provide new insight into the mechanism of action for individual chromatin remodelers. In this review, we summarize available data for the structure and mechanism of action of the four chromatin remodeling complex families.
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21
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Cucinotta CE, Dell RH, Braceros KCA, Tsukiyama T. RSC primes the quiescent genome for hypertranscription upon cell-cycle re-entry. eLife 2021; 10:e67033. [PMID: 34042048 PMCID: PMC8186906 DOI: 10.7554/elife.67033] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 05/26/2021] [Indexed: 12/14/2022] Open
Abstract
Quiescence is a reversible G0 state essential for differentiation, regeneration, stem-cell renewal, and immune cell activation. Necessary for long-term survival, quiescent chromatin is compact, hypoacetylated, and transcriptionally inactive. How transcription activates upon cell-cycle re-entry is undefined. Here we report robust, widespread transcription within the first minutes of quiescence exit. During quiescence, the chromatin-remodeling enzyme RSC was already bound to the genes induced upon quiescence exit. RSC depletion caused severe quiescence exit defects: a global decrease in RNA polymerase II (Pol II) loading, Pol II accumulation at transcription start sites, initiation from ectopic upstream loci, and aberrant antisense transcription. These phenomena were due to a combination of highly robust Pol II transcription and severe chromatin defects in the promoter regions and gene bodies. Together, these results uncovered multiple mechanisms by which RSC facilitates initiation and maintenance of large-scale, rapid gene expression despite a globally repressive chromatin state.
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Affiliation(s)
| | - Rachel H Dell
- Basic Sciences Division, Fred Hutchinson Cancer Research CenterSeattleUnited States
| | - Keean CA Braceros
- Basic Sciences Division, Fred Hutchinson Cancer Research CenterSeattleUnited States
| | - Toshio Tsukiyama
- Basic Sciences Division, Fred Hutchinson Cancer Research CenterSeattleUnited States
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22
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Clapier CR. Sophisticated Conversations between Chromatin and Chromatin Remodelers, and Dissonances in Cancer. Int J Mol Sci 2021; 22:5578. [PMID: 34070411 PMCID: PMC8197500 DOI: 10.3390/ijms22115578] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/18/2021] [Accepted: 05/18/2021] [Indexed: 01/13/2023] Open
Abstract
The establishment and maintenance of genome packaging into chromatin contribute to define specific cellular identity and function. Dynamic regulation of chromatin organization and nucleosome positioning are critical to all DNA transactions-in particular, the regulation of gene expression-and involve the cooperative action of sequence-specific DNA-binding factors, histone modifying enzymes, and remodelers. Remodelers are molecular machines that generate various chromatin landscapes, adjust nucleosome positioning, and alter DNA accessibility by using ATP binding and hydrolysis to perform DNA translocation, which is highly regulated through sophisticated structural and functional conversations with nucleosomes. In this review, I first present the functional and structural diversity of remodelers, while emphasizing the basic mechanism of DNA translocation, the common regulatory aspects, and the hand-in-hand progressive increase in complexity of the regulatory conversations between remodelers and nucleosomes that accompanies the increase in challenges of remodeling processes. Next, I examine how, through nucleosome positioning, remodelers guide the regulation of gene expression. Finally, I explore various aspects of how alterations/mutations in remodelers introduce dissonance into the conversations between remodelers and nucleosomes, modify chromatin organization, and contribute to oncogenesis.
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Affiliation(s)
- Cedric R Clapier
- Department of Oncological Sciences & Howard Hughes Medical Institute, Huntsman Cancer Institute, University of Utah School of Medicine, 2000 Circle of Hope, Salt Lake City, UT 84112, USA
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23
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Krstic A, Konietzny A, Halasz M, Cain P, Oppermann U, Kolch W, Duffy DJ. A Chemo-Genomic Approach Identifies Diverse Epigenetic Therapeutic Vulnerabilities in MYCN-Amplified Neuroblastoma. Front Cell Dev Biol 2021; 9:612518. [PMID: 33968920 PMCID: PMC8097097 DOI: 10.3389/fcell.2021.612518] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 03/25/2021] [Indexed: 11/13/2022] Open
Abstract
Although a rare disease, neuroblastoma accounts for the highest proportion of childhood cancer deaths. There is a lack of recurrent somatic mutations in neuroblastoma embryonal tumours, suggesting a possible role for epigenetic alterations in driving this cancer. While an increasing number of reports suggest an association of MYCN with epigenetic machinery, the mechanisms of these interactions are poorly understood in the neuroblastoma setting. Utilising chemo-genomic approaches we revealed global MYCN-epigenetic interactions and identified numerous epigenetic proteins as MYCN targets. The epigenetic regulators HDAC2, CBX8 and CBP (CREBBP) were all MYCN target genes and also putative MYCN interactors. MYCN-related epigenetic genes included SMARCs, HDACs, SMYDs, BRDs and CREBBP. Expression levels of the majority of MYCN-related epigenetic genes showed predictive ability for neuroblastoma patient outcome. Furthermore, a compound library screen targeting epigenetic proteins revealed broad susceptibility of neuroblastoma cells to all classes of epigenetic regulators, belonging to families of bromodomains, HDACs, HATs, histone methyltransferases, DNA methyltransferases and lysin demethylases. Ninety-six percent of the compounds reduced MYCN-amplified neuroblastoma cell viability. We show that the C646 (CBP-bromodomain targeting compound) exhibits switch-like temporal and dose response behaviour and is effective at reducing neuroblastoma viability. Responsiveness correlates with MYCN expression, with MYCN-amplified cells being more susceptible to C646 treatment. Thus, exploiting the broad vulnerability of neuroblastoma cells to epigenetic targeting compounds represents an exciting strategy in neuroblastoma treatment, particularly for high-risk MYCN-amplified tumours.
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Affiliation(s)
- Aleksandar Krstic
- Systems Biology Ireland and Precision Oncology Ireland, School of Medicine, University College Dublin, Dublin, Ireland
| | - Anja Konietzny
- Systems Biology Ireland and Precision Oncology Ireland, School of Medicine, University College Dublin, Dublin, Ireland.,Centre for Molecular Neurobiology Hamburg (ZMNH), Emmy-Noether Group "Neuronal Protein Transport", University Medical Centre Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Melinda Halasz
- Systems Biology Ireland and Precision Oncology Ireland, School of Medicine, University College Dublin, Dublin, Ireland
| | - Peter Cain
- Botnar Research Centre, NIHR Oxford Biomedical Research Unit, Institute of Musculoskeletal Sciences, University of Oxford, Oxford, United Kingdom.,Centre for Medicines Discovery, University of Oxford, Oxford, United Kingdom
| | - Udo Oppermann
- Botnar Research Centre, NIHR Oxford Biomedical Research Unit, Institute of Musculoskeletal Sciences, University of Oxford, Oxford, United Kingdom.,Centre for Medicines Discovery, University of Oxford, Oxford, United Kingdom
| | - Walter Kolch
- Systems Biology Ireland and Precision Oncology Ireland, School of Medicine, University College Dublin, Dublin, Ireland.,Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Dublin, Ireland
| | - David J Duffy
- Systems Biology Ireland and Precision Oncology Ireland, School of Medicine, University College Dublin, Dublin, Ireland.,The Whitney Laboratory for Marine Bioscience and Sea Turtle Hospital, University of Florida, St. Augustine, FL, United States.,Department of Biology, University of Florida, Gainesville, FL, United States
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24
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Donovan DA, Crandall JG, Truong VN, Vaaler AL, Bailey TB, Dinwiddie D, Banks OGB, McKnight LE, McKnight JN. Basis of specificity for a conserved and promiscuous chromatin remodeling protein. eLife 2021; 10:e64061. [PMID: 33576335 PMCID: PMC7968928 DOI: 10.7554/elife.64061] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 02/11/2021] [Indexed: 12/11/2022] Open
Abstract
Eukaryotic genomes are organized dynamically through the repositioning of nucleosomes. Isw2 is an enzyme that has been previously defined as a genome-wide, nonspecific nucleosome spacing factor. Here, we show that Isw2 instead acts as an obligately targeted nucleosome remodeler in vivo through physical interactions with sequence-specific factors. We demonstrate that Isw2-recruiting factors use small and previously uncharacterized epitopes, which direct Isw2 activity through highly conserved acidic residues in the Isw2 accessory protein Itc1. This interaction orients Isw2 on target nucleosomes, allowing for precise nucleosome positioning at targeted loci. Finally, we show that these critical acidic residues have been lost in the Drosophila lineage, potentially explaining the inconsistently characterized function of Isw2-like proteins. Altogether, these data suggest an 'interacting barrier model,' where Isw2 interacts with a sequence-specific factor to accurately and reproducibly position a single, targeted nucleosome to define the precise border of phased chromatin arrays.
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Affiliation(s)
- Drake A Donovan
- Institute of Molecular Biology, University of OregonEugeneUnited States
| | | | - Vi N Truong
- Institute of Molecular Biology, University of OregonEugeneUnited States
| | - Abigail L Vaaler
- Institute of Molecular Biology, University of OregonEugeneUnited States
| | - Thomas B Bailey
- Institute of Molecular Biology, University of OregonEugeneUnited States
| | - Devin Dinwiddie
- Institute of Molecular Biology, University of OregonEugeneUnited States
| | - Orion GB Banks
- Institute of Molecular Biology, University of OregonEugeneUnited States
| | - Laura E McKnight
- Institute of Molecular Biology, University of OregonEugeneUnited States
| | - Jeffrey N McKnight
- Institute of Molecular Biology, University of OregonEugeneUnited States
- Phil and Penny Knight Campus for Accelerating Scientific Impact, University of OregonEugeneUnited States
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25
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Gamarra N, Narlikar GJ. Collaboration through chromatin: motors of transcription and chromatin structure. J Mol Biol 2021; 433:166876. [PMID: 33556407 DOI: 10.1016/j.jmb.2021.166876] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/29/2021] [Accepted: 02/01/2021] [Indexed: 01/09/2023]
Abstract
Packaging of the eukaryotic genome into chromatin places fundamental physical constraints on transcription. Clarifying how transcription operates within these constraints is essential to understand how eukaryotic gene expression programs are established and maintained. Here we review what is known about the mechanisms of transcription on chromatin templates. Current models indicate that transcription through chromatin is accomplished by the combination of an inherent nucleosome disrupting activity of RNA polymerase and the action of ATP-dependent chromatin remodeling motors. Collaboration between these two types of molecular motors is proposed to occur at all stages of transcription through diverse mechanisms. Further investigation of how these two motors combine their basic activities is essential to clarify the interdependent relationship between genome structure and transcription.
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Affiliation(s)
- Nathan Gamarra
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States; TETRAD Graduate Program, University of California, San Francisco, San Francisco, United States
| | - Geeta J Narlikar
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States.
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26
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Sun L, Pierrakeas L, Li T, Luk E. Thermosensitive Nucleosome Editing Reveals the Role of DNA Sequence in Targeted Histone Variant Deposition. Cell Rep 2021; 30:257-268.e5. [PMID: 31914392 DOI: 10.1016/j.celrep.2019.12.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 11/04/2019] [Accepted: 12/03/2019] [Indexed: 10/25/2022] Open
Abstract
In preparation for transcription, the chromatin remodeler SWR installs homotypic ZZ nucleosomes at promoters by replacing the two nucleosomal H2A with H2A.Z in a stepwise manner. Nucleosome-free regions (NFRs) help recruit SWR to promoters; this is thought to position SWR asymmetrically on one side of the +1 nucleosome. How SWR accesses the opposite side of +1 to generate a ZZ nucleosome remains unclear. Using biochemical assays that monitor the sub-nucleosomal position of nascent H2A.Z, we find that NFR-recruited SWR switches sides to insert H2A.Z into asymmetrically positioned nucleosomes; however, at decreasing temperatures, H2A.Z insertion becomes progressively biased for one side. We find that a 16-bp element containing G/C runs (>3 consecutive G or C nucleotides) is sufficient to promote H2A.Z insertion. Because H2A.Z-rich +1 nucleosomes in yeast have more G/C runs, we propose that nucleosome editing is a thermosensitive process that can be hard coded by the genome.
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Affiliation(s)
- Lu Sun
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Leonidas Pierrakeas
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Tailai Li
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Ed Luk
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA; Renaissance School of Medicine, Stony Brook University, Stony Brook, NY 11794, USA.
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27
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Abstract
As primary carriers of epigenetic information and gatekeepers of genomic DNA, nucleosomes are essential for proper growth and development of all eukaryotic cells. Although they are intrinsically dynamic, nucleosomes are actively reorganized by ATP-dependent chromatin remodelers. Chromatin remodelers contain helicase-like ATPase motor domains that can translocate along DNA, and a long-standing question in the field is how this activity is used to reposition or slide nucleosomes. In addition to ratcheting along DNA like their helicase ancestors, remodeler ATPases appear to dictate specific alternating geometries of the DNA duplex, providing an unexpected means for moving DNA past the histone core. Emerging evidence supports twist-based mechanisms for ATP-driven repositioning of nucleosomes along DNA. In this review, we discuss core experimental findings and ideas that have shaped the view of how nucleosome sliding may be achieved.
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Affiliation(s)
- Ilana M Nodelman
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, USA;
| | - Gregory D Bowman
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, USA;
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28
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Aguilar M, Prieto P. Telomeres and Subtelomeres Dynamics in the Context of Early Chromosome Interactions During Meiosis and Their Implications in Plant Breeding. FRONTIERS IN PLANT SCIENCE 2021; 12:672489. [PMID: 34149773 PMCID: PMC8212018 DOI: 10.3389/fpls.2021.672489] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 05/06/2021] [Indexed: 05/08/2023]
Abstract
Genomic architecture facilitates chromosome recognition, pairing, and recombination. Telomeres and subtelomeres play an important role at the beginning of meiosis in specific chromosome recognition and pairing, which are critical processes that allow chromosome recombination between homologs (equivalent chromosomes in the same genome) in later stages. In plant polyploids, these terminal regions are even more important in terms of homologous chromosome recognition, due to the presence of homoeologs (equivalent chromosomes from related genomes). Although telomeres interaction seems to assist homologous pairing and consequently, the progression of meiosis, other chromosome regions, such as subtelomeres, need to be considered, because the DNA sequence of telomeres is not chromosome-specific. In addition, recombination operates at subtelomeres and, as it happens in rye and wheat, homologous recognition and pairing is more often correlated with recombining regions than with crossover-poor regions. In a plant breeding context, the knowledge of how homologous chromosomes initiate pairing at the beginning of meiosis can contribute to chromosome manipulation in hybrids or interspecific genetic crosses. Thus, recombination in interspecific chromosome associations could be promoted with the aim of transferring desirable agronomic traits from related genetic donor species into crops. In this review, we summarize the importance of telomeres and subtelomeres on chromatin dynamics during early meiosis stages and their implications in recombination in a plant breeding framework.
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Affiliation(s)
- Miguel Aguilar
- Área de Fisiología Vegetal, Universidad de Córdoba, Córdoba, Spain
| | - Pilar Prieto
- Plant Breeding Department, Institute for Sustainable Agriculture, Agencia Estatal Consejo Superior de Investigaciones Científicas (CSIC), Córdoba, Spain
- *Correspondence: Pilar Prieto, ; orcid.org/0000-0002-8160-808X
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29
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Morgan A, LeGresley S, Fischer C. Remodeler Catalyzed Nucleosome Repositioning: Influence of Structure and Stability. Int J Mol Sci 2020; 22:ijms22010076. [PMID: 33374740 PMCID: PMC7793527 DOI: 10.3390/ijms22010076] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 12/04/2020] [Accepted: 12/16/2020] [Indexed: 02/06/2023] Open
Abstract
The packaging of the eukaryotic genome into chromatin regulates the storage of genetic information, including the access of the cell’s DNA metabolism machinery. Indeed, since the processes of DNA replication, translation, and repair require access to the underlying DNA, several mechanisms, both active and passive, have evolved by which chromatin structure can be regulated and modified. One mechanism relies upon the function of chromatin remodeling enzymes which couple the free energy obtained from the binding and hydrolysis of ATP to the mechanical work of repositioning and rearranging nucleosomes. Here, we review recent work on the nucleosome mobilization activity of this essential family of molecular machines.
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30
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Clapier CR, Verma N, Parnell TJ, Cairns BR. Cancer-Associated Gain-of-Function Mutations Activate a SWI/SNF-Family Regulatory Hub. Mol Cell 2020; 80:712-725.e5. [PMID: 33058778 PMCID: PMC7853424 DOI: 10.1016/j.molcel.2020.09.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 09/21/2020] [Accepted: 09/22/2020] [Indexed: 01/17/2023]
Abstract
SWI/SNF-family remodelers (BAF/PBAF in mammals) are essential chromatin regulators, and mutations in human BAF/PBAF components are associated with ∼20% of cancers. Cancer-associated missense mutations in human BRG1 (encoding the catalytic ATPase) have been characterized previously as conferring loss-of-function. Here, we show that cancer-associated missense mutations in BRG1, when placed into the orthologous Sth1 ATPase of the yeast RSC remodeler, separate into two categories: loss-of-function enzymes, or instead, gain-of-function enzymes that greatly improve DNA translocation efficiency and nucleosome remodeling in vitro. Our work identifies a structural "hub," formed by the association of several Sth1 domains, that regulates ATPase activity and DNA translocation efficiency. Remarkably, all gain-of-function cancer-associated mutations and all loss-of-function mutations physically localize to distinct adjacent regions in the hub, which specifically regulate and implement DNA translocation, respectively. In vivo, only gain-of-function cancer-associated mutations conferred precocious chromatin accessibility. Taken together, we provide a structure-function mechanistic basis for cancer-associated hyperactivity.
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Affiliation(s)
- Cedric R Clapier
- Department of Oncological Sciences and Howard Hughes Medical Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA; Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA.
| | - Naveen Verma
- Department of Oncological Sciences and Howard Hughes Medical Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA; Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Timothy J Parnell
- Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Bradley R Cairns
- Department of Oncological Sciences and Howard Hughes Medical Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA; Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT 84112, USA.
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31
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Kirk J, Lee JY, Lee Y, Kang C, Shin S, Lee E, Song JJ, Hohng S. Yeast Chd1p Unwraps the Exit Side DNA upon ATP Binding to Facilitate the Nucleosome Translocation Occurring upon ATP Hydrolysis. Biochemistry 2020; 59:4481-4487. [PMID: 33174727 DOI: 10.1021/acs.biochem.0c00747] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chromodomain-helicase-DNA-binding protein 1 (CHD1) remodels chromatin by translocating nucleosomes along DNA, but its mechanism remains poorly understood. We use single-molecule fluorescence experiments to clarify the mechanism by which yeast CHD1 (Chd1p) remodels nucleosomes. We find that binding of ATP to Chd1p induces transient unwrapping of the DNA on the exit side of the nucleosome, facilitating nucleosome translocation. ATP hydrolysis is required to induce nucleosome translocation. The unwrapped DNA after translocation is then rewrapped after the release of the hydrolyzed nucleotide and phosphate, revealing that each step of the ATP hydrolysis cycle is responsible for a distinct step of nucleosome remodeling. These results show that Chd1p remodels nucleosomes via a mechanism that is unique among the other ATP-dependent chromatin remodelers.
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Affiliation(s)
- Jaewon Kirk
- Department of Physics and Astronomy, Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
| | - Ju Yeon Lee
- Department of Physics and Astronomy, Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
| | - Yejin Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Chanshin Kang
- Department of Physics and Astronomy, Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
| | - Soochul Shin
- Department of Physics and Astronomy, Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
| | - Eunhye Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Ji-Joon Song
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Sungchul Hohng
- Department of Physics and Astronomy, Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
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32
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Markert J, Luger K. Nucleosomes Meet Their Remodeler Match. Trends Biochem Sci 2020; 46:41-50. [PMID: 32917506 DOI: 10.1016/j.tibs.2020.08.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/12/2020] [Accepted: 08/14/2020] [Indexed: 12/12/2022]
Abstract
Over 85% of all genomic DNA in eukaryotes is organized in arrays of nucleosomes, the basic organizational principle of chromatin. The tight interaction of DNA with histones represents a significant barrier for all DNA-dependent machineries. This is in part overcome by enzymes, termed ATP-dependent remodelers, that are recruited to nucleosomes at defined locations and modulate their structure. There are several different classes of remodelers, and all use specific nucleosome features to bind to and alter nucleosomes. This review highlights and summarizes areas of interactions with the nucleosome that allow remodeling to occur.
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Affiliation(s)
- Jonathan Markert
- Department of Biochemistry, University of Colorado at Boulder, Boulder, CO 80309, USA; Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Karolin Luger
- Department of Biochemistry, University of Colorado at Boulder, Boulder, CO 80309, USA; Howard Hughes Medical Institute, Chevy Chase, MD, USA.
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33
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Marcum RD, Reyes AA, He Y. Structural Insights into the Evolutionarily Conserved BAF Chromatin Remodeling Complex. BIOLOGY 2020; 9:biology9070146. [PMID: 32629987 PMCID: PMC7408276 DOI: 10.3390/biology9070146] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 06/17/2020] [Accepted: 06/23/2020] [Indexed: 12/17/2022]
Abstract
The switch/sucrose nonfermentable (SWI/SNF) family of proteins acts to regulate chromatin accessibility and plays an essential role in multiple cellular processes. A high frequency of mutations has been found in SWI/SNF family subunits by exome sequencing in human cancer, and multiple studies support its role in tumor suppression. Recent structural studies of yeast SWI/SNF and its human homolog, BAF (BRG1/BRM associated factor), have provided a model for their complex assembly and their interaction with nucleosomal substrates, revealing the molecular function of individual subunits as well as the potential impact of cancer-associated mutations on the remodeling function. Here we review the structural conservation between yeast SWI/SNF and BAF and examine the role of highly mutated subunits within the BAF complex.
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Affiliation(s)
- Ryan D. Marcum
- Department of Molecular Biosciences, Northwestern University, 2205 Tech Drive, Evanston, IL 60208-3500, USA; (R.D.M.); (A.A.R.)
| | - Alexis A. Reyes
- Department of Molecular Biosciences, Northwestern University, 2205 Tech Drive, Evanston, IL 60208-3500, USA; (R.D.M.); (A.A.R.)
- Interdisciplinary Biological Sciences Program, Northwestern University, 2205 Tech Drive, Evanston, IL 60208-3500, USA
| | - Yuan He
- Department of Molecular Biosciences, Northwestern University, 2205 Tech Drive, Evanston, IL 60208-3500, USA; (R.D.M.); (A.A.R.)
- Interdisciplinary Biological Sciences Program, Northwestern University, 2205 Tech Drive, Evanston, IL 60208-3500, USA
- Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Northwestern University, 676 N. St. Clair, Chicago, IL 60611, USA
- Correspondence:
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34
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Mohapatra S, Lin CT, Feng XA, Basu A, Ha T. Single-Molecule Analysis and Engineering of DNA Motors. Chem Rev 2019; 120:36-78. [DOI: 10.1021/acs.chemrev.9b00361] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
| | | | | | | | - Taekjip Ha
- Howard Hughes Medical Institute, Baltimore, Maryland 21205, United States
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35
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Yan L, Chen Z. A Unifying Mechanism of DNA Translocation Underlying Chromatin Remodeling. Trends Biochem Sci 2019; 45:217-227. [PMID: 31623923 DOI: 10.1016/j.tibs.2019.09.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 09/01/2019] [Accepted: 09/06/2019] [Indexed: 12/18/2022]
Abstract
Chromatin remodelers alter the position and composition of nucleosomes, and play key roles in the regulation of chromatin structure and various chromatin-based transactions. Recent cryo-electron microscopy (cryo-EM) and single-molecule fluorescence resonance energy transfer (smFRET) studies have shed mechanistic light on the fundamental question of how the remodeling enzymes couple with ATP hydrolysis to slide nucleosomes. Structures of the chromatin remodeler Snf2 bound to the nucleosome reveal the conformational cycle of the enzyme and the induced DNA distortion. Investigations on ISWI, Chd1, and INO80 support a unifying fundamental mechanism of DNA translocation. Finally, studies of the SWR1 complex suggest that the enzyme distorts the DNA abnormally to achieve histone exchange without net DNA translocation.
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Affiliation(s)
- Lijuan Yan
- Ministry of Education (MOE) Key Laboratory of Protein Science, Tsinghua University, Beijing 100084, PRC; School of Life Science, Tsinghua University, Beijing 100084, PRC
| | - Zhucheng Chen
- Ministry of Education (MOE) Key Laboratory of Protein Science, Tsinghua University, Beijing 100084, PRC; School of Life Science, Tsinghua University, Beijing 100084, PRC; Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, Beijing 100084, PRC.
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36
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Tokuda JM, Ren R, Levendosky RF, Tay RJ, Yan M, Pollack L, Bowman GD. The ATPase motor of the Chd1 chromatin remodeler stimulates DNA unwrapping from the nucleosome. Nucleic Acids Res 2019; 46:4978-4990. [PMID: 29850894 PMCID: PMC6007315 DOI: 10.1093/nar/gky206] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 03/16/2018] [Indexed: 01/21/2023] Open
Abstract
Chromatin remodelers are ATP-dependent motors that reorganize DNA packaging by disrupting canonical histone–DNA contacts within the nucleosome. Here, we show that the Chd1 chromatin remodeler stimulates DNA unwrapping from the edge of the nucleosome in a nucleotide-dependent and DNA sequence-sensitive fashion. Nucleosome binding, monitored by stopped flow, was complex and sensitive to nucleotide, with AMP–PNP promoting faster binding than ADP·BeF3–. Nucleosome unwrapping by Chd1, examined by bulk FRET, occurred in the presence and absence of nucleotide and did not require the Chd1 DNA-binding domain. In AMP–PNP conditions, Chd1 unwrapped one side of the Widom 601 DNA more easily than the other, consistent with previous observations of 601 asymmetry and indicating that Chd1 amplifies intrinsic sequence properties of nucleosomal DNA. Using small angle X-ray scattering (SAXS) with contrast variation, we found distinct DNA conformations depending on the nucleotide analog bound to Chd1: with AMP–PNP, DNA primarily unwrapped in-plane with the nucleosomal disk, whereas with ADP·BeF3–, a significant fraction showed distinctive out-of-plane unwrapping as well. Taken together, our findings show tight coupling between entry/exit DNA of the nucleosome and the Chd1 ATPase motor, suggesting that dynamic nucleosome unwrapping is coupled to nucleosome binding and remodeling by Chd1.
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Affiliation(s)
- Joshua M Tokuda
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853 USA
| | - Ren Ren
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218 USA
| | - Robert F Levendosky
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218 USA
| | - Rebecca J Tay
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218 USA
| | - Ming Yan
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218 USA
| | - Lois Pollack
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853 USA
| | - Gregory D Bowman
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218 USA
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37
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Jang S, Song JJ. The big picture of chromatin biology by cryo-EM. Curr Opin Struct Biol 2019; 58:76-87. [PMID: 31233978 DOI: 10.1016/j.sbi.2019.05.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 05/10/2019] [Accepted: 05/20/2019] [Indexed: 01/07/2023]
Abstract
Modifications of chromatin structure are one of the key mechanisms regulating epigenetic gene expression. Proteins involved in chromatin modification mainly function as large multi-subunit complexes, and each component in the complex contributes to the function and activity of the complex. However, little is known about the structures of whole complexes and the mechanisms by which the chromatin-modifying complexes function, the functional roles of each component in the complexes, and how the complexes recognize the central unit of chromatin, the nucleosome. This lack of information is partially due to the lack of structural information for whole complexes. Recent advances in cryo-EM have begun to reveal the structures of whole chromatin-modifying complexes that enable us to understand the big picture of chromatin biology. In this review, we discuss the recent discoveries related to the mechanisms of chromatin-modifying complexes.
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Affiliation(s)
- Seongmin Jang
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Ji-Joon Song
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
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38
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Armache JP, Gamarra N, Johnson SL, Leonard JD, Wu S, Narlikar GJ, Cheng Y. Cryo-EM structures of remodeler-nucleosome intermediates suggest allosteric control through the nucleosome. eLife 2019; 8:46057. [PMID: 31210637 PMCID: PMC6611695 DOI: 10.7554/elife.46057] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 06/18/2019] [Indexed: 12/24/2022] Open
Abstract
The SNF2h remodeler slides nucleosomes most efficiently as a dimer, yet how the two protomers avoid a tug-of-war is unclear. Furthermore, SNF2h couples histone octamer deformation to nucleosome sliding, but the underlying structural basis remains unknown. Here we present cryo-EM structures of SNF2h-nucleosome complexes with ADP-BeFx that capture two potential reaction intermediates. In one structure, histone residues near the dyad and in the H2A-H2B acidic patch, distal to the active SNF2h protomer, appear disordered. The disordered acidic patch is expected to inhibit the second SNF2h protomer, while disorder near the dyad is expected to promote DNA translocation. The other structure doesn't show octamer deformation, but surprisingly shows a 2 bp translocation. FRET studies indicate that ADP-BeFx predisposes SNF2h-nucleosome complexes for an elemental translocation step. We propose a model for allosteric control through the nucleosome, where one SNF2h protomer promotes asymmetric octamer deformation to inhibit the second protomer, while stimulating directional DNA translocation.
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Affiliation(s)
- Jean Paul Armache
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Nathan Gamarra
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States.,Tetrad Graduate Program, University of California, San Francisco, San Francisco, United States
| | - Stephanie L Johnson
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - John D Leonard
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States.,Tetrad Graduate Program, University of California, San Francisco, San Francisco, United States
| | - Shenping Wu
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States
| | - Geeta J Narlikar
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - Yifan Cheng
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States.,Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States
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39
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Levendosky RF, Bowman GD. Asymmetry between the two acidic patches dictates the direction of nucleosome sliding by the ISWI chromatin remodeler. eLife 2019; 8:45472. [PMID: 31094676 PMCID: PMC6546392 DOI: 10.7554/elife.45472] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 05/16/2019] [Indexed: 01/15/2023] Open
Abstract
The acidic patch is a functionally important epitope on each face of the nucleosome that affects chromatin remodeling. Although related by 2-fold symmetry of the nucleosome, each acidic patch is uniquely positioned relative to a bound remodeler. An open question is whether remodelers are distinctly responsive to each acidic patch. Previously we reported a method for homogeneously producing asymmetric nucleosomes with distinct H2A/H2B dimers (Levendosky et al., 2016). Here, we use this methodology to show that the Chd1 remodeler from Saccharomyces cerevisiae and ISWI remodelers from human and Drosophila have distinct spatial requirements for the acidic patch. Unlike Chd1, which is equally affected by entry- and exit-side mutations, ISWI remodelers strongly depend on the entry-side acidic patch. Remarkably, asymmetry in the two acidic patches stimulates ISWI to slide mononucleosomes off DNA ends, overriding the remodeler’s preference to shift the histone core toward longer flanking DNA.
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Affiliation(s)
- Robert F Levendosky
- TC Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, United States
| | - Gregory D Bowman
- TC Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, United States
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40
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Direct observation of coordinated DNA movements on the nucleosome during chromatin remodelling. Nat Commun 2019; 10:1720. [PMID: 30979890 PMCID: PMC6461674 DOI: 10.1038/s41467-019-09657-1] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 03/20/2019] [Indexed: 11/11/2022] Open
Abstract
ATP-dependent chromatin remodelling enzymes (remodellers) regulate DNA accessibility in eukaryotic genomes. Many remodellers reposition (slide) nucleosomes, however, how DNA is propagated around the histone octamer during this process is unclear. Here we examine the real-time coordination of remodeller-induced DNA movements on both sides of the nucleosome using three-colour single-molecule FRET. During sliding by Chd1 and SNF2h remodellers, DNA is shifted discontinuously, with movement of entry-side DNA preceding that of exit-side DNA. The temporal delay between these movements implies a single rate-limiting step dependent on ATP binding and transient absorption or buffering of at least one base pair. High-resolution cross-linking experiments show that sliding can be achieved by buffering as few as 3 bp between entry and exit sides of the nucleosome. We propose that DNA buffering ensures nucleosome stability during ATP-dependent remodelling, and provides a means for communication between remodellers acting on opposite sides of the nucleosome. Chromatin remodelling enzymes (remodellers) regulate DNA accessibility of eukaryotic genomes, which rely in large part on an ability to reposition nucleosomes. Here the authors use three-colour single-molecule FRET to simultaneously monitor remodeller-induced DNA movements on both sides of the nucleosome in real-time.
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41
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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: 140] [Impact Index Per Article: 28.0] [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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42
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Mechanism of DNA translocation underlying chromatin remodelling by Snf2. Nature 2019; 567:409-413. [PMID: 30867599 DOI: 10.1038/s41586-019-1029-2] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 02/12/2019] [Indexed: 11/08/2022]
Abstract
Chromatin remodellers include diverse enzymes with distinct biological functions, but nucleosome-sliding activity appears to be a common theme1,2. Among the remodelling enzymes, Snf2 serves as the prototype to study the action of this protein family. Snf2 and related enzymes share two conserved RecA-like lobes3, which by themselves are able to couple ATP hydrolysis to chromatin remodelling. The mechanism by which these enzymes couple ATP hydrolysis to translocate the nucleosome along the DNA remains unclear2,4-8. Here we report the structures of Saccharomyces cerevisiae Snf2 bound to the nucleosome in the presence of ADP and ADP-BeFx. Snf2 in the ADP-bound state adopts an open conformation similar to that in the apo state, and induces a one-base-pair DNA bulge at superhelix location 2 (SHL2), with the tracking strand showing greater distortion than the guide strand. The DNA distortion propagates to the proximal end, leading to staggered translocation of the two strands. The binding of ADP-BeFx triggers a closed conformation of the enzyme, resetting the nucleosome to a relaxed state. Snf2 shows altered interactions with the DNA in different nucleotide states, providing the structural basis for DNA translocation. Together, our findings suggest a fundamental mechanism for the DNA translocation that underlies chromatin remodelling.
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43
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Yan L, Wu H, Li X, Gao N, Chen Z. Structures of the ISWI-nucleosome complex reveal a conserved mechanism of chromatin remodeling. Nat Struct Mol Biol 2019; 26:258-266. [PMID: 30872815 DOI: 10.1038/s41594-019-0199-9] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 02/07/2019] [Indexed: 01/08/2023]
Abstract
Chromatin remodelers are diverse enzymes, and different models have been proposed to explain how these proteins work. Here we report the 3.3 Å-resolution cryogenic electron microscopy (cryo-EM) structures of Saccharomyces cerevisiae ISWI (ISW1) in complex with the nucleosome in adenosine diphosphate (ADP)-bound and ADP-BeFx-bound states. The data show that after nucleosome binding, ISW1 is activated by substantial rearrangement of the catalytic domains, with the regulatory AutoN domain packing the first RecA-like core and the NegC domain being disordered. The high-resolution structure reveals local DNA distortion and translocation induced by ISW1 in the ADP-bound state, which is essentially identical to that induced by the Snf2 chromatin remodeler, suggesting a common mechanism of DNA translocation. The histone core remains largely unperturbed, and prevention of histone distortion by crosslinking did not inhibit the activity of yeast ISW1 or its human homolog. Together, our findings suggest a general mechanism of chromatin remodeling involving local DNA distortion without notable histone deformation.
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Affiliation(s)
- Lijuan Yan
- MOE Key Laboratory of Protein Science, Tsinghua University, Beijing, China.,School of Life Science, Tsinghua University, Beijing, China
| | - Hao Wu
- School of Life Science, Tsinghua University, Beijing, China.,Peking University-Tsinghua University-National Institute of Biological Sciences Joint Graduate Program, Beijing, China
| | - Xuemei Li
- Electron Microscopy Laboratory, School of Physics, Peking University, Beijing, China
| | - Ning Gao
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Center for Life Sciences, School of Life Sciences, Peking University, Beijing, China.
| | - Zhucheng Chen
- MOE Key Laboratory of Protein Science, Tsinghua University, Beijing, China. .,School of Life Science, Tsinghua University, Beijing, China. .,Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, Beijing, China.
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44
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Verma K, Patel A. Pyruvate Kinase M2 serves as blockade for nucleosome repositioning and abrogates Chd7 remodeling activity. PLoS One 2019; 14:e0211515. [PMID: 30735509 PMCID: PMC6368300 DOI: 10.1371/journal.pone.0211515] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 01/15/2019] [Indexed: 01/10/2023] Open
Abstract
Pyruvate Kinase M2 (PKM2) mediates metabolic reshuffling and is ubiquitously upregulated in several cancer types. The non-metabolic function of PKM2 as key nuclear kinase and modulator of gene expression is instrumental in cancer progression and tumorigenesis. Here, we attempt to discern the non-canonical function of PKM2 as an epigenetic modulator and the underlying implication of this activity. Using 5'-FAM labelled reconstituted mononucleosome we have shown that PKM2 interacts with the complex through Histone H3 and possibly obstruct the access to DNA binding factors. Subsequently, the interaction negatively impacts the ATP dependent remodeling activity of Chromodomain Helicase DNA binding protein-7 (Chd7). Chd7 remodeling activity is required to ameliorate DNA damage and is crucial to genome stability. Our study shows that PKM2 blocks the Chd7 mediated sliding of nucleosome. It can be conjectured that stalling Chd7 may lead to impaired DNA damage and increased genomic instability. We propose a mechanism in which PKM2 negatively regulate nucleosome repositioning in chromatin and may exacerbate cancer by altering the nucleosome architecture. This research is imperative to our understanding of how altered cancer metabolism can potentially modulate the gene expression and sustain incessant proliferation by tweaking the chromatin topography.
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Affiliation(s)
- Kirtika Verma
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, India
| | - Ashok Patel
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, India
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45
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Ricketts MD, Han J, Szurgot MR, Marmorstein R. Molecular basis for chromatin assembly and modification by multiprotein complexes. Protein Sci 2018; 28:329-343. [PMID: 30350439 DOI: 10.1002/pro.3535] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 10/05/2018] [Accepted: 10/08/2018] [Indexed: 12/29/2022]
Abstract
Epigenetic regulation of the chromatin landscape is often orchestrated through modulation of nucleosomes. Nucleosomes are composed of two copies each of the four core histones, H2A, H2B, H3, and H4, wrapped in ~150 bp of DNA. We focus this review on recent structural studies that further elucidate the mechanisms used by macromolecular complexes to mediate histone modification and nucleosome assembly. Nucleosome assembly, spacing, and variant histone incorporation are coordinated by chromatin remodeler and histone chaperone complexes. Several recent structural studies highlight how disparate families of histone chaperones and chromatin remodelers share similar features that underlie how they interact with their respective histone or nucleosome substrates. Post-translational modification of histone residues is mediated by enzymatic subunits within large complexes. Until recently, relatively little was known about how association with auxiliary subunits serves to modulate the activity and specificity of the enzymatic subunit. Analysis of several recent structures highlights the different modes that auxiliary subunits use to influence enzymatic activity or direct specificity toward individual histone residues.
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Affiliation(s)
- M Daniel Ricketts
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, 19104.,Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, Pennsylvania, 19104
| | - Joseph Han
- Department of Chemistry Graduate Group, University of Pennsylvania, Philadelphia, Pennsylvania, 19104
| | - Mary R Szurgot
- Graduate Group in Biochemistry and Molecular Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, 19104
| | - Ronen Marmorstein
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, 19104.,Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, Pennsylvania, 19104.,Department of Chemistry Graduate Group, University of Pennsylvania, Philadelphia, Pennsylvania, 19104.,Graduate Group in Biochemistry and Molecular Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, 19104
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46
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Brandani GB, Takada S. Chromatin remodelers couple inchworm motion with twist-defect formation to slide nucleosomal DNA. PLoS Comput Biol 2018; 14:e1006512. [PMID: 30395604 PMCID: PMC6237416 DOI: 10.1371/journal.pcbi.1006512] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 11/15/2018] [Accepted: 09/13/2018] [Indexed: 01/25/2023] Open
Abstract
ATP-dependent chromatin remodelers are molecular machines that control genome organization by repositioning, ejecting, or editing nucleosomes, activities that confer them essential regulatory roles on gene expression and DNA replication. Here, we investigate the molecular mechanism of active nucleosome sliding by means of molecular dynamics simulations of the Snf2 remodeler translocase in complex with a nucleosome. During its inchworm motion driven by ATP consumption, the translocase overwrites the original nucleosome energy landscape via steric and electrostatic interactions to induce sliding of nucleosomal DNA unidirectionally. The sliding is initiated at the remodeler binding location via the generation of a pair of twist defects, which then spontaneously propagate to complete sliding throughout the entire nucleosome. We also reveal how remodeler mutations and DNA sequence control active nucleosome repositioning, explaining several past experimental observations. These results offer a detailed mechanistic picture of remodeling important for the complete understanding of these key biological processes. Nucleosomes are the protein-DNA complexes underlying Eukaryotic genome organization, and serve as regulators of gene expression by occluding DNA to other proteins. This regulation requires the precise positioning of nucleosomes along DNA. Chromatin remodelers are the molecular machines that consume ATP to slide nucleosome at their correct locations, but the mechanisms of remodeling are still unclear. Based on the static structural information of a remodeler bound on nucleosome, we performed molecular dynamics computer simulations revealing the details of how remodelers slide nucleosomal DNA: the inchworm-like motion of remodelers create small DNA deformations called twist defects, which then spontaneously propagate throughout the nucleosome to induce sliding. These simulations explain several past experimental findings and are important for our understanding of genome organization.
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Affiliation(s)
- Giovanni B. Brandani
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Shoji Takada
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
- * E-mail:
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47
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Lorch Y, Maier-Davis B, Kornberg RD. Histone Acetylation Inhibits RSC and Stabilizes the +1 Nucleosome. Mol Cell 2018; 72:594-600.e2. [PMID: 30401433 PMCID: PMC6290470 DOI: 10.1016/j.molcel.2018.09.030] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 08/09/2018] [Accepted: 09/20/2018] [Indexed: 12/12/2022]
Abstract
The +1 nucleosome of yeast genes, within which reside transcription start sites, is characterized by histone acetylation, by the displacement of an H2A-H2B dimer, and by a persistent association with the RSC chromatin-remodeling complex. Here we demonstrate the interrelationship of these characteristics and the conversion of a nucleosome to the +1 state in vitro. Contrary to expectation, acetylation performs an inhibitory role, preventing the removal of a nucleosome by RSC. Inhibition is due to both enhanced RSC-histone interaction and diminished histone-chaperone interaction. Acetylation does not prevent all RSC activity, because stably bound RSC removes an H2A-H2B dimer on a timescale of seconds in an irreversible manner.
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Affiliation(s)
- Yahli Lorch
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - Barbara Maier-Davis
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Roger D Kornberg
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
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48
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Butryn A, Woike S, Shetty SJ, Auble DT, Hopfner KP. Crystal structure of the full Swi2/Snf2 remodeler Mot1 in the resting state. eLife 2018; 7:37774. [PMID: 30289385 PMCID: PMC6188472 DOI: 10.7554/elife.37774] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 10/04/2018] [Indexed: 01/12/2023] Open
Abstract
Swi2/Snf2 ATPases remodel protein:DNA complexes in all of the fundamental chromosome-associated processes. The single-subunit remodeler Mot1 dissociates TATA box-binding protein (TBP):DNA complexes and provides a simple model for obtaining structural insights into the action of Swi2/Snf2 ATPases. Previously we reported how the N-terminal domain of Mot1 binds TBP, NC2 and DNA, but the location of the C-terminal ATPase domain remained unclear (Butryn et al., 2015). Here, we report the crystal structure of the near full-length Mot1 from Chaetomium thermophilum. Our data show that Mot1 adopts a ring like structure with a catalytically inactive resting state of the ATPase. Biochemical analysis suggests that TBP binding switches Mot1 into an ATP hydrolysis-competent conformation. Combined with our previous results, these data significantly improve the structural model for the complete Mot1:TBP:DNA complex and suggest a general mechanism for Mot1 action.
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Affiliation(s)
- Agata Butryn
- Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany.,Gene Center, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Stephan Woike
- Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany.,Gene Center, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Savera J Shetty
- Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, United States
| | - David T Auble
- Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, United States
| | - Karl-Peter Hopfner
- Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany.,Gene Center, Ludwig-Maximilians-Universität München, Munich, Germany.,Center for Integrated Protein Sciences Munich, Munich, Germany
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49
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Sundaramoorthy R, Hughes AL, El-Mkami H, Norman DG, Ferreira H, Owen-Hughes T. Structure of the chromatin remodelling enzyme Chd1 bound to a ubiquitinylated nucleosome. eLife 2018; 7:35720. [PMID: 30079888 PMCID: PMC6118821 DOI: 10.7554/elife.35720] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 07/24/2018] [Indexed: 12/23/2022] Open
Abstract
ATP-dependent chromatin remodelling proteins represent a diverse family of proteins that share ATPase domains that are adapted to regulate protein-DNA interactions. Here, we present structures of the Saccharomyces cerevisiae Chd1 protein engaged with nucleosomes in the presence of the transition state mimic ADP-beryllium fluoride. The path of DNA strands through the ATPase domains indicates the presence of contacts conserved with single strand translocases and additional contacts with both strands that are unique to Snf2 related proteins. The structure provides connectivity between rearrangement of ATPase lobes to a closed, nucleotide bound state and the sensing of linker DNA. Two turns of linker DNA are prised off the surface of the histone octamer as a result of Chd1 binding, and both the histone H3 tail and ubiquitin conjugated to lysine 120 are re-orientated towards the unravelled DNA. This indicates how changes to nucleosome structure can alter the way in which histone epitopes are presented.
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Affiliation(s)
| | - Amanda L Hughes
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Hassane El-Mkami
- School of Physics and Astronomy, University of St Andrews, St Andrews, United Kingdom
| | - David G Norman
- Nucleic Acids Structure Research Group, University of Dundee, Dundee, United Kingdom
| | - Helder Ferreira
- School of Biology, University of St Andrews, St Andrews, United Kingdom
| | - Tom Owen-Hughes
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
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50
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Bögershausen N, Wollnik B. Mutational Landscapes and Phenotypic Spectrum of SWI/SNF-Related Intellectual Disability Disorders. Front Mol Neurosci 2018; 11:252. [PMID: 30123105 PMCID: PMC6085491 DOI: 10.3389/fnmol.2018.00252] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 07/03/2018] [Indexed: 12/29/2022] Open
Abstract
Mutations in genes that encode proteins of the SWI/SNF complex, called BAF complex in mammals, cause a spectrum of disorders that ranges from syndromic intellectual disability to Coffin-Siris syndrome (CSS) to Nicolaides-Baraitser syndrome (NCBRS). While NCBRS is known to be a recognizable and restricted phenotype, caused by missense mutations in SMARCA2, the term CSS has been used lately for a more heterogeneous group of phenotypes that are caused by mutations in either of the genes ARID1B, ARID1A, ARID2, SMARCA4, SMARCB1, SMARCE1, SOX11, or DPF2. In this review, we summarize the current knowledge on the phenotypic traits and molecular causes of the above named conditions, consider the question whether a clinical distinction of the phenotypes is still adequate, and suggest the term "SWI/SNF-related intellectual disability disorders" (SSRIDDs). We will also outline important features to identify the ARID1B-related phenotype in the absence of classic CSS features, and discuss distinctive and overlapping features of the SSRIDD subtypes. Moreover, we will briefly review the function of the SWI/SNF complex in development and describe the mutational landscapes of the genes involved in SSRIDD.
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Affiliation(s)
- Nina Bögershausen
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
| | - Bernd Wollnik
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
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