1
|
Morioka S, Oishi T, Hatazawa S, Kakuta T, Ogoshi T, Umeda K, Kodera N, Kurumizaka H, Shibata M. High-Speed Atomic Force Microscopy Reveals the Nucleosome Sliding and DNA Unwrapping/Wrapping Dynamics of Tail-less Nucleosomes. NANO LETTERS 2024; 24:5246-5254. [PMID: 38602428 DOI: 10.1021/acs.nanolett.4c00801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2024]
Abstract
Each nucleosome contains four types of histone proteins, each with a histone tail. These tails are essential for the epigenetic regulation of gene expression through post-translational modifications (PTMs). However, their influence on nucleosome dynamics at the single-molecule level remains undetermined. Here, we employed high-speed atomic force microscopy to visualize nucleosome dynamics in the absence of the N-terminal tail of each histone or all of the N-terminal tails. Loss of all tails stripped 6.7 base pairs of the nucleosome from the histone core, and the DNA entry-exit angle expanded by 18° from that of wild-type nucleosomes. Tail-less nucleosomes, particularly those without H2B and H3 tails, showed a 10-fold increase in dynamics, such as nucleosome sliding and DNA unwrapping/wrapping, within 0.3 s, emphasizing their role in histone-DNA interactions. Our findings illustrate that N-terminal histone tails stabilize the nucleosome structure, suggesting that histone tail PTMs modulate nucleosome dynamics.
Collapse
Affiliation(s)
- Shin Morioka
- Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Takumi Oishi
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Suguru Hatazawa
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Takahiro Kakuta
- Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
- WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Tomoki Ogoshi
- WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Kenichi Umeda
- WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Noriyuki Kodera
- WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| | - Hitoshi Kurumizaka
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Mikihiro Shibata
- WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
- Institute for Frontier Science Initiative, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
| |
Collapse
|
2
|
Rioux KL, Delaney S. Ionic strength modulates excision of uracil by SMUG1 from nucleosome core particles. DNA Repair (Amst) 2023; 125:103482. [PMID: 36931160 PMCID: PMC10073303 DOI: 10.1016/j.dnarep.2023.103482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 03/04/2023] [Accepted: 03/07/2023] [Indexed: 03/14/2023]
Abstract
Ionic strength affects many cellular processes including the packaging of genetic material in eukaryotes. For example, chromatin fibers are compacted in high ionic strength environments as are the minimal unit of packaging in chromatin, nucleosome core particles (NCPs). Furthermore, ionic strength is known to modulate several aspects of NCP dynamics including transient unwrapping of DNA from the histone protein core, nucleosome gaping, and intra- and internucleosomal interactions of the N-terminal histone tails. Changes in NCP structure may also impact interactions of transcriptional, repair, and other cellular machinery with nucleosomal DNA. One repair process, base excision repair (BER), is impacted by NCP structure and may be further influenced by changes in ionic strength. Here we examine the effects of ionic strength on the initiation of BER using biochemical assays. Using a population of NCPs containing uracil (U) at dozens of geometric locations, excision of U by single-strand selective monofunctional uracil DNA glycosylase (SMUG1) is assessed at higher and lower ionic strengths. SMUG1 has increased excision activity in the lower ionic strength conditions. On duplex DNA, however, SMUG1 activity is largely unaffected by ionic strength except at short incubation times, suggesting that changes in SMUG1 activity are likely due to alterations in NCP structure and dynamics. These results allow us to further understand the cellular role of SMUG1 in a changing ionic environment and broadly contribute to the understanding of BER on chromatin and genomic stability.
Collapse
Affiliation(s)
- Katelyn L Rioux
- Department of Chemistry, Brown University, Providence, RI, USA
| | - Sarah Delaney
- Department of Chemistry, Brown University, Providence, RI, USA.
| |
Collapse
|
3
|
Groehler AS, Kellum AH. Recent Advances in DNA Lesion Mapping and Repair Mechanisms. Chem Res Toxicol 2023; 36:5-7. [PMID: 36580364 PMCID: PMC9846823 DOI: 10.1021/acs.chemrestox.2c00307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Indexed: 12/30/2022]
Abstract
Recognition and repair of DNA lesions are critical for cell survival. Herein, we highlight recent advances in the sequencing, repair mechanisms, and biological consequences of DNA lesions presented at the 2022 Fall American Chemical Society meeting.
Collapse
Affiliation(s)
- Arnold S. Groehler
- Center
for Genomic Integrity, Institute for Basic
Science, Ulsan 44919 Republic of Korea
| | - Andrew H. Kellum
- Department
of Chemistry, University of California,
Riverside, Riverside, California 92521-0403, United States
| |
Collapse
|
4
|
Ryan BJ, Weaver TM, Spencer JJ, Freudenthal BD. Generation of Recombinant Nucleosomes Containing Site-Specific DNA Damage. Methods Mol Biol 2023; 2701:55-76. [PMID: 37574475 PMCID: PMC10794041 DOI: 10.1007/978-1-0716-3373-1_4] [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] [Indexed: 08/15/2023]
Abstract
Eukaryotic DNA exists in chromatin, where the genomic DNA is packaged into a fundamental repeating unit known as the nucleosome. In this chromatin environment, our genomic DNA is constantly under attack by exogenous and endogenous stressors that can lead to DNA damage. Importantly, this DNA damage must be repaired to prevent the accumulation of mutations and ensure normal cellular function. To date, most in-depth biochemical studies of DNA repair proteins have been performed in the context of free duplex DNA. However, chromatin can serve as a barrier that DNA repair enzymes must navigate in order find, access, and process DNA damage in the cell. To facilitate future studies of DNA repair in chromatin, we describe a protocol for generating nucleosome containing site-specific DNA damage that can be utilized for a variety of in vitro applications. This protocol describes several key steps including how to generate damaged DNA oligonucleotides, the expression and purification of recombinant histones, the refolding of histone complexes, and the reconstitution of nucleosomes containing site-specific DNA damage. These methods will enable researchers to generate nucleosomes containing site-specific DNA damage for extensive biochemical and structural studies of DNA repair in the nucleosome.
Collapse
Affiliation(s)
- Benjamin J Ryan
- Department of Biochemistry and Molecular Biology, Department of Cancer Biology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Tyler M Weaver
- Department of Biochemistry and Molecular Biology, Department of Cancer Biology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Jonah J Spencer
- Department of Biochemistry and Molecular Biology, Department of Cancer Biology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Bret D Freudenthal
- Department of Biochemistry and Molecular Biology, Department of Cancer Biology, University of Kansas Medical Center, Kansas City, KS, USA.
| |
Collapse
|
5
|
Obstacles and Opportunities for Base Excision Repair in Chromatin. DNA Repair (Amst) 2022; 116:103345. [PMID: 35689883 PMCID: PMC9253077 DOI: 10.1016/j.dnarep.2022.103345] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 05/20/2022] [Accepted: 05/24/2022] [Indexed: 01/01/2023]
Abstract
Most eukaryotic DNA is packaged into chromatin, which is made up of tandemly repeating nucleosomes. This packaging of DNA poses a significant barrier to the various enzymes that must act on DNA, including DNA damage response enzymes that interact intimately with DNA to prevent mutations and cell death. To regulate access to certain DNA regions, chromatin remodeling, variant histone exchange, and histone post-translational modifications have been shown to assist several DNA repair pathways including nucleotide excision repair, single strand break repair, and double strand break repair. While these chromatin-level responses have been directly linked to various DNA repair pathways, how they modulate the base excision repair (BER) pathway remains elusive. This review highlights recent findings that demonstrate how BER is regulated by the packaging of DNA into nucleosome core particles (NCPs) and higher orders of chromatin structures. We also summarize the available data that indicate BER may be enabled by chromatin modifications and remodeling.
Collapse
|
6
|
Molecular dynamics simulations reveal how H3K56 acetylation impacts nucleosome structure to promote DNA exposure for lesion sensing. DNA Repair (Amst) 2021; 107:103201. [PMID: 34399316 DOI: 10.1016/j.dnarep.2021.103201] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 07/12/2021] [Accepted: 08/02/2021] [Indexed: 01/04/2023]
Abstract
The first order of DNA packaging is the nucleosome with the DNA wrapped around the histone octamer. This leaves the nucleosomal DNA with access restrictions, which impose a significant barrier to repair of damaged DNA. The efficiency of DNA repair has been related to nucleosome structure and chromatin status, which is modulated in part by post-translational modifications (PTMs) of histones. Numerous studies have suggested a role for acetylation of lysine at position 56 of the H3 histone (H3K56ac) in various DNA transactions, including the response to DNA damage and its association with human cancer. Biophysical studies have revealed that H3K56ac increases DNA accessibility by facilitating spontaneous and transient unwrapping motions of the DNA ends. However, how this acetylation mark modulates nucleosome structure and dynamics to promote accessibility to the damaged DNA for repair factors and other proteins is still poorly understood. Here, we utilize approximately 5-6 microseconds of atomistic molecular dynamics simulations to delineate the impact of H3K56 acetylation on the nucleosome structure and dynamics, and to elucidate how these nucleosome properties are further impacted when a bulky benzo[a]pyrene-derived DNA lesion is placed near the acetylation site. Our findings reveal that H3K56ac alone induces considerable disturbance to the histone-DNA/histone-histone interactions, and amplifies the distortions imposed by the presence of the lesion. Our work highlights the important role of H3K56 acetylation in response to DNA damage and depicts how access to DNA lesions by the repair machinery can be facilitated within the nucleosome via a key acetylation event.
Collapse
|