1
|
Tamburri S, Rustichelli S, Amato S, Pasini D. Navigating the complexity of Polycomb repression: Enzymatic cores and regulatory modules. Mol Cell 2024:S1097-2765(24)00628-2. [PMID: 39178860 DOI: 10.1016/j.molcel.2024.07.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2024] [Revised: 07/12/2024] [Accepted: 07/30/2024] [Indexed: 08/26/2024]
Abstract
Polycomb proteins are a fundamental repressive system that plays crucial developmental roles by orchestrating cell-type-specific transcription programs that govern cell identity. Direct alterations of Polycomb activity are indeed implicated in human pathologies, including developmental disorders and cancer. General Polycomb repression is coordinated by three distinct activities that regulate the deposition of two histone post-translational modifications: tri-methylation of histone H3 lysine 27 (H3K27me3) and histone H2A at lysine 119 (H2AK119ub1). These activities exist in large and heterogeneous multiprotein ensembles consisting of common enzymatic cores regulated by heterogeneous non-catalytic modules composed of a large number of accessory proteins with diverse biochemical properties. Here, we have analyzed the current molecular knowledge, focusing on the functional interaction between the core enzymatic activities and their regulation mediated by distinct accessory modules. This provides a comprehensive analysis of the molecular details that control the establishment and maintenance of Polycomb repression, examining their underlying coordination and highlighting missing information and emerging new features of Polycomb-mediated transcriptional control.
Collapse
Affiliation(s)
- Simone Tamburri
- IEO, European Institute of Oncology IRCCS, Department of Experimental Oncology, Via Adamello 16, 20139 Milan, Italy; University of Milan, Department of Health Sciences, Via A. di Rudinì 8, 20142 Milan, Italy.
| | - Samantha Rustichelli
- IEO, European Institute of Oncology IRCCS, Department of Experimental Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Simona Amato
- IEO, European Institute of Oncology IRCCS, Department of Experimental Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Diego Pasini
- IEO, European Institute of Oncology IRCCS, Department of Experimental Oncology, Via Adamello 16, 20139 Milan, Italy; University of Milan, Department of Health Sciences, Via A. di Rudinì 8, 20142 Milan, Italy.
| |
Collapse
|
2
|
Moqri M, Cipriano A, Simpson DJ, Rasouli S, Murty T, de Jong TA, Nachun D, de Sena Brandine G, Ying K, Tarkhov A, Aberg KA, van den Oord E, Zhou W, Smith A, Mackall C, Gladyshev VN, Horvath S, Snyder MP, Sebastiano V. PRC2-AgeIndex as a universal biomarker of aging and rejuvenation. Nat Commun 2024; 15:5956. [PMID: 39009581 PMCID: PMC11250797 DOI: 10.1038/s41467-024-50098-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 07/01/2024] [Indexed: 07/17/2024] Open
Abstract
DNA methylation (DNAm) is one of the most reliable biomarkers of aging across mammalian tissues. While the age-dependent global loss of DNAm has been well characterized, DNAm gain is less characterized. Studies have demonstrated that CpGs which gain methylation with age are enriched in Polycomb Repressive Complex 2 (PRC2) targets. However, whole-genome examination of all PRC2 targets as well as determination of the pan-tissue or tissue-specific nature of these associations is lacking. Here, we show that low-methylated regions (LMRs) which are highly bound by PRC2 in embryonic stem cells (PRC2 LMRs) gain methylation with age in all examined somatic mitotic cells. We estimated that this epigenetic change represents around 90% of the age-dependent DNAm gain genome-wide. Therefore, we propose the "PRC2-AgeIndex," defined as the average DNAm in PRC2 LMRs, as a universal biomarker of cellular aging in somatic cells which can distinguish the effect of different anti-aging interventions.
Collapse
Affiliation(s)
- Mahdi Moqri
- Department of Biomedical Data Science, School of Medicine, Stanford University, Stanford, CA, USA
- Department of Obstetrics & Gynecology, School of Medicine, Stanford University, Stanford, CA, USA
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Department of Genetics, School of Medicine, Stanford University, Stanford, CA, USA
| | - Andrea Cipriano
- Department of Obstetrics & Gynecology, School of Medicine, Stanford University, Stanford, CA, USA
- Institute for Stem Cell Biology and Regenerative Medicine, School of Medicine, Stanford University, Stanford, CA, USA
| | - Daniel J Simpson
- Department of Obstetrics & Gynecology, School of Medicine, Stanford University, Stanford, CA, USA
- Institute for Stem Cell Biology and Regenerative Medicine, School of Medicine, Stanford University, Stanford, CA, USA
| | - Sajede Rasouli
- Department of Obstetrics & Gynecology, School of Medicine, Stanford University, Stanford, CA, USA
- Institute for Stem Cell Biology and Regenerative Medicine, School of Medicine, Stanford University, Stanford, CA, USA
| | - Tara Murty
- Center for Cancer Cell Therapy, Stanford Cancer Institute, School of Medicine, Stanford University, Stanford, CA, USA
| | - Tineke Anna de Jong
- Department of Obstetrics & Gynecology, School of Medicine, Stanford University, Stanford, CA, USA
- Institute for Stem Cell Biology and Regenerative Medicine, School of Medicine, Stanford University, Stanford, CA, USA
| | - Daniel Nachun
- Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA
| | | | - Kejun Ying
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Andrei Tarkhov
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Karolina A Aberg
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - Edwin van den Oord
- Center for Biomarker Research and Precision Medicine, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - Wanding Zhou
- Center for Computational and Genomic Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Andrew Smith
- Quantitative and Computational Biology, University of Southern California, Los Angeles, CA, USA
| | - Crystal Mackall
- Center for Cancer Cell Therapy, Stanford Cancer Institute, School of Medicine, Stanford University, Stanford, CA, USA
- Department of Pediatrics, Division of Hematology and Oncology, School of Medicine, Stanford University, Stanford, CA, USA
- Department of Medicine, Division of Stem Cell Transplantation and Cell Therapy, School of Medicine, Stanford University, Stanford, CA, USA
| | - Vadim N Gladyshev
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Steve Horvath
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
- Altos Labs, San Diego, CA, USA
| | - Michael P Snyder
- Department of Genetics, School of Medicine, Stanford University, Stanford, CA, USA.
- Center for Genomics and Personalized Medicine, Stanford University, Stanford, CA, USA.
| | - Vittorio Sebastiano
- Department of Obstetrics & Gynecology, School of Medicine, Stanford University, Stanford, CA, USA.
- Institute for Stem Cell Biology and Regenerative Medicine, School of Medicine, Stanford University, Stanford, CA, USA.
- Stanford Maternal & Child Health Research Institute, Stanford University, Stanford, CA, USA.
| |
Collapse
|
3
|
Lee JJ, Kim H, Park H, Lee U, Kim C, Lee M, Shin Y, Jung JJ, Lee HB, Han W, Lee H. Disruption of G-quadruplex dynamicity by BRCA2 abrogation instigates phase separation and break-induced replication at telomeres. Nucleic Acids Res 2024; 52:5756-5773. [PMID: 38587189 PMCID: PMC11162766 DOI: 10.1093/nar/gkae251] [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: 09/04/2023] [Revised: 03/08/2024] [Accepted: 04/03/2024] [Indexed: 04/09/2024] Open
Abstract
Dynamic interaction between BRCA2 and telomeric G-quadruplexes (G4) is crucial for maintaining telomere replication homeostasis. Cells lacking BRCA2 display telomeric damage with a subset of these cells bypassing senescence to initiate break-induced replication (BIR) for telomere synthesis. Here we show that the abnormal stabilization of telomeric G4 following BRCA2 depletion leads to telomeric repeat-containing RNA (TERRA)-R-loop accumulation, triggering liquid-liquid phase separation (LLPS) and the assembly of Alternative Lengthening of Telomeres (ALT)-associated promyelocytic leukemia (PML) bodies (APBs). Disruption of R-loops abolishes LLPS and impairs telomere synthesis. Artificial engineering of telomeric LLPS restores telomere synthesis, underscoring the critical role of LLPS in ALT. TERRA-R-loops also recruit Polycomb Repressive Complex 2 (PRC2), leading to tri-methylation of Lys27 on histone H3 (H3K27me3) at telomeres. Half of paraffin-embedded tissue sections from human breast cancers exhibit APBs and telomere length heterogeneity, suggesting that BRCA2 mutations can predispose individuals to ALT-type tumorigenesis. Overall, BRCA2 abrogation disrupts the dynamicity of telomeric G4, producing TERRA-R-loops, finally leading to the assembly of telomeric liquid condensates crucial for ALT. We propose that modulating the dynamicity of telomeric G4 and targeting TERRA-R-loops in telomeric LLPS maintenance may represent effective therapeutic strategies for treating ALT-like cancers with APBs, including those with BRCA2 disruptions.
Collapse
Affiliation(s)
- Jennifer J Lee
- Department of Biological Sciences & Institute of Molecular Biology and Genetics (IMBG), Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul 08826, Korea
| | - Hyungmin Kim
- Department of Biological Sciences & Institute of Molecular Biology and Genetics (IMBG), Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul 08826, Korea
| | - Haemin Park
- Department of Biological Sciences & Institute of Molecular Biology and Genetics (IMBG), Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul 08826, Korea
| | - UkJin Lee
- Department of Biological Sciences & Institute of Molecular Biology and Genetics (IMBG), Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul 08826, Korea
| | - Chaelim Kim
- Interdisciplinary Program in Bioengineering, Seoul National University, Seoul 08826, Korea
| | - Min Lee
- Interdisciplinary Program in Bioengineering, Seoul National University, Seoul 08826, Korea
| | - Yongdae Shin
- Department of Mechanical Engineering, Seoul National University, Seoul 08826, Korea
- Interdisciplinary Program in Bioengineering, Seoul National University, Seoul 08826, Korea
| | - Ji-Jung Jung
- Department of Surgery, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Han-Byoel Lee
- Department of Surgery, Seoul National University College of Medicine, Seoul 03080, Korea
- Biomedical Research Institute, Seoul National University Hospital, Seoul 03080, Korea
- Cancer Research Institute, Seoul National University, Seoul 03080, Korea
| | - Wonshik Han
- Department of Surgery, Seoul National University College of Medicine, Seoul 03080, Korea
- Biomedical Research Institute, Seoul National University Hospital, Seoul 03080, Korea
- Cancer Research Institute, Seoul National University, Seoul 03080, Korea
| | - Hyunsook Lee
- Department of Biological Sciences & Institute of Molecular Biology and Genetics (IMBG), Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul 08826, Korea
| |
Collapse
|
4
|
Seif E, Francis NJ. A Two-Step Mechanism for Creating Stable, Condensed Chromatin with the Polycomb Complex PRC1. Molecules 2024; 29:323. [PMID: 38257239 PMCID: PMC10821450 DOI: 10.3390/molecules29020323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 12/26/2023] [Accepted: 01/05/2024] [Indexed: 01/24/2024] Open
Abstract
The Drosophila PRC1 complex regulates gene expression by modifying histone proteins and chromatin architecture. Two PRC1 subunits, PSC and Ph, are most implicated in chromatin architecture. In vitro, PRC1 compacts chromatin and inhibits transcription and nucleosome remodeling. The long disordered C-terminal region of PSC (PSC-CTR) is important for these activities, while Ph has little effect. In cells, Ph is important for condensate formation, long-range chromatin interactions, and gene regulation, and its polymerizing sterile alpha motif (SAM) is implicated in these activities. In vitro, truncated Ph containing the SAM and two other conserved domains (mini-Ph) undergoes phase separation with chromatin, suggesting a mechanism for SAM-dependent condensate formation in vivo. How the distinct activities of PSC and Ph on chromatin function together in PRC1 is not known. To address this question, we analyzed structures formed with large chromatin templates and PRC1 in vitro. PRC1 bridges chromatin into extensive fibrillar networks. Ph, its SAM, and SAM polymerization activity have little effect on these structures. Instead, the PSC-CTR controls their growth, and is sufficient for their formation. To understand how phase separation driven by Ph SAM intersects with the chromatin bridging activity of the PSC-CTR, we used mini-Ph to form condensates with chromatin and then challenged them with PRC1 lacking Ph (PRC1ΔPh). PRC1ΔPh converts mini-Ph chromatin condensates into clusters of small non-fusing condensates and bridged fibers. These condensates retain a high level of chromatin compaction and do not intermix. Thus, phase separation of chromatin by mini-Ph, followed by the action of the PSC-CTR, creates a unique chromatin organization with regions of high nucleosome density and extraordinary stability. We discuss how this coordinated sequential activity of two proteins found in the same complex may occur and the possible implications of stable chromatin architectures in maintaining transcription states.
Collapse
Affiliation(s)
- Elias Seif
- Institut de Recherches Cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC H2W 1R7, Canada;
| | - Nicole J. Francis
- Institut de Recherches Cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC H2W 1R7, Canada;
- Division of Experimental Medicine, McGill University, 1001 Decarie Boulevard, Montréal, QC H4A 3J1, Canada
- Département de Biochimie et Médecine Moléculaire, Université de Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, QC H3T 1J4, Canada
| |
Collapse
|
5
|
Kumar C, Remus D. Looping out of control: R-loops in transcription-replication conflict. Chromosoma 2024; 133:37-56. [PMID: 37419963 PMCID: PMC10771546 DOI: 10.1007/s00412-023-00804-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 07/09/2023]
Abstract
Transcription-replication conflict is a major cause of replication stress that arises when replication forks collide with the transcription machinery. Replication fork stalling at sites of transcription compromises chromosome replication fidelity and can induce DNA damage with potentially deleterious consequences for genome stability and organismal health. The block to DNA replication by the transcription machinery is complex and can involve stalled or elongating RNA polymerases, promoter-bound transcription factor complexes, or DNA topology constraints. In addition, studies over the past two decades have identified co-transcriptional R-loops as a major source for impairment of DNA replication forks at active genes. However, how R-loops impede DNA replication at the molecular level is incompletely understood. Current evidence suggests that RNA:DNA hybrids, DNA secondary structures, stalled RNA polymerases, and condensed chromatin states associated with R-loops contribute to the of fork progression. Moreover, since both R-loops and replication forks are intrinsically asymmetric structures, the outcome of R-loop-replisome collisions is influenced by collision orientation. Collectively, the data suggest that the impact of R-loops on DNA replication is highly dependent on their specific structural composition. Here, we will summarize our current understanding of the molecular basis for R-loop-induced replication fork progression defects.
Collapse
Affiliation(s)
- Charanya Kumar
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, 10065, USA
| | - Dirk Remus
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York, 10065, USA.
| |
Collapse
|
6
|
Al Zouabi L, Stefanutti M, Roumeliotis S, Le Meur G, Boumard B, Riddiford N, Rubanova N, Bohec M, Gervais L, Servant N, Bardin AJ. Molecular underpinnings and environmental drivers of loss of heterozygosity in Drosophila intestinal stem cells. Cell Rep 2023; 42:113485. [PMID: 38032794 DOI: 10.1016/j.celrep.2023.113485] [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: 08/03/2022] [Revised: 09/29/2023] [Accepted: 11/08/2023] [Indexed: 12/02/2023] Open
Abstract
During development and aging, genome mutation leading to loss of heterozygosity (LOH) can uncover recessive phenotypes within tissue compartments. This phenomenon occurs in normal human tissues and is prevalent in pathological genetic conditions and cancers. While studies in yeast have defined DNA repair mechanisms that can promote LOH, the predominant pathways and environmental triggers in somatic tissues of multicellular organisms are not well understood. Here, we investigate mechanisms underlying LOH in intestinal stem cells in Drosophila. Infection with the pathogenic bacteria, Erwinia carotovora carotovora 15, but not Pseudomonas entomophila, increases LOH frequency. Using whole genome sequencing of somatic LOH events, we demonstrate that they arise primarily via mitotic recombination. Molecular features and genetic evidence argue against a break-induced replication mechanism and instead support cross-over via double Holliday junction-based repair. This study provides a mechanistic understanding of mitotic recombination, an important mediator of LOH, and its effects on stem cells in vivo.
Collapse
Affiliation(s)
- Lara Al Zouabi
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France
| | - Marine Stefanutti
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France
| | - Spyridon Roumeliotis
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France
| | - Gwenn Le Meur
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France
| | - Benjamin Boumard
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France
| | - Nick Riddiford
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France
| | - Natalia Rubanova
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France; Bioinformatics, Biostatistics, Epidemiology and Computational Systems Unit, Institut Curie, PSL Research University, INSERM U900, 75005 Paris, France
| | - Mylène Bohec
- ICGex Next-Generation Sequencing Platform, Institut Curie, PSL Research University, 75005 Paris, France
| | - Louis Gervais
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France
| | - Nicolas Servant
- Bioinformatics, Biostatistics, Epidemiology and Computational Systems Unit, Institut Curie, PSL Research University, INSERM U900, 75005 Paris, France
| | - Allison J Bardin
- Genetics and Developmental Biology Department, Institut Curie, PSL Research University, Sorbonne University, CNRS UMR 3215, INSERM U934, 75248 Paris, France.
| |
Collapse
|
7
|
Yu Y, Wang S, Wang Z, Gao R, Lee J. Arabidopsis thaliana: a powerful model organism to explore histone modifications and their upstream regulations. Epigenetics 2023; 18:2211362. [PMID: 37196184 DOI: 10.1080/15592294.2023.2211362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 04/07/2023] [Accepted: 04/28/2023] [Indexed: 05/19/2023] Open
Abstract
Histones are subjected to extensive covalent modifications that affect inter-nucleosomal interactions as well as alter chromatin structure and DNA accessibility. Through switching the corresponding histone modifications, the level of transcription and diverse downstream biological processes can be regulated. Although animal systems are widely used in studying histone modifications, the signalling processes that occur outside the nucleus prior to histone modifications have not been well understood due to the limitations including non viable mutants, partial lethality, and infertility of survivors. Here, we review the benefits of using Arabidopsis thaliana as the model organism to study histone modifications and their upstream regulations. Similarities among histones and key histone modifiers such as the Polycomb group (PcG) and Trithorax group (TrxG) in Drosophila, Human, and Arabidopsis are examined. Furthermore, prolonged cold-induced vernalization system has been well-studied and revealed the relationship between the controllable environment input (duration of vernalization), its chromatin modifications of FLOWERING LOCUS C (FLC), following gene expression, and the corresponding phenotypes. Such evidence suggests that research on Arabidopsis can bring insights into incomplete signalling pathways outside of the histone box, which can be achieved through viable reverse genetic screenings based on the phenotypes instead of direct monitoring of histone modifications among individual mutants. The potential upstream regulators in Arabidopsis can provide cues or directions for animal research based on the similarities between them.
Collapse
Affiliation(s)
- Yang Yu
- Division of Natural and Applied Sciences, Duke Kunshan University, Kunshan, Jiangsu, China
| | - Sihan Wang
- Division of Natural and Applied Sciences, Duke Kunshan University, Kunshan, Jiangsu, China
| | - Ziqin Wang
- Division of Natural and Applied Sciences, Duke Kunshan University, Kunshan, Jiangsu, China
| | - Renwei Gao
- Division of Natural and Applied Sciences, Duke Kunshan University, Kunshan, Jiangsu, China
| | - Joohyun Lee
- Division of Natural and Applied Sciences, Duke Kunshan University, Kunshan, Jiangsu, China
| |
Collapse
|
8
|
Jia Q, Zhang X, Liu Q, Li J, Wang W, Ma X, Zhu B, Li S, Gong S, Tian J, Yuan M, Zhao Y, Zhou DX. A DNA adenine demethylase impairs PRC2-mediated repression of genes marked by a specific chromatin signature. Genome Biol 2023; 24:198. [PMID: 37649077 PMCID: PMC10469495 DOI: 10.1186/s13059-023-03042-4] [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] [Received: 02/16/2023] [Accepted: 08/21/2023] [Indexed: 09/01/2023] Open
Abstract
BACKGROUND The Fe (II)- and α-ketoglutarate-dependent AlkB family dioxygenases are implicated in nucleotide demethylation. AlkB homolog1 (ALKBH1) is shown to demethylate DNA adenine methylation (6mA) preferentially from single-stranded or unpaired DNA, while its demethylase activity and function in the chromatin context are unclear. RESULTS Here, we find that loss-of-function of the rice ALKBH1 gene leads to increased 6mA in the R-loop regions of the genome but has a limited effect on the overall 6mA level. However, in the context of mixed tissues, rather than on individual loci, the ALKBH1 mutation or overexpression mainly affects the expression of genes with a specific combination of chromatin modifications in the body region marked with H3K4me3 and H3K27me3 but depleted of DNA CG methylation. In the similar context of mixed tissues, further analysis reveals that the ALKBH1 protein preferentially binds to genes marked by the chromatin signature and has a function to maintain a high H3K4me3/H3K27me3 ratio by impairing the binding of Polycomb repressive complex 2 (PRC2) to the targets, which is required for both the basal and stress-induced expression of the genes. CONCLUSION Our findings unravel a function of ALKBH1 to control the balance between the antagonistic histone methylations for gene activity and provide insight into the regulatory mechanism of PRC2-mediated H3K27me3 deposition within the gene body region.
Collapse
Affiliation(s)
- Qingxiao Jia
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xinran Zhang
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Qian Liu
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Junjie Li
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wentao Wang
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xuan Ma
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Bo Zhu
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Sheng Li
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Shicheng Gong
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jingjing Tian
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Meng Yuan
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yu Zhao
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Dao-Xiu Zhou
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China.
- Institute of Plant Science Paris-Saclay (IPS2), CNRS, INRAE, University Paris-Saclay, 91405, Orsay, France.
| |
Collapse
|
9
|
Hamba Y, Kamatani T, Miya F, Boroevich KA, Tsunoda T. Topologically associating domain underlies tissue specific expression of long intergenic non-coding RNAs. iScience 2023; 26:106640. [PMID: 37250307 PMCID: PMC10214471 DOI: 10.1016/j.isci.2023.106640] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 12/15/2022] [Accepted: 04/05/2023] [Indexed: 05/31/2023] Open
Abstract
Accumulating evidence indicates that long intergenic non-coding RNAs (lincRNAs) show more tissue-specific expression patterns than protein-coding genes (PCGs). However, although lincRNAs are subject to canonical transcriptional regulation like PCGs, the molecular basis for the specificity of their expression patterns remains unclear. Here, using expression data and coordinates of topologically associating domains (TADs) in human tissues, we show that lincRNA loci are significantly enriched in the more internal region of TADs compared to PCGs and that lincRNAs within TADs have higher tissue specificity than those outside TADs. Based on these, we propose an analytical framework to interpret transcriptional status using lincRNA as an indicator. We applied it to hypertrophic cardiomyopathy data and found disease-specific transcriptional regulation: ectopic expression of keratin at the TAD level and derepression of myocyte differentiation-related genes by E2F1 with down-regulation of LINC00881. Our results provide understanding of the function and regulation of lincRNAs according to genomic structure.
Collapse
Affiliation(s)
- Yu Hamba
- Laboratory for Medical Science Mathematics, Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan
- Laboratory for Medical Science Mathematics, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan
| | - Takashi Kamatani
- Laboratory for Medical Science Mathematics, Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan
- Department of AI Technology Development, M&D Data Science Center, Tokyo Medical and Dental University, Tokyo 101-0062, Japan
- Division of Precision Cancer Medicine, Tokyo Medical and Dental University Hospital, Tokyo 113-8519, Japan
- Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Fuyuki Miya
- Center for Medical Genetics, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Keith A. Boroevich
- Laboratory for Medical Science Mathematics, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan
| | - Tatsuhiko Tsunoda
- Laboratory for Medical Science Mathematics, Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan
- Laboratory for Medical Science Mathematics, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8562, Japan
| |
Collapse
|
10
|
Zhou J, Zhang W, Sun Q. R-loop: The new genome regulatory element in plants. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2022; 64:2275-2289. [PMID: 36223078 DOI: 10.1111/jipb.13383] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 10/10/2022] [Indexed: 06/16/2023]
Abstract
An R-loop is a three-stranded chromatin structure that consists of a displaced single strand of DNA and an RNA:DNA hybrid duplex, which was thought to be a rare by-product of transcription. However, recent genome-wide data have shown that R-loops are widespread and pervasive in a variety of genomes, and a growing body of experimental evidence indicates that R-loops have both beneficial and harmful effects on an organism. To maximize benefit and avoid harm, organisms have evolved several means by which they tightly regulate R-loop levels. Here, we summarize our current understanding of the biogenesis and effects of R-loops, the mechanisms that regulate them, and methods of R-loop profiling, reviewing recent research advances on R-loops in plants. Furthermore, we provide perspectives on future research directions for R-loop biology in plants, which might lead to a more comprehensive understanding of R-loop functions in plant genome regulation and contribute to future agricultural improvements.
Collapse
Affiliation(s)
- Jincong Zhou
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
| | - Weifeng Zhang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
| | - Qianwen Sun
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing, 100084, China
| |
Collapse
|
11
|
p300/CBP sustains Polycomb silencing by non-enzymatic functions. Mol Cell 2022; 82:3580-3597.e9. [DOI: 10.1016/j.molcel.2022.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 06/16/2022] [Accepted: 09/06/2022] [Indexed: 12/29/2022]
|
12
|
Miller HE, Montemayor D, Abdul J, Vines A, Levy SA, Hartono SR, Sharma K, Frost B, Chédin F, Bishop AJR. Quality-controlled R-loop meta-analysis reveals the characteristics of R-loop consensus regions. Nucleic Acids Res 2022; 50:7260-7286. [PMID: 35758606 PMCID: PMC9303298 DOI: 10.1093/nar/gkac537] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 06/16/2022] [Indexed: 12/13/2022] Open
Abstract
R-loops are three-stranded nucleic acid structures formed from the hybridization of RNA and DNA. While the pathological consequences of R-loops have been well-studied to date, the locations, classes, and dynamics of physiological R-loops remain poorly understood. R-loop mapping studies provide insight into R-loop dynamics, but their findings are challenging to generalize. This is due to the narrow biological scope of individual studies, the limitations of each mapping modality, and, in some cases, poor data quality. In this study, we reprocessed 810 R-loop mapping datasets from a wide array of biological conditions and mapping modalities. From this data resource, we developed an accurate R-loop data quality control method, and we reveal the extent of poor-quality data within previously published studies. We then identified a set of high-confidence R-loop mapping samples and used them to define consensus R-loop sites called 'R-loop regions' (RL regions). In the process, we identified a stark divergence between RL regions detected by S9.6 and dRNH-based mapping methods, particularly with respect to R-loop size, location, and colocalization with RNA binding factors. Taken together, this work provides a much-needed method to assess R-loop data quality and offers novel context regarding the differences between dRNH- and S9.6-based R-loop mapping approaches.
Collapse
Affiliation(s)
- Henry E Miller
- Department of Cell Systems and Anatomy, UT Health San Antonio, San Antonio, TX, USA.,Greehey Children's Cancer Research Institute, UT Health San Antonio, San Antonio, TX, USA.,Bioinformatics Research Network, Atlanta, GA, USA
| | - Daniel Montemayor
- Department of Medicine, UT Health San Antonio, San Antonio, TX, USA.,Center for Precision Medicine, UT Health San Antonio, San Antonio, TX, USA
| | - Jebriel Abdul
- Bioinformatics Research Network, Atlanta, GA, USA.,Department of Biology, University of Ottawa, Ottawa, Canada
| | - Anna Vines
- Bioinformatics Research Network, Atlanta, GA, USA.,Faculty of Arts, University of Bristol, Bristol, U.K
| | - Simon A Levy
- Department of Cell Systems and Anatomy, UT Health San Antonio, San Antonio, TX, USA.,Bioinformatics Research Network, Atlanta, GA, USA.,Sam & Ann Barshop Institute for Longevity & Aging Studies, UT Health San Antonio, San Antonio, TX, USA.,Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases, UT Health San Antonio, San Antonio, TX, USA
| | - Stella R Hartono
- Department of Molecular and Cellular Biology, UC Davis, Davis, CA, USA
| | - Kumar Sharma
- Department of Medicine, UT Health San Antonio, San Antonio, TX, USA.,Center for Precision Medicine, UT Health San Antonio, San Antonio, TX, USA
| | - Bess Frost
- Department of Cell Systems and Anatomy, UT Health San Antonio, San Antonio, TX, USA.,Sam & Ann Barshop Institute for Longevity & Aging Studies, UT Health San Antonio, San Antonio, TX, USA.,Glenn Biggs Institute for Alzheimer's and Neurodegenerative Diseases, UT Health San Antonio, San Antonio, TX, USA
| | - Frédéric Chédin
- Department of Molecular and Cellular Biology, UC Davis, Davis, CA, USA
| | - Alexander J R Bishop
- Department of Cell Systems and Anatomy, UT Health San Antonio, San Antonio, TX, USA.,Greehey Children's Cancer Research Institute, UT Health San Antonio, San Antonio, TX, USA.,May's Cancer Center, UT Health San Antonio, San Antonio, TX, USA
| |
Collapse
|
13
|
Stanek TJ, Cao W, Mehra RM, Ellison CE. Sex-specific variation in R-loop formation in Drosophila melanogaster. PLoS Genet 2022; 18:e1010268. [PMID: 35687614 PMCID: PMC9223372 DOI: 10.1371/journal.pgen.1010268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 06/23/2022] [Accepted: 05/22/2022] [Indexed: 11/18/2022] Open
Abstract
R-loops are three-stranded nucleotide structures consisting of a DNA:RNA hybrid and a displaced ssDNA non-template strand. Previous work suggests that R-loop formation is primarily determined by the thermodynamics of DNA:RNA binding, which are governed by base composition (e.g., GC skew) and transcription-induced DNA superhelicity. However, R-loops have been described at genomic locations that lack these properties, suggesting that they may serve other context-specific roles. To better understand the genetic determinants of R-loop formation, we have characterized the Drosophila melanogaster R-loop landscape across strains and between sexes using DNA:RNA immunoprecipitation followed by high-throughput sequencing (DRIP-seq). We find that R-loops are associated with sequence motifs that are G-rich or exhibit G/C skew, as well as highly expressed genes, tRNAs, and small nuclear RNAs, consistent with a role for DNA sequence and torsion in R-loop specification. However, we also find motifs associated with R-loops that are A/T-rich and lack G/C skew as well as a subset of R-loops that are enriched in polycomb-repressed chromatin. Differential enrichment analysis reveals a small number of sex-biased R-loops: while non-differentially enriched and male-enriched R-loops form at similar genetic features and chromatin states and contain similar sequence motifs, female-enriched R-loops form at unique genetic features, chromatin states, and sequence motifs and are associated with genes that show ovary-biased expression. Male-enriched R-loops are most abundant on the dosage-compensated X chromosome, where R-loops appear stronger compared to autosomal R-loops. R-loop-containing genes on the X chromosome are dosage-compensated yet show lower MOF binding and reduced H4K16ac compared to R-loop-absent genes, suggesting that H4K16ac or MOF may attenuate R-loop formation. Collectively, these results suggest that R-loop formation in vivo is not fully explained by DNA sequence and topology and raise the possibility that a distinct subset of these hybrid structures plays an important role in the establishment and maintenance of epigenetic differences between sexes.
Collapse
Affiliation(s)
- Timothy J. Stanek
- Department of Genetics, Human Genetics Institute of New Jersey, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
- Department of Pathology, Robert Wood Johnson Medical School, Piscataway, New Jersey, United States of America
| | - Weihuan Cao
- Department of Genetics, Human Genetics Institute of New Jersey, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
| | - Rohan M Mehra
- Department of Genetics, Human Genetics Institute of New Jersey, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
| | - Christopher E. Ellison
- Department of Genetics, Human Genetics Institute of New Jersey, Rutgers, The State University of New Jersey, Piscataway, New Jersey, United States of America
- * E-mail:
| |
Collapse
|
14
|
Munden A, Benton ML, Capra JA, Nordman JT. R-loop mapping and characterization during Drosophila embryogenesis reveals developmental plasticity in R-loop signatures. J Mol Biol 2022; 434:167645. [PMID: 35609632 PMCID: PMC9254486 DOI: 10.1016/j.jmb.2022.167645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 05/16/2022] [Accepted: 05/18/2022] [Indexed: 11/26/2022]
Abstract
R-loops are involved in transcriptional regulation, DNA and histone post-translational modifications, genome replication and genome stability. To what extent R-loop abundance and genome-wide localization is actively regulated during metazoan embryogenesis is unknown. Drosophila embryogenesis provides a powerful system to address these questions due to its well-characterized developmental program, the sudden onset of zygotic transcription and available genome-wide data sets. Here, we measure the overall abundance and genome localization of R-loops in early and late-stage embryos relative to Drosophila cultured cells. We demonstrate that absolute R-loop levels change during embryogenesis and that RNaseH1 catalytic activity is critical for embryonic development. R-loop mapping by strand-specific DRIP-seq reveals that R-loop localization is plastic across development, both in the genes which form R-loops and where they localize relative to gene bodies. Importantly, these changes are not driven by changes in the transcriptional program. Negative GC skew and absolute changes in AT skew are associated with R-loop formation in Drosophila. Furthermore, we demonstrate that while some chromatin binding proteins and histone modifications such as H3K27me3 are associated with R-loops throughout development, other chromatin factors associated with R-loops in a developmental specific manner. Our findings highlight the importance and developmental plasticity of R-loops during Drosophila embryogenesis.
Collapse
Affiliation(s)
- Alexander Munden
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37212, USA
| | | | - John A Capra
- Bakar Computational Health Sciences Institute and Department of Epidemiology and Biostatistics, University of California, San Francisco, CA 94103, USA
| | - Jared T Nordman
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37212, USA.
| |
Collapse
|
15
|
Bencivenga D, Stampone E, Vastante A, Barahmeh M, Della Ragione F, Borriello A. An Unanticipated Modulation of Cyclin-Dependent Kinase Inhibitors: The Role of Long Non-Coding RNAs. Cells 2022; 11:cells11081346. [PMID: 35456025 PMCID: PMC9028986 DOI: 10.3390/cells11081346] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 04/08/2022] [Accepted: 04/11/2022] [Indexed: 12/13/2022] Open
Abstract
It is now definitively established that a large part of the human genome is transcribed. However, only a scarce percentage of the transcriptome (about 1.2%) consists of RNAs that are translated into proteins, while the large majority of transcripts include a variety of RNA families with different dimensions and functions. Within this heterogeneous RNA world, a significant fraction consists of sequences with a length of more than 200 bases that form the so-called long non-coding RNA family. The functions of long non-coding RNAs range from the regulation of gene transcription to the changes in DNA topology and nucleosome modification and structural organization, to paraspeckle formation and cellular organelles maturation. This review is focused on the role of long non-coding RNAs as regulators of cyclin-dependent kinase inhibitors’ (CDKIs) levels and activities. Cyclin-dependent kinases are enzymes necessary for the tuned progression of the cell division cycle. The control of their activity takes place at various levels. Among these, interaction with CDKIs is a vital mechanism. Through CDKI modulation, long non-coding RNAs implement control over cellular physiology and are associated with numerous pathologies. However, although there are robust data in the literature, the role of long non-coding RNAs in the modulation of CDKIs appears to still be underestimated, as well as their importance in cell proliferation control.
Collapse
|
16
|
Alecki C, Vera M. Role of Nuclear Non-Canonical Nucleic Acid Structures in Organismal Development and Adaptation to Stress Conditions. Front Genet 2022; 13:823241. [PMID: 35281835 PMCID: PMC8906566 DOI: 10.3389/fgene.2022.823241] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 01/25/2022] [Indexed: 11/21/2022] Open
Abstract
Over the last decades, numerous examples have involved nuclear non-coding RNAs (ncRNAs) in the regulation of gene expression. ncRNAs can interact with the genome by forming non-canonical nucleic acid structures such as R-loops or DNA:RNA triplexes. They bind chromatin and DNA modifiers and transcription factors and favor or prevent their targeting to specific DNA sequences and regulate gene expression of diverse genes. We review the function of these non-canonical nucleic acid structures in regulating gene expression of multicellular organisms during development and in response to different stress conditions and DNA damage using examples described in several organisms, from plants to humans. We also overview recent techniques developed to study where R-loops or DNA:RNA triplexes are formed in the genome and their interaction with proteins.
Collapse
Affiliation(s)
- Célia Alecki
- Department of Biochemistry, McGill University, Montreal, QC, Canada
| | - Maria Vera
- Department of Biochemistry, McGill University, Montreal, QC, Canada
| |
Collapse
|
17
|
Jauregui‐Lozano J, Escobedo S, Easton A, Lanman N, Weake VM, Hall H. Proper control of R-loop homeostasis is required for maintenance of gene expression and neuronal function during aging. Aging Cell 2022; 21:e13554. [PMID: 35048512 PMCID: PMC8844117 DOI: 10.1111/acel.13554] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 12/03/2021] [Accepted: 01/03/2022] [Indexed: 01/25/2023] Open
Abstract
Age-related loss of cellular function and increased cell death are characteristic hallmarks of aging. While defects in gene expression and RNA metabolism have been linked with age-associated human neuropathies, it is not clear how the changes that occur in aging neurons contribute to loss of gene expression homeostasis. R-loops are RNA-DNA hybrids that typically form co-transcriptionally via annealing of the nascent RNA to the template DNA strand, displacing the non-template DNA strand. Dysregulation of R-loop homeostasis has been associated with both transcriptional impairment and genome instability. Importantly, a growing body of evidence links R-loop accumulation with cellular dysfunction, increased cell death, and chronic disease onset. Here, we characterized the R-loop landscape in aging Drosophila melanogaster photoreceptor neurons and showed that bulk R-loop levels increased with age. Further, genome-wide mapping of R-loops revealed that transcribed genes accumulated R-loops over gene bodies during aging, which correlated with decreased expression of long and highly expressed genes. Importantly, while photoreceptor-specific down-regulation of Top3β, a DNA/RNA topoisomerase associated with R-loop resolution, lead to decreased visual function, over-expression of Top3β or nuclear-localized RNase H1, which resolves R-loops, enhanced positive light response during aging. Together, our studies highlight the functional link between dysregulation of R-loop homeostasis, gene expression, and visual function during aging.
Collapse
Affiliation(s)
| | - Spencer Escobedo
- Department of BiochemistryPurdue UniversityWest LafayetteIndianaUSA
| | - Alyssa Easton
- Department of Agricultural and Biological EngineeringPurdue UniversityWest LafayetteIndianaUSA
| | - Nadia A. Lanman
- Department of Comparative PathobiologyCollege of Veterinary MedicinePurdue UniversityWest LafayetteIndianaUSA
- Purdue University Center for Cancer ResearchPurdue UniversityWest LafayetteIndianaUSA
| | - Vikki M. Weake
- Department of BiochemistryPurdue UniversityWest LafayetteIndianaUSA
- Purdue University Center for Cancer ResearchPurdue UniversityWest LafayetteIndianaUSA
| | - Hana Hall
- Department of BiochemistryPurdue UniversityWest LafayetteIndianaUSA
- Purdue Institute for Integrative NeurosciencePurdue UniversityWest LafayetteIndianaUSA
| |
Collapse
|
18
|
Vijayanathan M, Trejo-Arellano MG, Mozgová I. Polycomb Repressive Complex 2 in Eukaryotes-An Evolutionary Perspective. EPIGENOMES 2022; 6:3. [PMID: 35076495 PMCID: PMC8788455 DOI: 10.3390/epigenomes6010003] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 01/12/2022] [Accepted: 01/12/2022] [Indexed: 12/23/2022] Open
Abstract
Polycomb repressive complex 2 (PRC2) represents a group of evolutionarily conserved multi-subunit complexes that repress gene transcription by introducing trimethylation of lysine 27 on histone 3 (H3K27me3). PRC2 activity is of key importance for cell identity specification and developmental phase transitions in animals and plants. The composition, biochemistry, and developmental function of PRC2 in animal and flowering plant model species are relatively well described. Recent evidence demonstrates the presence of PRC2 complexes in various eukaryotic supergroups, suggesting conservation of the complex and its function. Here, we provide an overview of the current understanding of PRC2-mediated repression in different representatives of eukaryotic supergroups with a focus on the green lineage. By comparison of PRC2 in different eukaryotes, we highlight the possible common and diverged features suggesting evolutionary implications and outline emerging questions and directions for future research of polycomb repression and its evolution.
Collapse
Affiliation(s)
- Mallika Vijayanathan
- Biology Centre, Institute of Plant Molecular Biology, Czech Academy of Sciences, 370 05 Ceske Budejovice, Czech Republic; (M.V.); (M.G.T.-A.)
| | - María Guadalupe Trejo-Arellano
- Biology Centre, Institute of Plant Molecular Biology, Czech Academy of Sciences, 370 05 Ceske Budejovice, Czech Republic; (M.V.); (M.G.T.-A.)
| | - Iva Mozgová
- Biology Centre, Institute of Plant Molecular Biology, Czech Academy of Sciences, 370 05 Ceske Budejovice, Czech Republic; (M.V.); (M.G.T.-A.)
- Faculty of Science, University of South Bohemia, 370 05 Ceske Budejovice, Czech Republic
| |
Collapse
|
19
|
Kim A, Wang GG. R-loop and its functions at the regulatory interfaces between transcription and (epi)genome. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2021; 1864:194750. [PMID: 34461314 PMCID: PMC8627470 DOI: 10.1016/j.bbagrm.2021.194750] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/10/2021] [Accepted: 08/19/2021] [Indexed: 01/08/2023]
Abstract
R-loop represents a prevalent and specialized chromatin structure critically involved in a wide range of biological processes. In particular, co-transcriptional R-loops, produced often due to RNA polymerase pausing or RNA biogenesis malfunction, can initiate molecular events to context-dependently regulate local gene transcription and crosstalk with chromatin modifications. Cellular "readers" of R-loops are identified, exerting crucial impacts on R-loop homeostasis and gene regulation. Mounting evidence also supports R-loop deregulation as a frequent, sometimes initiating, event during the development of human pathologies, notably cancer and neurological disorder. The purpose of this review is to cover recent advances in understanding the fundamentals of R-loop biology, which have started to unveil complex interplays of R-loops with factors involved in various biological processes such as transcription, RNA processing and epitranscriptomic modification (such as N6-methyladenosine), DNA damage sensing and repair, and epigenetic regulation.
Collapse
Affiliation(s)
- Arum Kim
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Gang Greg Wang
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA.
| |
Collapse
|
20
|
Bieluszewski T, Xiao J, Yang Y, Wagner D. PRC2 activity, recruitment, and silencing: a comparative perspective. TRENDS IN PLANT SCIENCE 2021; 26:1186-1198. [PMID: 34294542 DOI: 10.1016/j.tplants.2021.06.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 06/08/2021] [Accepted: 06/16/2021] [Indexed: 05/22/2023]
Abstract
Polycomb repressive complex (PRC)-mediated gene silencing is vital for cell identity and development in both the plant and the animal kingdoms. It also modulates responses to stress. Two major protein complexes, PRC1 and PRC2, execute conserved nuclear functions in metazoans and plants through covalent modification of histones and by compacting chromatin. While a general requirement for Polycomb complexes in mitotically heritable gene repression in the context of chromatin is well established, recent studies have brought new insights into the regulation of Polycomb complex activity and recruitment. Here, we discuss these recent advances with emphasis on PRC2.
Collapse
Affiliation(s)
- Tomasz Bieluszewski
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19103, USA
| | - Jun Xiao
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China; Centre of Excellence for Plant and Microbial Science (CEPAMS), the John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Yiman Yang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China; College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Doris Wagner
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19103, USA.
| |
Collapse
|
21
|
Castillo-Guzman D, Chédin F. Defining R-loop classes and their contributions to genome instability. DNA Repair (Amst) 2021; 106:103182. [PMID: 34303066 PMCID: PMC8691176 DOI: 10.1016/j.dnarep.2021.103182] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 07/14/2021] [Accepted: 07/16/2021] [Indexed: 01/20/2023]
Abstract
R-loops are non-B DNA structures that form during transcription when the nascent RNA anneals to the template DNA strand forming a RNA:DNA hybrid. Understanding the genomic distribution and function of R-loops is an important goal, since R-loops have been implicated in a number of adaptive and maladaptive processes under physiological and pathological conditions. Based on R-loop mapping datasets, we propose the existence of two main classes of R-loops, each associated with unique characteristics. Promoter-paused R-loops (Class I) are short R-loops that form at high frequency during promoter-proximal pausing by RNA polymerase II. Elongation-associated R-loops (Class II) are long structures that occur throughout gene bodies at modest frequencies. We further discuss the relationships between each R-loop class with instances of genome instability and suggest that increased class I R-loops, resulting from enhanced promoter-proximal pausing, represent the main culprits for R-loop mediated genome instability under pathological conditions.
Collapse
Affiliation(s)
- Daisy Castillo-Guzman
- Department of Molecular and Cellular Biology and Genome Center, University of California, Davis, Davis, CA, 95616, United States
| | - Frédéric Chédin
- Department of Molecular and Cellular Biology and Genome Center, University of California, Davis, Davis, CA, 95616, United States.
| |
Collapse
|
22
|
Zhao X, Usdin K. (Dys)function Follows Form: Nucleic Acid Structure, Repeat Expansion, and Disease Pathology in FMR1 Disorders. Int J Mol Sci 2021; 22:ijms22179167. [PMID: 34502075 PMCID: PMC8431139 DOI: 10.3390/ijms22179167] [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: 07/30/2021] [Revised: 08/17/2021] [Accepted: 08/18/2021] [Indexed: 12/26/2022] Open
Abstract
Fragile X-related disorders (FXDs), also known as FMR1 disorders, are examples of repeat expansion diseases (REDs), clinical conditions that arise from an increase in the number of repeats in a disease-specific microsatellite. In the case of FXDs, the repeat unit is CGG/CCG and the repeat tract is located in the 5' UTR of the X-linked FMR1 gene. Expansion can result in neurodegeneration, ovarian dysfunction, or intellectual disability depending on the number of repeats in the expanded allele. A growing body of evidence suggests that the mutational mechanisms responsible for many REDs share several common features. It is also increasingly apparent that in some of these diseases the pathologic consequences of expansion may arise in similar ways. It has long been known that many of the disease-associated repeats form unusual DNA and RNA structures. This review will focus on what is known about these structures, the proteins with which they interact, and how they may be related to the causative mutation and disease pathology in the FMR1 disorders.
Collapse
Affiliation(s)
- Xiaonan Zhao
- Correspondence: (X.Z.); (K.U.); Tel.: +1-301-451-6322 (X.Z.); +1-301-496-2189 (K.U.)
| | - Karen Usdin
- Correspondence: (X.Z.); (K.U.); Tel.: +1-301-451-6322 (X.Z.); +1-301-496-2189 (K.U.)
| |
Collapse
|
23
|
Morrison O, Thakur J. Molecular Complexes at Euchromatin, Heterochromatin and Centromeric Chromatin. Int J Mol Sci 2021; 22:6922. [PMID: 34203193 PMCID: PMC8268097 DOI: 10.3390/ijms22136922] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 06/23/2021] [Accepted: 06/24/2021] [Indexed: 01/19/2023] Open
Abstract
Chromatin consists of a complex of DNA and histone proteins as its core components and plays an important role in both packaging DNA and regulating DNA metabolic pathways such as DNA replication, transcription, recombination, and chromosome segregation. Proper functioning of chromatin further involves a network of interactions among molecular complexes that modify chromatin structure and organization to affect the accessibility of DNA to transcription factors leading to the activation or repression of the transcription of target DNA loci. Based on its structure and compaction state, chromatin is categorized into euchromatin, heterochromatin, and centromeric chromatin. In this review, we discuss distinct chromatin factors and molecular complexes that constitute euchromatin-open chromatin structure associated with active transcription; heterochromatin-less accessible chromatin associated with silencing; centromeric chromatin-the site of spindle binding in chromosome segregation.
Collapse
Affiliation(s)
| | - Jitendra Thakur
- Department of Biology, Emory University, 1510 Clifton Rd #2006, Atlanta, GA 30322, USA;
| |
Collapse
|
24
|
Palancade B, Rothstein R. The Ultimate (Mis)match: When DNA Meets RNA. Cells 2021; 10:cells10061433. [PMID: 34201169 PMCID: PMC8227541 DOI: 10.3390/cells10061433] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/04/2021] [Accepted: 06/05/2021] [Indexed: 12/20/2022] Open
Abstract
RNA-containing structures, including ribonucleotide insertions, DNA:RNA hybrids and R-loops, have recently emerged as critical players in the maintenance of genome integrity. Strikingly, different enzymatic activities classically involved in genome maintenance contribute to their generation, their processing into genotoxic or repair intermediates, or their removal. Here we review how this substrate promiscuity can account for the detrimental and beneficial impacts of RNA insertions during genome metabolism. We summarize how in vivo and in vitro experiments support the contribution of DNA polymerases and homologous recombination proteins in the formation of RNA-containing structures, and we discuss the role of DNA repair enzymes in their removal. The diversity of pathways that are thus affected by RNA insertions likely reflects the ancestral function of RNA molecules in genome maintenance and transmission.
Collapse
Affiliation(s)
- Benoit Palancade
- Institut Jacques Monod, Université de Paris, CNRS, F-75006 Paris, France
- Correspondence: (B.P.); (R.R.)
| | - Rodney Rothstein
- Department of Genetics & Development, Columbia University Irving Medical Center, New York, NY 10032, USA
- Correspondence: (B.P.); (R.R.)
| |
Collapse
|
25
|
Guo Y, Zhao S, Wang GG. Polycomb Gene Silencing Mechanisms: PRC2 Chromatin Targeting, H3K27me3 'Readout', and Phase Separation-Based Compaction. Trends Genet 2021; 37:547-565. [PMID: 33494958 PMCID: PMC8119337 DOI: 10.1016/j.tig.2020.12.006] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 12/18/2020] [Accepted: 12/22/2020] [Indexed: 12/20/2022]
Abstract
Modulation of chromatin structure and/or modification by Polycomb repressive complexes (PRCs) provides an important means to partition the genome into functionally distinct subdomains and to regulate the activity of the underlying genes. Both the enzymatic activity of PRC2 and its chromatin recruitment, spreading, and eviction are exquisitely regulated via interactions with cofactors and DNA elements (such as unmethylated CpG islands), histones, RNA (nascent mRNA and long noncoding RNA), and R-loops. PRC2-catalyzed histone H3 lysine 27 trimethylation (H3K27me3) is recognized by distinct classes of effectors such as canonical PRC1 and BAH module-containing proteins (notably BAHCC1 in human). These effectors mediate gene silencing by different mechanisms including phase separation-related chromatin compaction and histone deacetylation. We discuss recent advances in understanding the structural architecture of PRC2, the regulation of its activity and chromatin recruitment, and the molecular mechanisms underlying Polycomb-mediated gene silencing. Because PRC deregulation is intimately associated with the development of diseases, a better appreciation of Polycomb-based (epi)genomic regulation will have far-reaching implications in biology and medicine.
Collapse
Affiliation(s)
- Yiran Guo
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Shuai Zhao
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Gang Greg Wang
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA.
| |
Collapse
|
26
|
Alecki C, Francis NJ. Identification of R-loop-forming Sequences in Drosophila melanogaster Embryos and Tissue Culture Cells Using DRIP-seq. Bio Protoc 2021; 11:e4011. [PMID: 34124311 DOI: 10.21769/bioprotoc.4011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 02/18/2021] [Accepted: 02/22/2021] [Indexed: 11/02/2022] Open
Abstract
R-loops are non-canonical nucleic structures composed of an RNA-DNA hybrid and a displaced ssDNA. Originally identified as a source of genomic instability, R-loops have been shown over the last decade to be involved in the targeting of proteins and to be associated with different histone modifications, suggesting a regulatory function. In addition, R-loops have been demonstrated to form differentially during the development of different tissues in plants and to be associated with diseases in mammals. Here, we provide a single-strand DRIP-seq protocol to identify R-loop-forming sequences in Drosophila melanogaster embryos and tissue culture cells. This protocol differs from earlier DRIP protocols in the fragmentation step. Sonication, unlike restriction enzymes, generates a homogeneous and highly reproducible nucleic acid fragment pool. In addition, it allows the use of this protocol in any organism with minimal optimization. This protocol integrates several steps from published protocols to identify R-loop-forming sequences with high stringency, suitable for de novo characterization. Graphic abstract: Figure 1.Overview of the strand-specific DRIP-seq protocol.
Collapse
Affiliation(s)
- Célia Alecki
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada.,Département de biochimie et médecine moléculaire Université de Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, QC, H3T 1J4, Canada
| | - Nicole J Francis
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada.,Département de biochimie et médecine moléculaire Université de Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, QC, H3T 1J4, Canada.,Division of Experimental Medicine, McGill University, 1001 Decarie Boulevard, Montreal, QC, H4A 3J1, Canada
| |
Collapse
|
27
|
Wang Y, Fan Y, Zhang X, Tang H, Song Q, Han J, Xiao S. Highly Controllable Etchless Perovskite Microlasers Based on Bound States in the Continuum. ACS NANO 2021; 15:7386-7391. [PMID: 33729762 DOI: 10.1021/acsnano.1c00673] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Lead halide perovskites have been promising materials for lasing applications. Despite that a series of perovskite microlasers have been reported, their lasing modes are confined by either the as-grown morphology or the etched boundary. The first one is quite random and incompatible with integration, whereas the latter one strongly spoils the laser performances. Herein, we propose and experimentally demonstrate a robust and generic mechanism to realize well-controlled perovskite microlasers without the etching process. By patterning a one-dimensional polymer grating onto a perovskite film, we show that the symmetry-protected bound states in the continuum (BICs) can be formed in it. The intriguing properties of BICs including a widely spread mode profile and high Q factor, associated with the exceptional gain of perovskite, produce single-mode microlasers with high repeatability, controllability, directionality, and a polarization vortex. This mechanism can also be extended to two-dimensional nanostructures, enabling BIC lasers with different topological charges.
Collapse
Affiliation(s)
- Yuhan Wang
- Ministry of Industry and Information Technology Key Lab of Micro-Nano Optoelectronic Information System, Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055, People's Republic of China
| | - Yubin Fan
- Ministry of Industry and Information Technology Key Lab of Micro-Nano Optoelectronic Information System, Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055, People's Republic of China
| | - Xudong Zhang
- Ministry of Industry and Information Technology Key Lab of Micro-Nano Optoelectronic Information System, Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055, People's Republic of China
| | - Haijun Tang
- Ministry of Industry and Information Technology Key Lab of Micro-Nano Optoelectronic Information System, Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055, People's Republic of China
| | - Qinghai Song
- Ministry of Industry and Information Technology Key Lab of Micro-Nano Optoelectronic Information System, Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055, People's Republic of China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, Shanxi, People's Republic of China
| | - Jiecai Han
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin 150080, People's Republic of China
| | - Shumin Xiao
- Ministry of Industry and Information Technology Key Lab of Micro-Nano Optoelectronic Information System, Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055, People's Republic of China
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin 150080, People's Republic of China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, Shanxi, People's Republic of China
| |
Collapse
|
28
|
Song L, Xiao M, Lai W, Li L, Wan Y, Pei H. Intracellular Logic Computation with Framework Nucleic
Acid‐Based
Circuits for
mRNA
Imaging
†. CHINESE J CHEM 2021. [DOI: 10.1002/cjoc.202000575] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Ling Song
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes School of Chemistry and Molecular Engineering, East China Normal University 500 Dongchuan Road Shanghai 200241 China
| | - Mingshu Xiao
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes School of Chemistry and Molecular Engineering, East China Normal University 500 Dongchuan Road Shanghai 200241 China
| | - Wei Lai
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes School of Chemistry and Molecular Engineering, East China Normal University 500 Dongchuan Road Shanghai 200241 China
| | - Li Li
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes School of Chemistry and Molecular Engineering, East China Normal University 500 Dongchuan Road Shanghai 200241 China
| | - Ying Wan
- School of Mechanical Engineering Nanjing University of Science and Technology Nanjing Jiangsu 210094 China
| | - Hao Pei
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes School of Chemistry and Molecular Engineering, East China Normal University 500 Dongchuan Road Shanghai 200241 China
| |
Collapse
|
29
|
Abstract
Evidence accumulated over the past decade shows that long non-coding RNAs (lncRNAs) are widely expressed and have key roles in gene regulation. Recent studies have begun to unravel how the biogenesis of lncRNAs is distinct from that of mRNAs and is linked with their specific subcellular localizations and functions. Depending on their localization and their specific interactions with DNA, RNA and proteins, lncRNAs can modulate chromatin function, regulate the assembly and function of membraneless nuclear bodies, alter the stability and translation of cytoplasmic mRNAs and interfere with signalling pathways. Many of these functions ultimately affect gene expression in diverse biological and physiopathological contexts, such as in neuronal disorders, immune responses and cancer. Tissue-specific and condition-specific expression patterns suggest that lncRNAs are potential biomarkers and provide a rationale to target them clinically. In this Review, we discuss the mechanisms of lncRNA biogenesis, localization and functions in transcriptional, post-transcriptional and other modes of gene regulation, and their potential therapeutic applications.
Collapse
|
30
|
Wu SK, Roberts JT, Balas MM, Johnson AM. RNA matchmaking in chromatin regulation. Biochem Soc Trans 2020; 48:2467-2481. [PMID: 33245317 PMCID: PMC7888525 DOI: 10.1042/bst20191225] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 10/05/2020] [Accepted: 10/07/2020] [Indexed: 01/12/2023]
Abstract
Beyond being the product of gene expression, RNA can also influence the regulation of chromatin. The majority of the human genome has the capacity to be transcribed and the majority of the non-protein-coding transcripts made by RNA Polymerase II are enriched in the nucleus. Many chromatin regulators can bind to these ncRNAs in the nucleus; in some cases, there are clear examples of direct RNA-mediated chromatin regulation mechanisms stemming from these interactions, while others have yet to be determined. Recent studies have highlighted examples of chromatin regulation via RNA matchmaking, a term we use broadly here to describe intermolecular base-pairing interactions between one RNA molecule and an RNA or DNA match. This review provides examples of RNA matchmaking that regulates chromatin processes and summarizes the technical approaches used to capture these events.
Collapse
Affiliation(s)
- Stephen K. Wu
- Molecular Biology Program, University of Colorado Denver Anschutz Medical Campus 12801 East 17 Ave., Aurora, CO, United States
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver Anschutz Medical Campus 12801 East 17 Ave., Aurora, CO, United States
| | - Justin T. Roberts
- Molecular Biology Program, University of Colorado Denver Anschutz Medical Campus 12801 East 17 Ave., Aurora, CO, United States
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver Anschutz Medical Campus 12801 East 17 Ave., Aurora, CO, United States
| | - Maggie M. Balas
- Molecular Biology Program, University of Colorado Denver Anschutz Medical Campus 12801 East 17 Ave., Aurora, CO, United States
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver Anschutz Medical Campus 12801 East 17 Ave., Aurora, CO, United States
| | - Aaron M. Johnson
- Molecular Biology Program, University of Colorado Denver Anschutz Medical Campus 12801 East 17 Ave., Aurora, CO, United States
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver Anschutz Medical Campus 12801 East 17 Ave., Aurora, CO, United States
| |
Collapse
|
31
|
Jain SU, Rashoff AQ, Krabbenhoft SD, Hoelper D, Do TJ, Gibson TJ, Lundgren SM, Bondra ER, Deshmukh S, Harutyunyan AS, Juretic N, Jabado N, Harrison MM, Lewis PW. H3 K27M and EZHIP Impede H3K27-Methylation Spreading by Inhibiting Allosterically Stimulated PRC2. Mol Cell 2020; 80:726-735.e7. [PMID: 33049227 PMCID: PMC7680438 DOI: 10.1016/j.molcel.2020.09.028] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 08/28/2020] [Accepted: 09/23/2020] [Indexed: 11/19/2022]
Abstract
Diffuse midline gliomas and posterior fossa type A ependymomas contain the recurrent histone H3 lysine 27 (H3 K27M) mutation and express the H3 K27M-mimic EZHIP (CXorf67), respectively. H3 K27M and EZHIP are competitive inhibitors of Polycomb Repressive Complex 2 (PRC2) lysine methyltransferase activity. In vivo, these proteins reduce overall H3 lysine 27 trimethylation (H3K27me3) levels; however, residual peaks of H3K27me3 remain at CpG islands (CGIs) through an unknown mechanism. Here, we report that EZHIP and H3 K27M preferentially interact with PRC2 that is allosterically activated by H3K27me3 at CGIs and impede its spreading. Moreover, H3 K27M oncohistones reduce H3K27me3 in trans, independent of their incorporation into the chromatin. Although EZHIP is not found outside placental mammals, expression of human EZHIP reduces H3K27me3 in Drosophila melanogaster through a conserved mechanism. Our results provide mechanistic insights for the retention of residual H3K27me3 in tumors driven by H3 K27M and EZHIP.
Collapse
Affiliation(s)
- Siddhant U Jain
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53706, USA
| | - Andrew Q Rashoff
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53706, USA
| | - Samuel D Krabbenhoft
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53706, USA
| | - Dominik Hoelper
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53706, USA
| | - Truman J Do
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53706, USA
| | - Tyler J Gibson
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53706, USA
| | - Stefan M Lundgren
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53706, USA
| | - Eliana R Bondra
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53706, USA
| | - Shriya Deshmukh
- Department of Experimental Medicine, McGill University, Montreal, QC, Canada
| | - Ashot S Harutyunyan
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada; Department of Pediatrics, McGill University and The Research Institute of the McGill University Health Center, Montreal, QC H4A 3J1, Canada
| | - Nikoleta Juretic
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada; Department of Pediatrics, McGill University and The Research Institute of the McGill University Health Center, Montreal, QC H4A 3J1, Canada
| | - Nada Jabado
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada; Department of Pediatrics, McGill University and The Research Institute of the McGill University Health Center, Montreal, QC H4A 3J1, Canada
| | - Melissa M Harrison
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53706, USA
| | - Peter W Lewis
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53706, USA.
| |
Collapse
|
32
|
Seif E, Kang JJ, Sasseville C, Senkovich O, Kaltashov A, Boulier EL, Kapur I, Kim CA, Francis NJ. Phase separation by the polyhomeotic sterile alpha motif compartmentalizes Polycomb Group proteins and enhances their activity. Nat Commun 2020; 11:5609. [PMID: 33154383 PMCID: PMC7644731 DOI: 10.1038/s41467-020-19435-z] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 10/08/2020] [Indexed: 02/07/2023] Open
Abstract
Polycomb Group (PcG) proteins organize chromatin at multiple scales to regulate gene expression. A conserved Sterile Alpha Motif (SAM) in the Polycomb Repressive Complex 1 (PRC1) subunit Polyhomeotic (Ph) has been shown to play an important role in chromatin compaction and large-scale chromatin organization. Ph SAM forms helical head to tail polymers, and SAM-SAM interactions between chromatin-bound Ph/PRC1 are believed to compact chromatin and mediate long-range interactions. To understand the underlying mechanism, here we analyze the effects of Ph SAM on chromatin in vitro. We find that incubation of chromatin or DNA with a truncated Ph protein containing the SAM results in formation of concentrated, phase-separated condensates. Ph SAM-dependent condensates can recruit PRC1 from extracts and enhance PRC1 ubiquitin ligase activity towards histone H2A. We show that overexpression of Ph with an intact SAM increases ubiquitylated H2A in cells. Thus, SAM-induced phase separation, in the context of Ph, can mediate large-scale compaction of chromatin into biochemical compartments that facilitate histone modification.
Collapse
Affiliation(s)
- Elias Seif
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
| | - Jin Joo Kang
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
- Division of Experimental Medicine, McGill University, 1001 Decarie Boulevard, Montreal, QC, H4A 3J1, Canada
| | - Charles Sasseville
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
| | - Olga Senkovich
- Department of Biochemistry and Molecular Genetics, Midwestern University, 19555N. 59th St., Glendale, AZ, 85308, USA
| | - Alexander Kaltashov
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
| | - Elodie L Boulier
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
| | - Ibani Kapur
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
- Division of Experimental Medicine, McGill University, 1001 Decarie Boulevard, Montreal, QC, H4A 3J1, Canada
| | - Chongwoo A Kim
- Department of Biochemistry and Molecular Genetics, Midwestern University, 19555N. 59th St., Glendale, AZ, 85308, USA
| | - Nicole J Francis
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada.
- Division of Experimental Medicine, McGill University, 1001 Decarie Boulevard, Montreal, QC, H4A 3J1, Canada.
- Département de biochimie et médecine moléculaire Université de Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, QC, H3T 1J4, Canada.
| |
Collapse
|
33
|
Ma Q, Qu Z, Wang X, Qiao K, Mangi N, Fan S. EMBRYONIC FLOWER2B, coming from a stable QTL, represses the floral transition in cotton. Int J Biol Macromol 2020; 163:1087-1096. [DOI: 10.1016/j.ijbiomac.2020.07.116] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 07/09/2020] [Accepted: 07/10/2020] [Indexed: 11/27/2022]
|
34
|
Yan B, Lv Y, Zhao C, Wang X. Knowing When to Silence: Roles of Polycomb-Group Proteins in SAM Maintenance, Root Development, and Developmental Phase Transition. Int J Mol Sci 2020; 21:E5871. [PMID: 32824274 PMCID: PMC7461556 DOI: 10.3390/ijms21165871] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/06/2020] [Accepted: 08/06/2020] [Indexed: 01/01/2023] Open
Abstract
Polycomb repressive complex 1 (PRC1) and PRC2 are the major complexes composed of polycomb-group (PcG) proteins in plants. PRC2 catalyzes trimethylation of lysine 27 on histone 3 to silence target genes. Like Heterochromatin Protein 1/Terminal Flower 2 (LHP1/TFL2) recognizes and binds to H3K27me3 generated by PRC2 activities and enrolls PRC1 complex to further silence the chromatin through depositing monoubiquitylation of lysine 119 on H2A. Mutations in PcG genes display diverse developmental defects during shoot apical meristem (SAM) maintenance and differentiation, seed development and germination, floral transition, and so on so forth. PcG proteins play essential roles in regulating plant development through repressing gene expression. In this review, we are focusing on recent discovery about the regulatory roles of PcG proteins in SAM maintenance, root development, embryo development to seedling phase transition, and vegetative to reproductive phase transition.
Collapse
Affiliation(s)
| | | | | | - Xiaoxue Wang
- Rice Research Institute, Shenyang Agricultural University, Shenyang 110866, China; (B.Y.); (Y.L.); (C.Z.)
| |
Collapse
|
35
|
Bylino OV, Ibragimov AN, Shidlovskii YV. Evolution of Regulated Transcription. Cells 2020; 9:E1675. [PMID: 32664620 PMCID: PMC7408454 DOI: 10.3390/cells9071675] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/07/2020] [Accepted: 07/10/2020] [Indexed: 12/12/2022] Open
Abstract
The genomes of all organisms abound with various cis-regulatory elements, which control gene activity. Transcriptional enhancers are a key group of such elements in eukaryotes and are DNA regions that form physical contacts with gene promoters and precisely orchestrate gene expression programs. Here, we follow gradual evolution of this regulatory system and discuss its features in different organisms. In eubacteria, an enhancer-like element is often a single regulatory element, is usually proximal to the core promoter, and is occupied by one or a few activators. Activation of gene expression in archaea is accompanied by the recruitment of an activator to several enhancer-like sites in the upstream promoter region. In eukaryotes, activation of expression is accompanied by the recruitment of activators to multiple enhancers, which may be distant from the core promoter, and the activators act through coactivators. The role of the general DNA architecture in transcription control increases in evolution. As a whole, it can be seen that enhancers of multicellular eukaryotes evolved from the corresponding prototypic enhancer-like regulatory elements with the gradually increasing genome size of organisms.
Collapse
Affiliation(s)
- Oleg V. Bylino
- Laboratory of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia; (O.V.B.); (A.N.I.)
| | - Airat N. Ibragimov
- Laboratory of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia; (O.V.B.); (A.N.I.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia
| | - Yulii V. Shidlovskii
- Laboratory of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334 Moscow, Russia; (O.V.B.); (A.N.I.)
- I.M. Sechenov First Moscow State Medical University, 8, bldg. 2 Trubetskaya St., 119048 Moscow, Russia
| |
Collapse
|
36
|
Kang JJ, Faubert D, Boulais J, Francis NJ. DNA Binding Reorganizes the Intrinsically Disordered C-Terminal Region of PSC in Drosophila PRC1. J Mol Biol 2020; 432:4856-4871. [PMID: 32628956 DOI: 10.1016/j.jmb.2020.07.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 07/01/2020] [Accepted: 07/01/2020] [Indexed: 12/27/2022]
Abstract
Polycomb Group proteins regulate gene expression by modifying chromatin. Polycomb Repressive Complex 1 (PRC1) has two activities: a ubiquitin ligase activity for histone H2A and a chromatin compacting activity. In Drosophila, the Posterior Sex Combs (PSC) subunit of PRC1 is central to both activities. The N-terminal of PSC assembles into PRC1, including partnering with dRING to form the ubiquitin ligase. The intrinsically disordered C-terminal region of PSC compacts chromatin and inhibits chromatin remodeling and transcription in vitro. Both regions of PSC are essential in vivo. To understand how these two activities may be coordinated in PRC1, we used crosslinking mass spectrometry to analyze the conformations of the C-terminal region of PSC in PRC1 and how they change on binding DNA. Crosslinking identifies interactions between the C-terminal region of PSC and the core of PRC1, including between N and C-terminal regions of PSC. New contacts and overall more compacted PSC C-terminal region conformations are induced by DNA binding. Protein footprinting of accessible lysine residues reveals an extended, bipartite candidate DNA/chromatin binding surface in the C-terminal region of PSC. Our data suggest a model in which DNA (or chromatin) follows a long path on the flexible disordered region of PSC. Intramolecular interactions of PSC detected by crosslinking can bring the high-affinity DNA/chromatin binding region close to the core of PRC1 without disrupting the interface between the ubiquitin ligase and the nucleosome. Our approach may be applicable to understanding the global organization of other large intrinsically disordered regions that bind nucleic acids.
Collapse
Affiliation(s)
- Jin Joo Kang
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC H2W 1R7, Canada; Division of Experimental Medicine, McGill University, 1001 Decarie Boulevard, Montreal, QC H4A 3J1, Canada.
| | - Denis Faubert
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC H2W 1R7, Canada.
| | - Jonathan Boulais
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC H2W 1R7, Canada.
| | - Nicole J Francis
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC H2W 1R7, Canada; Division of Experimental Medicine, McGill University, 1001 Decarie Boulevard, Montreal, QC H4A 3J1, Canada; Département de biochimie et médecine moléculaire Université de Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, QC H3T 1J4, Canada..
| |
Collapse
|