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Sanidas I, Lawrence MS, Dyson NJ. Patterns in the tapestry of chromatin-bound RB. Trends Cell Biol 2024; 34:288-298. [PMID: 37648594 PMCID: PMC10899529 DOI: 10.1016/j.tcb.2023.07.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 07/27/2023] [Accepted: 07/28/2023] [Indexed: 09/01/2023]
Abstract
The retinoblastoma protein (RB)-mediated regulation of E2F is a component of a highly conserved cell cycle machine. However, RB's tumor suppressor activity, like RB's requirement in animal development, is tissue-specific, context-specific, and sometimes appears uncoupled from cell proliferation. Detailed new information about RB's genomic distribution provides a new perspective on the complexity of RB function, suggesting that some of its functional specificity results from context-specific RB association with chromatin. Here we summarize recent evidence showing that RB targets different types of chromatin regulatory elements at different cell cycle stages. RB controls traditional RB/E2F targets prior to S-phase, but, when cells proliferate, RB redistributes to cell type-specific chromatin loci. We discuss the broad implications of the new data for RB research.
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Affiliation(s)
- Ioannis Sanidas
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Building 149, 13th Street, Charlestown, MA 02129, USA
| | - Michael S Lawrence
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Building 149, 13th Street, Charlestown, MA 02129, USA; Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, MA 02142, USA
| | - Nicholas J Dyson
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Building 149, 13th Street, Charlestown, MA 02129, USA.
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2
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Liu H, Cheng J, Zhuang X, Qi B, Li F, Zhang B. Genomic instability and eye diseases. ADVANCES IN OPHTHALMOLOGY PRACTICE AND RESEARCH 2023; 3:103-111. [PMID: 37846358 PMCID: PMC10577848 DOI: 10.1016/j.aopr.2023.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 03/30/2023] [Accepted: 03/30/2023] [Indexed: 10/18/2023]
Abstract
Background Genetic information is stored in the bases of double-stranded DNA. However, the integrity of DNA molecules is constantly threatened by various mutagenic agents, including pollutants, ultraviolet light (UV), and medications. To counteract these environmental damages, cells have established multiple mechanisms, such as producing molecules to identify and eliminate damaged DNA, as well as reconstruct the original DNA structures. Failure or insufficiency of these mechanisms can cause genetic instability. However, the role of genome stability in eye diseases is still under-researched, despite extensive study in cancer biology. Main text As the eye is directly exposed to the external environment, the genetic materials of ocular cells are constantly under threat. Some of the proteins essential for DNA damage repair, such as pRb, p53, and RAD21, are also key during the ocular disease development. In this review, we discuss five ocular diseases that are associated with genomic instability. Retinoblastoma and pterygium are linked to abnormal cell cycles. Fuchs' corneal endothelial dystrophy and age-related macular degeneration are related to the accumulation of DNA damage caused by oxidative damage and UV. The mutation of the subunit of the cohesin complex during eye development is linked to sclerocornea. Conclusions Failure of DNA damage detection or repair leads to increased genomic instability. Deciphering the role of genomic instability in ocular diseases can lead to the development of new treatments and strategies, such as protecting vulnerable cells from risk factors or intensifying damage to unwanted cells.
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Affiliation(s)
- Hongyan Liu
- Eye Institute of Shandong First Medical University, Qingdao Eye Hospital of Shandong First Medical University, Qingdao, China
- School of Ophthalmology, Shandong First Medical University, Qingdao, China
| | - Jun Cheng
- Eye Institute of Shandong First Medical University, Qingdao Eye Hospital of Shandong First Medical University, Qingdao, China
- School of Ophthalmology, Shandong First Medical University, Qingdao, China
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Qingdao, China
| | - Xiaoyun Zhuang
- School of Ophthalmology, Shandong First Medical University, Qingdao, China
- Eye Institute of Shandong First Medical University, Eye Hospital of Shandong First Medical University (Shandong Eye Hospital), Jinan, China
- Department of Ophthalmology, School of Clinical Medicine, Weifang Medical University, Weifang, China
| | - Benxiang Qi
- Eye Institute of Shandong First Medical University, Qingdao Eye Hospital of Shandong First Medical University, Qingdao, China
- School of Ophthalmology, Shandong First Medical University, Qingdao, China
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Qingdao, China
| | - Fenfen Li
- The Eye Hospital of Wenzhou Medical University, Hangzhou, China
| | - Bining Zhang
- Eye Institute of Shandong First Medical University, Qingdao Eye Hospital of Shandong First Medical University, Qingdao, China
- School of Ophthalmology, Shandong First Medical University, Qingdao, China
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Qingdao, China
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3
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Sekar A, Leiblich A, Wainwright SM, Mendes CC, Sarma D, Hellberg JEEU, Gandy C, Goberdhan DCI, Hamdy FC, Wilson C. Rbf/E2F1 control growth and endoreplication via steroid-independent Ecdysone Receptor signalling in Drosophila prostate-like secondary cells. PLoS Genet 2023; 19:e1010815. [PMID: 37363926 PMCID: PMC10328346 DOI: 10.1371/journal.pgen.1010815] [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: 12/07/2022] [Revised: 07/07/2023] [Accepted: 06/06/2023] [Indexed: 06/28/2023] Open
Abstract
In prostate cancer, loss of the tumour suppressor gene, Retinoblastoma (Rb), and consequent activation of transcription factor E2F1 typically occurs at a late-stage of tumour progression. It appears to regulate a switch to an androgen-independent form of cancer, castration-resistant prostate cancer (CRPC), which frequently still requires androgen receptor (AR) signalling. We have previously shown that upon mating, binucleate secondary cells (SCs) of the Drosophila melanogaster male accessory gland (AG), which share some similarities with prostate epithelial cells, switch their growth regulation from a steroid-dependent to a steroid-independent form of Ecdysone Receptor (EcR) control. This physiological change induces genome endoreplication and allows SCs to rapidly replenish their secretory compartments, even when ecdysone levels are low because the male has not previously been exposed to females. Here, we test whether the Drosophila Rb homologue, Rbf, and E2F1 regulate this switch. Surprisingly, we find that excess Rbf activity reversibly suppresses binucleation in adult SCs. We also demonstrate that Rbf, E2F1 and the cell cycle regulators, Cyclin D (CycD) and Cyclin E (CycE), are key regulators of mating-dependent SC endoreplication, as well as SC growth in both virgin and mated males. Importantly, we show that the CycD/Rbf/E2F1 axis requires the EcR, but not ecdysone, to trigger CycE-dependent endoreplication and endoreplication-associated growth in SCs, mirroring changes seen in CRPC. Furthermore, Bone Morphogenetic Protein (BMP) signalling, mediated by the BMP ligand Decapentaplegic (Dpp), intersects with CycD/Rbf/E2F1 signalling to drive endoreplication in these fly cells. Overall, our work reveals a signalling switch, which permits rapid growth of SCs and increased secretion after mating, independently of previous exposure to females. The changes observed share mechanistic parallels with the pathological switch to hormone-independent AR signalling seen in CRPC, suggesting that the latter may reflect the dysregulation of a currently unidentified physiological process.
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Affiliation(s)
- Aashika Sekar
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Aaron Leiblich
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| | - S. Mark Wainwright
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Cláudia C. Mendes
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Dhruv Sarma
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | | | - Carina Gandy
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Deborah C. I. Goberdhan
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Freddie C. Hamdy
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| | - Clive Wilson
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
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Krishnan B, Sanidas I, Dyson NJ. Seeing is believing: the impact of RB on nuclear organization. Cell Cycle 2023; 22:1357-1366. [PMID: 37139582 DOI: 10.1080/15384101.2023.2206352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023] Open
Abstract
The retinoblastoma tumor suppressor (RB) prevents G1 to S cell cycle transition by inhibiting E2F activity. This function requires that RB remains un- or underphosphorylated (the so-called active forms of RB). Recently, we showed that active forms of RB cause widespread changes in nuclear architecture that are visible under a microscope. These phenotypes did not correlate with cell cycle arrest or repression of the E2F transcriptional program, but appeared later, and were associated with the appearance of autophagy or in IMR-90 cells with senescence markers. In this perspective, we describe the relative timing of these RB-induced events and discuss the mechanisms that may underlie RB-induced chromatin dispersion. We consider the relationship between RB-induced dispersion, autophagy, and senescence and the potential connection between dispersion and cell cycle exit.
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Affiliation(s)
- Badri Krishnan
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, MA, USA
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | - Ioannis Sanidas
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, MA, USA
| | - Nicholas J Dyson
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, MA, USA
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5
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Pieroni S, Castelli M, Piobbico D, Ferracchiato S, Scopetti D, Di-Iacovo N, Della-Fazia MA, Servillo G. The Four Homeostasis Knights: In Balance upon Post-Translational Modifications. Int J Mol Sci 2022; 23:ijms232214480. [PMID: 36430960 PMCID: PMC9696182 DOI: 10.3390/ijms232214480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/14/2022] [Accepted: 11/17/2022] [Indexed: 11/23/2022] Open
Abstract
A cancer outcome is a multifactorial event that comes from both exogenous injuries and an endogenous predisposing background. The healthy state is guaranteed by the fine-tuning of genes controlling cell proliferation, differentiation, and development, whose alteration induces cellular behavioral changes finally leading to cancer. The function of proteins in cells and tissues is controlled at both the transcriptional and translational level, and the mechanism allowing them to carry out their functions is not only a matter of level. A major challenge to the cell is to guarantee that proteins are made, folded, assembled and delivered to function properly, like and even more than other proteins when referring to oncogenes and onco-suppressors products. Over genetic, epigenetic, transcriptional, and translational control, protein synthesis depends on additional steps of regulation. Post-translational modifications are reversible and dynamic processes that allow the cell to rapidly modulate protein amounts and function. Among them, ubiquitination and ubiquitin-like modifications modulate the stability and control the activity of most of the proteins that manage cell cycle, immune responses, apoptosis, and senescence. The crosstalk between ubiquitination and ubiquitin-like modifications and post-translational modifications is a keystone to quickly update the activation state of many proteins responsible for the orchestration of cell metabolism. In this light, the correct activity of post-translational machinery is essential to prevent the development of cancer. Here we summarize the main post-translational modifications engaged in controlling the activity of the principal oncogenes and tumor suppressors genes involved in the development of most human cancers.
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Ward JR, Khan A, Torres S, Crawford B, Nock S, Frisbie T, Moran J, Longworth M. Condensin I and condensin II proteins form a LINE-1 dependent super condensin complex and cooperate to repress LINE-1. Nucleic Acids Res 2022; 50:10680-10694. [PMID: 36169232 PMCID: PMC9561375 DOI: 10.1093/nar/gkac802] [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: 08/04/2022] [Revised: 08/31/2022] [Accepted: 09/06/2022] [Indexed: 11/17/2022] Open
Abstract
Condensin I and condensin II are multi-subunit complexes that are known for their individual roles in genome organization and preventing genomic instability. However, interactions between condensin I and condensin II subunits and cooperative roles for condensin I and condensin II, outside of their genome organizing functions, have not been reported. We previously discovered that condensin II cooperates with Gamma Interferon Activated Inhibitor of Translation (GAIT) proteins to associate with Long INterspersed Element-1 (LINE-1 or L1) RNA and repress L1 protein expression and the retrotransposition of engineered L1 retrotransposition in cultured human cells. Here, we report that the L1 3'UTR is required for condensin II and GAIT association with L1 RNA, and deletion of the L1 RNA 3'UTR results in increased L1 protein expression and retrotransposition. Interestingly, like condensin II, we report that condensin I also binds GAIT proteins, associates with the L1 RNA 3'UTR, and represses L1 retrotransposition. We provide evidence that the condensin I protein, NCAPD2, is required for condensin II and GAIT protein association with L1 RNA. Furthermore, condensin I and condensin II subunits interact to form a L1-dependent super condensin complex (SCC) which is located primarily within the cytoplasm of both transformed and primary epithelial cells. These data suggest that increases in L1 expression in epithelial cells promote cytoplasmic condensin protein associations that facilitate a feedback loop in which condensins may cooperate to mediate L1 repression.
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Affiliation(s)
- Jacqueline R Ward
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Afshin Khan
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Sabrina Torres
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Bert Crawford
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Sarah Nock
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH 44195, USA
| | - Trenton Frisbie
- Department of Human Genetics, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - John V Moran
- Department of Human Genetics, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
- Internal Medicine, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - Michelle S Longworth
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Cleveland Clinic Lerner College of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH 44195, USA
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7
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Yao Y, Gu X, Xu X, Ge S, Jia R. Novel insights into RB1 mutation. Cancer Lett 2022; 547:215870. [PMID: 35964818 DOI: 10.1016/j.canlet.2022.215870] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 08/05/2022] [Accepted: 08/05/2022] [Indexed: 01/09/2023]
Abstract
Since the discovery of the retinoblastoma susceptibility gene (RB1) decades ago, RB1 has been regarded as a prototype tumor suppressor gene providing a paradigm for tumor genetic research. Constant research has updated the understanding of RB1-related pathways and their impact on tumor and nontumor diseases. Mutation of RB1 gene has been observed in multiple types of malignant tumors including prostate cancer, lung cancer, breast cancer, and almost every familial and sporadic case of retinoblastoma. Even if well-known and long-investigated, the application potential of RB1 mutation has not been fully tapped. In this review, we focus on the mechanism underlying RB1 mutation during oncogenesis. Therapeutically, we have further discussed potential clinical strategies by targeting RB1-mutated cancers. The unsolved problems and prospects of RB1 mutation are also discussed.
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Affiliation(s)
- Yiran Yao
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, China.
| | - Xiang Gu
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, China.
| | - Xiaofang Xu
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, China.
| | - Shengfang Ge
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, China.
| | - Renbing Jia
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology, Shanghai, China.
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8
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Lee C, Kim J. Genome maintenance in retinoblastoma: Implications for therapeutic vulnerabilities (Review). Oncol Lett 2022; 23:192. [PMID: 35527780 PMCID: PMC9073582 DOI: 10.3892/ol.2022.13312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 04/08/2022] [Indexed: 11/19/2022] Open
Abstract
Retinoblastoma (RB) is a pediatric ocular malignancy that is initiated mostly by biallelic inactivation of the RB transcriptional corepressor 1 (RB1) tumor suppressor gene in the developing retina. Unlike the prevailing prediction based on multiple studies involving RB1 gene disruption in experimental models, human RB tumors have been demonstrated to possess a relatively stable genome, characterized by a low mutation rate and a few recurrent chromosomal alterations related to somatic copy number changes. This suggests that RB may harbor heightened genome maintenance mechanisms to counteract or compensate for the risk of massive genome instability, which can potentially be driven by the early RB1 loss as a tumor-initiating event. Although the genome maintenance mechanisms might have been evolved to promote RB cell survival by preventing lethal genomic defects, emerging evidence suggests that the dependency of RB cells on these mechanisms also exposes their unique vulnerability to chemotherapy, particularly when the genome maintenance machineries are tumor cell-specific. This review summarizes the genome maintenance mechanisms identified in RB, including findings on the roles of chromatin regulators in DNA damage response/repair and protein factors involved in maintaining chromosome stability and promoting survival in RB. In addition, advantages and challenges for exploiting these therapeutic vulnerabilities in RB are discussed.
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Affiliation(s)
- Chunsik Lee
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Jong Kim
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‑sen University, Guangzhou, Guangdong 510060, P.R. China
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9
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Krishnan B, Yasuhara T, Rumde P, Stanzione M, Lu C, Lee H, Lawrence MS, Zou L, Nieman LT, Sanidas I, Dyson NJ. Active RB causes visible changes in nuclear organization. J Cell Biol 2022; 221:e202102144. [PMID: 35019938 PMCID: PMC8759594 DOI: 10.1083/jcb.202102144] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 10/21/2021] [Accepted: 12/09/2021] [Indexed: 12/13/2022] Open
Abstract
RB restricts G1/S progression by inhibiting E2F. Here, we show that sustained expression of active RB, and prolonged G1 arrest, causes visible changes in chromosome architecture that are not directly associated with E2F inhibition. Using FISH probes against two euchromatin RB-associated regions, two heterochromatin domains that lack RB-bound loci, and two whole-chromosome probes, we found that constitutively active RB (ΔCDK-RB) promoted a more diffuse, dispersed, and scattered chromatin organization. These changes were RB dependent, were driven by specific isoforms of monophosphorylated RB, and required known RB-associated activities. ΔCDK-RB altered physical interactions between RB-bound genomic loci, but the RB-induced changes in chromosome architecture were unaffected by dominant-negative DP1. The RB-induced changes appeared to be widespread and influenced chromosome localization within nuclei. Gene expression profiles revealed that the dispersion phenotype was associated with an increased autophagy response. We infer that, after cell cycle arrest, RB acts through noncanonical mechanisms to significantly change nuclear organization, and this reorganization correlates with transitions in cellular state.
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Affiliation(s)
- Badri Krishnan
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, MA
| | - Takaaki Yasuhara
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, MA
| | - Purva Rumde
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, MA
| | - Marcello Stanzione
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, MA
| | - Chenyue Lu
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, MA
| | - Hanjun Lee
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, MA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA
| | - Michael S. Lawrence
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, MA
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA
| | - Lee Zou
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, MA
| | - Linda T. Nieman
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, MA
| | - Ioannis Sanidas
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, MA
| | - Nicholas J. Dyson
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, MA
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10
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Yin Y, Liu Q, Shao Y, He X, Zhu Q, Lu S, Liu P. Regulatory mechanism of androgen receptor on NCAPD3 gene expression in prostate cancer. Prostate 2022; 82:26-40. [PMID: 34591337 DOI: 10.1002/pros.24245] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 07/24/2021] [Accepted: 07/30/2021] [Indexed: 12/17/2022]
Abstract
BACKGROUND Androgen receptor (AR) is an essential transcriptional factor that contributes to the development and progression of prostate cancer (PCa). NCAPD3 is a component of the condensin II complex and plays a critical role in cell mitosis by regulating chromosome condensation; however, the relationship between NCAPD3 and AR remains unknown. METHODS Transcriptome sequencing assay is carried out to analyze the expression of the NCAP family in clinic samples. Chromatin immunoprecipitation (ChIP) sequencing, ChIP assay, and dual-luciferase assay are used to identify the androgen-responsive element in NCAPD3 enhancer. Immunohistochemistry, quantitative reverse transcription-polymerase chain reaction, and western-blot assay are employed to check the expression of genes in PCa tissues and in PCa cells. Confocal immunofluorescence microscopy analysis is used for identifying the regulation of AR on NCAPD3-mediated chromosome condensation. Colony formation, cell cycle assay, wound healing assay, and transwell experiments are used to explore the regulation of AR on the functions of NCAPD3. In vivo experiment is employed to identify in vitro experimental results. RESULTS NCAPD3 is an androgen/AR axis-targeted gene and is involved in AR-induced PCa cell proliferation, migration, and invasion in vitro and in vivo. Androgen treatment and AR overexpression increase the expression of NCAPD3 in PCa cell lines. The canonical exist in the enhancer region of NCAPD3. Androgen/AR axis regulates NCAPD3-invovled chromosome condensation during cell mitosis. CONCLUSIONS Our report demonstrated that NCAPD3 is an androgen-responsive gene and upregulated by androgen/AR axis and involved in AR-promoted progression of PCa, suggesting a potential role of NCAPD3 in the PCa development.
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Affiliation(s)
- Yingying Yin
- Department of Biochemistry,Jiangsu Province Key Laboratory for Molecular and Medicine Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Qianmei Liu
- Department of Biochemistry,Jiangsu Province Key Laboratory for Molecular and Medicine Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Yingying Shao
- Department of Biochemistry,Jiangsu Province Key Laboratory for Molecular and Medicine Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Xinyuan He
- Department of Biochemistry,Jiangsu Province Key Laboratory for Molecular and Medicine Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Qingyi Zhu
- Department of Urology Surgery, Central Laboratory, Jiangsu Province Hospital of Chinese Medicine, Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China
| | - Shan Lu
- Department of Biochemistry,Jiangsu Province Key Laboratory for Molecular and Medicine Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Ping Liu
- Department of Biochemistry,Jiangsu Province Key Laboratory for Molecular and Medicine Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
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11
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Vernizzi L, Lehner CF. Bivalent individualization during chromosome territory formation in Drosophila spermatocytes by controlled condensin II protein activity and additional force generators. PLoS Genet 2021; 17:e1009870. [PMID: 34669718 PMCID: PMC8559962 DOI: 10.1371/journal.pgen.1009870] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 11/01/2021] [Accepted: 10/11/2021] [Indexed: 12/12/2022] Open
Abstract
Reduction of genome ploidy from diploid to haploid necessitates stable pairing of homologous chromosomes into bivalents before the start of the first meiotic division. Importantly, this chromosome pairing must avoid interlocking of non-homologous chromosomes. In spermatocytes of Drosophila melanogaster, where homolog pairing does not involve synaptonemal complex formation and crossovers, associations between non-homologous chromosomes are broken up by chromosome territory formation in early spermatocytes. Extensive non-homologous associations arise from the coalescence of the large blocks of pericentromeric heterochromatin into a chromocenter and from centromere clustering. Nevertheless, during territory formation, bivalents are moved apart into spatially separate subnuclear regions. The condensin II subunits, Cap-D3 and Cap-H2, have been implicated, but the remarkable separation of bivalents during interphase might require more than just condensin II. For further characterization of this process, we have applied time-lapse imaging using fluorescent markers of centromeres, telomeres and DNA satellites in pericentromeric heterochromatin. We describe the dynamics of the disruption of centromere clusters and the chromocenter in normal spermatocytes. Mutations in Cap-D3 and Cap-H2 abolish chromocenter disruption, resulting in excessive chromosome missegregation during M I. Chromocenter persistence in the mutants is not mediated by the special system, which conjoins homologs in compensation for the absence of crossovers in Drosophila spermatocytes. However, overexpression of Cap-H2 precluded conjunction between autosomal homologs, resulting in random segregation of univalents. Interestingly, Cap-D3 and Cap-H2 mutant spermatocytes displayed conspicuous stretching of the chromocenter, as well as occasional chromocenter disruption, suggesting that territory formation might involve forces unrelated to condensin II. While the molecular basis of these forces remains to be clarified, they are not destroyed by inhibitors of F actin and microtubules. Our results indicate that condensin II activity promotes chromosome territory formation in co-operation with additional force generators and that careful co-ordination with alternative homolog conjunction is crucial.
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Affiliation(s)
- Luisa Vernizzi
- Department of Molecular Life Science (DMLS), University of Zurich, Zurich, Switzerland
| | - Christian F. Lehner
- Department of Molecular Life Science (DMLS), University of Zurich, Zurich, Switzerland
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12
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Municio C, Antosz W, Grasser KD, Kornobis E, Van Bel M, Eguinoa I, Coppens F, Bräutigam A, Lermontova I, Bruckmann A, Zelkowska K, Houben A, Schubert V. The Arabidopsis condensin CAP-D subunits arrange interphase chromatin. THE NEW PHYTOLOGIST 2021; 230:972-987. [PMID: 33475158 DOI: 10.1111/nph.17221] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 01/11/2021] [Indexed: 06/12/2023]
Abstract
Condensins are best known for their role in shaping chromosomes. Other functions such as organizing interphase chromatin and transcriptional control have been reported in yeasts and animals, but little is known about their function in plants. To elucidate the specific composition of condensin complexes and the expression of CAP-D2 (condensin I) and CAP-D3 (condensin II), we performed biochemical analyses in Arabidopsis. The role of CAP-D3 in interphase chromatin organization and function was evaluated using cytogenetic and transcriptome analysis in cap-d3 T-DNA insertion mutants. CAP-D2 and CAP-D3 are highly expressed in mitotically active tissues. In silico and pull-down experiments indicate that both CAP-D proteins interact with the other condensin I and II subunits. In cap-d3 mutants, an association of heterochromatic sequences occurs, but the nuclear size and the general histone and DNA methylation patterns remain unchanged. Also, CAP-D3 influences the expression of genes affecting the response to water, chemicals, and stress. The expression and composition of the condensin complexes in Arabidopsis are similar to those in other higher eukaryotes. We propose a model for the CAP-D3 function during interphase in which CAP-D3 localizes in euchromatin loops to stiffen them and consequently separates centromeric regions and 45S rDNA repeats.
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Affiliation(s)
- Celia Municio
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstraße 3, D-06466, Seeland, Germany
| | - Wojciech Antosz
- Cell Biology and Plant Biochemistry, Biochemistry Center, University of Regensburg, Universitätsstraße 31, D-93053, Regensburg, Germany
| | - Klaus D Grasser
- Cell Biology and Plant Biochemistry, Biochemistry Center, University of Regensburg, Universitätsstraße 31, D-93053, Regensburg, Germany
| | - Etienne Kornobis
- Plate-forme Technologique Biomics - Centre de Ressources et Recherches Technologiques (C2RT), Institut Pasteur, 75015, Paris, France
- Hub de Bioinformatique et Biostatistique -Département Biologie Computationnelle, Institut Pasteur, 75015, Paris, France
| | - Michiel Van Bel
- VIB-UGent Center for Plant Systems Biology, Technologiepark 71, 9052, Gent, Belgium
| | - Ignacio Eguinoa
- VIB-UGent Center for Plant Systems Biology, Technologiepark 71, 9052, Gent, Belgium
| | - Frederik Coppens
- VIB-UGent Center for Plant Systems Biology, Technologiepark 71, 9052, Gent, Belgium
| | - Andrea Bräutigam
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstraße 3, D-06466, Seeland, Germany
| | - Inna Lermontova
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstraße 3, D-06466, Seeland, Germany
- Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Brno, CZ-62500, Czech Republic
| | - Astrid Bruckmann
- Department for Biochemistry I, Biochemistry Center, University of Regensburg, Universitätsstraße 31, D-93053, Regensburg, Germany
| | - Katarzyna Zelkowska
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstraße 3, D-06466, Seeland, Germany
| | - Andreas Houben
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstraße 3, D-06466, Seeland, Germany
| | - Veit Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstraße 3, D-06466, Seeland, Germany
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13
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Direct Regulation of DNA Repair by E2F and RB in Mammals and Plants: Core Function or Convergent Evolution? Cancers (Basel) 2021; 13:cancers13050934. [PMID: 33668093 PMCID: PMC7956360 DOI: 10.3390/cancers13050934] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/10/2021] [Accepted: 02/19/2021] [Indexed: 12/13/2022] Open
Abstract
Simple Summary Retinoblastoma (RB) proteins and E2F transcription factors partner together to regulate the cell cycle in many eukaryotic organisms. In organisms that lack one or both of these proteins, other proteins have taken on the essential function of cell cycle regulation. RB and E2F also have important functions outside of the cell cycle, including DNA repair. This review summarizes the non-canonical functions of RB and E2F in maintaining genome integrity and raises the question of whether such functions have always been present or have evolved more recently. Abstract Members of the E2F transcription factor family regulate the expression of genes important for DNA replication and mitotic cell division in most eukaryotes. Homologs of the retinoblastoma (RB) tumor suppressor inhibit the activity of E2F factors, thus controlling cell cycle progression. Organisms such as budding and fission yeast have lost genes encoding E2F and RB, but have gained genes encoding other proteins that take on E2F and RB cell cycle-related functions. In addition to regulating cell proliferation, E2F and RB homologs have non-canonical functions outside the mitotic cell cycle in a variety of eukaryotes. For example, in both mammals and plants, E2F and RB homologs localize to DNA double-strand breaks (DSBs) and directly promote repair by homologous recombination (HR). Here, we discuss the parallels between mammalian E2F1 and RB and their Arabidopsis homologs, E2FA and RB-related (RBR), with respect to their recruitment to sites of DNA damage and how they help recruit repair factors important for DNA end resection. We also explore the question of whether this role in DNA repair is a conserved ancient function of the E2F and RB homologs in the last eukaryotic common ancestor or whether this function evolved independently in mammals and plants.
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14
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Kim SJ, MacDonald JI, Dick FA. Phosphorylation of the RB C-terminus regulates condensin II release from chromatin. J Biol Chem 2021; 296:100108. [PMID: 33219128 PMCID: PMC7948394 DOI: 10.1074/jbc.ra120.016511] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 11/20/2020] [Indexed: 12/31/2022] Open
Abstract
The retinoblastoma tumor suppressor protein (RB) plays an important role in biological processes such as cell cycle control, DNA damage repair, epigenetic regulation, and genome stability. The canonical model of RB regulation is that cyclin-CDKs phosphorylate and render RB inactive in late G1/S, promoting entry into S phase. Recently, monophosphorylated RB species were described to have distinct cell-cycle-independent functions, suggesting that a phosphorylation code dictates diversity of RB function. However, a biologically relevant, functional role of RB phosphorylation at non-CDK sites has remained elusive. Here, we investigated S838/T841 dual phosphorylation, its upstream stimulus, and downstream functional output. We found that mimicking T-cell receptor activation in Jurkat leukemia cells induced sequential activation of downstream kinases including p38 MAPK and RB S838/T841 phosphorylation. This signaling pathway disrupts RB and condensin II interaction with chromatin. Using cells expressing a WT or S838A/T841A mutant RB fragment, we present evidence that deficiency for this phosphorylation event prevents condensin II release from chromatin.
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Affiliation(s)
- Seung J Kim
- London Regional Cancer Program, Lawson Health Research Institute, London, Ontario, Canada; Children's Health Research Institute, Lawson Health Research Institute, London, Ontario, Canada; Department of Biochemistry, Western University, London, Ontario, Canada
| | - James I MacDonald
- London Regional Cancer Program, Lawson Health Research Institute, London, Ontario, Canada; Children's Health Research Institute, Lawson Health Research Institute, London, Ontario, Canada; Department of Pathology and Laboratory Medicine, Western University, London, Ontario, Canada
| | - Frederick A Dick
- London Regional Cancer Program, Lawson Health Research Institute, London, Ontario, Canada; Children's Health Research Institute, Lawson Health Research Institute, London, Ontario, Canada; Department of Pathology and Laboratory Medicine, Western University, London, Ontario, Canada.
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15
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Cutts EE, Vannini A. Condensin complexes: understanding loop extrusion one conformational change at a time. Biochem Soc Trans 2020; 48:2089-2100. [PMID: 33005926 PMCID: PMC7609036 DOI: 10.1042/bst20200241] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/07/2020] [Accepted: 09/09/2020] [Indexed: 12/12/2022]
Abstract
Condensin and cohesin, both members of the structural maintenance of chromosome (SMC) family, contribute to the regulation and structure of chromatin. Recent work has shown both condensin and cohesin extrude DNA loops and most likely work via a conserved mechanism. This review focuses on condensin complexes, highlighting recent in vitro work characterising DNA loop formation and protein structure. We discuss similarities between condensin and cohesin complexes to derive a possible mechanistic model, as well as discuss differences that exist between the different condensin isoforms found in higher eukaryotes.
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Affiliation(s)
- Erin E. Cutts
- Division of Structural Biology, The Institute of Cancer Research, London SW7 3RP, U.K
| | - Alessandro Vannini
- Division of Structural Biology, The Institute of Cancer Research, London SW7 3RP, U.K
- Fondazione Human Technopole, Structural Biology Research Centre, 20157 Milan, Italy
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16
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Weyburne E, Bosco G. Cancer-associated mutations in the condensin II subunit CAPH2 cause genomic instability through telomere dysfunction and anaphase chromosome bridges. J Cell Physiol 2020; 236:3579-3598. [PMID: 33078399 PMCID: PMC7983937 DOI: 10.1002/jcp.30113] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 09/21/2020] [Accepted: 09/23/2020] [Indexed: 01/10/2023]
Abstract
Genome instability in cancer drives tumor heterogeneity, undermines the success of therapies, and leads to metastasis and recurrence. Condensins are conserved chromatin‐binding proteins that promote genomic stability, mainly by ensuring proper condensation of chromatin and mitotic chromosome segregation. Condensin mutations are found in human tumors, but it is not known how or even if such mutations promote cancer progression. In this study, we focus on condensin II subunit CAPH2 and specific CAPH2 mutations reported to be enriched in human cancer patients, and we test how CAPH2 cancer‐specific mutations may lead to condensin II complex dysfunction and contribute to genome instability. We find that R551P, R551S, and S556F mutations in CAPH2 cause genomic instability by causing DNA damage, anaphase defects, micronuclei, and chromosomal instability. DNA damage and anaphase defects are caused primarily by ataxia telangiectasia and Rad3‐related‐dependent telomere dysfunction, as anaphase bridges are enriched for telomeric repeat sequences. We also show that these mutations decrease the binding of CAPH2 to the ATPase subunit SMC4 as well as the rest of the condensin II complex, and decrease the amount of CAPH2 protein bound to chromatin. Thus, in vivo the R551P, R551S, and S556F cancer‐specific CAPH2 mutant proteins are likely to impair condensin II complex formation, impede condensin II activity during mitosis and interphase, and promote genetic heterogeneity in cell populations that can lead to clonal outgrowth of cancer cells with highly diverse genotypes.
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Affiliation(s)
- Emily Weyburne
- Department of Molecular and Systems Biology, Dartmouth College, Hanover, New Hampshire, USA
| | - Giovanni Bosco
- Department of Molecular and Systems Biology, Dartmouth College, Hanover, New Hampshire, USA
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17
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Kleinschnitz K, Vießmann N, Jordan M, Heidmann SK. Condensin I is required for faithful meiosis in Drosophila males. Chromosoma 2020; 129:141-160. [PMID: 32314039 PMCID: PMC7260282 DOI: 10.1007/s00412-020-00733-w] [Citation(s) in RCA: 5] [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: 10/11/2019] [Revised: 02/17/2020] [Accepted: 02/20/2020] [Indexed: 01/03/2023]
Abstract
The heteropentameric condensin complexes play vital roles in the formation and faithful segregation of mitotic chromosomes in eukaryotes. While the different contributions of the two common condensin complexes, condensin I and condensin II, to chromosome morphology and behavior in mitosis have been thoroughly investigated, much less is known about the specific roles of the two complexes during meiotic divisions. In Drosophila melanogaster, faithful mitotic divisions depend on functional condensin I, but not on condensin II. However, meiotic divisions in Drosophila males require functional condensin II subunits. The role of condensin I during male meiosis in Drosophila has been unresolved. Here, we show that condensin I-specific subunits localize to meiotic chromatin in both meiosis I and II during Drosophila spermatogenesis. Live cell imaging reveals defects during meiotic divisions after RNAi-mediated knockdown of condensin I-specific mRNAs. This phenotype correlates with reduced male fertility and an increase in nondisjunction events both in meiosis I and meiosis II. Consistently, a reduction in male fertility was also observed after proteasome-mediated degradation of the condensin I subunit Barren. Taken together, our results demonstrate an essential role of condensin I during male meiosis in Drosophila melanogaster.
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Affiliation(s)
| | - Nina Vießmann
- Lehrstuhl für Genetik, University of Bayreuth, Bayreuth, Germany
| | - Mareike Jordan
- Lehrstuhl für Genetik, University of Bayreuth, Bayreuth, Germany
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
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18
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Pei X, Du E, Sheng Z, Du W. Rb family-independent activating E2F increases genome stability, promotes homologous recombination, and decreases non-homologous end joining. Mech Dev 2020; 162:103607. [PMID: 32217105 DOI: 10.1016/j.mod.2020.103607] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 03/13/2020] [Accepted: 03/22/2020] [Indexed: 11/15/2022]
Abstract
The retinoblastoma protein Rb is a prototype tumor suppressor inactivated in a variety of cancers. In addition to deregulated cell proliferation, Rb inactivation also causes genome instability that contributes to tumorigenesis. Although the genome instability effects of Rb inactivation was shown to be mediated mainly by E2F-independent mechanisms, little is known about whether the constitutive free activating E2F proteins released by Rb-inactivation affects genome stability. In this manuscript, we take advantage of the dE2F1su89 mutant, which contains a point mutation in the conserved Rb-binding domain that disrupts its interaction with the Rb family proteins, to characterize the effect of constitutive free activating E2F on genome stability in the presence of WT Rb. We showed that dE2F1su89 promoted genome stability in the mwh genome stability assay. We found that the genome stability effects of dE2F1su89 was sensitive to the levels of activating E2F activity and to the levels of E2F targets involved in DNA replication and repair but not to the level of E2F cell cycle target Cyclin E. Importantly, we showed that dE2F1su89 promoted DNA double-strand break (DSB) repair by homologous recombination and decreased DSB repair by Non-homologous end joining (NHEJ). These results show that the constitutive free activating E2F promotes genome stability, which potentially contributes the observed tumor development in E2F1 knockout mice and the reported NHEJ defects in Rb mutant cells. These results also explain why constitutive free activating E2F alone was not sufficient for tumor development.
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Affiliation(s)
- Xun Pei
- Ben May Department for Cancer Research, The University of Chicago, 929 E. 57(th) St, Chicago, IL 60637, United States of America
| | - Elbert Du
- Harvard University, Cambridge, MA 02138, United States of America
| | - Zhentao Sheng
- Ben May Department for Cancer Research, The University of Chicago, 929 E. 57(th) St, Chicago, IL 60637, United States of America
| | - Wei Du
- Ben May Department for Cancer Research, The University of Chicago, 929 E. 57(th) St, Chicago, IL 60637, United States of America.
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19
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Tretina K, Haidar M, Madsen-Bouterse SA, Sakura T, Mfarrej S, Fry L, Chaussepied M, Pain A, Knowles DP, Nene VM, Ginsberg D, Daubenberger CA, Bishop RP, Langsley G, Silva JC. Theileria parasites subvert E2F signaling to stimulate leukocyte proliferation. Sci Rep 2020; 10:3982. [PMID: 32132598 PMCID: PMC7055300 DOI: 10.1038/s41598-020-60939-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 02/18/2020] [Indexed: 01/22/2023] Open
Abstract
Intracellular pathogens have evolved intricate mechanisms to subvert host cell signaling pathways and ensure their own propagation. A lineage of the protozoan parasite genus Theileria infects bovine leukocytes and induces their uncontrolled proliferation causing a leukemia-like disease. Given the importance of E2F transcription factors in mammalian cell cycle regulation, we investigated the role of E2F signaling in Theileria-induced host cell proliferation. Using comparative genomics and surface plasmon resonance, we identified parasite-derived peptides that have the sequence-specific ability to increase E2F signaling by binding E2F negative regulator Retinoblastoma-1 (RB). Using these peptides as a tool to probe host E2F signaling, we show that the disruption of RB complexes ex vivo leads to activation of E2F-driven transcription and increased leukocyte proliferation in an infection-dependent manner. This result is consistent with existing models and, together, they support a critical role of E2F signaling for Theileria-induced host cell proliferation, and its potential direct manipulation by one or more parasite proteins.
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Affiliation(s)
- Kyle Tretina
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
- Program in Molecular Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Malak Haidar
- Laboratoire de Biologie Comparative des Apicomplexes, Faculté de Médicine, Université Paris Descartes, Sorbonne, Paris Cité, France
- Inserm U1016, Cnrs UMR8104, Cochin Institute, Paris, 75014, France
| | - Sally A Madsen-Bouterse
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, 99164-7040, USA
| | - Takaya Sakura
- Laboratoire de Biologie Comparative des Apicomplexes, Faculté de Médicine, Université Paris Descartes, Sorbonne, Paris Cité, France
- Inserm U1016, Cnrs UMR8104, Cochin Institute, Paris, 75014, France
| | - Sara Mfarrej
- Pathogen Genomics Laboratory, Biological and Environmental Sciences and Engineering (BESE) Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Lindsay Fry
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, 99164-7040, USA
- Animal Disease Research Unit, Agricultural Research Service, USDA, Pullman, WA, 99164-7030, USA
| | - Marie Chaussepied
- Laboratoire de Biologie Comparative des Apicomplexes, Faculté de Médicine, Université Paris Descartes, Sorbonne, Paris Cité, France
- Inserm U1016, Cnrs UMR8104, Cochin Institute, Paris, 75014, France
- Weizmann Institute of Science, Molecular Cell Biology Department, PO Box 26, Rehovot, 76100, Israel
| | - Arnab Pain
- Pathogen Genomics Laboratory, Biological and Environmental Sciences and Engineering (BESE) Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Donald P Knowles
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, 99164-7040, USA
| | | | - Doron Ginsberg
- Weizmann Institute of Science, Molecular Cell Biology Department, PO Box 26, Rehovot, 76100, Israel
- The Mina and Everard Goodman Faculty of Life Sciences Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Claudia A Daubenberger
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Richard P Bishop
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, 99164-7040, USA
| | - Gordon Langsley
- Laboratoire de Biologie Comparative des Apicomplexes, Faculté de Médicine, Université Paris Descartes, Sorbonne, Paris Cité, France
- Inserm U1016, Cnrs UMR8104, Cochin Institute, Paris, 75014, France
| | - Joana C Silva
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA.
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20
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An RB-Condensin II Complex Mediates Long-Range Chromosome Interactions and Influences Expression at Divergently Paired Genes. Mol Cell Biol 2020; 40:MCB.00452-19. [PMID: 31685548 DOI: 10.1128/mcb.00452-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 10/23/2019] [Indexed: 12/19/2022] Open
Abstract
Interphase chromosomes are organized into topologically associated domains in order to establish and maintain integrity of transcriptional programs that remain poorly understood. Here, we show that condensin II and TFIIIC are recruited to bidirectionally transcribed promoters by a mechanism that is dependent on the retinoblastoma (RB) protein. Long-range chromosome contacts are disrupted by loss of condensin II loading, which leads to altered expression at bidirectional gene pairs. This study demonstrates that mammalian condensin II functions to organize long-range chromosome contacts and regulate transcription at specific genes. In addition, RB dependence of condensin II suggests that widespread misregulation of chromosome contacts and transcriptional alterations are a consequence of RB mutation.
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21
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Deutschman E, Ward JR, Kumar A, Ray G, Welch N, Lemieux ME, Dasarathy S, Longworth MS. Condensin II protein dysfunction impacts mitochondrial respiration and mitochondrial oxidative stress responses. J Cell Sci 2019; 132:jcs233783. [PMID: 31653782 PMCID: PMC6899004 DOI: 10.1242/jcs.233783] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 10/21/2019] [Indexed: 12/28/2022] Open
Abstract
The maintenance of mitochondrial respiratory function and homeostasis is essential to human health. Here, we identify condensin II subunits as novel regulators of mitochondrial respiration and mitochondrial stress responses. Condensin II is present in the nucleus and cytoplasm. While the effects of condensin II depletion on nuclear genome organization are well studied, the effects on essential cytoplasmic and metabolic processes are not as well understood. Excitingly, we observe that condensin II chromosome-associated protein (CAP) subunits individually localize to different regions of mitochondria, suggesting possible mitochondrial-specific functions independent from those mediated by the canonical condensin II holocomplex. Changes in cellular ATP levels and mitochondrial respiration are observed in condensin II CAP subunit-deficient cells. Surprisingly, we find that loss of NCAPD3 also sensitizes cells to oxidative stress. Together, these studies identify new, and possibly independent, roles for condensin II CAP subunits in preventing mitochondrial damage and dysfunction. These findings reveal a new area of condensin protein research that could contribute to the identification of targets to treat diseases where aberrant function of condensin II proteins is implicated.
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Affiliation(s)
- Emily Deutschman
- Department of Inflammation and Immunity, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
- Department of Genetics and Genome Sciences, Case Western Reserve University Cleveland, OH 44106, USA
| | - Jacqueline R Ward
- Department of Inflammation and Immunity, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Avinash Kumar
- Department of Inflammation and Immunity, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Greeshma Ray
- Department of Inflammation and Immunity, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Nicole Welch
- Department of Inflammation and Immunity, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | | | - Srinivisan Dasarathy
- Department of Inflammation and Immunity, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Michelle S Longworth
- Department of Inflammation and Immunity, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
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22
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RB1 Deletion in Retinoblastoma Protein Pathway-Disrupted Cells Results in DNA Damage and Cancer Progression. Mol Cell Biol 2019; 39:MCB.00105-19. [PMID: 31138663 DOI: 10.1128/mcb.00105-19] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 05/20/2019] [Indexed: 12/12/2022] Open
Abstract
Proliferative control in cancer cells is frequently disrupted by mutations in the retinoblastoma protein (RB) pathway. Intriguingly, RB1 mutations can arise late in tumorigenesis in cancer cells whose RB pathway is already compromised by another mutation. In this study, we present evidence for increased DNA damage and instability in cancer cells with RB pathway defects when RB1 mutations are induced. We generated isogenic RB1 mutant genotypes with CRISPR/Cas9 in a number of cell lines. Cells with even one mutant copy of RB1 have increased basal levels of DNA damage and increased mitotic errors. Elevated levels of reactive oxygen species as well as impaired homologous recombination repair underlie this DNA damage. When xenografted into immunocompromised mice, RB1 mutant cells exhibit an elevated propensity to seed new tumors in recipient lungs. This study offers evidence that late-arising RB1 mutations can facilitate genome instability and cancer progression that are beyond the preexisting proliferative control deficit.
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23
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Oser MG, Fonseca R, Chakraborty AA, Brough R, Spektor A, Jennings RB, Flaifel A, Novak JS, Gulati A, Buss E, Younger ST, McBrayer SK, Cowley GS, Bonal DM, Nguyen QD, Brulle-Soumare L, Taylor P, Cairo S, Ryan CJ, Pease EJ, Maratea K, Travers J, Root DE, Signoretti S, Pellman D, Ashton S, Lord CJ, Barry ST, Kaelin WG. Cells Lacking the RB1 Tumor Suppressor Gene Are Hyperdependent on Aurora B Kinase for Survival. Cancer Discov 2019; 9:230-247. [PMID: 30373918 PMCID: PMC6368871 DOI: 10.1158/2159-8290.cd-18-0389] [Citation(s) in RCA: 114] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 08/22/2018] [Accepted: 10/05/2018] [Indexed: 12/26/2022]
Abstract
Small cell lung cancer (SCLC) accounts for 15% of lung cancers and is almost always linked to inactivating RB1 and TP53 mutations. SCLC frequently responds, albeit briefly, to chemotherapy. The canonical function of the RB1 gene product RB1 is to repress the E2F transcription factor family. RB1 also plays both E2F-dependent and E2F-independent mitotic roles. We performed a synthetic lethal CRISPR/Cas9 screen in an RB1 -/- SCLC cell line that conditionally expresses RB1 to identify dependencies that are caused by RB1 loss and discovered that RB1 -/- SCLC cell lines are hyperdependent on multiple proteins linked to chromosomal segregation, including Aurora B kinase. Moreover, we show that an Aurora B kinase inhibitor is efficacious in multiple preclinical SCLC models at concentrations that are well tolerated in mice. These results suggest that RB1 loss is a predictive biomarker for sensitivity to Aurora B kinase inhibitors in SCLC and perhaps other RB1 -/- cancers. SIGNIFICANCE: SCLC is rarely associated with actionable protooncogene mutations. We did a CRISPR/Cas9-based screen that showed that RB1 -/- SCLC are hyperdependent on AURKB, likely because both genes control mitotic fidelity, and confirmed that Aurora B kinase inhibitors are efficacious against RB1 -/- SCLC tumors in mice at nontoxic doses.See related commentary by Dick and Li, p. 169.This article is highlighted in the In This Issue feature, p. 151.
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Affiliation(s)
- Matthew G Oser
- Department of Medical Oncology, Dana-Farber Cancer Institute and Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
- Lowe Center for Thoracic Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Raquel Fonseca
- Department of Medical Oncology, Dana-Farber Cancer Institute and Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Abhishek A Chakraborty
- Department of Medical Oncology, Dana-Farber Cancer Institute and Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Rachel Brough
- The CRUK Gene Function Laboratory, The Institute of Cancer Research, London, United Kingdom
- Breast Cancer Now Toby Robins Breast Cancer Research Centre, The Institute of Cancer Research, London, United Kingdom
| | - Alexander Spektor
- Howard Hughes Medical Institute, Chevy Chase, Maryland
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts; Department of Cell Biology, Harvard Medical School, Boston, Massachusetts
- Department of Radiation Oncology, Brigham and Women's Hospital, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Rebecca B Jennings
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Abdallah Flaifel
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Jesse S Novak
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Aditi Gulati
- The CRUK Gene Function Laboratory, The Institute of Cancer Research, London, United Kingdom
- Breast Cancer Now Toby Robins Breast Cancer Research Centre, The Institute of Cancer Research, London, United Kingdom
| | - Elizabeth Buss
- Department of Medical Oncology, Dana-Farber Cancer Institute and Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
- Howard Hughes Medical Institute, Chevy Chase, Maryland
| | - Scott T Younger
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts
| | - Samuel K McBrayer
- Department of Medical Oncology, Dana-Farber Cancer Institute and Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Glenn S Cowley
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts
| | - Dennis M Bonal
- Lurie Family Imaging Center, Center for Biomedical Imaging in Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Quang-De Nguyen
- Lurie Family Imaging Center, Center for Biomedical Imaging in Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts
| | | | - Paula Taylor
- IMED Oncology, AstraZeneca, Cheshire, United Kingdom
| | | | - Colm J Ryan
- Systems Biology Ireland, University College Dublin, Dublin, Republic of Ireland
| | | | - Kim Maratea
- IMED Drug Safety and Metabolism, AstraZeneca, Boston, Massachusetts
| | - Jon Travers
- IMED Oncology, AstraZeneca, Cheshire, United Kingdom
| | - David E Root
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts
| | - Sabina Signoretti
- Department of Medical Oncology, Dana-Farber Cancer Institute and Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - David Pellman
- Howard Hughes Medical Institute, Chevy Chase, Maryland
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts; Department of Cell Biology, Harvard Medical School, Boston, Massachusetts
| | - Susan Ashton
- IMED Oncology, AstraZeneca, Cheshire, United Kingdom
| | - Christopher J Lord
- The CRUK Gene Function Laboratory, The Institute of Cancer Research, London, United Kingdom
- Breast Cancer Now Toby Robins Breast Cancer Research Centre, The Institute of Cancer Research, London, United Kingdom
| | - Simon T Barry
- IMED Oncology, AstraZeneca, Cambridge, United Kingdom
| | - William G Kaelin
- Department of Medical Oncology, Dana-Farber Cancer Institute and Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
- Howard Hughes Medical Institute, Chevy Chase, Maryland
- Broad Institute of Harvard and MIT, Cambridge, Massachusetts
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Abstract
Inflammatory bowel diseases (IBDs) are chronic inflammatory disorders affecting the gastrointestinal tract. The incidence of IBD is increasing, with more cases occurring in developed countries. Multiple factors such as genetics, environmental changes, gut microbiota, and immune abnormalities have been associated with development of IBD. In recent years, it has become increasingly apparent that epigenetic modifications of chromatin and the manner in which chromatin is organized in the nucleus are additionally important elements that can influence responses induced by the factors described above, and may therefore contribute to the onset and pathogenesis of IBD. Epigenetics and chromatin organization regulate diverse functions that include maintenance of homeostasis in the intestinal epithelium, the development and differentiation of immune cells, and modulation of responses generated by the immune system to defend against potential pathogens. Furthermore, changes in epigenetic chromatin marks and in chromatin organization have now been linked to differential gene expression in IBD patient cells. Although direct evidence for a role of histone modifications in IBD is currently very limited, in this review, we summarize the links between various epigenetic modifications, the proteins that catalyze or recognize these modifications, and the development or progression of IBD in human and experimental IBD. We also discuss how epigenetics influence the organization of DNA contacts to regulate gene expression and the implications this may have for diagnosing and treating IBD.
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Affiliation(s)
- Greeshma Ray
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Michelle S Longworth
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA,Address correspondence to: Michelle S. Longworth, 9500 Euclid Ave NC22, Cleveland, OH 44195 ()
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The Role of RB in Prostate Cancer Progression. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1210:301-318. [PMID: 31900914 DOI: 10.1007/978-3-030-32656-2_13] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The RB tumor suppressor is one of the most commonly deleted/mutated genes in human cancers. In prostate cancer specifically, mutation of RB is most frequently observed in aggressive, metastatic disease. As one of the earliest tumor suppressors to be identified, the molecular functions of RB that are lost in tumor development have been studied for decades. Earlier work focused on the canonical RB pathway connecting mitogenic signaling to the cell cycle via Cyclin/CDK inactivation of RB, thereby releasing the E2F transcription factors. More in-depth analysis revealed that RB-E2F complexes regulate cellular processes beyond proliferation. Most recently, "non-canonical" roles for RB function have been expanded beyond its E2F interactions, which may play a particular role in advanced prostate cancer. For example, in mouse models of prostate cancer, loss of RB has been shown to induce lineage plasticity, which enables resistance to androgen deprivation therapy. This increased understanding of the potential downstream functions of RB in prostate cancer may lead the way to identifying therapeutic vulnerabilities in cells following RB loss.
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Comparing and Contrasting the Effects of Drosophila Condensin II Subunit dCAP-D3 Overexpression and Depletion in Vivo. Genetics 2018; 210:531-546. [PMID: 30068527 PMCID: PMC6216582 DOI: 10.1534/genetics.118.301344] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 07/31/2018] [Indexed: 11/18/2022] Open
Abstract
The Condensin II complex plays important, conserved roles in genome organization throughout the cell cycle and in the regulation of gene expression. Previous studies have linked decreased Condensin II subunit expression with a variety of diseases. Here, we show that elevated levels of Condensin II subunits are detected in somatic cancers. To evaluate potential biological effects of elevated Condensin II levels, we overexpressed the Condensin II subunit, dCAP-D3 in Drosophila melanogaster larval tissues and examined the effects on the mitotic- and interphase-specific functions of Condensin II. Interestingly, while ubiquitous overexpression resulted in pupal lethality, tissue specific overexpression of dCAP-D3 caused formation of nucleoplasmic protein aggregates which slowed mitotic prophase progression, mimicking results observed when dCAP-D3 levels are depleted. Surprisingly, dCAP-D3 aggregate formation resulted in faster transitions from metaphase to anaphase. Overexpressed dCAP-D3 protein failed to precipitate other Condensin II subunits in nondividing tissues, but did cause changes to gene expression which occurred in a manner opposite of what was observed when dCAP-D3 levels were depleted in both dividing and nondividing tissues. Our findings show that altering dCAP-D3 levels in either direction has detrimental effects on mitotic timing, the regulation of gene expression, and organism development. Taken together, these data suggest that the different roles for Condensin II throughout the cell cycle may be independent of each other and/or that dCAP-D3 may possess functions that are separate from those involving its association with the Condensin II complex. If conserved, these findings could have implications for tumors harboring elevated CAP-D3 levels.
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27
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Abstract
The canonical model of RB-mediated tumour suppression developed over the past 30 years is based on the regulation of E2F transcription factors to restrict cell cycle progression. Several additional functions have been proposed for RB, on the basis of which a non-canonical RB pathway can be described. Mechanistically, the non-canonical RB pathway promotes histone modification and regulates chromosome structure in a manner distinct from cell cycle regulation. These functions have implications for chemotherapy response and resistance to targeted anticancer agents. This Opinion offers a framework to guide future studies of RB in basic and clinical research.
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Affiliation(s)
- Frederick A Dick
- London Regional Cancer Program, Children's Health Research Institute, Western University, London, Ontario, Canada.
- London Regional Cancer Program, Department of Biochemistry, Western University, London, Ontario, Canada.
| | - David W Goodrich
- Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, NY, USA
| | - Julien Sage
- Departments of Pediatrics and Genetics, Stanford University, Stanford, CA, USA
| | - Nicholas J Dyson
- Massachusetts General Hospital Cancer Center, Laboratory of Molecular Oncology, Harvard Medical School, Charlestown, MA, USA
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28
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Palopoli N, González Foutel NS, Gibson TJ, Chemes LB. Short linear motif core and flanking regions modulate retinoblastoma protein binding affinity and specificity. Protein Eng Des Sel 2018; 31:69-77. [DOI: 10.1093/protein/gzx068] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Accepted: 01/10/2018] [Indexed: 12/11/2022] Open
Affiliation(s)
- Nicolás Palopoli
- Department of Science and Technology, Universidad Nacional de Quilmes, CONICET. Roque Sáenz Peña 352. CP (B1876BXD), Bernal, Buenos Aires, Argentina
- Structural Bioinformatics Unit, Fundación Instituto Leloir and IIBBA-CONICET. Av. Patricias Argentinas 435 CP 1405, Buenos Aires, Argentina
| | - Nicolás S González Foutel
- Protein Structure Function and Engineering Laboratory, Fundación Instituto Leloir and IIBBA-CONICET. Av. Patricias Argentinas 435 CP 1405, Buenos Aires, Argentina
| | - Toby J Gibson
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstraße 1, 69117, Heidelberg, Germany
| | - Lucía B Chemes
- Protein Structure Function and Engineering Laboratory, Fundación Instituto Leloir and IIBBA-CONICET. Av. Patricias Argentinas 435 CP 1405, Buenos Aires, Argentina
- Instituto de Investigaciones Biotecnológicas IIB-INTECH, Universidad Nacional de San Martín. Av. 25 de Mayo y Francia CP 1650, San Martín, Buenos Aires, Argentina
- Departamento de Fisiología y Biología Molecular y Celular (DFBMC), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Intendente Güiraldes 2160, Ciudad Universitaria, C1428EGA, Argentina
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29
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Lai AG, Kosaka N, Abnave P, Sahu S, Aboobaker AA. The abrogation of condensin function provides independent evidence for defining the self-renewing population of pluripotent stem cells. Dev Biol 2018; 433:218-226. [PMID: 28757112 PMCID: PMC5771471 DOI: 10.1016/j.ydbio.2017.07.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Revised: 07/18/2017] [Accepted: 07/27/2017] [Indexed: 12/18/2022]
Abstract
Heterogeneity of planarian stem cells has been categorised on the basis of single cell expression analyses and subsequent experiments to demonstrate lineage relationships. Some data suggest that despite heterogeneity in gene expression amongst cells in the cell cycle, in fact only one sub-population, known as sigma neoblasts, can self-renew. Without the tools to perform live in vivo lineage analysis, we instead took an alternative approach to provide independent evidence for defining the self-renewing stem cell population. We exploited the role of highly conserved condensin family genes to functionally assay neoblast self-renewal properties. Condensins are involved in forming properly condensed chromosomes to allow cell division to proceed during mitosis, and their abrogation inhibits mitosis and can lead to repeated endoreplication of the genome in cells that make repeated attempts to divide. We find that planarians possess only the condensin I complex, and that this is required for normal stem cell function. Abrogation of condensin function led to rapid stem cell depletion accompanied by the appearance of 'giant' cells with increased DNA content. Using previously discovered markers of heterogeneity we show that enlarged cells are always from the sigma-class of the neoblast population and we never observe evidence for endoreplication for the other neoblast subclasses. Overall, our data establish that condensins are essential for stem cell maintenance and provide independent evidence that only sigma-neoblasts are capable of multiple rounds of cell division and hence self-renewal.
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Affiliation(s)
- Alvina G Lai
- Department of Zoology, University of Oxford, Tinbergen Building, South Parks Road, Oxford OX1 3PS, United Kingdom
| | - Nobuyoshi Kosaka
- Department of Zoology, University of Oxford, Tinbergen Building, South Parks Road, Oxford OX1 3PS, United Kingdom
| | - Prasad Abnave
- Department of Zoology, University of Oxford, Tinbergen Building, South Parks Road, Oxford OX1 3PS, United Kingdom
| | - Sounak Sahu
- Department of Zoology, University of Oxford, Tinbergen Building, South Parks Road, Oxford OX1 3PS, United Kingdom
| | - A Aziz Aboobaker
- Department of Zoology, University of Oxford, Tinbergen Building, South Parks Road, Oxford OX1 3PS, United Kingdom.
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30
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Abstract
Structural maintenance of chromosome (SMC) protein complexes, including cohesin and condensin, are increasingly being recognized for their important role in cancer and development, making it critical that we understand how these evolutionarily conserved multi-subunit protein complexes associate with and organize the genome. We review adaptor proteins for SMC complexes and how these adaptors may capture SMC complexes following loop extrusion to provide a framework for chromosome organization.
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Affiliation(s)
- Kobe C. Yuen
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
- Department of Oncology Biomarker Development, Genentech, Inc., South San Francisco, California, United States of America
| | - Jennifer L. Gerton
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
- Department of Biochemistry and Molecular Biology, University of Kansas School of Medicine, Kansas City, Kansas, United States of America
- University of Kansas Cancer Center, Kansas City, Kansas, United States of America
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31
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Ma Y, Buttitta L. Chromatin organization changes during the establishment and maintenance of the postmitotic state. Epigenetics Chromatin 2017; 10:53. [PMID: 29126440 PMCID: PMC5681785 DOI: 10.1186/s13072-017-0159-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 10/30/2017] [Indexed: 02/06/2023] Open
Abstract
Background Genome organization changes during development as cells differentiate. Chromatin motion becomes increasingly constrained and heterochromatin clusters as cells become restricted in their developmental potential. These changes coincide with slowing of the cell cycle, which can also influence chromatin organization and dynamics. Terminal differentiation is often coupled with permanent exit from the cell cycle, and existing data suggest a close relationship between a repressive chromatin structure and silencing of the cell cycle in postmitotic cells. Heterochromatin clustering could also contribute to stable gene repression to maintain terminal differentiation or cell cycle exit, but whether clustering is initiated by differentiation, cell cycle changes, or both is unclear. Here we examine the relationship between chromatin organization, terminal differentiation and cell cycle exit. Results We focused our studies on the Drosophila wing, where epithelial cells transition from active proliferation to a postmitotic state in a temporally controlled manner. We find there are two stages of G0 in this tissue, a flexible G0 period where cells can be induced to reenter the cell cycle under specific genetic manipulations and a state we call “robust,” where cells become strongly refractory to cell cycle reentry. Compromising the flexible G0 by driving ectopic expression of cell cycle activators causes a global disruption of the clustering of heterochromatin-associated histone modifications such as H3K27 trimethylation and H3K9 trimethylation, as well as their associated repressors, Polycomb and heterochromatin protein 1 (HP1). However, this disruption is reversible. When cells enter a robust G0 state, even in the presence of ectopic cell cycle activity, clustering of heterochromatin-associated modifications is restored. If cell cycle exit is bypassed, cells in the wing continue to terminally differentiate, but heterochromatin clustering is severely disrupted. Heterochromatin-dependent gene silencing does not appear to be required for cell cycle exit, as compromising the H3K27 methyltransferase Enhancer of zeste, and/or HP1 cannot prevent the robust cell cycle exit, even in the face of normally oncogenic cell cycle activities. Conclusions Heterochromatin clustering during terminal differentiation is a consequence of cell cycle exit, rather than differentiation. Compromising heterochromatin-dependent gene silencing does not disrupt cell cycle exit. Electronic supplementary material The online version of this article (10.1186/s13072-017-0159-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yiqin Ma
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Laura Buttitta
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA.
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32
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Condensin II and GAIT complexes cooperate to restrict LINE-1 retrotransposition in epithelial cells. PLoS Genet 2017; 13:e1007051. [PMID: 29028794 PMCID: PMC5656329 DOI: 10.1371/journal.pgen.1007051] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 10/25/2017] [Accepted: 10/03/2017] [Indexed: 12/15/2022] Open
Abstract
LINE-1 (L1) retrotransposons can mobilize (retrotranspose) within the human genome, and mutagenic de novo L1 insertions can lead to human diseases, including cancers. As a result, cells are actively engaged in preventing L1 retrotransposition. This work reveals that the human Condensin II complex restricts L1 retrotransposition in both non-transformed and transformed cell lines through inhibition of L1 transcription and translation. Condensin II subunits, CAP-D3 and CAP-H2, interact with members of the Gamma-Interferon Activated Inhibitor of Translation (GAIT) complex including the glutamyl-prolyl-tRNA synthetase (EPRS), the ribosomal protein L13a, Glyceraldehyde 3-phosphate dehydrogenase (GAPDH), and NS1 associated protein 1 (NSAP1). GAIT has been shown to inhibit translation of mRNAs encoding inflammatory proteins in myeloid cells by preventing the binding of the translation initiation complex, in response to Interferon gamma (IFN-γ). Excitingly, our data show that Condensin II promotes complexation of GAIT subunits. Furthermore, RNA-Immunoprecipitation experiments in epithelial cells demonstrate that Condensin II and GAIT subunits associate with L1 RNA in a co-dependent manner, independent of IFN-γ. These findings suggest that cooperation between the Condensin II and GAIT complexes may facilitate a novel mechanism of L1 repression, thus contributing to the maintenance of genome stability in somatic cells.
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33
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Poonperm R, Takata H, Uchiyama S, Fukui K. Interdependency and phosphorylation of KIF4 and condensin I are essential for organization of chromosome scaffold. PLoS One 2017; 12:e0183298. [PMID: 28817632 PMCID: PMC5560531 DOI: 10.1371/journal.pone.0183298] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 08/02/2017] [Indexed: 11/20/2022] Open
Abstract
Kinesin family member 4 (KIF4) and condensins I and II are essential chromosomal proteins for chromosome organization by locating primarily to the chromosome scaffold. However, the mechanism of how KIF4 and condensins localize to the chromosome scaffold is poorly understood. Here, we demonstrate a close relationship between the chromosome localization of KIF4 and condensin I, but not condensin II, and show that KIF4 and condensin I assist each other for stable scaffold formation by forming a stable complex. Moreover, phosphorylation of KIF4 and condensin I by Aurora B and polo-like kinase 1 (Plk1) is important for KIF4 and condensin I localization to the chromosome. Aurora B activity facilitates the targeting of KIF4 and condensin I to the chromosome, whereas Plk1 activity promotes the dissociation of these proteins from the chromosome. Thus, the interdependency between KIF4 and condensin I, and their phosphorylation states play important roles in chromosome scaffold organization during mitosis.
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Affiliation(s)
- Rawin Poonperm
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan
| | - Hideaki Takata
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Ikeda, Osaka, JAPAN
- * E-mail: (KF); (HT)
| | - Susumu Uchiyama
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan
| | - Kiichi Fukui
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan
- Chromosome Engineering Research Center, Tottori University, Yonago, Japan
- * E-mail: (KF); (HT)
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34
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Vélez-Cruz R, Johnson DG. The Retinoblastoma (RB) Tumor Suppressor: Pushing Back against Genome Instability on Multiple Fronts. Int J Mol Sci 2017; 18:ijms18081776. [PMID: 28812991 PMCID: PMC5578165 DOI: 10.3390/ijms18081776] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 08/13/2017] [Accepted: 08/13/2017] [Indexed: 12/13/2022] Open
Abstract
The retinoblastoma (RB) tumor suppressor is known as a master regulator of the cell cycle. RB is mutated or functionally inactivated in the majority of human cancers. This transcriptional regulator exerts its function in cell cycle control through its interaction with the E2F family of transcription factors and with chromatin remodelers and modifiers that contribute to the repression of genes important for cell cycle progression. Over the years, studies have shown that RB participates in multiple processes in addition to cell cycle control. Indeed, RB is known to interact with over 200 different proteins and likely exists in multiple complexes. RB, in some cases, acts through its interaction with E2F1, other members of the pocket protein family (p107 and p130), and/or chromatin remodelers and modifiers. RB is a tumor suppressor with important chromatin regulatory functions that affect genomic stability. These functions include the role of RB in DNA repair, telomere maintenance, chromosome condensation and cohesion, and silencing of repetitive regions. In this review we will discuss recent advances in RB biology related to RB, partner proteins, and their non-transcriptional functions fighting back against genomic instability.
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Affiliation(s)
- Renier Vélez-Cruz
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, 1808 Park Road 1C, P.O. Box 389, Smithville, TX 78957, USA.
- Department of Biochemistry, Midwestern University, Chicago College of Osteopathic Medicine, 555 31st Street, Downers Grove, IL 60515, USA.
| | - David G Johnson
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, 1808 Park Road 1C, P.O. Box 389, Smithville, TX 78957, USA.
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35
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Ishak CA, Coschi CH, Roes MV, Dick FA. Disruption of CDK-resistant chromatin association by pRB causes DNA damage, mitotic errors, and reduces Condensin II recruitment. Cell Cycle 2017; 16:1430-1439. [PMID: 28723239 DOI: 10.1080/15384101.2017.1338984] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Organization of chromatin structure is indispensible to the maintenance of genome integrity. The retinoblastoma tumor suppressor protein (pRB) mediates both transcriptional repression and chromatin organization, but the independent contributions of these functions have been difficult to study. Here, we utilize a synthetic Rb1 mutant allele (F832A) that maintains pRB association at cell cycle gene promoters, but disrupts a cyclin-dependent kinase (CDK)-resistant interaction with E2F1 to reduce occupancy of pRB on intergenic chromatin. Reduced pRB chromatin association increases spontaneous γH2AX deposition and aneuploidy. Our data indicates that the CDK-resistant pRB-E2F1 scaffold recruits Condensin II to major satellite repeats to stabilize chromatin structure in interphase and mitosis through mechanisms that are distinct from silencing of repetitive sequence expression.
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Affiliation(s)
- Charles A Ishak
- a London Regional Cancer Program , London , Ontario , Canada.,b Department of Biochemistry , Western University , London , Ontario , Canada
| | - Courtney H Coschi
- a London Regional Cancer Program , London , Ontario , Canada.,b Department of Biochemistry , Western University , London , Ontario , Canada
| | - Michael V Roes
- a London Regional Cancer Program , London , Ontario , Canada.,b Department of Biochemistry , Western University , London , Ontario , Canada
| | - Frederick A Dick
- a London Regional Cancer Program , London , Ontario , Canada.,b Department of Biochemistry , Western University , London , Ontario , Canada.,c Children's Health Research Institute , London , Ontario , Canada
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36
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Cheng MH, Andrejka L, Vorster PJ, Hinman A, Lipsick JS. The Drosophila LIN54 homolog Mip120 controls two aspects of oogenesis. Biol Open 2017; 6:967-978. [PMID: 28522430 PMCID: PMC5550918 DOI: 10.1242/bio.025825] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The conserved multi-protein MuvB core associates with the Myb oncoproteins and with the RB-E2F-DP tumor suppressor proteins in complexes that regulate cell proliferation, differentiation, and apoptosis. Drosophila Mip120, a homolog of LIN54, is a sequence-specific DNA-binding protein within the MuvB core. A mutant of Drosophilamip120 was previously shown to cause female and male sterility. We now show that Mip120 regulates two different aspects of oogenesis. First, in the absence of the Mip120 protein, egg chambers arrest during the transition from stage 7 to 8 with a failure of the normal program of chromosomal dynamics in the ovarian nurse cells. Specifically, the decondensation, disassembly and dispersion of the endoreplicated polytene chromosomes fail to occur without Mip120. The conserved carboxy-terminal DNA-binding and protein-protein interaction domains of Mip120 are necessary but not sufficient for this process. Second, we show that a lack of Mip120 causes a dramatic increase in the expression of benign gonial cell neoplasm (bgcn), a gene that is normally expressed in only a small number of cells within the ovary including the germline stem cells. Summary:Drosophila Mip120/LIN54, regulates ovarian nurse cell chromosome disassembly and germline-specific gene expression. These functions of Mip120 require its less conserved N-terminus in addition to its CXC DNA-binding and HCH protein-interaction domains.
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Affiliation(s)
- Mei-Hsin Cheng
- Departments of Pathology, Genetics, and Biology, Stanford University, Stanford, CA 94305-5324, USA
| | - Laura Andrejka
- Departments of Pathology, Genetics, and Biology, Stanford University, Stanford, CA 94305-5324, USA
| | - Paul J Vorster
- Departments of Pathology, Genetics, and Biology, Stanford University, Stanford, CA 94305-5324, USA
| | - Albert Hinman
- Departments of Pathology, Genetics, and Biology, Stanford University, Stanford, CA 94305-5324, USA
| | - Joseph S Lipsick
- Departments of Pathology, Genetics, and Biology, Stanford University, Stanford, CA 94305-5324, USA
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37
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Abstract
In this review, Dyson summarizes some recent developments in pRB research and focuses on progress toward answers for the three fundamental questions that sit at the heart of the pRB literature: What does pRB do? How does the inactivation of RB change the cell? How can our knowledge of RB function be exploited to provide better treatment for cancer patients? The retinoblastoma susceptibility gene (RB1) was the first tumor suppressor gene to be molecularly defined. RB1 mutations occur in almost all familial and sporadic forms of retinoblastoma, and this gene is mutated at variable frequencies in a variety of other human cancers. Because of its early discovery, the recessive nature of RB1 mutations, and its frequency of inactivation, RB1 is often described as a prototype for the class of tumor suppressor genes. Its gene product (pRB) regulates transcription and is a negative regulator of cell proliferation. Although these general features are well established, a precise description of pRB's mechanism of action has remained elusive. Indeed, in many regards, pRB remains an enigma. This review summarizes some recent developments in pRB research and focuses on progress toward answers for the three fundamental questions that sit at the heart of the pRB literature: What does pRB do? How does the inactivation of RB change the cell? How can our knowledge of RB function be exploited to provide better treatment for cancer patients?
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38
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An SMC-like protein binds and regulates Caenorhabditis elegans condensins. PLoS Genet 2017; 13:e1006614. [PMID: 28301465 PMCID: PMC5373644 DOI: 10.1371/journal.pgen.1006614] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 03/30/2017] [Accepted: 02/01/2017] [Indexed: 01/17/2023] Open
Abstract
Structural Maintenance of Chromosomes (SMC) family proteins participate in multisubunit complexes that govern chromosome structure and dynamics. SMC-containing condensin complexes create chromosome topologies essential for mitosis/meiosis, gene expression, recombination, and repair. Many eukaryotes have two condensin complexes (I and II); C. elegans has three (I, II, and the X-chromosome specialized condensin IDC) and their regulation is poorly understood. Here we identify a novel SMC-like protein, SMCL-1, that binds to C. elegans condensin SMC subunits, and modulates condensin functions. Consistent with a possible role as a negative regulator, loss of SMCL-1 partially rescued the lethal and sterile phenotypes of a hypomorphic condensin mutant, while over-expression of SMCL-1 caused lethality, chromosome mis-segregation, and disruption of condensin IDC localization on X chromosomes. Unlike canonical SMC proteins, SMCL-1 lacks hinge and coil domains, and its ATPase domain lacks conserved amino acids required for ATP hydrolysis, leading to the speculation that it may inhibit condensin ATPase activity. SMCL-1 homologs are apparent only in the subset of Caenorhabditis species in which the condensin I and II subunit SMC-4 duplicated to create the condensin IDC- specific subunit DPY-27, suggesting that SMCL-1 helps this lineage cope with the regulatory challenges imposed by evolution of a third condensin complex. Our findings uncover a new regulator of condensins and highlight how the duplication and divergence of SMC complex components in various lineages has created new proteins with diverse functions in chromosome dynamics.
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Roles of pRB in the Regulation of Nucleosome and Chromatin Structures. BIOMED RESEARCH INTERNATIONAL 2016; 2016:5959721. [PMID: 28101510 PMCID: PMC5215604 DOI: 10.1155/2016/5959721] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 11/08/2016] [Indexed: 01/31/2023]
Abstract
Retinoblastoma protein (pRB) interacts with E2F and other protein factors to play a pivotal role in regulating the expression of target genes that induce cell cycle arrest, apoptosis, and differentiation. pRB controls the local promoter activity and has the ability to change the structure of nucleosomes and/or chromosomes via histone modification, epigenetic changes, chromatin remodeling, and chromosome organization. Functional inactivation of pRB perturbs these cellular events and causes dysregulated cell growth and chromosome instability, which are hallmarks of cancer cells. The role of pRB in regulation of nucleosome/chromatin structures has been shown to link to tumor suppression. This review focuses on the ability of pRB to control nucleosome/chromatin structures via physical interactions with histone modifiers and chromatin factors and describes cancer therapies based on targeting these protein factors.
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The loading of condensin in the context of chromatin. Curr Genet 2016; 63:577-589. [PMID: 27909798 DOI: 10.1007/s00294-016-0669-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 11/24/2016] [Accepted: 11/25/2016] [Indexed: 12/23/2022]
Abstract
The packaging of DNA into chromosomes is a ubiquitous process that enables living organisms to structure and transmit their genome accurately through cell divisions. In the three kingdoms of life, the architecture and dynamics of chromosomes rely upon ring-shaped SMC (Structural Maintenance of Chromosomes) condensin complexes. To understand how condensin rings organize chromosomes, it is essential to decipher how they associate with chromatin filaments. Here, we use recent evidence to discuss the role played by nucleosomes and transcription factors in the loading of condensin at transcribed genes. We propose a model whereby cis-acting features nestled in the promoters of active genes synergistically attract condensin rings and promote their association with DNA.
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Woodward J, Taylor GC, Soares DC, Boyle S, Sie D, Read D, Chathoth K, Vukovic M, Tarrats N, Jamieson D, Campbell KJ, Blyth K, Acosta JC, Ylstra B, Arends MJ, Kranc KR, Jackson AP, Bickmore WA, Wood AJ. Condensin II mutation causes T-cell lymphoma through tissue-specific genome instability. Genes Dev 2016; 30:2173-2186. [PMID: 27737961 PMCID: PMC5088566 DOI: 10.1101/gad.284562.116] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 09/15/2016] [Indexed: 12/14/2022]
Abstract
Chromosomal instability is a hallmark of cancer, but mitotic regulators are rarely mutated in tumors. Mutations in the condensin complexes, which restructure chromosomes to facilitate segregation during mitosis, are significantly enriched in cancer genomes, but experimental evidence implicating condensin dysfunction in tumorigenesis is lacking. We report that mice inheriting missense mutations in a condensin II subunit (Caph2nes) develop T-cell lymphoma. Before tumors develop, we found that the same Caph2 mutation impairs ploidy maintenance to a different extent in different hematopoietic cell types, with ploidy most severely perturbed at the CD4+CD8+ T-cell stage from which tumors initiate. Premalignant CD4+CD8+ T cells show persistent catenations during chromosome segregation, triggering DNA damage in diploid daughter cells and elevated ploidy. Genome sequencing revealed that Caph2 single-mutant tumors are near diploid but carry deletions spanning tumor suppressor genes, whereas P53 inactivation allowed Caph2 mutant cells with whole-chromosome gains and structural rearrangements to form highly aggressive disease. Together, our data challenge the view that mitotic chromosome formation is an invariant process during development and provide evidence that defective mitotic chromosome structure can promote tumorigenesis.
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Affiliation(s)
- Jessica Woodward
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Gillian C Taylor
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Dinesh C Soares
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
- Centre for Genomic and Experimental Medicine, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Shelagh Boyle
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Daoud Sie
- Department of Pathology, VU University Medical Center, 1007 MB Amsterdam, The Netherlands
| | - David Read
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Keerthi Chathoth
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Milica Vukovic
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH16 4UU, United Kingdom
| | - Nuria Tarrats
- Edinburgh Cancer Research UK Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - David Jamieson
- Northern Institute for Cancer Research, University of Newcastle upon Tyne, Newcastle upon Tyne NE2 4AD, United Kingdom
| | - Kirsteen J Campbell
- Cancer Research UK Beatson Institute, Bearsden, Glasgow G61 1BD, United Kingdom
| | - Karen Blyth
- Cancer Research UK Beatson Institute, Bearsden, Glasgow G61 1BD, United Kingdom
| | - Juan Carlos Acosta
- Edinburgh Cancer Research UK Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Bauke Ylstra
- Department of Pathology, VU University Medical Center, 1007 MB Amsterdam, The Netherlands
| | - Mark J Arends
- Edinburgh Cancer Research UK Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Kamil R Kranc
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH16 4UU, United Kingdom
- Edinburgh Cancer Research UK Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Andrew P Jackson
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Wendy A Bickmore
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
| | - Andrew J Wood
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, United Kingdom
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Yokoyama Y, Zhu H, Zhang R, Noma KI. A novel role for the condensin II complex in cellular senescence. Cell Cycle 2016; 14:2160-70. [PMID: 26017022 DOI: 10.1080/15384101.2015.1049778] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Although cellular senescence is accompanied by global alterations in genome architecture, how the genome is restructured during the senescent processes is not well understood. Here, we show that the hCAP-H2 subunit of the condensin II complex exists as either a full-length protein or an N-terminus truncated variant (ΔN). While the full-length hCAP-H2 associates with mitotic chromosomes, the ΔN variant exists as an insoluble nuclear structure. When overexpressed, both hCAP-H2 isoforms assemble this nuclear architecture and induce senescence-associated heterochromatic foci (SAHF). The hCAP-H2ΔN protein accumulates as cells approach senescence, and hCAP-H2 knockdown inhibits oncogene-induced senescence. This study identifies a novel mechanism whereby condensin drives senescence via nuclear/genomic reorganization.
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Key Words
- BrdU, bromodeoxyuridine
- CDK, cyclin dependent kinase
- DAPI, 4,6-diamidino-2-phenylindole
- NCAPH2, non-SMC chromosome-associated protein H2 gene
- RPE-1, hTERT-immortalized retinal pigment epithelial cell line
- Rb, retinoblastoma protein
- SA-β-gal, senescence-associated β-galactosidase
- SADS, senescence-associated distension of satellites
- SAHF
- SAHF, senescence-associated heterochromatic foci
- SMC, structural maintenance of chromosomes
- cellular senescence
- condensin
- genome organization
- hCAP-H2, human chromosome-associated protein H2
- hTERT, human telomerase reverse transcriptase
- human
- nuclear architecture
- oncogene-induced senescence
- shRNA, short-hairpin RNA.
- uORF, upstream open reading frame
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Sex Differences in Drosophila melanogaster Heterochromatin Are Regulated by Non-Sex Specific Factors. PLoS One 2015; 10:e0128114. [PMID: 26053165 PMCID: PMC4459879 DOI: 10.1371/journal.pone.0128114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 04/22/2015] [Indexed: 12/26/2022] Open
Abstract
The eukaryotic genome is assembled into distinct types of chromatin. Gene-rich euchromatin has active chromatin marks, while heterochromatin is gene-poor and enriched for silencing marks. In spite of this, genes native to heterochromatic regions are dependent on their normal environment for full expression. Expression of genes in autosomal heterochromatin is reduced in male flies mutated for the noncoding roX RNAs, but not in females. roX mutations also disrupt silencing of reporter genes in male, but not female, heterochromatin, revealing a sex difference in heterochromatin. We adopted a genetic approach to determine how this difference is regulated, and found no evidence that known X chromosome counting elements, or the sex determination pathway that these control, are involved. This suggested that the sex chromosome karyotype regulates autosomal heterochromatin by a different mechanism. To address this, candidate genes that regulate chromosome organization were examined. In XX flies mutation of Topoisomerase II (Top2), a gene involved in chromatin organization and homolog pairing, made heterochromatic silencing dependent on roX, and thus male-like. Interestingly, Top2 also binds to a large block of pericentromeric satellite repeats (359 bp repeats) that are unique to the X chromosome. Deletion of X heterochromatin also makes autosomal heterochromatin in XX flies dependent on roX and enhances the effect of Top2 mutations, suggesting a combinatorial action. We postulate that Top2 and X heterochromatin in Drosophila comprise a novel karyotype-sensing pathway that determines the sensitivity of autosomal heterochromatin to loss of roX RNA.
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Schuster AT, Homer CR, Kemp JR, Nickerson KP, Deutschman E, Kim Y, West G, Sadler T, Stylianou E, Krokowski D, Hatzoglou M, de la Motte C, Rubin BP, Fiocchi C, McDonald C, Longworth MS. Chromosome-associated protein D3 promotes bacterial clearance in human intestinal epithelial cells by repressing expression of amino acid transporters. Gastroenterology 2015; 148:1405-1416.e3. [PMID: 25701737 PMCID: PMC4446190 DOI: 10.1053/j.gastro.2015.02.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 01/28/2015] [Accepted: 02/13/2015] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Defects in colonic epithelial barrier defenses are associated with ulcerative colitis (UC). The proteins that regulate bacterial clearance in the colonic epithelium have not been completely identified. The Drosophila chromosome-associated protein D3 (dCAP-D3) regulates responses to bacterial infection. We examined whether CAP-D3 promotes bacterial clearance in human colonic epithelium. METHODS Clearance of Salmonella or adherent-invasive Escherichia coli LF82 was assessed by gentamycin protection assays in HT-29 and Caco-2 cells expressing small hairpin RNAs against CAP-D3. We used immunoblot assays to measure levels of CAP-D3 in colonic epithelial cells from patients with UC and healthy individuals (controls). RNA sequencing identified genes activated by CAP-D3. We analyzed the roles of CAP-D3 target genes in bacterial clearance using gentamycin protection and immunofluorescence assays and studies with pharmacologic inhibitors. RESULTS CAP-D3 expression was reduced in colonic epithelial cells from patients with active UC. Reduced CAP-D3 expression decreased autophagy and impaired intracellular bacterial clearance by HT-29 and Caco-2 colonic epithelial cells. Lower levels of CAP-D3 increased transcription of genes encoding SLC7A5 and SLC3A2, the products of which heterodimerize to form an amino acid transporter in HT-29 cells after bacterial infection; levels of SLC7A5-SLC3A2 were increased in tissues from patients with UC compared with controls. Reduced CAP-D3 in HT-29 cells resulted in earlier recruitment of SLC7A5 to Salmonella-containing vacuoles, increased activity of mTORC1, and increased survival of bacteria. Inhibition of SLC7A5-SLC3A2 or mTORC1 activity rescued the bacterial clearance defects of CAP-D3-deficient cells. CONCLUSIONS CAP-D3 down-regulates transcription of genes that encode amino acid transporters (SLC7A5 and SLC3A2) to promote bacterial autophagy by colon epithelial cells. Levels of CAP-D3 protein are reduced in patients with active UC; strategies to increase its levels might restore mucosal homeostasis to patients with active UC.
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Affiliation(s)
- Andrew T Schuster
- Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Craig R Homer
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Jacqueline R Kemp
- Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Kourtney P Nickerson
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Emily Deutschman
- Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Yeojung Kim
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Gail West
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Tammy Sadler
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Eleni Stylianou
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Dawid Krokowski
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio
| | - Maria Hatzoglou
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio
| | - Carol de la Motte
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Brian P Rubin
- Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
- Department of Anatomic Pathology, Taussig Cancer Institute, Cleveland, Ohio
| | - Claudio Fiocchi
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Christine McDonald
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Michelle S Longworth
- Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
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Condensin II Regulates Interphase Chromatin Organization Through the Mrg-Binding Motif of Cap-H2. G3-GENES GENOMES GENETICS 2015; 5:803-17. [PMID: 25758823 PMCID: PMC4426367 DOI: 10.1534/g3.115.016634] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The spatial organization of the genome within the eukaryotic nucleus is a dynamic process that plays a central role in cellular processes such as gene expression, DNA replication, and chromosome segregation. Condensins are conserved multi-subunit protein complexes that contribute to chromosome organization by regulating chromosome compaction and homolog pairing. Previous work in our laboratory has shown that the Cap-H2 subunit of condensin II physically and genetically interacts with the Drosophila homolog of human MORF4-related gene on chromosome 15 (MRG15). Like Cap-H2, Mrg15 is required for interphase chromosome compaction and homolog pairing. However, the mechanism by which Mrg15 and Cap-H2 cooperate to maintain interphase chromatin organization remains unclear. Here, we show that Cap-H2 localizes to interband regions on polytene chromosomes and co-localizes with Mrg15 at regions of active transcription across the genome. We show that co-localization of Cap-H2 on polytene chromosomes is partially dependent on Mrg15. We have identified a binding motif within Cap-H2 that is essential for its interaction with Mrg15, and have found that mutation of this motif results in loss of localization of Cap-H2 on polytene chromosomes and results in partial suppression of Cap-H2-mediated compaction and homolog unpairing. Our data are consistent with a model in which Mrg15 acts as a loading factor to facilitate Cap-H2 binding to chromatin and mediate changes in chromatin organization.
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46
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Popov B, Petrov N. pRb-E2F signaling in life of mesenchymal stem cells: Cell cycle, cell fate, and cell differentiation. Genes Dis 2014; 1:174-187. [PMID: 30258863 PMCID: PMC6150080 DOI: 10.1016/j.gendis.2014.09.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 09/14/2014] [Indexed: 02/07/2023] Open
Abstract
Mesenchymal stem cells (MSCs) are multipotent cells that can differentiate into various mesodermal lines forming fat, muscle, bone, and other lineages of connective tissue. MSCs possess plasticity and under special metabolic conditions may transform into cells of unusual phenotypes originating from ecto- and endoderm. After transplantation, MSCs release the humoral factors promoting regeneration of the damaged tissue. During last five years, the numbers of registered clinical trials of MSCs have increased about 10 folds. This gives evidence that MSCs present a new promising resource for cell therapy of the most dangerous diseases. The efficacy of the MSCs therapy is limited by low possibilities to regulate their conversion into cells of damaged tissues that is implemented by the pRb-E2F signaling. The widely accepted viewpoint addresses pRb as ubiquitous regulator of cell cycle and tumor suppressor. However, current publications suggest that basic function of the pRb-E2F signaling in development is to regulate cell fate and differentiation. Through facultative and constitutive chromatin modifications, pRb-E2F signaling promotes transient and stable cells quiescence, cell fate choice to differentiate, to senesce, or to die. Loss of pRb is associated with cancer cell fate. pRb regulates cell fate by retaining quiescence of one cell population in favor of commitment of another or by suppression of genes of different cell phenotype. pRb is the founder member of the "pocket protein" family possessing functional redundancy. Critical increase in the efficacy of the MSCs based cell therapy will depend on precise understanding of various aspects of the pRb-E2F signaling.
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Affiliation(s)
- Boris Popov
- Institute of Cytology, Russian Academy of Sciences, St.Petersburg, 4, Tikhoretsky Av., 194064, Russia
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Miles WO, Korenjak M, Griffiths LM, Dyer MA, Provero P, Dyson NJ. Post-transcriptional gene expression control by NANOS is up-regulated and functionally important in pRb-deficient cells. EMBO J 2014; 33:2201-15. [PMID: 25100735 PMCID: PMC4282507 DOI: 10.15252/embj.201488057] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 07/11/2014] [Accepted: 07/15/2014] [Indexed: 11/09/2022] Open
Abstract
Inactivation of the retinoblastoma tumor suppressor (pRb) is a common oncogenic event that alters the expression of genes important for cell cycle progression, senescence, and apoptosis. However, in many contexts, the properties of pRb-deficient cells are similar to wild-type cells suggesting there may be processes that counterbalance the transcriptional changes associated with pRb inactivation. Therefore, we have looked for sets of evolutionary conserved, functionally related genes that are direct targets of pRb/E2F proteins. We show that the expression of NANOS, a key facilitator of the Pumilio (PUM) post-transcriptional repressor complex, is directly repressed by pRb/E2F in flies and humans. In both species, NANOS expression increases following inactivation of pRb/RBF1 and becomes important for tissue homeostasis. By analyzing datasets from normal retinal tissue and pRb-null retinoblastomas, we find a strong enrichment for putative PUM substrates among genes de-regulated in tumors. These include pro-apoptotic genes that are transcriptionally down-regulated upon pRb loss, and we characterize two such candidates, MAP2K3 and MAP3K1, as direct PUM substrates. Our data suggest that NANOS increases in importance in pRb-deficient cells and helps to maintain homeostasis by repressing the translation of transcripts containing PUM Regulatory Elements (PRE).
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Affiliation(s)
- Wayne O Miles
- Massachusetts General Hospital Cancer Center and Harvard Medical School Laboratory of Molecular Oncology, Charlestown, MA, USA
| | - Michael Korenjak
- Massachusetts General Hospital Cancer Center and Harvard Medical School Laboratory of Molecular Oncology, Charlestown, MA, USA
| | - Lyra M Griffiths
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Michael A Dyer
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Paolo Provero
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy Center for Translational Genomics and Bioinformatics, San Raffaele Scientific Institute, Milan, Italy
| | - Nicholas J Dyson
- Massachusetts General Hospital Cancer Center and Harvard Medical School Laboratory of Molecular Oncology, Charlestown, MA, USA
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Kranz AL, Jiao CY, Winterkorn LH, Albritton SE, Kramer M, Ercan S. Genome-wide analysis of condensin binding in Caenorhabditis elegans. Genome Biol 2014; 14:R112. [PMID: 24125077 PMCID: PMC3983662 DOI: 10.1186/gb-2013-14-10-r112] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 10/14/2013] [Indexed: 11/26/2022] Open
Abstract
Background Condensins are multi-subunit protein complexes that are essential for chromosome condensation during mitosis and meiosis, and play key roles in transcription regulation during interphase. Metazoans contain two condensins, I and II, which perform different functions and localize to different chromosomal regions. Caenorhabditis elegans contains a third condensin, IDC, that is targeted to and represses transcription of the X chromosome for dosage compensation. Results To understand condensin binding and function, we performed ChIP-seq analysis of C. elegans condensins in mixed developmental stage embryos, which contain predominantly interphase nuclei. Condensins bind to a subset of active promoters, tRNA genes and putative enhancers. Expression analysis in kle-2-mutant larvae suggests that the primary effect of condensin II on transcription is repression. A DNA sequence motif, GCGC, is enriched at condensin II binding sites. A sequence extension of this core motif, AGGG, creates the condensin IDC motif. In addition to differences in recruitment that result in X-enrichment of condensin IDC and condensin II binding to all chromosomes, we provide evidence for a shared recruitment mechanism, as condensin IDC recruiter SDC-2 also recruits condensin II to the condensin IDC recruitment sites on the X. In addition, we found that condensin sites overlap extensively with the cohesin loader SCC-2, and that SDC-2 also recruits SCC-2 to the condensin IDC recruitment sites. Conclusions Our results provide the first genome-wide view of metazoan condensin II binding in interphase, define putative recruitment motifs, and illustrate shared loading mechanisms for condensin IDC and condensin II.
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Korenjak M, Kwon E, Morris RT, Anderssen E, Amzallag A, Ramaswamy S, Dyson NJ. dREAM co-operates with insulator-binding proteins and regulates expression at divergently paired genes. Nucleic Acids Res 2014; 42:8939-53. [PMID: 25053843 PMCID: PMC4132727 DOI: 10.1093/nar/gku609] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
dREAM complexes represent the predominant form of E2F/RBF repressor complexes in Drosophila. dREAM associates with thousands of sites in the fly genome but its mechanism of action is unknown. To understand the genomic context in which dREAM acts we examined the distribution and localization of Drosophila E2F and dREAM proteins. Here we report a striking and unexpected overlap between dE2F2/dREAM sites and binding sites for the insulator-binding proteins CP190 and Beaf-32. Genetic assays show that these components functionally co-operate and chromatin immunoprecipitation experiments on mutant animals demonstrate that dE2F2 is important for association of CP190 with chromatin. dE2F2/dREAM binding sites are enriched at divergently transcribed genes, and the majority of genes upregulated by dE2F2 depletion represent the repressed half of a differentially expressed, divergently transcribed pair of genes. Analysis of mutant animals confirms that dREAM and CP190 are similarly required for transcriptional integrity at these gene pairs and suggest that dREAM functions in concert with CP190 to establish boundaries between repressed/activated genes. Consistent with the idea that dREAM co-operates with insulator-binding proteins, genomic regions bound by dREAM possess enhancer-blocking activity that depends on multiple dREAM components. These findings suggest that dREAM functions in the organization of transcriptional domains.
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Affiliation(s)
- Michael Korenjak
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, MA 02129, USA
| | - Eunjeong Kwon
- Massachusetts General Hospital, Cutaneous Biology Research Center, Charlestown, MA 02129, USA
| | - Robert T Morris
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, MA 02129, USA
| | - Endre Anderssen
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, MA 02129, USA
| | - Arnaud Amzallag
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, MA 02129, USA
| | - Sridhar Ramaswamy
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, MA 02129, USA
| | - Nicholas J Dyson
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, MA 02129, USA
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50
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Kim JH, Zhang T, Wong NC, Davidson N, Maksimovic J, Oshlack A, Earnshaw WC, Kalitsis P, Hudson DF. Condensin I associates with structural and gene regulatory regions in vertebrate chromosomes. Nat Commun 2014; 4:2537. [PMID: 24088984 DOI: 10.1038/ncomms3537] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 09/03/2013] [Indexed: 11/09/2022] Open
Abstract
The condensin complex is essential for correct packaging and segregation of chromosomes during mitosis and meiosis in all eukaryotes. To date, the genome-wide location and the nature of condensin-binding sites have remained elusive in vertebrates. Here we report the genome-wide map of condensin I in chicken DT40 cells. Unexpectedly, we find that condensin I binds predominantly to promoter sequences in mitotic cells. We also find a striking enrichment at both centromeres and telomeres, highlighting the importance of the complex in chromosome segregation. Taken together, the results show that condensin I is largely absent from heterochromatic regions. This map of the condensin I binding sites on the chicken genome reveals that patterns of condensin distribution on chromosomes are conserved from prokaryotes, through yeasts to vertebrates. Thus in three kingdoms of life, condensin is enriched on promoters of actively transcribed genes and at loci important for chromosome segregation.
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Affiliation(s)
- Ji Hun Kim
- 1] Murdoch Childrens Research Institute, Royal Children's Hospital, Parkville, Melbourne, Victoria 3052, Australia [2] Department of Paediatrics, University of Melbourne, Parkville, Melbourne, Victoria 3052, Australia
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