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CAI LISHENG, MA XUDONG, HUANG YIQUN, ZOU YONG, CHEN XINGSHENG. Aberrant histone methylation and the effect of Suv39H1 siRNA on gastric carcinoma. Oncol Rep 2014; 31:2593-600. [DOI: 10.3892/or.2014.3135] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 03/21/2014] [Indexed: 11/05/2022] Open
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2
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Lu Z, Huang X, Ouyang Y, Yao J. Genome-wide identification, phylogenetic and co-expression analysis of OsSET gene family in rice. PLoS One 2013; 8:e65426. [PMID: 23762371 PMCID: PMC3676427 DOI: 10.1371/journal.pone.0065426] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2013] [Accepted: 04/23/2013] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND SET domain is responsible for the catalytic activity of histone lysine methyltransferases (HKMTs) during developmental process. Histone lysine methylation plays a crucial and diverse regulatory function in chromatin organization and genome function. Although several SET genes have been identified and characterized in plants, the understanding of OsSET gene family in rice is still very limited. METHODOLOGY/PRINCIPAL FINDINGS In this study, a systematic analysis was performed and revealed the presence of at least 43 SET genes in rice genome. Phylogenetic and structural analysis grouped SET proteins into five classes, and supposed that the domains out of SET domain were significant for the specific of histone lysine methylation, as well as the recognition of methylated histone lysine. Based on the global microarray, gene expression profile revealed that the transcripts of OsSET genes were accumulated differentially during vegetative and reproductive developmental stages and preferentially up or down-regulated in different tissues. Cis-elements identification, co-expression analysis and GO analysis of expression correlation of 12 OsSET genes suggested that OsSET genes might be involved in cell cycle regulation and feedback. CONCLUSIONS/SIGNIFICANCE This study will facilitate further studies on OsSET family and provide useful clues for functional validation of OsSETs.
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Affiliation(s)
- Zhanhua Lu
- College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, PR China
| | - Xiaolong Huang
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, PR China
| | - Yidan Ouyang
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, PR China
| | - Jialing Yao
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, PR China
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3
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Effects of epigenetic-based anti-cancer drugs in leukaemia and multiple myeloma cells. Cell Biol Int 2011; 35:1195-203. [DOI: 10.1042/cbi20100820] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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4
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Sdek P, Zhao P, Wang Y, Huang CJ, Ko CY, Butler PC, Weiss JN, Maclellan WR. Rb and p130 control cell cycle gene silencing to maintain the postmitotic phenotype in cardiac myocytes. ACTA ACUST UNITED AC 2011; 194:407-23. [PMID: 21825075 PMCID: PMC3153646 DOI: 10.1083/jcb.201012049] [Citation(s) in RCA: 135] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The mammalian heart loses its regenerative potential soon after birth. Adult cardiac myocytes (ACMs) permanently exit the cell cycle, and E2F-dependent genes are stably silenced, although the underlying mechanism is unclear. Heterochromatin, which silences genes in many biological contexts, accumulates with cardiac differentiation. H3K9me3, a histone methylation characteristic of heterochromatin, also increases in ACMs and at E2F-dependent promoters. We hypothesize that genes relevant for cardiac proliferation are targeted to heterochromatin by retinoblastoma (Rb) family members interacting with E2F transcription factors and recruiting heterochromatin protein 1 (HP1) proteins. To test this hypothesis, we created cardiac-specific Rb and p130 inducible double knockout (IDKO) mice. IDKO ACMs showed a decrease in total heterochromatin, and cell cycle genes were derepressed, leading to proliferation of ACMs. Although Rb/p130 deficiency had no effect on total H3K9me3 levels, recruitment of HP1-γ to promoters was lost. Depleting HP1-γ up-regulated proliferation-promoting genes in ACMs. Thus, Rb and p130 have overlapping roles in maintaining the postmitotic state of ACMs through their interaction with HP1-γ to direct heterochromatin formation and silencing of proliferation-promoting genes.
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Affiliation(s)
- Patima Sdek
- Cardiovascular Research Laboratory, Department of Medicine and Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
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5
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Kwon SH, Workman JL. The changing faces of HP1: From heterochromatin formation and gene silencing to euchromatic gene expression: HP1 acts as a positive regulator of transcription. Bioessays 2011; 33:280-9. [PMID: 21271610 DOI: 10.1002/bies.201000138] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Heterochromatin protein 1 (HP1) is a positive regulator of active transcription in euchromatin. HP1 was first identified in Drosophila melanogaster as a major component of heterochromatin. Most eukaryotes have at least three isoforms of HP1, which are conserved in overall structure but localize differentially to heterochromatin and euchromatin. Although initial studies revealed a key role for HP1 in heterochromatin formation and gene silencing, recent progress has shed light on additional roles for HP1 in processes such as euchromatic gene expression. Recent studies have highlighted the importance of HP1-mediated gene regulation in euchromatin. Here, we focus on recent advances in understanding the role of HP1 in active transcription in euchromatin and how modification and localization of HP1 can regulate distinct functions for this protein in different contexts.
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Affiliation(s)
- So Hee Kwon
- Stowers Institute for Medical Research, Kansas City, MO, USA
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6
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Varier RA, Timmers HTM. Histone lysine methylation and demethylation pathways in cancer. Biochim Biophys Acta Rev Cancer 2010; 1815:75-89. [PMID: 20951770 DOI: 10.1016/j.bbcan.2010.10.002] [Citation(s) in RCA: 169] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Revised: 10/06/2010] [Accepted: 10/07/2010] [Indexed: 12/21/2022]
Abstract
The genetic changes leading to the development of human cancer are accompanied by alterations in the structure and modification status of chromatin, which represent powerful regulatory mechanisms for gene expression and genome stability. These epigenetic alterations have sparked interest into deciphering the regulatory pathways and function of post-translational modifications of histones during the initiation and progression of cancer. In this review we describe and summarize the current knowledge of several histone lysine methyltransferase and demethylase pathways relevant to cancer. Mechanistic insight into histone modifications will pave the way for the development and therapeutic application of "epidrugs" in cancer.
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Affiliation(s)
- Radhika A Varier
- Department of Physiological Chemistry, University Medical Centre, Utrecht, The Netherlands
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7
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Olson BJ, Oberholzer M, Li Y, Zones JM, Kohli HS, Bisova K, Fang SC, Meisenhelder J, Hunter T, Umen JG. Regulation of the Chlamydomonas cell cycle by a stable, chromatin-associated retinoblastoma tumor suppressor complex. THE PLANT CELL 2010; 22:3331-47. [PMID: 20978220 PMCID: PMC2990127 DOI: 10.1105/tpc.110.076067] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Revised: 08/31/2010] [Accepted: 10/09/2010] [Indexed: 05/19/2023]
Abstract
We examined the cell cycle dynamics of the retinoblastoma (RB) protein complex in the unicellular alga Chlamydomonas reinhardtii that has single homologs for each subunit-RB, E2F, and DP. We found that Chlamydomonas RB (encoded by MAT3) is a cell cycle-regulated phosphoprotein, that E2F1-DP1 can bind to a consensus E2F site, and that all three proteins interact in vivo to form a complex that can be quantitatively immunopurified. Yeast two-hybrid assays revealed the formation of a ternary complex between MAT3, DP1, and E2F1 that requires a C-terminal motif in E2F1 analogous to the RB binding domain of plant and animal E2Fs. We examined the abundance of MAT3/RB and E2F1-DP1 in highly synchronous cultures and found that they are synthesized and remain stably associated throughout the cell cycle with no detectable fraction of free E2F1-DP1. Consistent with their stable association, MAT3/RB and DP1 are constitutively nuclear, and MAT3/RB does not require DP1-E2F1 for nuclear localization. In the nucleus, MAT3/RB remains bound to chromatin throughout the cell cycle, and its chromatin binding is mediated through E2F1-DP1. Together, our data show that E2F-DP complexes can regulate the cell cycle without dissociation of their RB-related subunit and that other changes may be sufficient to convert RB-E2F-DP from a cell cycle repressor to an activator.
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Affiliation(s)
- Bradley J.S.C. Olson
- Plant Molecular and Cellular Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037
| | - Michael Oberholzer
- Plant Molecular and Cellular Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037
| | - Yubing Li
- Plant Molecular and Cellular Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037
| | - James M. Zones
- Plant Molecular and Cellular Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037
| | - Harjivan S. Kohli
- Plant Molecular and Cellular Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037
| | - Katerina Bisova
- Plant Molecular and Cellular Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037
| | - Su-Chiung Fang
- Plant Molecular and Cellular Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037
| | - Jill Meisenhelder
- Molecular and Cell Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037
| | - Tony Hunter
- Molecular and Cell Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037
| | - James G. Umen
- Plant Molecular and Cellular Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037
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8
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De Koning L, Savignoni A, Boumendil C, Rehman H, Asselain B, Sastre-Garau X, Almouzni G. Heterochromatin protein 1alpha: a hallmark of cell proliferation relevant to clinical oncology. EMBO Mol Med 2010; 1:178-91. [PMID: 20049717 PMCID: PMC3378125 DOI: 10.1002/emmm.200900022] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Mammalian cells contain three closely related heterochromatin protein 1 (HP1) isoforms, HP1α, β and γ, which, by analogy to their unique counterpart in Schizosaccharomyces pombe, have been implicated in gene silencing, genome stability and chromosome segregation. However, the individual importance of each isoform during normal cell cycle and disease has remained an unresolved issue. Here, we reveal that HP1α shows a proliferation-dependent regulation, which neither HP1β nor γ display. During transient cell cycle exit, the HP1α mRNA and protein levels diminish. Transient depletion of HP1α, but not HP1β or γ, in tumoural and primary human cells leads to defects in chromosome segregation. Notably, analysis of an annotated collection of samples derived from carcinomas reveals an overexpression of HP1α mRNA and protein, which correlates with clinical data and disease outcome. Our results unveil a specific expression pattern for the HP1α isoform, suggesting a unique function related to cell division and tumour growth. The overexpression of HP1α constitutes a new example of a potential epigenetic contribution to tumourigenesis that is of clinical interest for cancer prognosis.
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Affiliation(s)
- Leanne De Koning
- Laboratory of Nuclear Dynamics and Genome Plasticity (UMR218), Institut Curie/CNRS/UPMC, 26 Rue d'Ulm, 75248 Paris Cedex 05, France
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9
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The contribution of cell cycle regulation to endosperm development. ACTA ACUST UNITED AC 2009; 22:207-19. [DOI: 10.1007/s00497-009-0105-4] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Accepted: 07/05/2009] [Indexed: 01/08/2023]
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10
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Domains of heterochromatin protein 1 required for Drosophila melanogaster heterochromatin spreading. Genetics 2009; 182:967-77. [PMID: 19487560 DOI: 10.1534/genetics.109.105338] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Centric regions of eukaryotic genomes are packaged into heterochromatin, which possesses the ability to spread along the chromosome and silence gene expression. The process of spreading has been challenging to study at the molecular level due to repetitious sequences within centric regions. A heterochromatin protein 1 (HP1) tethering system was developed that generates "ectopic heterochromatin" at sites within euchromatic regions of the Drosophila melanogaster genome. Using this system, we show that HP1 dimerization and the PxVxL interaction platform formed by dimerization of the HP1 chromo shadow domain are necessary for spreading to a downstream reporter gene located 3.7 kb away. Surprisingly, either the HP1 chromo domain or the chromo shadow domain alone is sufficient for spreading and silencing at a downstream reporter gene located 1.9 kb away. Spreading is dependent on at least two H3K9 methyltransferases, with SU(VAR)3-9 playing a greater role at the 3.7-kb reporter and dSETDB1 predominately acting at the 1.9 kb reporter. These data support a model whereby HP1 takes part in multiple mechanisms of silencing and spreading.
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11
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Sanchez MDLP, Caro E, Desvoyes B, Ramirez-Parra E, Gutierrez C. Chromatin dynamics during the plant cell cycle. Semin Cell Dev Biol 2008; 19:537-46. [PMID: 18707013 DOI: 10.1016/j.semcdb.2008.07.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2008] [Revised: 07/23/2008] [Accepted: 07/24/2008] [Indexed: 11/30/2022]
Abstract
Cell cycle progression depends on a highly regulated series of events of which transcriptional control plays a major role. In addition, during the S-phase not only DNA but chromatin as a whole needs to be faithfully duplicated. Therefore, both nucleosome dynamics as well as local changes in chromatin organization, including introduction and/or removal of covalent DNA and histone modifications, at genes with a key role in cell proliferation, are of primary relevance. Chromatin duplication during the S-phase and the chromosome segregation during mitosis are cell cycle stages critical for maintenance of epigenetic marks or for allowing the daughter products to acquire a distinct epigenetic landscape and, consequently, a unique cell fate decision. These aspects of chromatin dynamics together with the strict coupling of cell proliferation, cell differentiation and post-embryonic organogenesis have a profound impact on plant growth, development and response to external signals.
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Affiliation(s)
- María de la Paz Sanchez
- Centro de Biologia Molecular "Severo Ochoa", Consejo Superior de Investigaciones Cientificas, Universidad Autonoma de Madrid, Nicolas Cabrera 1, Cantoblanco, Madrid, Spain
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12
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Zhao XY, Su YH, Cheng ZJ, Zhang XS. Cell fate switch during in vitro plant organogenesis. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2008; 50:816-24. [PMID: 18713392 DOI: 10.1111/j.1744-7909.2008.00701.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Plant mature cells have the capability to reverse their state of differentiation and produce new organs under cultured conditions. Two phases, dedifferentiation and redifferentiation, are commonly characterized during in vitro organogenesis. In these processes, cells undergo fate switch several times regulated by both extrinsic and intrinsic factors, which are associated with reentry to the cell cycle, the balance between euchromatin and heterochromatin, reprogramming of gene expression, and so forth. This short article reviews the advances in the mechanism of organ regeneration from plant somatic cells in molecular, genomic and epigenetic aspects, aiming to provide important information on the mechanism underlying cell fate switch during in vitro plant organogenesis.
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Affiliation(s)
- Xiang Yu Zhao
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, China
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13
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Abstract
Plant growth and development are driven by the continuous generation of new cells. Whereas much has been learned at a molecular level about the mechanisms that orchestrate progression through the different cell-cycle phases, little is known about how the cell-cycle machinery operates in the context of an entire plant and contributes to growth, cell differentiation and the formation of new tissues and organs. Here, we discuss how intrinsic developmental signals and environmental cues affect cell-cycle entry and exit.
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Affiliation(s)
- Lieven De Veylder
- Department of Plant Systems Biology, VIB, Technologiepark 927, 9052 Gent, Belgium
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14
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Abstract
The plant life cycle involves a series of developmental phase transitions. These transitions require the regulation and highly co-ordinated expression of many genes. Epigenetic controls have now been shown to be a key element of this mechanism of regulation. In the model plant Arabidopsis, recent genetic and molecular studies on chromatin have begun to dissect the molecular basis of these epigenetic controls. Chromatin dynamics represent the emerging and exciting field of gene regulation notably involved in plant developmental transitions. By comparing plant and animal systems, new insights into the molecular complexes and mechanisms governing development can be delineated. We are now beginning to identify the components of chromatin complexes and their functions.
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Affiliation(s)
- Frédéric Berger
- Laboratoire RDP, UMR 5667, ENS-Lyon, 46 allée d'Italie, F-69364 Lyon cedex 07, France
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15
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Mosquna A, Katz A, Shochat S, Grafi G, Ohad N. Interaction of FIE, a polycomb protein, with pRb: a possible mechanism regulating endosperm development. Mol Genet Genomics 2004; 271:651-7. [PMID: 15221456 DOI: 10.1007/s00438-004-1024-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2004] [Accepted: 05/05/2004] [Indexed: 01/30/2023]
Abstract
Inactivation of the Arabidopsis protein FERTILIZATION INDEPENDENT ENDOSPERM (FIE) induces division of the central cell of the embryo sac, leading to endosperm development in the absence of fertilization. The mechanism whereby FIE regulates this process is unknown. We postulated that activation of central cell division in fie mutant plants might involve the retinoblastoma protein (pRb), a cell cycle regulatory element. Pull-down and surface plasmon resonance assays demonstrated that FIE interacts in-vitro with the pRb homologues from Arabidopsis (AtRb), maize (ZmRb) and human (HuRb). The interaction of FIE with ZmRB and HuRb in the yeast two-hybrid system supports the possibility that a FIE-pRb interaction may occur also in planta. Mutational analysis showed that this interaction does not occur via the LxCxE motif of the FIE protein nor via the pocket B domain of pRb. These results suggest that FIE may inhibit premature division of the central cell of the embryo sac, at least partly, through interaction with pRb, and suppression of pRb-regulated genes.
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Affiliation(s)
- A Mosquna
- Department of Plant Sciences, Tel-Aviv University, 69978, Tel Aviv, Israel
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16
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Ausín I, Alonso-Blanco C, Jarillo JA, Ruiz-García L, Martínez-Zapater JM. Regulation of flowering time by FVE, a retinoblastoma-associated protein. Nat Genet 2004; 36:162-6. [PMID: 14745447 DOI: 10.1038/ng1295] [Citation(s) in RCA: 238] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2003] [Accepted: 12/31/2003] [Indexed: 11/08/2022]
Abstract
The initiation of flowering in plants is controlled by environmental and endogenous signals. Molecular analysis of this process in Arabidopsis thaliana indicates that environmental control is exerted through the photoperiod and vernalization pathways, whereas endogenous signals regulate the autonomous and gibberellin pathways. The vernalization and autonomous pathways converge on the negative regulation of FLC, a gene encoding a MADS-box protein that inhibits flowering. We cloned FVE, a component of the autonomous pathway that encodes AtMSI4, a putative retinoblastoma-associated protein. FVE interacted with retinoblastoma protein in immunoprecipitation assays, and FLC chromatin was enriched in acetylated histones in fve mutants. We conclude that FVE participates in a protein complex repressing FLC transcription through a histone deacetylation mechanism. Our data provide genetic evidence of a new developmental function of these conserved proteins and identify a new genetic mechanism in the regulation of flowering.
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Affiliation(s)
- Israel Ausín
- Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Campus de la Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
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17
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Li Y, Kirschmann DA, Wallrath LL. Does heterochromatin protein 1 always follow code? Proc Natl Acad Sci U S A 2002; 99 Suppl 4:16462-9. [PMID: 12151603 PMCID: PMC139909 DOI: 10.1073/pnas.162371699] [Citation(s) in RCA: 154] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Heterochromatin protein 1 (HP1) is a conserved chromosomal protein that participates in chromatin packaging and gene silencing. A loss of HP1 leads to lethality in Drosophila and correlates with metastasis in human breast cancer cells. On Drosophila polytene chromosomes HP1 is localized to centric regions, telomeric regions, in a banded pattern along the fourth chromosome, and at many sites scattered throughout the euchromatic arms. Recently, one mechanism of HP1 chromosome association was revealed; the amino-terminal chromo domain of HP1 interacts with methylated lysine nine of histone H3, consistent with the histone code hypothesis. Compelling data support this mechanism of HP1 association at centric regions. Is this the only mechanism by which HP1 associates with chromosomes? Interest is now shifting toward the role of HP1 within euchromatic domains. Accumulating evidence in Drosophila and mammals suggests that HP1 associates with chromosomes through interactions with nonhistone chromosomal proteins at locations other than centric heterochromatin. Does HP1 play a similar role in chromatin packaging and gene regulation at these sites as it does in centric heterochromatin? Does HP1 associate with the same proteins at these sites as it does in centric heterochromatin? A first step toward answering these questions is the identification of sequences associated with HP1 within euchromatic domains. Such sequences are likely to include HP1 "target genes" whose discovery will aid in our understanding of HP1 lethality in Drosophila and metastasis of breast cancer cells.
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Affiliation(s)
- Yuhong Li
- Department of Biochemistry, University of Iowa, Iowa City 52242, USA
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18
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Abstract
Plants and animals use the E2F-Rb pathway as a major mechanism of control in the decision to continue or stop cell division. The E2F-Rb pathway controls the G1-to-S-phase transition by the timely activation of genes involved in DNA synthesis and cell-cycle control. Recent findings reveal that the E2F-Rb pathway communicates with chromatin-remodelling factors in the control of transcription and cell-cycle progression. This article highlights the fast-moving advances in the molecular and functional characterization of plant E2F proteins, and in our understanding of how the E2F-Rb pathway is activated and repressed.
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Affiliation(s)
- Wen-Hui Shen
- Institut de Biologie Moléculaire des Plantes (IBMP), CNRS-ULP, 12 rue du Général Zimmer, 67084 Strasbourg, France.
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19
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Reyes JC, Hennig L, Gruissem W. Chromatin-remodeling and memory factors. New regulators of plant development. PLANT PHYSIOLOGY 2002; 130:1090-101. [PMID: 12427976 PMCID: PMC1540260 DOI: 10.1104/pp.006791] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Affiliation(s)
- José C Reyes
- Instituto de Bioquímica Vegetal y Fotosíntesis, Centro de Investigaciones Isla de la Cartuja, Avenida Américo Vespucio s/n, 41092 Sevilla, Spain
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20
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Fass E, Shahar S, Zhao J, Zemach A, Avivi Y, Grafi G. Phosphorylation of histone h3 at serine 10 cannot account directly for the detachment of human heterochromatin protein 1gamma from mitotic chromosomes in plant cells. J Biol Chem 2002; 277:30921-7. [PMID: 12060650 DOI: 10.1074/jbc.m112250200] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Heterochromatin protein 1 (HP1) controls heterochromatin formation in animal cells, at least partly through interaction with lysine 9 (Lys-9)-methylated histone H3. We aimed to determine whether a structurally conserved human HP1 protein exhibits conserved heterochromatin localization in plant cells and studied its relation to modified histone H3. We generated transgenic tobacco plants and cycling cells expressing the human HP1gamma fused to green fluorescent protein (GFP) and followed its association with chromatin. Plants expressing GFP-HP1gamma showed no phenotypic perturbations. We found that GFP-HP1gamma is preferentially associated with the transcriptionally "inactive" heterochromatin fraction, a fraction enriched in Lys-9-methylated histone H3. During mitosis GFP-HP1gamma is detached from chromosomes concomitantly with phosphorylation of histone H3 at serine 10 and reassembles as cells exit mitosis. However, this phosphorylation cannot directly account for the dissociation of GFP-HP1gamma from mitotic chromosomes inasmuch as phosphorylation does not interfere with binding to HP1gamma. It is, therefore, possible that phosphorylation at serine 10 creates a "code" that is read by as yet an unknown factor(s), eventually leading to detachment of GFP-HP1gamma from mitotic chromosomes. Together, our results suggest that chromatin organization in plants and animals is conserved, being controlled at least partly by the association of HP1 proteins with methylated histone H3.
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Affiliation(s)
- Ephraim Fass
- Department of Plant Sciences, The Weizmann Institute of Science, Rehovot 76100 Israel
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21
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Czvitkovich S, Sauer S, Peters AH, Deiner E, Wolf A, Laible G, Opravil S, Beug H, Jenuwein T. Over-expression of the SUV39H1 histone methyltransferase induces altered proliferation and differentiation in transgenic mice. Mech Dev 2001; 107:141-53. [PMID: 11520670 DOI: 10.1016/s0925-4773(01)00464-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The development of multi-cellular organisms is regulated by the ordered definition of gene expression programmes that govern cell proliferation and differentiation. Although differential gene activity is mainly controlled by transcription factors, it is also dependent upon the underlying chromatin structure, which can stabilize transcriptional "on" or "off" states. We have recently isolated human (SUV39H1) and mouse (Suv39h1) histone methyltransferases (HMTases) and shown that they are important regulators for the organization of repressive chromatin domains. To investigate whether a SUV39H1-induced modulation of heterochromatin would affect mammalian development, we generated transgenic mice that over-express the SUV39H1 HMTase early during embryogenesis. SUV39H1 transgenic mice are growth retarded, display a weak penetrance of skeletal transformations and are largely characterized by impaired erythroid differentiation, consistent with highest transgene expression in foetal liver. Ex vivo transgenic foetal liver cultures initially contain reduced numbers of cells in G1 but progress to immortalized erythroblasts that are compromised in executing an erythroid differentiation programme. The outgrowing SUV39H1-immortalized erythroblasts can maintain a diploid karyotype despite deregulation of several tumour suppressor proteins and dispersed distribution of the heterochromatin component HP1. Together, these data provide evidence for a role of the SUV39H1 HMTase during the mammalian development and indicate a possible function for higher-order chromatin in contributing to the balance between proliferation and differentiation potentials of progenitor cells.
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Affiliation(s)
- S Czvitkovich
- Research Institute of Molecular Pathology (IMP), The Vienna Biocenter, Dr Bohrgasse 7, A-1030 Vienna, Austria
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Nielsen SJ, Schneider R, Bauer UM, Bannister AJ, Morrison A, O'Carroll D, Firestein R, Cleary M, Jenuwein T, Herrera RE, Kouzarides T. Rb targets histone H3 methylation and HP1 to promoters. Nature 2001; 412:561-5. [PMID: 11484059 DOI: 10.1038/35087620] [Citation(s) in RCA: 658] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In eukaryotic cells the histone methylase SUV39H1 and the methyl-lysine binding protein HP1 functionally interact to repress transcription at heterochromatic sites. Lysine 9 of histone H3 is methylated by SUV39H1 (ref. 2), creating a binding site for the chromo domain of HP1 (refs 3, 4). Here we show that SUV39H1 and HP1 are both involved in the repressive functions of the retinoblastoma (Rb) protein. Rb associates with SUV39H1 and HP1 in vivo by means of its pocket domain. SUV39H1 cooperates with Rb to repress the cyclin E promoter, and in fibroblasts that are disrupted for SUV39, the activity of the cyclin E and cyclin A2 genes are specifically elevated. Chromatin immunoprecipitations show that Rb is necessary to direct methylation of histone H3, and is necessary for binding of HP1 to the cyclin E promoter. These results indicate that the SUV39H1-HP1 complex is not only involved in heterochromatic silencing but also has a role in repression of euchromatic genes by Rb and perhaps other co-repressor proteins.
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Affiliation(s)
- S J Nielsen
- Wellcome/CRC Institute and Department of Pathology, Tennis Court Road, Cambridge CB2 1QR, UK
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