1
|
Tachiwana H, Dacher M, Maehara K, Harada A, Seto Y, Katayama R, Ohkawa Y, Kimura H, Kurumizaka H, Saitoh N. Chromatin structure-dependent histone incorporation revealed by a genome-wide deposition assay. eLife 2021; 10:66290. [PMID: 33970102 PMCID: PMC8110306 DOI: 10.7554/elife.66290] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 04/05/2021] [Indexed: 12/25/2022] Open
Abstract
In eukaryotes, histone variant distribution within the genome is the key epigenetic feature. To understand how each histone variant is targeted to the genome, we developed a new method, the RhIP (Reconstituted histone complex Incorporation into chromatin of Permeabilized cell) assay, in which epitope-tagged histone complexes are introduced into permeabilized cells and incorporated into their chromatin. Using this method, we found that H3.1 and H3.3 were incorporated into chromatin in replication-dependent and -independent manners, respectively. We further found that the incorporation of histones H2A and H2A.Z mainly occurred at less condensed chromatin (open), suggesting that condensed chromatin (closed) is a barrier for histone incorporation. To overcome this barrier, H2A, but not H2A.Z, uses a replication-coupled deposition mechanism. Our study revealed that the combination of chromatin structure and DNA replication dictates the differential histone deposition to maintain the epigenetic chromatin states.
Collapse
Affiliation(s)
- Hiroaki Tachiwana
- Division of Cancer Biology, The Cancer Institute of Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Mariko Dacher
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, Japan
| | - Kazumitsu Maehara
- Division of Transcriptomics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Akihito Harada
- Division of Transcriptomics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Yosuke Seto
- Division of Experimental Chemotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Ryohei Katayama
- Division of Experimental Chemotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Yasuyuki Ohkawa
- Division of Transcriptomics, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Hiroshi Kimura
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Hitoshi Kurumizaka
- Laboratory of Chromatin Structure and Function, Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, Japan
| | - Noriko Saitoh
- Division of Cancer Biology, The Cancer Institute of Japanese Foundation for Cancer Research, Tokyo, Japan
| |
Collapse
|
2
|
An embryonic stem cell-specific heterochromatin state promotes core histone exchange in the absence of DNA accessibility. Nat Commun 2020; 11:5095. [PMID: 33037201 PMCID: PMC7547087 DOI: 10.1038/s41467-020-18863-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 09/14/2020] [Indexed: 12/17/2022] Open
Abstract
Nucleosome turnover concomitant with incorporation of the replication-independent histone variant H3.3 is a hallmark of regulatory regions in the animal genome. Nucleosome turnover is known to be universally linked to DNA accessibility and histone acetylation. In mouse embryonic stem cells, H3.3 is also highly enriched at interstitial heterochromatin, most prominently at intracisternal A-particle endogenous retroviral elements. Interstitial heterochromatin is established over confined domains by the TRIM28-KAP1/SETDB1 corepressor complex and has stereotypical features of repressive chromatin, such as H3K9me3 and recruitment of all HP1 isoforms. Here, we demonstrate that fast histone turnover and H3.3 incorporation is compatible with these hallmarks of heterochromatin. Further, we find that Smarcad1 chromatin remodeler evicts nucleosomes generating accessible DNA. Free DNA is repackaged via DAXX-mediated nucleosome assembly with histone variant H3.3 in this dynamic heterochromatin state. Loss of H3.3 in mouse embryonic stem cells elicits a highly specific opening of interstitial heterochromatin with minimal effects on other silent or active regions of the genome. Nucleosome turnover concomitant with incorporation of the histone variant H3.3 is a hallmark of regulatory regions in the animal genome. Here, the authors demonstrate that fast histone turnover and H3.3 incorporation defines a dynamic heterochromatin state in pluripotent stem cells.
Collapse
|
3
|
Molenaar TM, Pagès-Gallego M, Meyn V, van Leeuwen F. Application of Recombination -Induced Tag Exchange (RITE) to study histone dynamics in human cells. Epigenetics 2020; 15:901-913. [PMID: 32228348 PMCID: PMC7518693 DOI: 10.1080/15592294.2020.1741777] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
In eukaryotes, nucleosomes form a barrier to DNA templated reactions and must be dynamically disrupted to provide access to the genome. During nucleosome (re)assembly, histones can be replaced by new histones, erasing post-translational modifications. Measuring histone turnover in mammalian cells has mostly relied on inducible overexpression of histones, which may influence and distort natural histone deposition rates. We have previously used recombination-induced tag exchange (RITE) to study histone dynamics in budding yeast. RITE is a method to follow protein turnover by genetic switching of epitope tags using Cre recombinase and does not rely on inducible overexpression. Here, we applied RITE to study the dynamics of the replication-independent histone variant H3.3 in human cells. Epitope tag-switching could be readily detected upon induction of Cre-recombinase, enabling the monitoring old and new H3.3 in the same pool of cells. However, the rate of tag-switching was lower than in yeast cells. Analysis of histone H3.3 incorporation by chromatin immunoprecipitation did not recapitulate previously reported aspects of H3.3 dynamics such as high turnover rates in active promoters and enhancers. We hypothesize that asynchronous Cre-mediated DNA recombination in the cell population leads to a low time resolution of the H3.3-RITE system in human cells. We conclude that RITE enables the detection of old and new proteins in human cells and that the time-scale of tag-switching prevents the capture of high turnover events in a population of cells. Instead, RITE might be more suited for tracking long-lived histone proteins in human cells.
Collapse
Affiliation(s)
- Thom M Molenaar
- Division of Gene Regulation, Netherlands Cancer Institute , Amsterdam, The Netherlands
| | - Marc Pagès-Gallego
- Division of Gene Regulation, Netherlands Cancer Institute , Amsterdam, The Netherlands
| | - Vanessa Meyn
- Division of Gene Regulation, Netherlands Cancer Institute , Amsterdam, The Netherlands
| | - Fred van Leeuwen
- Division of Gene Regulation, Netherlands Cancer Institute , Amsterdam, The Netherlands.,Department of Medical Biology, Amsterdam UMC, Location AMC, University of Amsterdam , Amsterdam, The Netherlands
| |
Collapse
|
4
|
Pichon X, Lagha M, Mueller F, Bertrand E. A Growing Toolbox to Image Gene Expression in Single Cells: Sensitive Approaches for Demanding Challenges. Mol Cell 2018; 71:468-480. [DOI: 10.1016/j.molcel.2018.07.022] [Citation(s) in RCA: 112] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 07/19/2018] [Accepted: 07/20/2018] [Indexed: 12/21/2022]
|
5
|
Obier N, Bonifer C. Chromatin programming by developmentally regulated transcription factors: lessons from the study of haematopoietic stem cell specification and differentiation. FEBS Lett 2016; 590:4105-4115. [PMID: 27497427 DOI: 10.1002/1873-3468.12343] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 07/26/2016] [Accepted: 07/31/2016] [Indexed: 01/08/2023]
Abstract
Although the body plan of individuals is encoded in their genomes, each cell type expresses a different gene expression programme and therefore has access to only a subset of this information. Alterations to gene expression programmes are the underlying basis for the differentiation of multiple cell types and are driven by tissue-specific transcription factors (TFs) that interact with the epigenetic regulatory machinery to programme the chromatin landscape into transcriptionally active and inactive states. The haematopoietic system has long served as a paradigm for studying the molecular principles that regulate gene expression in development. In this review article, we summarize the current knowledge on the mechanism of action of TFs regulating haematopoietic stem cell specification and differentiation, and place this information into the context of general principles governing development.
Collapse
Affiliation(s)
- Nadine Obier
- Institute of Cancer and Genomic Sciences, College of Medicine and Dentistry, University of Birmingham, UK
| | - Constanze Bonifer
- Institute of Cancer and Genomic Sciences, College of Medicine and Dentistry, University of Birmingham, UK
| |
Collapse
|
6
|
Abstract
Chromatin regulatory processes, like all biological reactions, are dynamic and stochastic in nature but can give rise to stable and inheritable changes in gene expression patterns. A molecular understanding of those processes is key for fundamental biological insight into gene regulation, epigenetic inheritance, lineage determination, and therapeutic intervention in the case of disease. In recent years, great progress has been made in identifying important molecular players involved in key chromatin regulatory pathways. Conversely, we are only beginning to understand the dynamic interplay between protein effectors, transcription factors, and the chromatin substrate itself. Single-molecule approaches employing both highly defined chromatin substrates in vitro, as well as direct observation of complex regulatory processes in vivo, open new avenues for a molecular view of chromatin regulation. This review highlights recent applications of single-molecule methods and related techniques to investigate fundamental chromatin regulatory processes.
Collapse
Affiliation(s)
- Beat Fierz
- Laboratory
of Biophysical
Chemistry of Macromolecules, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| |
Collapse
|
7
|
Valero ML, Sendra R, Pamblanco M. Tandem affinity purification of histones, coupled to mass spectrometry, identifies associated proteins and new sites of post-translational modification in Saccharomyces cerevisiae. J Proteomics 2016; 136:183-92. [PMID: 26778144 DOI: 10.1016/j.jprot.2016.01.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 12/17/2015] [Accepted: 01/04/2016] [Indexed: 02/06/2023]
Abstract
Histones and their post-translational modifications contribute to regulating fundamental biological processes in all eukaryotic cells. We have applied a conventional tandem affinity purification strategy to histones H3 and H4 of the yeast Saccharomyces cerevisiae. Mass spectrometry analysis of the co-purified proteins revealed multiple associated proteins, including core histones, which indicates that tagged histones may be incorporated to the nucleosome particle. Among the many other co-isolated proteins there are histone chaperones, elements of chromatin remodeling, of nucleosome assembly/disassembly, and of histone modification complexes. The histone chaperone Rtt106p, two members of chromatin assembly FACT complex and Psh1p, an ubiquitin ligase, were the most abundant proteins obtained with both H3-TAP and H4-TAP, regardless of the cell extraction medium stringency. Our mass spectrometry analyses have also revealed numerous novel post-translational modifications, including 30 new chemical modifications in histones, mainly by ubiquitination. We have discovered not only new sites of ubiquitination but that, besides lysine, also serine and threonine residues are targets of ubiquitination on yeast histones. Our results show the standard tandem affinity purification procedure is suitable for application to yeast histones, in order to isolate and characterize histone-binding proteins and post-translational modifications, avoiding the bias caused by histone purification from a chromatin-enriched fraction.
Collapse
Affiliation(s)
- M Luz Valero
- Secció de Proteòmica, Servei Central de Suport a la Investigació Experimental (SCSIE), Universitat de València, C/Dr. Moliner 50, 46100, Burjassot, València, Spain.
| | - Ramon Sendra
- Departament de Bioquímica i Biologia Molecular, Universitat de València, C/Dr. Moliner 50, 46100, Burjassot, València, Spain.
| | - Mercè Pamblanco
- Departament de Bioquímica i Biologia Molecular, Universitat de València, C/Dr. Moliner 50, 46100, Burjassot, València, Spain.
| |
Collapse
|
8
|
Svensson JP, Shukla M, Menendez-Benito V, Norman-Axelsson U, Audergon P, Sinha I, Tanny JC, Allshire RC, Ekwall K. A nucleosome turnover map reveals that the stability of histone H4 Lys20 methylation depends on histone recycling in transcribed chromatin. Genome Res 2015; 25:872-83. [PMID: 25778913 PMCID: PMC4448683 DOI: 10.1101/gr.188870.114] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 03/12/2015] [Indexed: 12/16/2022]
Abstract
Nucleosome composition actively contributes to chromatin structure and accessibility. Cells have developed mechanisms to remove or recycle histones, generating a landscape of differentially aged nucleosomes. This study aimed to create a high-resolution, genome-wide map of nucleosome turnover in Schizosaccharomyces pombe. The recombination-induced tag exchange (RITE) method was used to study replication-independent nucleosome turnover through the appearance of new histone H3 and the disappearance or preservation of old histone H3. The genome-wide location of histones was determined by chromatin immunoprecipitation-exonuclease methodology (ChIP-exo). The findings were compared with diverse chromatin marks, including histone variant H2A.Z, post-translational histone modifications, and Pol II binding. Finally, genome-wide mapping of the methylation states of H4K20 was performed to determine the relationship between methylation (mono, di, and tri) of this residue and nucleosome turnover. Our analysis showed that histone recycling resulted in low nucleosome turnover in the coding regions of active genes, stably expressed at intermediate levels. High levels of transcription resulted in the incorporation of new histones primarily at the end of transcribed units. H4K20 was methylated in low-turnover nucleosomes in euchromatic regions, notably in the coding regions of long genes that were expressed at low levels. This transcription-dependent accumulation of histone methylation was dependent on the histone chaperone complex FACT. Our data showed that nucleosome turnover is highly dynamic in the genome and that several mechanisms are at play to either maintain or suppress stability. In particular, we found that FACT-associated transcription conserves histones by recycling them and is required for progressive H4K20 methylation.
Collapse
Affiliation(s)
- J Peter Svensson
- Department of Biosciences and Nutrition, Karolinska Institutet, Novum, 141 57 Huddinge, Sweden
| | - Manu Shukla
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3JR, Scotland, United Kingdom
| | | | - Ulrika Norman-Axelsson
- Department of Biosciences and Nutrition, Karolinska Institutet, Novum, 141 57 Huddinge, Sweden
| | - Pauline Audergon
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3JR, Scotland, United Kingdom
| | - Indranil Sinha
- Department of Biosciences and Nutrition, Karolinska Institutet, Novum, 141 57 Huddinge, Sweden
| | - Jason C Tanny
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Robin C Allshire
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3JR, Scotland, United Kingdom
| | - Karl Ekwall
- Department of Biosciences and Nutrition, Karolinska Institutet, Novum, 141 57 Huddinge, Sweden
| |
Collapse
|
9
|
Weiner A, Hsieh THS, Appleboim A, Chen HV, Rahat A, Amit I, Rando OJ, Friedman N. High-resolution chromatin dynamics during a yeast stress response. Mol Cell 2015; 58:371-86. [PMID: 25801168 PMCID: PMC4405355 DOI: 10.1016/j.molcel.2015.02.002] [Citation(s) in RCA: 133] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 12/16/2014] [Accepted: 01/29/2015] [Indexed: 11/22/2022]
Abstract
Covalent histone modifications are highly conserved and play multiple roles in eukaryotic transcription regulation. Here, we mapped 26 histone modifications genome-wide in exponentially growing yeast and during a dramatic transcriptional reprogramming—the response to diamide stress. We extend prior studies showing that steady-state histone modification patterns reflect genomic processes, especially transcription, and display limited combinatorial complexity. Interestingly, during the stress response we document a modest increase in the combinatorial complexity of histone modification space, resulting from roughly 3% of all nucleosomes transiently populating rare histone modification states. Most of these rare histone states result from differences in the kinetics of histone modification that transiently uncouple highly correlated marks, with slow histone methylation changes often lagging behind the more rapid acetylation changes. Explicit analysis of modification dynamics uncovers ordered sequences of events in gene activation and repression. Together, our results provide a comprehensive view of chromatin dynamics during a massive transcriptional upheaval. Comprehensive map of 26 histone marks during a transcriptional response in yeast Stress does not alter global relationships between marks and transcription Limited combinatorial complexity with transient modest increase during response Ordered waves of histone modifications during transcriptional reprogramming
Collapse
Affiliation(s)
- Assaf Weiner
- School of Computer Science and Engineering, The Hebrew University, Jerusalem 9190401, Israel; Institute of Life Sciences, The Hebrew University, Jerusalem 9190401, Israel
| | - Tsung-Han S Hsieh
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Alon Appleboim
- School of Computer Science and Engineering, The Hebrew University, Jerusalem 9190401, Israel; Institute of Life Sciences, The Hebrew University, Jerusalem 9190401, Israel
| | - Hsiuyi V Chen
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Ayelet Rahat
- School of Computer Science and Engineering, The Hebrew University, Jerusalem 9190401, Israel; Institute of Life Sciences, The Hebrew University, Jerusalem 9190401, Israel
| | - Ido Amit
- Department of Immunology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Oliver J Rando
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
| | - Nir Friedman
- School of Computer Science and Engineering, The Hebrew University, Jerusalem 9190401, Israel; Institute of Life Sciences, The Hebrew University, Jerusalem 9190401, Israel.
| |
Collapse
|
10
|
Histone exchange, chromatin structure and the regulation of transcription. Nat Rev Mol Cell Biol 2015; 16:178-89. [DOI: 10.1038/nrm3941] [Citation(s) in RCA: 650] [Impact Index Per Article: 72.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
11
|
Vicente-Muñoz S, Romero P, Magraner-Pardo L, Martinez-Jimenez CP, Tordera V, Pamblanco M. Comprehensive analysis of interacting proteins and genome-wide location studies of the Sas3-dependent NuA3 histone acetyltransferase complex. FEBS Open Bio 2014; 4:996-1006. [PMID: 25473596 PMCID: PMC4248121 DOI: 10.1016/j.fob.2014.11.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 11/05/2014] [Accepted: 11/05/2014] [Indexed: 12/22/2022] Open
Abstract
We characterise Sas3p and Gcn5p active HAT complexes in WT and deleted TAP-strains. We confirm that Pdp3p interacts with NuA3, histones and chromatin regulators. Pdp3p MS-analysis reveals its phosphorylation, ubiquitination and methylation. Sas3p can substitute Gcn5p in acetylation of histone H3K14 but not of H3K9. Genome-wide profiling of Sas3p supports its involvement in transcriptional elongation.
Histone acetylation affects several aspects of gene regulation, from chromatin remodelling to gene expression, by modulating the interplay between chromatin and key transcriptional regulators. The exact molecular mechanism underlying acetylation patterns and crosstalk with other epigenetic modifications requires further investigation. In budding yeast, these epigenetic markers are produced partly by histone acetyltransferase enzymes, which act as multi-protein complexes. The Sas3-dependent NuA3 complex has received less attention than other histone acetyltransferases (HAT), such as Gcn5-dependent complexes. Here, we report our analysis of Sas3p-interacting proteins using tandem affinity purification (TAP), coupled with mass spectrometry. This analysis revealed Pdp3p, a recently described component of NuA3, to be one of the most abundant Sas3p-interacting proteins. The PDP3 gene, was TAP-tagged and protein complex purification confirmed that Pdp3p co-purified with the NuA3 protein complex, histones, and several transcription-related and chromatin remodelling proteins. Our results also revealed that the protein complexes associated with Sas3p presented HAT activity even in the absence of Gcn5p and vice versa. We also provide evidence that Sas3p cannot substitute Gcn5p in acetylation of lysine 9 in histone H3 in vivo. Genome-wide occupancy of Sas3p using ChIP-on-chip tiled microarrays showed that Sas3p was located preferentially within the 5′-half of the coding regions of target genes, indicating its probable involvement in the transcriptional elongation process. Hence, this work further characterises the function and regulation of the NuA3 complex by identifying novel post-translational modifications in Pdp3p, additional Pdp3p-co-purifying chromatin regulatory proteins involved in chromatin-modifying complex dynamics and gene regulation, and a subset of genes whose transcriptional elongation is controlled by this complex.
Collapse
Key Words
- ChIP-on-chip
- ChIP-on-chip, chromatin immunoprecipitation with genome-wide location arrays
- Chromatin
- HAT, histone acetyltransferase
- Histones
- NuA3, nucleosomal acetyltransferase of histone H3
- PTM, post-translational modification
- Pdp3
- RNAPII, RNA polymerase II
- SAGA, Spt-Ada-Gcn acetyltransferase
- TAP, tandem affinity purification
- TAP–MS strategy
- TSS, transcription start site
- WCE, whole cell extract
- WT, wild-type
- Yeast
- nt, nucleotide
Collapse
Affiliation(s)
- Sara Vicente-Muñoz
- Structural Biochemistry Laboratory, Centro de Investigación Príncipe Felipe (CIPF), Eduardo Primo Yúfera, 3, 46012 València, Spain
| | - Paco Romero
- Departament de Bioquímica i Biologia Molecular, Universitat de València, C/Dr. Moliner 50, 46100 Burjassot, València, Spain
| | - Lorena Magraner-Pardo
- Departament de Bioquímica i Biologia Molecular, Universitat de València, C/Dr. Moliner 50, 46100 Burjassot, València, Spain
| | - Celia P Martinez-Jimenez
- Departament de Bioquímica i Biologia Molecular, Universitat de València, C/Dr. Moliner 50, 46100 Burjassot, València, Spain
| | - Vicente Tordera
- Departament de Bioquímica i Biologia Molecular, Universitat de València, C/Dr. Moliner 50, 46100 Burjassot, València, Spain
| | - Mercè Pamblanco
- Departament de Bioquímica i Biologia Molecular, Universitat de València, C/Dr. Moliner 50, 46100 Burjassot, València, Spain
| |
Collapse
|
12
|
Kraushaar DC, Jin W, Maunakea A, Abraham B, Ha M, Zhao K. Genome-wide incorporation dynamics reveal distinct categories of turnover for the histone variant H3.3. Genome Biol 2014; 14:R121. [PMID: 24176123 PMCID: PMC3983652 DOI: 10.1186/gb-2013-14-10-r121] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 10/31/2013] [Indexed: 11/16/2022] Open
Abstract
Background Nucleosomes are present throughout the genome and must be dynamically regulated to accommodate binding of transcription factors and RNA polymerase machineries by various mechanisms. Despite the development of protocols and techniques that have enabled us to map nucleosome occupancy genome-wide, the dynamic properties of nucleosomes remain poorly understood, particularly in mammalian cells. The histone variant H3.3 is incorporated into chromatin independently of DNA replication and requires displacement of existing nucleosomes for its deposition. Here, we measure H3.3 turnover at high resolution in the mammalian genome in order to present a genome-wide characterization of replication-independent H3.3-nucleosome dynamics. Results We developed a system to study the DNA replication-independent turnover of nucleosomes containing the histone variant H3.3 in mammalian cells. By measuring the genome-wide incorporation of H3.3 at different time points following epitope-tagged H3.3 expression, we find three categories of H3.3-nucleosome turnover in vivo: rapid turnover, intermediate turnover and, specifically at telomeres, slow turnover. Our data indicate that H3.3-containing nucleosomes at enhancers and promoters undergo rapid turnover that is associated with active histone modification marks including H3K4me1, H3K4me3, H3K9ac, H3K27ac and the histone variant H2A.Z. The rate of turnover is negatively correlated with H3K27me3 at regulatory regions and with H3K36me3 at gene bodies. Conclusions We have established a reliable approach to measure turnover rates of H3.3-containing nucleosomes on a genome-wide level in mammalian cells. Our results suggest that distinct mechanisms control the dynamics of H3.3 incorporation at functionally different genomic regions.
Collapse
|
13
|
Carlberg C, Raunio H. From pharmacogenomics to integrated personal omics profiling: a gap in implementation into healthcare. Per Med 2014; 11:625-629. [PMID: 29764051 DOI: 10.2217/pme.14.38] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Carsten Carlberg
- School of Medicine, Institute of Biomedicine, University of Eastern Finland, PO Box 1627, FIN-70211 Kuopio, Finland
| | - Hannu Raunio
- School of Pharmacy, Institute of Pharmacology & Toxicology, University of Eastern Finland, FIN-70211 Kuopio, Finland
| |
Collapse
|
14
|
Tallafuss A, Washbourne P, Postlethwait J. Temporally and spatially restricted gene expression profiling. Curr Genomics 2014; 15:278-92. [PMID: 25132798 PMCID: PMC4133951 DOI: 10.2174/1389202915666140602230106] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 05/29/2014] [Accepted: 05/30/2014] [Indexed: 12/02/2022] Open
Abstract
Identifying gene function in specific cells is critical for understanding the processes that make cells unique. Several different methods are available to isolate actively transcribed RNA or actively translated RNA in specific cells at a chosen time point. Cell-specific mRNA isolation can be accomplished by the expression of transgenes in cells of interest, either directly from a specific promoter or using a modular system such as Gal4/UAS or Cre/lox. All of the methods described in this review, namely thiol-labeling of RNA (TU-tagging or RABT), TRAP (translating ribosome affinity purification) and INTACT (isolation of nuclei tagged in specific cell types), allow next generation sequencing, permitting the identification of enriched gene transcripts within the specific cell-type. We describe here the general concept of each method, include examples, evaluate possible problems related to each technique, and suggest the types of questions for which each method is best suited.
Collapse
Affiliation(s)
- Alexandra Tallafuss
- Institute of Neuroscience, 1254-University of Oregon, 1425 E. 13th Avenue, Eugene, OR-97403, USA
| | - Philip Washbourne
- Institute of Neuroscience, 1254-University of Oregon, 1425 E. 13th Avenue, Eugene, OR-97403, USA
| | - John Postlethwait
- Institute of Neuroscience, 1254-University of Oregon, 1425 E. 13th Avenue, Eugene, OR-97403, USA
| |
Collapse
|
15
|
Yildirim O, Hung JH, Cedeno RJ, Weng Z, Lengner CJ, Rando OJ. A system for genome-wide histone variant dynamics in ES cells reveals dynamic MacroH2A2 replacement at promoters. PLoS Genet 2014; 10:e1004515. [PMID: 25102063 PMCID: PMC4125097 DOI: 10.1371/journal.pgen.1004515] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 06/03/2014] [Indexed: 12/30/2022] Open
Abstract
Dynamic exchange of a subset of nucleosomes in vivo plays important roles in epigenetic inheritance of chromatin states, chromatin insulator function, chromosome folding, and the maintenance of the pluripotent state of embryonic stem cells. Here, we extend a pulse-chase strategy for carrying out genome-wide measurements of histone dynamics to several histone variants in murine embryonic stem cells and somatic tissues, recapitulating expected characteristics of the well characterized H3.3 histone variant. We extended this system to the less-studied MacroH2A2 variant, commonly described as a "repressive" histone variant whose accumulation in chromatin is thought to fix the epigenetic state of differentiated cells. Unexpectedly, we found that while large intergenic blocks of MacroH2A2 were stably associated with the genome, promoter-associated peaks of MacroH2A2 exhibited relatively rapid exchange dynamics in ES cells, particularly at highly-transcribed genes. Upon differentiation to embryonic fibroblasts, MacroH2A2 was gained primarily in additional long, stably associated blocks across gene-poor regions, while overall turnover at promoters was greatly dampened. Our results reveal unanticipated dynamic behavior of the MacroH2A2 variant in pluripotent cells, and provide a resource for future studies of tissue-specific histone dynamics in vivo.
Collapse
Affiliation(s)
- Ozlem Yildirim
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Jui-Hung Hung
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Ryan J. Cedeno
- Department of Animal Biology, School of Veterinary Medicine and Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Zhiping Weng
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Christopher J. Lengner
- Department of Animal Biology, School of Veterinary Medicine and Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail: (CJL); (OJR)
| | - Oliver J. Rando
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- * E-mail: (CJL); (OJR)
| |
Collapse
|
16
|
Quantitative epigenetic co-variation in CpG islands and co-regulation of developmental genes. Sci Rep 2014; 3:2576. [PMID: 23999385 PMCID: PMC6505400 DOI: 10.1038/srep02576] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 08/16/2013] [Indexed: 12/21/2022] Open
Abstract
The genome-wide variation of multiple epigenetic modifications in CpG islands (CGIs) and the interactions between them are of great interest. Here, we optimized an entropy-based strategy to quantify variation of epigenetic modifications and explored their interaction across mouse embryonic stem cells, neural precursor cells and brain. Our results showed that four epigenetic modifications (DNA methylation, H3K4me2, H3K4me3 and H3K27me3) of CGIs in the mouse genome undergo combinatorial variation during neuron differentiation. DNA methylation variation was positively correlated with H3K27me3 variation, and negatively correlated with H3K4me2/3 variation. We identified 5,194 CGIs differentially modified by epigenetic modifications (DEM-CGIs). Among them, the differentially DNA methylated CGIs overlapped significantly with the CGIs differentially modified by H3K27me3. Moreover, DEM-CGIs may contribute to co-regulation of related developmental genes including core transcription factors. Our entropy-based strategy provides an effective way of investigating dynamic cross-talk among epigenetic modifications in various biological processes at the macro scale.
Collapse
|
17
|
Affiliation(s)
- Amanda L. Hughes
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605;
| | - Oliver J. Rando
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605;
| |
Collapse
|
18
|
Regulatory role of the 90-kDa-heat-shock protein (Hsp90) and associated factors on gene expression. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1839:71-87. [DOI: 10.1016/j.bbagrm.2013.12.006] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2013] [Revised: 12/23/2013] [Accepted: 12/26/2013] [Indexed: 12/31/2022]
|
19
|
|
20
|
Abstract
Researchers in the field of epigenomics are developing more nuanced understandings of biological complexity, and exploring the multiple pathways that lead to phenotypic expression. The concept of degeneracy-referring to the multiple pathways that a system recruits to achieve functional plasticity-is an important conceptual accompaniment to the growing body of knowledge in epigenomics. Distinct from degradation, redundancy and dilapidation; degeneracy refers to the plasticity of traits whose function overlaps in some environments, but diverges in others. While a redundant system is composed of repeated identical elements performing the same function, a degenerate system is composed of different elements performing similar or overlapping functions. Here, we describe the degenerate structure of gene regulatory systems from the basic genetic code to flexible epigenomic modifications, and discuss how these structural features have contributed to organism complexity, robustness, plasticity and evolvability.
Collapse
|
21
|
Oh JH, Gertych A, Tajbakhsh J. Nuclear DNA methylation and chromatin condensation phenotypes are distinct between normally proliferating/aging, rapidly growing/immortal, and senescent cells. Oncotarget 2013; 4:474-93. [PMID: 23562889 PMCID: PMC3717309 DOI: 10.18632/oncotarget.942] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
This study reports on probing the utility of in situ chromatin texture features such as nuclear DNA methylation and chromatin condensation patterns — visualized by fluorescent staining and evaluated by dedicated three-dimensional (3D) quantitative and high-throughput cell-by-cell image analysis — in assessing the proliferative capacity, i.e. growth behavior of cells: to provide a more dynamic picture of a cell population with potential implications in basic science, cancer diagnostics/prognostics and therapeutic drug development. Two types of primary cells and four different cancer cell lines were propagated and subjected to cell-counting, flow cytometry, confocal imaging, and 3D image analysis at various points in culture. Additionally a subset of primary and cancer cells was accelerated into senescence by oxidative stress. DNA methylation and chromatin condensation levels decreased with declining doubling times when primary cells aged in culture with the lowest levels reached at the stage of proliferative senescence. In comparison, immortal cancer cells with constant but higher doubling times mostly displayed lower and constant levels of the two in situ-derived features. However, stress-induced senescent primary and cancer cells showed similar levels of these features compared with primary cells that had reached natural growth arrest. With regards to global DNA methylation and chromatin condensation levels, aggressively growing cancer cells seem to take an intermediate level between normally proliferating and senescent cells. Thus, normal cells apparently reach cancer-cell equivalent stages of the two parameters at some point in aging, which might challenge phenotypic distinction between these two types of cells. Companion high-resolution molecular profiling could provide information on possible underlying differences that would explain benign versus malign cell growth behaviors.
Collapse
Affiliation(s)
- Jin Ho Oh
- Translational Cytomics Group, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | | | | |
Collapse
|
22
|
Lombraña R, Almeida R, Revuelta I, Madeira S, Herranz G, Saiz N, Bastolla U, Gómez M. High-resolution analysis of DNA synthesis start sites and nucleosome architecture at efficient mammalian replication origins. EMBO J 2013; 32:2631-44. [PMID: 23995398 DOI: 10.1038/emboj.2013.195] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 08/07/2013] [Indexed: 11/09/2022] Open
Abstract
DNA replication origins are poorly characterized genomic regions that are essential to recruit and position the initiation complex to start DNA synthesis. Despite the lack of specific replicator sequences, initiation of replication does not occur at random sites in the mammalian genome. This has lead to the view that DNA accessibility could be a major determinant of mammalian origins. Here, we performed a high-resolution analysis of nucleosome architecture and initiation sites along several origins of different genomic location and firing efficiencies. We found that mammalian origins are highly variable in nucleosome conformation and initiation patterns. Strikingly, initiation sites at efficient CpG island-associated origins always occur at positions of high-nucleosome occupancy. Origin recognition complex (ORC) binding sites, however, occur at adjacent but distinct positions marked by labile nucleosomes. We also found that initiation profiles mirror nucleosome architecture, both at endogenous origins and at a transgene in a heterologous system. Our studies provide a unique insight into the relationship between chromatin structure and initiation sites in the mammalian genome that has direct implications for how the replication programme can be accommodated to diverse epigenetic scenarios.
Collapse
Affiliation(s)
- Rodrigo Lombraña
- 1Functional Organization of the Genome Group, Centro de Biología Molecular 'Severo Ochoa', Consejo Superior de Investigaciones Científicas/Universidad Autónoma de Madrid (CSIC/UAM), Madrid, Spain
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Recombination-induced tag exchange (RITE) cassette series to monitor protein dynamics in Saccharomyces cerevisiae. G3-GENES GENOMES GENETICS 2013; 3:1261-72. [PMID: 23708297 PMCID: PMC3737166 DOI: 10.1534/g3.113.006213] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Proteins are not static entities. They are highly mobile, and their steady-state levels are achieved by a balance between ongoing synthesis and degradation. The dynamic properties of a protein can have important consequences for its function. For example, when a protein is degraded and replaced by a newly synthesized one, posttranslational modifications are lost and need to be reincorporated in the new molecules. Protein stability and mobility are also relevant for the duplication of macromolecular structures or organelles, which involves coordination of protein inheritance with the synthesis and assembly of newly synthesized proteins. To measure protein dynamics, we recently developed a genetic pulse-chase assay called recombination-induced tag exchange (RITE). RITE has been successfully used in Saccharomyces cerevisiae to measure turnover and inheritance of histone proteins, to study changes in posttranslational modifications on aging proteins, and to visualize the spatiotemporal inheritance of protein complexes and organelles in dividing cells. Here we describe a series of successful RITE cassettes that are designed for biochemical analyses, genomics studies, as well as single cell fluorescence applications. Importantly, the genetic nature and the stability of the tag switch offer the unique possibility to combine RITE with high-throughput screening for protein dynamics mutants and mechanisms. The RITE cassettes are widely applicable, modular by design, and can therefore be easily adapted for use in other cell types or organisms.
Collapse
|
24
|
Richardson K. The evolution of intelligent developmental systems. ADVANCES IN CHILD DEVELOPMENT AND BEHAVIOR 2013; 44:127-59. [PMID: 23834004 DOI: 10.1016/b978-0-12-397947-6.00005-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This chapter aims to understand the relations between the evolution and development of complex cognitive functions by emphasizing the context of complex, changeable environments. What evolves and develops in such contexts cannot be achieved by linear deterministic processes based on stable "codes". Rather, what is needed, even in the molecular ensembles of single-cell organisms, are "intelligent" systems with nonlinear dynamic processing, sensitive to informational structures, not just elements, in environments. This is the view emerging in recent molecular biology. The research is also constructing a new "biologic" of both evolution and development, providing a clearer rationale for transitions into more complex forms, including epigenetic, physiological, nervous, cognitive, and human sociocognitive forms. This chapter explains how these transitions form a nested hierarchical system in which the dynamics within and between levels creates emergent abilities so often underestimated or even demeaned in previous accounts, especially regarding human cognition. The implications of the view for human development in modern societies are also briefly considered.
Collapse
|
25
|
Gertych A, Oh JH, Wawrowsky KA, Weisenberger DJ, Tajbakhsh J. 3-D DNA methylation phenotypes correlate with cytotoxicity levels in prostate and liver cancer cell models. BMC Pharmacol Toxicol 2013; 14:11. [PMID: 23394161 PMCID: PMC3598242 DOI: 10.1186/2050-6511-14-11] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 01/14/2013] [Indexed: 11/10/2022] Open
Abstract
Background The spatial organization of the genome is being evaluated as a novel indicator of toxicity in conjunction with drug-induced global DNA hypomethylation and concurrent chromatin reorganization. 3D quantitative DNA methylation imaging (3D-qDMI) was applied as a cell-by-cell high-throughput approach to investigate this matter by assessing genome topology through represented immunofluorescent nuclear distribution patterns of 5-methylcytosine (MeC) and global DNA (4,6-diamidino-2-phenylindole = DAPI) in labeled nuclei. Methods Differential progression of global DNA hypomethylation was studied by comparatively dosing zebularine (ZEB) and 5-azacytidine (AZA). Treated and untreated (control) human prostate and liver cancer cells were subjected to confocal scanning microscopy and dedicated 3D image analysis for the following features: differential nuclear MeC/DAPI load and codistribution patterns, cell similarity based on these patterns, and corresponding differences in the topology of low-intensity MeC (LIM) and low in intensity DAPI (LID) sites. Results Both agents generated a high fraction of similar MeC phenotypes across applied concentrations. ZEB exerted similar effects at 10–100-fold higher drug concentrations than its AZA analogue: concentration-dependent progression of global cytosine demethylation, validated by measuring differential MeC levels in repeat sequences using MethyLight, and the concurrent increase in nuclear LIM densities correlated with cellular growth reduction and cytotoxicity. Conclusions 3D-qDMI demonstrated the capability of quantitating dose-dependent drug-induced spatial progression of DNA demethylation in cell nuclei, independent from interphase cell-cycle stages and in conjunction with cytotoxicity. The results support the notion of DNA methylation topology being considered as a potential indicator of causal impacts on chromatin distribution with a conceivable application in epigenetic drug toxicology.
Collapse
Affiliation(s)
- Arkadiusz Gertych
- Translational Cytomics Group, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | | | | | | | | |
Collapse
|
26
|
Delporte F, Jacquemin JM, Masson P, Watillon B. Insights into the regenerative property of plant cells and their receptivity to transgenesis: wheat as a research case study. PLANT SIGNALING & BEHAVIOR 2012; 7:1608-20. [PMID: 23072995 PMCID: PMC3578902 DOI: 10.4161/psb.22424] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
From a holistic perspective, the discovery of cellular plasticity, a very interesting property of totipotency, underlies many topical issues in biology with important medical applications, while transgenesis is a core research tool in biology. Partially known, some basic mechanisms involved in the regenerative property of cells and in their receptivity to transgenesis are common to plant and animal cells and highlight the principle of the unity of life. Transgenesis provides an important investigative instrument in plant physiology and is regarded as a valuable tool for crop improvement. The economic, social, cultural and scientific importance of cereals has led to a rich stream of research into their genetics, biology and evolution. Sustained efforts to achieve the results obtained in the fields of genetic engineering and applied biotechnology reflect this deep interest. Difficulties encountered in creating genetically modified cereals, especially wheat, highlighted the central notions of tissue culture regeneration and transformation competencies. From the perspective of combining or encountering these competencies in the same cell lineage, this reputedly recalcitrant species provides a stimulating biological system in which to explore the physiological and genetic complexity of both competencies. The former involves two phases, dedifferentiation and redifferentiation. Cells undergo development switches regulated by extrinsic and intrinsic factors. The re-entry into the cell division cycle progressively culminates in the development of organized structures. This is achieved by global chromatin reorganization associated with the reprogramming of the gene expression pattern. The latter is linked with surveillance mechanisms and DNA repair, aimed at maintaining genome integrity before cells move into mitosis, and with those mechanisms aimed at genome expression control and regulation. In order to clarify the biological basis of these two physiological properties and their interconnectedness, we look at both competencies at the core of defense/adaptive mechanisms and survival, between undifferentiated cell proliferation and organization, constituting a transition phase between two different dynamic regimes, a typical feature of critical dynamic systems. Opting for a candidate-gene strategy, several gene families could be proposed as relevant targets for investigating this hypothesis at the molecular level.
Collapse
Affiliation(s)
- Fabienne Delporte
- Walloon Agricultural Research Centre (CRAw), Department of Life Sciences, Bioengineering Unit, Gembloux, Belgium.
| | | | | | | |
Collapse
|
27
|
Pliss A, Malyavantham KS, Bhattacharya S, Berezney R. Chromatin dynamics in living cells: Identification of oscillatory motion. J Cell Physiol 2012; 228:609-16. [DOI: 10.1002/jcp.24169] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2012] [Accepted: 07/31/2012] [Indexed: 01/13/2023]
|
28
|
Baumgartel K, Zelazny J, Timcheck T, Snyder C, Bell M, Conley YP. Molecular genomic research designs. ANNUAL REVIEW OF NURSING RESEARCH 2012; 29:1-26. [PMID: 22891496 DOI: 10.1891/0739-6686.29.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Genetic and genomic research approaches have the capability to expand our understanding of the complex pathophysiology of disease susceptibility, susceptibility to complications related to disease, trajectory of recovery from acquired injuries and infections, patient response to interventions and therapeutics, as well as informing diagnoses and prognoses. Nurse scientists are actively involved in all of these fields of inquiry, and the goal of this chapter is to assist with incorporation of genetic and genomic trajectories into their research and facilitate the design and execution of these studies. New studies that are going to embark on recruitment, phenotyping, and sample collection will benefit from forethought about research design to ensure that it addresses the research questions or hypotheses being tested. Studies that will use existing data or samples will also benefit from forethought about research design for the same reason but will also address the fact that some designs may not be feasible with the available data or samples. This chapter discusses candidate gene association, genome-wide association, candidate gene expression, global gene expression, and epigenetic/epigenomic study designs. Information provided includes rationale for selecting an appropriate study design, important methodology considerations for each design, key technologies available to accomplish each type of study, and online resources available to assist in executing each type of study design.
Collapse
|
29
|
Huebert DJ, Gasch AP. Defining flexible vs. inherent promoter architectures: the importance of dynamics and environmental considerations. Nucleus 2012; 3:399-403. [PMID: 22751015 PMCID: PMC3474658 DOI: 10.4161/nucl.21172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The degree to which nucleosome positioning regulates transcription is an ongoing debate. To address this question, we recently followed dynamic changes in nucleosome occupancy, transcription factor binding and gene expression in yeast cells responding to oxidative stress. Integrating across these dynamic processes revealed new insights into the functions of nucleosome reorganization. Here, we used our data to address the extent to which upstream promoter architecture is a static feature inherent to specific genes vs. a dynamic platform that changes across conditions. Our results argue that, while some aspects of promoter architecture are fixed across environments, the level to which promoters are "open" or "covered" by nucleosomes depends on the conditions investigated.
Collapse
Affiliation(s)
- Dana J Huebert
- Program in Cellular and Molecular Biology; University of Wisconsin-Madison; Madison, WI USA
| | | |
Collapse
|
30
|
Phenotypic diversity and epigenomic variation – The utility of mass spectrometric analysis of DNA methylation. J Proteomics 2012; 75:3400-9. [DOI: 10.1016/j.jprot.2012.01.036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Revised: 01/09/2012] [Accepted: 01/30/2012] [Indexed: 01/10/2023]
|
31
|
Affiliation(s)
- Hanneke Vlaming
- Division of Gene Regulation & Netherlands Proteomics Center, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - Fred van Leeuwen
- Division of Gene Regulation & Netherlands Proteomics Center, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| |
Collapse
|
32
|
Tajbakhsh J. DNA methylation topology: potential of a chromatin landmark for epigenetic drug toxicology. Epigenomics 2011; 3:761-70. [PMID: 22126294 PMCID: PMC3250213 DOI: 10.2217/epi.11.101] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Targeting chromatin and its basic components through epigenetic drug therapy has become an increased focus in the treatment of complex diseases. This boost calls for the implementation of high-throughput cell-based assays that exploit the increasing knowledge about epigenetic mechanisms and their interventions for genotoxicity testing of epigenetic drugs. 3D quantitative DNA methylation imaging is a novel approach for detecting drug-induced DNA demethylation and concurrent heterochromatin decondensation/reorganization in cells through the analysis of differential nuclear distribution patterns of methylcytosine and gDNA visualized by fluorescence and processed by machine-learning algorithms. Utilizing 3D DNA methylation patterns is a powerful precursor to a series of fully automatable assays that employ chromatin structure and higher organization as novel pharmacodynamic biomarkers for various epigenetic drug actions.
Collapse
Affiliation(s)
- Jian Tajbakhsh
- Chromatin Biology Laboratory, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.
| |
Collapse
|
33
|
Dynamic nucleosome-depleted regions at androgen receptor enhancers in the absence of ligand in prostate cancer cells. Mol Cell Biol 2011; 31:4648-62. [PMID: 21969603 DOI: 10.1128/mcb.05934-11] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nucleosome positioning at transcription start sites is known to regulate gene expression by altering DNA accessibility to transcription factors; however, its role at enhancers is poorly understood. We investigated nucleosome positioning at the androgen receptor (AR) enhancers of TMPRSS2, KLK2, and KLK3/PSA in prostate cancer cells. Surprisingly, a population of enhancer modules in androgen-deprived cultures showed nucleosome-depleted regions (NDRs) in all three loci. Under androgen-deprived conditions, NDRs at the TMPRSS2 enhancer were maintained by the pioneer AR transcriptional collaborator GATA-2. Androgen treatment resulted in AR occupancy, an increased number of enhancer modules with NDRs without changes in footprint width, increased levels of histone H3 acetylation (AcH3), and dimethylation (H3K4me2) at nucleosomes flanking the NDRs. Our data suggest that, in the absence of ligand, AR enhancers exist in an equilibrium in which a percentage of modules are occupied by nucleosomes while others display NDRs. We propose that androgen treatment leads to the disruption of the equilibrium toward a nucleosome-depleted state, rather than to enhancer de novo "remodeling." This allows the recruitment of histone modifiers, chromatin remodelers, and ultimately gene activation. The "receptive" state described here could help explain AR signaling activation under very low ligand concentrations.
Collapse
|
34
|
Verzijlbergen KF, van Welsem T, Sie D, Lenstra TL, Turner DJ, Holstege FCP, Kerkhoven RM, van Leeuwen F. A barcode screen for epigenetic regulators reveals a role for the NuB4/HAT-B histone acetyltransferase complex in histone turnover. PLoS Genet 2011; 7:e1002284. [PMID: 21998594 PMCID: PMC3188528 DOI: 10.1371/journal.pgen.1002284] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Accepted: 07/29/2011] [Indexed: 11/18/2022] Open
Abstract
Dynamic modification of histone proteins plays a key role in regulating gene expression. However, histones themselves can also be dynamic, which potentially affects the stability of histone modifications. To determine the molecular mechanisms of histone turnover, we developed a parallel screening method for epigenetic regulators by analyzing chromatin states on DNA barcodes. Histone turnover was quantified by employing a genetic pulse-chase technique called RITE, which was combined with chromatin immunoprecipitation and high-throughput sequencing. In this screen, the NuB4/HAT-B complex, containing the conserved type B histone acetyltransferase Hat1, was found to promote histone turnover. Unexpectedly, the three members of this complex could be functionally separated from each other as well as from the known interacting factor and histone chaperone Asf1. Thus, systematic and direct interrogation of chromatin structure on DNA barcodes can lead to the discovery of genes and pathways involved in chromatin modification and dynamics.
Collapse
Affiliation(s)
| | - Tibor van Welsem
- Department of Gene Regulation, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Daoud Sie
- Genome Center, Netherlands Cancer Institute, Amsterdam, The Netherlands
- Netherlands Proteomics Center, Amsterdam, The Netherlands
| | - Tineke L. Lenstra
- Department of Molecular Cancer Research, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Daniel J. Turner
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, United Kingdom
| | - Frank C. P. Holstege
- Department of Molecular Cancer Research, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Ron M. Kerkhoven
- Genome Center, Netherlands Cancer Institute, Amsterdam, The Netherlands
- Netherlands Proteomics Center, Amsterdam, The Netherlands
| | - Fred van Leeuwen
- Department of Gene Regulation, Netherlands Cancer Institute, Amsterdam, The Netherlands
| |
Collapse
|
35
|
Iyer BV, Kenward M, Arya G. Hierarchies in eukaryotic genome organization: Insights from polymer theory and simulations. BMC BIOPHYSICS 2011; 4:8. [PMID: 21595865 PMCID: PMC3102647 DOI: 10.1186/2046-1682-4-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Accepted: 04/15/2011] [Indexed: 12/11/2022]
Abstract
Eukaryotic genomes possess an elaborate and dynamic higher-order structure within the limiting confines of the cell nucleus. Knowledge of the physical principles and the molecular machinery that govern the 3D organization of this structure and its regulation are key to understanding the relationship between genome structure and function. Elegant microscopy and chromosome conformation capture techniques supported by analysis based on polymer models are important steps in this direction. Here, we review results from these efforts and provide some additional insights that elucidate the relationship between structure and function at different hierarchical levels of genome organization.
Collapse
Affiliation(s)
- Balaji Vs Iyer
- Department of NanoEngineering, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0448, USA.
| | | | | |
Collapse
|