1
|
Brown JL, Zhang L, Rocha PP, Kassis JA, Sun MA. Polycomb protein binding and looping in the ON transcriptional state. SCIENCE ADVANCES 2024; 10:eadn1837. [PMID: 38657072 PMCID: PMC11042752 DOI: 10.1126/sciadv.adn1837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 03/22/2024] [Indexed: 04/26/2024]
Abstract
Polycomb group (PcG) proteins mediate epigenetic silencing of important developmental genes by modifying histones and compacting chromatin through two major protein complexes, PRC1 and PRC2. These complexes are recruited to DNA by CpG islands (CGIs) in mammals and Polycomb response elements (PREs) in Drosophila. When PcG target genes are turned OFF, PcG proteins bind to PREs or CGIs, and PREs serve as anchors that loop together and stabilize gene silencing. Here, we address which PcG proteins bind to PREs and whether PREs mediate looping when their targets are in the ON transcriptional state. While the binding of most PcG proteins decreases at PREs in the ON state, one PRC1 component, Ph, remains bound. Further, PREs can loop to each other and with presumptive enhancers in the ON state and, like CGIs, may act as tethering elements between promoters and enhancers. Overall, our data suggest that PREs are important looping elements for developmental loci in both the ON and OFF states.
Collapse
Affiliation(s)
- J. Lesley Brown
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Liangliang Zhang
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, China
| | - Pedro P. Rocha
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
- National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Judith A. Kassis
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ming-an Sun
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, Jiangsu, China
| |
Collapse
|
2
|
Gao Z, Wang M, Smith A, Boyes J. YY1 Binding to Regulatory Elements That Lack Enhancer Activity Promotes Locus Folding and Gene Activation. J Mol Biol 2023; 435:168315. [PMID: 37858706 DOI: 10.1016/j.jmb.2023.168315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 09/25/2023] [Accepted: 10/12/2023] [Indexed: 10/21/2023]
Abstract
Enhancers activate their cognate promoters over huge distances but how enhancer/promoter interactions become established is not completely understood. There is strong evidence that cohesin-mediated loop extrusion is involved but this does not appear to be a universal mechanism. Here, we identify an element within the mouse immunoglobulin lambda (Igλ) light chain locus, HSCλ1, that has characteristics of active regulatory elements but lacks intrinsic enhancer or promoter activity. Remarkably, knock-out of the YY1 binding site from HSCλ1 reduces Igλ transcription significantly and disrupts enhancer/promoter interactions, even though these elements are >10 kb from HSCλ1. Genome-wide analyses of mouse embryonic stem cells identified 2671 similar YY1-bound, putative genome organizing elements that lie within CTCF/cohesin loop boundaries but that lack intrinsic enhancer activity. We suggest that such elements play a fundamental role in locus folding and in facilitating enhancer/promoter interactions.
Collapse
Affiliation(s)
- Zeqian Gao
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Miao Wang
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Alastair Smith
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Joan Boyes
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.
| |
Collapse
|
3
|
Brown JL, Zhang L, Rocha PP, Kassis JA, Sun MA. Polycomb protein binding and looping mediated by Polycomb Response Elements in the ON transcriptional state. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.02.565256. [PMID: 38076900 PMCID: PMC10705551 DOI: 10.1101/2023.11.02.565256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
Polycomb group proteins (PcG) mediate epigenetic silencing of important developmental genes and other targets. In Drosophila, canonical PcG-target genes contain Polycomb Response Elements (PREs) that recruit PcG protein complexes including PRC2 that trimethylates H3K27 forming large H3K27me3 domains. In the OFF transcriptional state, PREs loop with each other and this looping strengthens silencing. Here we address the question of what PcG proteins bind to PREs when canonical PcG target genes are expressed, and whether PREs loop when these genes are ON. Our data show that the answer to this question is PRE-specific but general conclusions can be made. First, within a PcG-target gene, some regulatory DNA can remain covered with H3K27me3 and PcG proteins remain bound to PREs in these regions. Second, when PREs are within H3K27ac domains, PcG-binding decreases, however, this depends on the protein and PRE. The DNA binding protein GAF, and the PcG protein Ph remain at PREs even when other PcG proteins are greatly depleted. In the ON state, PREs can still loop with each other, but also form loops with presumptive enhancers. These data support the model that, in addition to their role in PcG silencing, PREs can act as "promoter-tethering elements" mediating interactions between promoter proximal PREs and distant enhancers.
Collapse
Affiliation(s)
- J. Lesley Brown
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Liangliang Zhang
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, China
| | - Pedro P Rocha
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
- National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Judith A. Kassis
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ming-an Sun
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Important Animal Infectious Diseases and Zoonoses of Jiangsu Higher Education Institutions, Yangzhou, Jiangsu, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, Jiangsu, China
| |
Collapse
|
4
|
Sun L, Dong X, Song X. PtrABR1 Increases Tolerance to Drought Stress by Enhancing Lateral Root Formation in Populus trichocarpa. Int J Mol Sci 2023; 24:13748. [PMID: 37762051 PMCID: PMC10530772 DOI: 10.3390/ijms241813748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Revised: 08/31/2023] [Accepted: 09/04/2023] [Indexed: 09/29/2023] Open
Abstract
Roots are the main organ for water uptake and the earliest part of a plant's response to drought, making them of great importance to our understanding of the root system's response to drought. However, little is known about the underlying molecular mechanisms that control root responses to drought stress. Here, we identified and functionally characterized the AP2/ERF family transcription factor (TF) PtrABR1 and the upstream target gene zinc-finger protein TF PtrYY1, which respond to drought stress by promoting the growth and development of lateral roots in Populus trichocarpa. A root-specific induction of PtrABR1 under drought stress was explored. The overexpression of PtrABR1 (PtrABR1-OE) promoted root growth and development, thereby increasing tolerance to drought stress. In addition, PtrYY1 is directly bound to the promoter of PtrABR1 under drought stress, and the overexpression of PtrYY1 (PtrYY1-OE) promoted lateral root growth and development and increased tolerance to drought stress. An RNA-seq analysis of PtrABR1-OE with wild-type (WT) poplar identified PtrGH3.6 and PtrPP2C44, which share the same pattern of expression changes as PtrABR1. A qRT-PCR and cis-element analysis further suggested that PtrGH3.6 and PtrPP2C44 may act as potential downstream targets of PtrABR1 genes in the root response pathway to drought stress. In conclusion, these results reveal a novel drought regulatory pathway in which PtrABR1 regulates the network through the upstream target gene PtrYY1 and the potential downstream target genes PtrGH3.6 and PtrPP2C44, thereby promoting root growth and development and improving tolerance to drought stress.
Collapse
Affiliation(s)
- Lijiao Sun
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China; (L.S.); (X.D.)
- College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Xinxin Dong
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China; (L.S.); (X.D.)
- College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Xingshun Song
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040, China; (L.S.); (X.D.)
- College of Life Science, Northeast Forestry University, Harbin 150040, China
| |
Collapse
|
5
|
Brown JL, Price JD, Erokhin M, Kassis JA. Context-dependent role of Pho binding sites in Polycomb complex recruitment in Drosophila. Genetics 2023; 224:iyad096. [PMID: 37216193 PMCID: PMC10411561 DOI: 10.1093/genetics/iyad096] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 05/05/2023] [Accepted: 05/11/2023] [Indexed: 05/24/2023] Open
Abstract
Polycomb group (PcG) proteins maintain the silenced state of key developmental genes, but how these proteins are recruited to specific regions of the genome is still not completely understood. In Drosophila, PcG proteins are recruited to Polycomb response elements (PREs) comprised of a flexible array of sites for sequence-specific DNA binding proteins, "PcG recruiters," including Pho, Spps, Cg, and GAF. Pho is thought to play a central role in PcG recruitment. Early data showed that mutation of Pho binding sites in PREs in transgenes abrogated the ability of those PREs to repress gene expression. In contrast, genome-wide experiments in pho mutants or by Pho knockdown showed that PcG proteins can bind to PREs in the absence of Pho. Here, we directly addressed the importance of Pho binding sites in 2 engrailed (en) PREs at the endogenous locus and in transgenes. Our results show that Pho binding sites are required for PRE activity in transgenes with a single PRE. In a transgene, 2 PREs together lead to stronger, more stable repression and confer some resistance to the loss of Pho binding sites. Making the same mutation in Pho binding sites has little effect on PcG-protein binding at the endogenous en gene. Overall, our data support the model that Pho is important for PcG binding but emphasize how multiple PREs and chromatin environment increase the ability of PREs to function in the absence of Pho. This supports the view that multiple mechanisms contribute to PcG recruitment in Drosophila.
Collapse
Affiliation(s)
- Janet Lesley Brown
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Joshua D Price
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Maksim Erokhin
- Group of Chromatin Biology, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow 119334, Russia
| | - Judith A Kassis
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| |
Collapse
|
6
|
Noguera NI, Travaglini S, Scalea S, Catalanotto C, Reale A, Zampieri M, Zaza A, Ricciardi MR, Angelini DF, Tafuri A, Ottone T, Voso MT, Zardo G. YY1 Knockdown Relieves the Differentiation Block and Restores Apoptosis in AML Cells. Cancers (Basel) 2023; 15:4010. [PMID: 37568827 PMCID: PMC10417667 DOI: 10.3390/cancers15154010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 08/01/2023] [Accepted: 08/02/2023] [Indexed: 08/13/2023] Open
Abstract
In this study we analyzed the expression of Yin and Yang 1 protein (YY1), a member of the noncanonical PcG complexes, in AML patient samples and AML cell lines and the effect of YY1 downregulation on the AML differentiation block. Our results show that YY1 is significantly overexpressed in AML patient samples and AML cell lines and that YY1 knockdown relieves the differentiation block. YY1 downregulation in two AML cell lines (HL-60 and OCI-AML3) and one AML patient sample restored the expression of members of the CEBP protein family, increased the expression of extrinsic growth factors/receptors and surface antigenic markers, induced morphological cell characteristics typical of myeloid differentiation, and sensitized cells to retinoic acid treatment and to apoptosis. Overall, our data show that YY1 is not a secondary regulator of myeloid differentiation but that, if overexpressed, it can play a predominant role in myeloid differentiation block.
Collapse
Affiliation(s)
- Nelida Ines Noguera
- Department of Biomedicine and Prevention, Tor Vergata University, 00133 Rome, Italy; (S.T.); (T.O.); (M.T.V.)
- Unit of Neuro-Oncoematologia, Santa Lucia Foundation IRCCS, 00143 Rome, Italy
| | - Serena Travaglini
- Department of Biomedicine and Prevention, Tor Vergata University, 00133 Rome, Italy; (S.T.); (T.O.); (M.T.V.)
- Unit of Neuro-Oncoematologia, Santa Lucia Foundation IRCCS, 00143 Rome, Italy
| | - Stefania Scalea
- Department of Experimental Medicine, Sapienza University, 00185 Rome, Italy;
| | - Caterina Catalanotto
- Department of Molecular Medicine, Sapienza University, 00185 Rome, Italy; (C.C.); (A.R.); (M.Z.)
| | - Anna Reale
- Department of Molecular Medicine, Sapienza University, 00185 Rome, Italy; (C.C.); (A.R.); (M.Z.)
| | - Michele Zampieri
- Department of Molecular Medicine, Sapienza University, 00185 Rome, Italy; (C.C.); (A.R.); (M.Z.)
| | - Alessandra Zaza
- Unit of Neuro-Oncoematologia, Santa Lucia Foundation IRCCS, 00143 Rome, Italy
- Department of Medical and Surgical Sciences and Biotechnologies, Sapienza University, 00185 Rome, Italy
| | - Maria Rosaria Ricciardi
- Department of Clinical and Molecular Medicine, Sapienza University, 00185 Rome, Italy; (M.R.R.); (A.T.)
| | | | - Agostino Tafuri
- Department of Clinical and Molecular Medicine, Sapienza University, 00185 Rome, Italy; (M.R.R.); (A.T.)
| | - Tiziana Ottone
- Department of Biomedicine and Prevention, Tor Vergata University, 00133 Rome, Italy; (S.T.); (T.O.); (M.T.V.)
- Unit of Neuro-Oncoematologia, Santa Lucia Foundation IRCCS, 00143 Rome, Italy
| | - Maria Teresa Voso
- Department of Biomedicine and Prevention, Tor Vergata University, 00133 Rome, Italy; (S.T.); (T.O.); (M.T.V.)
- Unit of Neuro-Oncoematologia, Santa Lucia Foundation IRCCS, 00143 Rome, Italy
| | - Giuseppe Zardo
- Department of Experimental Medicine, Sapienza University, 00185 Rome, Italy;
| |
Collapse
|
7
|
Erokhin M, Mogila V, Lomaev D, Chetverina D. Polycomb Recruiters Inside and Outside of the Repressed Domains. Int J Mol Sci 2023; 24:11394. [PMID: 37511153 PMCID: PMC10379775 DOI: 10.3390/ijms241411394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 06/24/2023] [Accepted: 07/11/2023] [Indexed: 07/30/2023] Open
Abstract
The establishment and stable inheritance of individual patterns of gene expression in different cell types are required for the development of multicellular organisms. The important epigenetic regulators are the Polycomb group (PcG) and Trithorax group (TrxG) proteins, which control the silenced and active states of genes, respectively. In Drosophila, the PcG/TrxG group proteins are recruited to the DNA regulatory sequences termed the Polycomb response elements (PREs). The PREs are composed of the binding sites for different DNA-binding proteins, the so-called PcG recruiters. Currently, the role of the PcG recruiters in the targeting of the PcG proteins to PREs is well documented. However, there are examples where the PcG recruiters are also implicated in the active transcription and in the TrxG function. In addition, there is increasing evidence that the genome-wide PcG recruiters interact with the chromatin outside of the PREs and overlap with the proteins of differing regulatory classes. Recent studies of the interactomes of the PcG recruiters significantly expanded our understanding that they have numerous interactors besides the PcG proteins and that their functions extend beyond the regulation of the PRE repressive activity. Here, we summarize current data about the functions of the PcG recruiters.
Collapse
Affiliation(s)
- Maksim Erokhin
- Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow 119334, Russia
| | - Vladic Mogila
- Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow 119334, Russia
| | - Dmitry Lomaev
- Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow 119334, Russia
| | - Darya Chetverina
- Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow 119334, Russia
| |
Collapse
|
8
|
Erokhin M, Brown JL, Lomaev D, Vorobyeva NE, Zhang L, Fab L, Mazina M, Kulakovskiy I, Ziganshin R, Schedl P, Georgiev P, Sun MA, Kassis J, Chetverina D. Crol contributes to PRE-mediated repression and Polycomb group proteins recruitment in Drosophila. Nucleic Acids Res 2023; 51:6087-6100. [PMID: 37140047 PMCID: PMC10325914 DOI: 10.1093/nar/gkad336] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 04/20/2023] [Indexed: 05/05/2023] Open
Abstract
The Polycomb group (PcG) proteins are fundamental epigenetic regulators that control the repressive state of target genes in multicellular organisms. One of the open questions is defining the mechanisms of PcG recruitment to chromatin. In Drosophila, the crucial role in PcG recruitment is thought to belong to DNA-binding proteins associated with Polycomb response elements (PREs). However, current data suggests that not all PRE-binding factors have been identified. Here, we report the identification of the transcription factor Crooked legs (Crol) as a novel PcG recruiter. Crol is a C2H2-type Zinc Finger protein that directly binds to poly(G)-rich DNA sequences. Mutation of Crol binding sites as well as crol CRISPR/Cas9 knockout diminish the repressive activity of PREs in transgenes. Like other PRE-DNA binding proteins, Crol co-localizes with PcG proteins inside and outside of H3K27me3 domains. Crol knockout impairs the recruitment of the PRC1 subunit Polyhomeotic and the PRE-binding protein Combgap at a subset of sites. The decreased binding of PcG proteins is accompanied by dysregulated transcription of target genes. Overall, our study identified Crol as a new important player in PcG recruitment and epigenetic regulation.
Collapse
Affiliation(s)
- Maksim Erokhin
- Group of Chromatin Biology, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow 119334, Russia
| | - J Lesley Brown
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Dmitry Lomaev
- Group of Epigenetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow 119334, Russia
| | - Nadezhda E Vorobyeva
- Group of transcriptional complexes dynamics, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Liangliang Zhang
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, China
| | - Lika V Fab
- Group of Chromatin Biology, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow 119334, Russia
| | - Marina Yu Mazina
- Group of hormone-dependent transcription regulation, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Ivan V Kulakovskiy
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow119991, Russia
| | - Rustam H Ziganshin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia
| | - Paul Schedl
- Department of Molecular Biology Princeton University, Princeton, NJ 08544, USA
| | - Pavel Georgiev
- Department of Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow 119334, Russia
| | - Ming-an Sun
- Institute of Comparative Medicine, College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, China
| | - Judith A Kassis
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Darya Chetverina
- Group of Epigenetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow 119334, Russia
| |
Collapse
|
9
|
Poliacikova G, Barthez M, Rival T, Aouane A, Luis NM, Richard F, Daian F, Brouilly N, Schnorrer F, Maurel-Zaffran C, Graba Y, Saurin AJ. M1BP is an essential transcriptional activator of oxidative metabolism during Drosophila development. Nat Commun 2023; 14:3187. [PMID: 37268614 DOI: 10.1038/s41467-023-38986-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 05/23/2023] [Indexed: 06/04/2023] Open
Abstract
Oxidative metabolism is the predominant energy source for aerobic muscle contraction in adult animals. How the cellular and molecular components that support aerobic muscle physiology are put in place during development through their transcriptional regulation is not well understood. Using the Drosophila flight muscle model, we show that the formation of mitochondria cristae harbouring the respiratory chain is concomitant with a large-scale transcriptional upregulation of genes linked with oxidative phosphorylation (OXPHOS) during specific stages of flight muscle development. We further demonstrate using high-resolution imaging, transcriptomic and biochemical analyses that Motif-1-binding protein (M1BP) transcriptionally regulates the expression of genes encoding critical components for OXPHOS complex assembly and integrity. In the absence of M1BP function, the quantity of assembled mitochondrial respiratory complexes is reduced and OXPHOS proteins aggregate in the mitochondrial matrix, triggering a strong protein quality control response. This results in isolation of the aggregate from the rest of the matrix by multiple layers of the inner mitochondrial membrane, representing a previously undocumented mitochondrial stress response mechanism. Together, this study provides mechanistic insight into the transcriptional regulation of oxidative metabolism during Drosophila development and identifies M1BP as a critical player in this process.
Collapse
Affiliation(s)
- Gabriela Poliacikova
- Aix-Marseille Univ, CNRS, Developmental Biology Institute of Marseille (IBDM), UMR 7288, Case 907, Turing Center for Living Systems, Parc Scientifique de Luminy, 13288, Marseille Cedex 09, France
| | - Marine Barthez
- Aix-Marseille Univ, CNRS, Developmental Biology Institute of Marseille (IBDM), UMR 7288, Case 907, Turing Center for Living Systems, Parc Scientifique de Luminy, 13288, Marseille Cedex 09, France
| | - Thomas Rival
- Aix-Marseille Univ, CNRS, Developmental Biology Institute of Marseille (IBDM), UMR 7288, Case 907, Turing Center for Living Systems, Parc Scientifique de Luminy, 13288, Marseille Cedex 09, France
| | - Aïcha Aouane
- Aix-Marseille Univ, CNRS, Developmental Biology Institute of Marseille (IBDM), UMR 7288, Case 907, Turing Center for Living Systems, Parc Scientifique de Luminy, 13288, Marseille Cedex 09, France
| | - Nuno Miguel Luis
- Aix-Marseille Univ, CNRS, Developmental Biology Institute of Marseille (IBDM), UMR 7288, Case 907, Turing Center for Living Systems, Parc Scientifique de Luminy, 13288, Marseille Cedex 09, France
| | - Fabrice Richard
- Aix-Marseille Univ, CNRS, Developmental Biology Institute of Marseille (IBDM), UMR 7288, Case 907, Turing Center for Living Systems, Parc Scientifique de Luminy, 13288, Marseille Cedex 09, France
| | - Fabrice Daian
- Aix-Marseille Univ, CNRS, Developmental Biology Institute of Marseille (IBDM), UMR 7288, Case 907, Turing Center for Living Systems, Parc Scientifique de Luminy, 13288, Marseille Cedex 09, France
| | - Nicolas Brouilly
- Aix-Marseille Univ, CNRS, Developmental Biology Institute of Marseille (IBDM), UMR 7288, Case 907, Turing Center for Living Systems, Parc Scientifique de Luminy, 13288, Marseille Cedex 09, France
| | - Frank Schnorrer
- Aix-Marseille Univ, CNRS, Developmental Biology Institute of Marseille (IBDM), UMR 7288, Case 907, Turing Center for Living Systems, Parc Scientifique de Luminy, 13288, Marseille Cedex 09, France
| | - Corinne Maurel-Zaffran
- Aix-Marseille Univ, CNRS, Developmental Biology Institute of Marseille (IBDM), UMR 7288, Case 907, Turing Center for Living Systems, Parc Scientifique de Luminy, 13288, Marseille Cedex 09, France
| | - Yacine Graba
- Aix-Marseille Univ, CNRS, Developmental Biology Institute of Marseille (IBDM), UMR 7288, Case 907, Turing Center for Living Systems, Parc Scientifique de Luminy, 13288, Marseille Cedex 09, France
| | - Andrew J Saurin
- Aix-Marseille Univ, CNRS, Developmental Biology Institute of Marseille (IBDM), UMR 7288, Case 907, Turing Center for Living Systems, Parc Scientifique de Luminy, 13288, Marseille Cedex 09, France.
| |
Collapse
|
10
|
Liu X, Xing Q, Liu X, Müller-Xing R. Expression of the Populus Orthologues of AtYY1, YIN and YANG Activates the Floral Identity Genes AGAMOUS and SEPALLATA3 Accelerating Floral Transition in Arabidopsis thaliana. Int J Mol Sci 2023; 24:ijms24087639. [PMID: 37108801 PMCID: PMC10146089 DOI: 10.3390/ijms24087639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 04/06/2023] [Accepted: 04/10/2023] [Indexed: 04/29/2023] Open
Abstract
YIN YANG 1 (YY1) encodes a dual-function transcription factor, evolutionary conserved between the animal and plant kingdom. In Arabidopsis thaliana, AtYY1 is a negative regulator of ABA responses and floral transition. Here, we report the cloning and functional characterization of the two AtYY1 paralogs, YIN and YANG (also named PtYY1a and PtYY1b) from Populus (Populus trichocarpa). Although the duplication of YY1 occurred early during the evolution of the Salicaceae, YIN and YANG are highly conserved in the willow tree family. In the majority of Populus tissues, YIN was more strongly expressed than YANG. Subcellular analysis showed that YIN-GFP and YANG-GFP are mainly localized in the nuclei of Arabidopsis. Stable and constitutive expression of YIN and YANG resulted in curled leaves and accelerated floral transition of Arabidopsis plants, which was accompanied by high expression of the floral identity genes AGAMOUS (AG) and SEPELLATA3 (SEP3) known to promote leaf curling and early flowering. Furthermore, the expression of YIN and YANG had similar effects as AtYY1 overexpression to seed germination and root growth in Arabidopsis. Our results suggest that YIN and YANG are functional orthologues of the dual-function transcription factor AtYY1 with similar roles in plant development conserved between Arabidopsis and Populus.
Collapse
Affiliation(s)
- Xinying Liu
- Institute of Genetics, College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Qian Xing
- Lushan Botanical Garden, Chinese Academy of Sciences (CAS), Jiujiang 332900, China
| | - Xuemei Liu
- Institute of Genetics, College of Life Science, Northeast Forestry University, Harbin 150040, China
| | - Ralf Müller-Xing
- Lushan Botanical Garden, Chinese Academy of Sciences (CAS), Jiujiang 332900, China
| |
Collapse
|
11
|
Shirahama Y, Yamamoto K. The E2F6 Transcription Factor is Associated with the Mammalian SUZ12-Containing Polycomb Complex. Kurume Med J 2023; 67:171-183. [PMID: 36464274 DOI: 10.2739/kurumemedj.ms674006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
The Polycomb group protein (PcG) SUZ12 forms Polycomb repressive complexes together with histone methyltransferase EZH2. Although the complexes have been demonstrated to be involved in epigenetic maintenance of gene expression in a transcriptional repressive state, it is unclear how they are recruited to the target genes. Here we report that SUZ12 directly interacts with site-specific transcriptional repressor E2F6 and forms a complex together with EZH2. SUZ12 interacts with E2F6 selectively among the E2F family proteins and E2F6- containing SUZ12-EZH2 complex was biochemically purified from HEK293 cells stably expressing Flag-tagged SUZ12. Chromatin immunoprecipitation assays revealed the target genes of the E2F6-SUZ12-EZH2 complex. Contrary to expectation, the promoter regions of these genes are not or only weakly tri-methylated at histone H3-K27, and their expression is down-regulated by depletion of EZH2. Given that the transactivation function of SUZ12-EZH2 has been previously reported, the inhibitory effect on E2F6-mediated transcriptional repression by physical interaction can be considered a candidate mechanism of gene activation by these PcGs.
Collapse
Affiliation(s)
- Yuko Shirahama
- Department of Medical Biochemistry, Kurume University School of Medicine
| | - Ken Yamamoto
- Department of Medical Biochemistry, Kurume University School of Medicine
| |
Collapse
|
12
|
Regulation of Polyhomeotic Condensates by Intrinsically Disordered Sequences That Affect Chromatin Binding. EPIGENOMES 2022; 6:epigenomes6040040. [PMID: 36412795 PMCID: PMC9680516 DOI: 10.3390/epigenomes6040040] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 10/30/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022] Open
Abstract
The Polycomb group (PcG) complex PRC1 localizes in the nucleus in condensed structures called Polycomb bodies. The PRC1 subunit Polyhomeotic (Ph) contains an oligomerizing sterile alpha motif (SAM) that is implicated in both PcG body formation and chromatin organization in Drosophila and mammalian cells. A truncated version of Ph containing the SAM (mini-Ph) forms phase-separated condensates with DNA or chromatin in vitro, suggesting that PcG bodies may form through SAM-driven phase separation. In cells, Ph forms multiple small condensates, while mini-Ph typically forms a single large nuclear condensate. We therefore hypothesized that sequences outside of mini-Ph, which are predicted to be intrinsically disordered, are required for proper condensate formation. We identified three distinct low-complexity regions in Ph based on sequence composition. We systematically tested the role of each of these sequences in Ph condensates using live imaging of transfected Drosophila S2 cells. Each sequence uniquely affected Ph SAM-dependent condensate size, number, and morphology, but the most dramatic effects occurred when the central, glutamine-rich intrinsically disordered region (IDR) was removed, which resulted in large Ph condensates. Like mini-Ph condensates, condensates lacking the glutamine-rich IDR excluded chromatin. Chromatin fractionation experiments indicated that the removal of the glutamine-rich IDR reduced chromatin binding and that the removal of either of the other IDRs increased chromatin binding. Our data suggest that all three IDRs, and functional interactions among them, regulate Ph condensate size and number. Our results can be explained by a model in which tight chromatin binding by Ph IDRs antagonizes Ph SAM-driven phase separation. Our observations highlight the complexity of regulation of biological condensates housed in single proteins.
Collapse
|
13
|
Onyango SA, Ochwedo KO, Machani MG, Olumeh JO, Debrah I, Omondi CJ, Ogolla SO, Lee MC, Zhou G, Kokwaro E, Kazura JW, Afrane YA, Githeko AK, Zhong D, Yan G. Molecular characterization and genotype distribution of thioester-containing protein 1 gene in Anopheles gambiae mosquitoes in western Kenya. Malar J 2022; 21:235. [PMID: 35948910 PMCID: PMC9364548 DOI: 10.1186/s12936-022-04256-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 08/03/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Evolutionary pressures lead to the selection of efficient malaria vectors either resistant or susceptible to Plasmodium parasites. These forces may favour the introduction of species genotypes that adapt to new breeding habitats, potentially having an impact on malaria transmission. Thioester-containing protein 1 (TEP1) of Anopheles gambiae complex plays an important role in innate immune defenses against parasites. This study aims to characterize the distribution pattern of TEP1 polymorphisms among populations of An. gambiae sensu lato (s.l.) in western Kenya. METHODS Anopheles gambiae adult and larvae were collected using pyrethrum spray catches (PSC) and plastic dippers respectively from Homa Bay, Kakamega, Bungoma, and Kisumu counties between 2017 and 2020. Collected adults and larvae reared to the adult stage were morphologically identified and then identified to sibling species by PCR. TEP1 alleles were determined in 627 anopheles mosquitoes using restriction fragment length polymorphisms-polymerase chain reaction (RFLP-PCR) and to validate the TEP1 genotyping results, a representative sample of the alleles was sequenced. RESULTS Two TEP1 alleles (TEP1*S1 and TEP1*R2) and three corresponding genotypes (*S1/S1, *R2/S1, and *R2/R2) were identified. TEP1*S1 and TEP1*R2 with their corresponding genotypes, homozygous *S1/S1 and heterozygous *R2/S1 were widely distributed across all sites with allele frequencies of approximately 80% and 20%, respectively both in Anopheles gambiae and Anopheles arabiensis. There was no significant difference detected among the populations and between the two mosquito species in TEP1 allele frequency and genotype frequency. The overall low levels in population structure (FST = 0.019) across all sites corresponded to an effective migration index (Nm = 12.571) and low Nei's genetic distance values (< 0.500) among the subpopulation. The comparative fixation index values revealed minimal genetic differentiation between species and high levels of gene flow among populations. CONCLUSION Genotyping TEP1 has identified two common TEP1 alleles (TEP1*S1 and TEP1*R2) and three corresponding genotypes (*S1/S1, *R2/S1, and *R2/R2) in An. gambiae s.l. The TEP1 allele genetic diversity and population structure are low in western Kenya.
Collapse
Affiliation(s)
- Shirley A Onyango
- Department of Zoological Sciences, School of Science and Technology, Kenyatta University, Nairobi, Kenya.,Sub-Saharan Africa International Centre of Excellence for Malaria Research, Homa bay, Kenya
| | - Kevin O Ochwedo
- Sub-Saharan Africa International Centre of Excellence for Malaria Research, Homa bay, Kenya.,Department of Biology, Faculty of Science and Technology, University of Nairobi, Nairobi, Kenya
| | - Maxwell G Machani
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Julius O Olumeh
- Sub-Saharan Africa International Centre of Excellence for Malaria Research, Homa bay, Kenya
| | - Isaiah Debrah
- Sub-Saharan Africa International Centre of Excellence for Malaria Research, Homa bay, Kenya.,Department of Biochemistry, Cell and Molecular Biology, West Africa Centre for Cell Biology of Infectious Pathogen, University of Ghana, Accra, Ghana
| | - Collince J Omondi
- Sub-Saharan Africa International Centre of Excellence for Malaria Research, Homa bay, Kenya.,Department of Biology, Faculty of Science and Technology, University of Nairobi, Nairobi, Kenya
| | | | - Ming-Chieh Lee
- Program in Public Health, College of Health Sciences, University of California at Irvine, Irvine, CA, 92697, USA
| | - Guofa Zhou
- Program in Public Health, College of Health Sciences, University of California at Irvine, Irvine, CA, 92697, USA
| | - Elizabeth Kokwaro
- Department of Zoological Sciences, School of Science and Technology, Kenyatta University, Nairobi, Kenya
| | - James W Kazura
- Center for Global Health and Diseases, Case Western Reserve University, LC 4983, Cleveland, OH, 44106, USA
| | - Yaw A Afrane
- Department of Medical Microbiology, Medical School, University of Ghana, University of Ghana, Accra, Ghana
| | - Andrew K Githeko
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Daibin Zhong
- Program in Public Health, College of Health Sciences, University of California at Irvine, Irvine, CA, 92697, USA.
| | - Guiyun Yan
- Program in Public Health, College of Health Sciences, University of California at Irvine, Irvine, CA, 92697, USA.
| |
Collapse
|
14
|
Chetverina D, Vorobyeva NE, Mazina MY, Fab LV, Lomaev D, Golovnina A, Mogila V, Georgiev P, Ziganshin RH, Erokhin M. Comparative interactome analysis of the PRE DNA-binding factors: purification of the Combgap-, Zeste-, Psq-, and Adf1-associated proteins. Cell Mol Life Sci 2022; 79:353. [PMID: 35676368 PMCID: PMC11072172 DOI: 10.1007/s00018-022-04383-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 04/14/2022] [Accepted: 05/08/2022] [Indexed: 01/08/2023]
Abstract
The Polycomb group (PcG) and Trithorax group (TrxG) proteins are key epigenetic regulators controlling the silenced and active states of genes in multicellular organisms, respectively. In Drosophila, PcG/TrxG proteins are recruited to the chromatin via binding to specific DNA sequences termed polycomb response elements (PREs). While precise mechanisms of the PcG/TrxG protein recruitment remain unknown, the important role is suggested to belong to sequence-specific DNA-binding factors. At the same time, it was demonstrated that the PRE DNA-binding proteins are not exclusively localized to PREs but can bind other DNA regulatory elements, including enhancers, promoters, and boundaries. To gain an insight into the PRE DNA-binding protein regulatory network, here, using ChIP-seq and immuno-affinity purification coupled to the high-throughput mass spectrometry, we searched for differences in abundance of the Combgap, Zeste, Psq, and Adf1 PRE DNA-binding proteins. While there were no conspicuous differences in co-localization of these proteins with other functional transcription factors, we show that Combgap and Zeste are more tightly associated with the Polycomb repressive complex 1 (PRC1), while Psq interacts strongly with the TrxG proteins, including the BAP SWI/SNF complex. The Adf1 interactome contained Mediator subunits as the top interactors. In addition, Combgap efficiently interacted with AGO2, NELF, and TFIID. Combgap, Psq, and Adf1 have architectural proteins in their networks. We further investigated the existence of direct interactions between different PRE DNA-binding proteins and demonstrated that Combgap-Adf1, Psq-Dsp1, and Pho-Spps can interact in the yeast two-hybrid assay. Overall, our data suggest that Combgap, Psq, Zeste, and Adf1 are associated with the protein complexes implicated in different regulatory activities and indicate their potential multifunctional role in the regulation of transcription.
Collapse
Affiliation(s)
- Darya Chetverina
- Group of Epigenetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow, 119334, Russia.
| | - Nadezhda E Vorobyeva
- Group of Dynamics of Transcriptional Complexes, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Marina Yu Mazina
- Group of Hormone-Dependent Transcriptional Regulation, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Lika V Fab
- Group of Chromatin Biology, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow, 119334, Russia
| | - Dmitry Lomaev
- Group of Epigenetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow, 119334, Russia
| | - Alexandra Golovnina
- Group of Epigenetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow, 119334, Russia
| | - Vladic Mogila
- Department of Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow, 119334, Russia
| | - Pavel Georgiev
- Department of Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow, 119334, Russia
| | - Rustam H Ziganshin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia
| | - Maksim Erokhin
- Group of Chromatin Biology, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, Moscow, 119334, Russia.
| |
Collapse
|
15
|
Owen BM, Davidovich C. DNA binding by polycomb-group proteins: searching for the link to CpG islands. Nucleic Acids Res 2022; 50:4813-4839. [PMID: 35489059 PMCID: PMC9122586 DOI: 10.1093/nar/gkac290] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 03/25/2022] [Accepted: 04/25/2022] [Indexed: 11/13/2022] Open
Abstract
Polycomb group proteins predominantly exist in polycomb repressive complexes (PRCs) that cooperate to maintain the repressed state of thousands of cell-type-specific genes. Targeting PRCs to the correct sites in chromatin is essential for their function. However, the mechanisms by which PRCs are recruited to their target genes in mammals are multifactorial and complex. Here we review DNA binding by polycomb group proteins. There is strong evidence that the DNA-binding subunits of PRCs and their DNA-binding activities are required for chromatin binding and CpG targeting in cells. In vitro, CpG-specific binding was observed for truncated proteins externally to the context of their PRCs. Yet, the mere DNA sequence cannot fully explain the subset of CpG islands that are targeted by PRCs in any given cell type. At this time we find very little structural and biophysical evidence to support a model where sequence-specific DNA-binding activity is required or sufficient for the targeting of CpG-dinucleotide sequences by polycomb group proteins while they are within the context of their respective PRCs, either PRC1 or PRC2. We discuss the current knowledge and open questions on how the DNA-binding activities of polycomb group proteins facilitate the targeting of PRCs to chromatin.
Collapse
Affiliation(s)
- Brady M Owen
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, VIC, Australia
| | - Chen Davidovich
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, VIC, Australia.,EMBL-Australia, Clayton, VIC, Australia
| |
Collapse
|
16
|
Elizarev P, Finkl K, Müller J. Distinct requirements for Pho, Sfmbt, and Ino80 for cell survival in Drosophila. Genetics 2021; 219:6323657. [PMID: 34849913 PMCID: PMC8633127 DOI: 10.1093/genetics/iyab096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 06/09/2021] [Indexed: 11/25/2022] Open
Abstract
The Drosophila proteins Pleiohomeotic (Pho) and its paralog Pho-like (Phol) are the homologs of the mammalian transcription factor YY1. Pho and Phol are subunits of the Polycomb group protein complex PhoRC and they are also stably associated with the INO80 nucleosome remodeling complex. Drosophila lacking both Pho and Phol arrest development as larvae with small misshaped imaginal discs. The basis of this phenotype is poorly understood. We find that in pho phol mutant animals cells retain the capacity to proliferate but show a high incidence of apoptotic cell death that results in tissue hypoplasia. Clonal analyses establish that cells stringently require Pho and Phol to survive. In contrast, the PhoRC subunit Sfmbt and the ATP-dependent nucleosome remodeling factor Ino80 are not essential for cell viability. Pho and Phol, therefore, execute their critical role for cell survival through mechanisms that do not involve Sfmbt function or INO80 nucleosome remodeling.
Collapse
Affiliation(s)
- Pavel Elizarev
- Laboratory of Chromatin Biology, Max-Planck Institute of Biochemistry, Martinsried 82152, Germany
| | - Katja Finkl
- Laboratory of Chromatin Biology, Max-Planck Institute of Biochemistry, Martinsried 82152, Germany
| | - Jürg Müller
- Laboratory of Chromatin Biology, Max-Planck Institute of Biochemistry, Martinsried 82152, Germany
| |
Collapse
|
17
|
Erokhin M, Gorbenko F, Lomaev D, Mazina MY, Mikhailova A, Garaev AK, Parshikov A, Vorobyeva NE, Georgiev P, Schedl P, Chetverina D. Boundaries potentiate polycomb response element-mediated silencing. BMC Biol 2021; 19:113. [PMID: 34078365 PMCID: PMC8170967 DOI: 10.1186/s12915-021-01047-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 05/07/2021] [Indexed: 12/21/2022] Open
Abstract
Background Epigenetic memory plays a critical role in the establishment and maintenance of cell identities in multicellular organisms. Polycomb and trithorax group (PcG and TrxG) proteins are responsible for epigenetic memory, and in flies, they are recruited to specialized DNA regulatory elements termed polycomb response elements (PREs). Previous transgene studies have shown that PREs can silence reporter genes outside of their normal context, often by pairing sensitive (PSS) mechanism; however, their silencing activity is non-autonomous and depends upon the surrounding chromatin context. It is not known why PRE activity depends on the local environment or what outside factors can induce silencing. Results Using an attP system in Drosophila, we find that the so-called neutral chromatin environments vary substantially in their ability to support the silencing activity of the well-characterized bxdPRE. In refractory chromosomal contexts, factors required for PcG-silencing are unable to gain access to the PRE. Silencing activity can be rescued by linking the bxdPRE to a boundary element (insulator). When placed next to the PRE, the boundaries induce an alteration in chromatin structure enabling factors critical for PcG silencing to gain access to the bxdPRE. When placed at a distance from the bxdPRE, boundaries induce PSS by bringing the bxdPREs on each homolog in close proximity. Conclusion This proof-of-concept study demonstrates that the repressing activity of PREs can be induced or enhanced by nearby boundary elements. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-01047-8.
Collapse
Affiliation(s)
- Maksim Erokhin
- Group of Chromatin Biology, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow, 119334, Russia.
| | - Fedor Gorbenko
- Group of Chromatin Biology, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow, 119334, Russia.,Present address: Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Dmitry Lomaev
- Group of Epigenetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow, 119334, Russia
| | - Marina Yu Mazina
- Group of Transcriptional Complexes Dynamics, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Anna Mikhailova
- Group of Chromatin Biology, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow, 119334, Russia
| | - Azat K Garaev
- Laboratory of Structural and Functional Organization of Chromosomes, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow, 119334, Russia
| | - Aleksander Parshikov
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow, 119334, Russia
| | - Nadezhda E Vorobyeva
- Group of Transcriptional Complexes Dynamics, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Pavel Georgiev
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow, 119334, Russia
| | - Paul Schedl
- Department of Molecular Biology Princeton University, Princeton, NJ, 08544, USA.
| | - Darya Chetverina
- Group of Epigenetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow, 119334, Russia.
| |
Collapse
|
18
|
Postika N, Schedl P, Georgiev P, Kyrchanova O. Mapping of functional elements of the Fab-6 boundary involved in the regulation of the Abd-B hox gene in Drosophila melanogaster. Sci Rep 2021; 11:4156. [PMID: 33603202 PMCID: PMC7892861 DOI: 10.1038/s41598-021-83734-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 02/03/2021] [Indexed: 01/31/2023] Open
Abstract
The autonomy of segment-specific regulatory domains in the Bithorax complex is conferred by boundary elements and associated Polycomb response elements (PREs). The Fab-6 boundary is located at the junction of the iab-5 and iab-6 domains. Previous studies mapped it to a nuclease hypersensitive region 1 (HS1), while the iab-6 PRE was mapped to a second hypersensitive region HS2 nearly 3 kb away. To analyze the role of HS1 and HS2 in boundary we generated deletions of HS1 or HS1 + HS2 that have attP site for boundary replacement experiments. The 1389 bp HS1 deletion can be rescued by a 529 bp core Fab-6 sequence that includes two CTCF sites. However, Fab-6 HS1 cannot rescue the HS1 + HS2 deletion or substitute for another BX-C boundary - Fab-7. For this it must be combined with a PRE, either Fab-7 HS3, or Fab-6 HS2. These findings suggest that the boundary function of Fab-6 HS1 must be bolstered by a second element that has PRE activity.
Collapse
Affiliation(s)
- Nikolay Postika
- grid.419021.f0000 0004 0380 8267Department of the Control of Genetic Processes, Institute of Gene Biology Russian Academy of Sciences, 34/5 Vavilov St., Moscow, Russia 119334
| | - Paul Schedl
- grid.419021.f0000 0004 0380 8267Laboratory of Gene Expression Regulation in Development, Institute of Gene Biology Russian Academy of Sciences, 34/5 Vavilov St., Moscow, Russia 119334 ,grid.16750.350000 0001 2097 5006Department of Molecular Biology, Princeton University, Princeton, NJ 08544 USA
| | - Pavel Georgiev
- grid.419021.f0000 0004 0380 8267Department of the Control of Genetic Processes, Institute of Gene Biology Russian Academy of Sciences, 34/5 Vavilov St., Moscow, Russia 119334
| | - Olga Kyrchanova
- grid.419021.f0000 0004 0380 8267Department of the Control of Genetic Processes, Institute of Gene Biology Russian Academy of Sciences, 34/5 Vavilov St., Moscow, Russia 119334 ,grid.419021.f0000 0004 0380 8267Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology Russian Academy of Sciences, 34/5 Vavilov St., Moscow, Russia 119334
| |
Collapse
|
19
|
Chetverina D, Erokhin M, Schedl P. GAGA factor: a multifunctional pioneering chromatin protein. Cell Mol Life Sci 2021; 78:4125-4141. [PMID: 33528710 DOI: 10.1007/s00018-021-03776-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 12/08/2020] [Accepted: 01/19/2021] [Indexed: 12/27/2022]
Abstract
The Drosophila GAGA factor (GAF) is a multifunctional protein implicated in nucleosome organization and remodeling, activation and repression of gene expression, long distance enhancer-promoter communication, higher order chromosome structure, and mitosis. This broad range of activities poses questions about how a single protein can perform so many seemingly different and unrelated functions. Current studies argue that GAF acts as a "pioneer" factor, generating nucleosome-free regions of chromatin for different classes of regulatory elements. The removal of nucleosomes from regulatory elements in turn enables other factors to bind to these elements and carry out their specialized functions. Consistent with this view, GAF associates with a collection of chromatin remodelers and also interacts with proteins implicated in different regulatory functions. In this review, we summarize the known activities of GAF and the functions of its protein partners.
Collapse
Affiliation(s)
- Darya Chetverina
- Group of Epigenetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow, 119334, Russia.
| | - Maksim Erokhin
- Group of Chromatin Biology, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., Moscow, 119334, Russia
| | - Paul Schedl
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA.
| |
Collapse
|
20
|
Polycomb group-mediated histone H2A monoubiquitination in epigenome regulation and nuclear processes. Nat Commun 2020; 11:5947. [PMID: 33230107 PMCID: PMC7683540 DOI: 10.1038/s41467-020-19722-9] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Accepted: 10/12/2020] [Indexed: 12/19/2022] Open
Abstract
Histone posttranslational modifications are key regulators of chromatin-associated processes including gene expression, DNA replication and DNA repair. Monoubiquitinated histone H2A, H2Aub (K118 in Drosophila or K119 in vertebrates) is catalyzed by the Polycomb group (PcG) repressive complex 1 (PRC1) and reversed by the PcG-repressive deubiquitinase (PR-DUB)/BAP1 complex. Here we critically assess the current knowledge regarding H2Aub deposition and removal, its crosstalk with PcG repressive complex 2 (PRC2)-mediated histone H3K27 methylation, and the recent attempts toward discovering its readers and solving its enigmatic functions. We also discuss mounting evidence of the involvement of H2A ubiquitination in human pathologies including cancer, while highlighting some knowledge gaps that remain to be addressed. Histone H2A monoubiquitination on lysine 119 in vertebrate and lysine 118 in Drosophila (H2Aub) is an epigenomic mark usually associated with gene repression by Polycomb group factors. Here the authors review the current knowledge on the deposition and removal of H2Aub, its function in transcription and other DNA-associated processes as well as its relevance to human disease.
Collapse
|
21
|
Giner-Laguarda N, Vidal M. Functions of Polycomb Proteins on Active Targets. EPIGENOMES 2020; 4:17. [PMID: 34968290 PMCID: PMC8594714 DOI: 10.3390/epigenomes4030017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 08/12/2020] [Accepted: 08/13/2020] [Indexed: 12/15/2022] Open
Abstract
Chromatin regulators of the Polycomb group of genes are well-known by their activities as transcriptional repressors. Characteristically, their presence at genomic sites occurs with specific histone modifications and sometimes high-order chromatin structures correlated with silencing of genes involved in cell differentiation. However, evidence gathered in recent years, on flies and mammals, shows that in addition to these sites, Polycomb products bind to a large number of active regulatory regions. Occupied sites include promoters and also intergenic regions, containing enhancers and super-enhancers. Contrasting with occupancies at repressed targets, characteristic histone modifications are low or undetectable. Functions on active targets are dual, restraining gene expression at some targets while promoting activity at others. Our aim here is to summarize the evidence available and discuss the convenience of broadening the scope of research to include Polycomb functions on active targets.
Collapse
Affiliation(s)
| | - Miguel Vidal
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas Margarita Salas, Ramiro de Maeztu 9, 28040 Madrid, Spain;
| |
Collapse
|
22
|
DeLuca SZ, Ghildiyal M, Pang LY, Spradling AC. Differentiating Drosophila female germ cells initiate Polycomb silencing by regulating PRC2-interacting proteins. eLife 2020; 9:56922. [PMID: 32773039 PMCID: PMC7438113 DOI: 10.7554/elife.56922] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 08/06/2020] [Indexed: 01/18/2023] Open
Abstract
Polycomb silencing represses gene expression and provides a molecular memory of chromatin state that is essential for animal development. We show that Drosophila female germline stem cells (GSCs) provide a powerful system for studying Polycomb silencing. GSCs have a non-canonical distribution of PRC2 activity and lack silenced chromatin like embryonic progenitors. As GSC daughters differentiate into nurse cells and oocytes, nurse cells, like embryonic somatic cells, silence genes in traditional Polycomb domains and in generally inactive chromatin. Developmentally controlled expression of two Polycomb repressive complex 2 (PRC2)-interacting proteins, Pcl and Scm, initiate silencing during differentiation. In GSCs, abundant Pcl inhibits PRC2-dependent silencing globally, while in nurse cells Pcl declines and newly induced Scm concentrates PRC2 activity on traditional Polycomb domains. Our results suggest that PRC2-dependent silencing is developmentally regulated by accessory proteins that either increase the concentration of PRC2 at target sites or inhibit the rate that PRC2 samples chromatin.
Collapse
Affiliation(s)
- Steven Z DeLuca
- Howard Hughes Medical Institute Research Laboratories Department of Embryology, Carnegie Institution for Science, Baltimore, United States
| | - Megha Ghildiyal
- Howard Hughes Medical Institute Research Laboratories Department of Embryology, Carnegie Institution for Science, Baltimore, United States
| | - Liang-Yu Pang
- Howard Hughes Medical Institute Research Laboratories Department of Embryology, Carnegie Institution for Science, Baltimore, United States
| | - Allan C Spradling
- Howard Hughes Medical Institute Research Laboratories Department of Embryology, Carnegie Institution for Science, Baltimore, United States
| |
Collapse
|
23
|
Kang SJ, Chun T. Structural heterogeneity of the mammalian polycomb repressor complex in immune regulation. Exp Mol Med 2020; 52:1004-1015. [PMID: 32636442 PMCID: PMC8080698 DOI: 10.1038/s12276-020-0462-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 04/21/2020] [Accepted: 05/25/2020] [Indexed: 12/16/2022] Open
Abstract
Epigenetic regulation is mainly mediated by enzymes that can modify the structure of chromatin by altering the structure of DNA or histones. Proteins involved in epigenetic processes have been identified to study the detailed molecular mechanisms involved in the regulation of specific mRNA expression. Evolutionarily well-conserved polycomb group (PcG) proteins can function as transcriptional repressors by the trimethylation of histone H3 at the lysine 27 residue (H3K27me3) and the monoubiquitination of histone H2A at the lysine 119 residue (H2AK119ub). PcG proteins form two functionally distinct protein complexes: polycomb repressor complex 1 (PRC1) and PRC2. In mammals, the structural heterogeneity of each PRC complex is dramatically increased by several paralogs of its subunit proteins. Genetic studies with transgenic mice along with RNA-seq and chromatin immunoprecipitation (ChIP)-seq analyses might be helpful for defining the cell-specific functions of paralogs of PcG proteins. Here, we summarize current knowledge about the immune regulatory role of PcG proteins related to the compositional diversity of each PRC complex and introduce therapeutic drugs that target PcG proteins in hematopoietic malignancy. Protein complexes that suppress gene activity by remodeling chromatin, the substance that contains most of a cell’s DNA, play a critical role in regulating the immune system and provide a therapeutic target for treating blood cancers. Seok-Jin Kang and Taehoon Chun from Korea University in Seoul, South Korea, review how polycomb group proteins, best known for their function in embryonic development, also contribute to the formation of immune cells from blood stem cell precursors. Studies with stem cells and cancer cells have begun to reveal many targets of these proteins, and drug companies are evaluating candidate agents directed against some polycomb group proteins in patients with lymphoma and other cancers. More comprehensive profiling of protein function across a broad range of immune cell types could reveal new targets for additional diseases associated with immune dysfunction.
Collapse
Affiliation(s)
- Seok-Jin Kang
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, 02841, Republic of Korea
| | - Taehoon Chun
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, 02841, Republic of Korea.
| |
Collapse
|
24
|
Abstract
Predicting regulatory potential from primary DNA sequences or transcription factor binding patterns is not possible. However, the annotation of the genome by chromatin proteins, histone modifications, and differential compaction is largely sufficient to reveal the locations of genes and their differential activity states. The Polycomb Group (PcG) and Trithorax Group (TrxG) proteins are the central players in this cell type-specific chromatin organization. PcG function was originally viewed as being solely repressive and irreversible, as observed at the homeotic loci in flies and mammals. However, it is now clear that modular and reversible PcG function is essential at most developmental genes. Focusing mainly on recent advances, we review evidence for how PcG and TrxG patterns change dynamically during cell type transitions. The ability to implement cell type-specific transcriptional programming with exquisite fidelity is essential for normal development.
Collapse
Affiliation(s)
- Mitzi I Kuroda
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA; ,
| | - Hyuckjoon Kang
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA; ,
| | - Sandip De
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA; ,
| | - Judith A Kassis
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA; ,
| |
Collapse
|
25
|
Hoxha S, Shepard A, Troutman S, Diao H, Doherty JR, Janiszewska M, Witwicki RM, Pipkin ME, Ja WW, Kareta MS, Kissil JL. YAP-Mediated Recruitment of YY1 and EZH2 Represses Transcription of Key Cell-Cycle Regulators. Cancer Res 2020; 80:2512-2522. [PMID: 32409309 DOI: 10.1158/0008-5472.can-19-2415] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 03/11/2020] [Accepted: 04/22/2020] [Indexed: 11/16/2022]
Abstract
The Hippo pathway regulates cell proliferation and organ size through control of the transcriptional regulators YAP (yes-associated protein) and TAZ. Upon extracellular stimuli such as cell-cell contact, the pathway negatively regulates YAP through cytoplasmic sequestration. Under conditions of low cell density, YAP is nuclear and associates with enhancer regions and gene promoters. YAP is mainly described as a transcriptional activator of genes involved in cell proliferation and survival. Using a genome-wide approach, we show here that, in addition to its known function as a transcriptional activator, YAP functions as a transcriptional repressor by interacting with the multifunctional transcription factor Yin Yang 1 (YY1) and Polycomb repressive complex member enhancer of zeste homologue 2 (EZH2). YAP colocalized with YY1 and EZH2 on the genome to transcriptionally repress a broad network of genes mediating a host of cellular functions, including repression of the cell-cycle kinase inhibitor p27, whose role is to functionally promote contact inhibition. This work unveils a broad and underappreciated aspect of YAP nuclear function as a transcriptional repressor and highlights how loss of contact inhibition in cancer is mediated in part through YAP repressive function. SIGNIFICANCE: This study provides new insights into YAP as a broad transcriptional repressor of key regulators of the cell cycle, in turn influencing contact inhibition and tumorigenesis.
Collapse
Affiliation(s)
- Sany Hoxha
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, Florida
| | - Alyssa Shepard
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, Florida
| | - Scott Troutman
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, Florida
| | - Huitian Diao
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, Florida
| | - Joanne R Doherty
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, Florida
| | | | - Robert M Witwicki
- Genetic Perturbation Screening Core, The Scripps Research Institute, Jupiter, Florida
| | - Matthew E Pipkin
- Department of Immunology and Microbiology, The Scripps Research Institute, Jupiter, Florida
| | - William W Ja
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida
| | - Michael S Kareta
- Genetics and Genomics Group, Sanford Research, Sioux Falls, South Dakota
| | - Joseph L Kissil
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, Florida.
| |
Collapse
|
26
|
Jain S, Maini J, Narang A, Maiti S, Brahmachari V. The regulatory function of dIno80 correlates with its DNA binding activity. Gene 2020; 732:144368. [PMID: 31954859 DOI: 10.1016/j.gene.2020.144368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 01/10/2020] [Accepted: 01/13/2020] [Indexed: 01/06/2023]
Abstract
The INO80 complex, including the Ino80 protein, forms a highly conserved canonical complex that remodels chromatin in the context of multiple cellular functions. The Drosophila homologue, dIno80, is involved in homeotic gene regulation during development as a canonical Pho-dIno80 complex. Previously, we found that dIno80 regulates homeotic genes by interacting with epigenetic regulators, such as polycomb and trithorax, suggesting the occurrence of non-canonical Ino80 complexes. Here using spectroscopic methods and gel retardation assays, we identified a set of consensus DNA sequences that DNA binding domain of dIno80 (DBINO) interacts with having differential affinity and high specificity. Testing these sequences in reporter assays, showed that this interaction can positively regulate transcription. These results suggest that, dIno80 has a sequence preference for interaction with DNA leading to transcriptional changes.
Collapse
Affiliation(s)
- Shruti Jain
- Dr. B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi 110007, India.
| | - Jayant Maini
- Dr. B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi 110007, India
| | - Ankita Narang
- Dr. B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi 110007, India
| | - Souvik Maiti
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, Delhi 110025, India
| | - Vani Brahmachari
- Dr. B. R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi 110007, India.
| |
Collapse
|
27
|
Genomic organization of Polycomb Response Elements and its functional implication in Drosophila and other insects. J Biosci 2020. [DOI: 10.1007/s12038-019-9975-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
28
|
Bredesen BA, Rehmsmeier M. DNA sequence models of genome-wide Drosophila melanogaster Polycomb binding sites improve generalization to independent Polycomb Response Elements. Nucleic Acids Res 2019; 47:7781-7797. [PMID: 31340029 PMCID: PMC6735708 DOI: 10.1093/nar/gkz617] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 07/01/2019] [Accepted: 07/11/2019] [Indexed: 12/12/2022] Open
Abstract
Polycomb Response Elements (PREs) are cis-regulatory DNA elements that maintain gene transcription states through DNA replication and mitosis. PREs have little sequence similarity, but are enriched in a number of sequence motifs. Previous methods for modelling Drosophila melanogaster PRE sequences (PREdictor and EpiPredictor) have used a set of 7 motifs and a training set of 12 PREs and 16-23 non-PREs. Advances in experimental methods for mapping chromatin binding factors and modifications has led to the publication of several genome-wide sets of Polycomb targets. In addition to the seven motifs previously used, PREs are enriched in the GTGT motif, recently associated with the sequence-specific DNA binding protein Combgap. We investigated whether models trained on genome-wide Polycomb sites generalize to independent PREs when trained with control sequences generated by naive PRE models and including the GTGT motif. We also developed a new PRE predictor: SVM-MOCCA. Training PRE predictors with genome-wide experimental data improves generalization to independent data, and SVM-MOCCA predicts the majority of PREs in three independent experimental sets. We present 2908 candidate PREs enriched in sequence and chromatin signatures. 2412 of these are also enriched in H3K4me1, a mark of Trithorax activated chromatin, suggesting that PREs/TREs have a common sequence code.
Collapse
Affiliation(s)
- Bjørn André Bredesen
- Computational Biology Unit, Department of Informatics, University of Bergen, P.O. Box 7803, N-5020 Bergen, Norway
| | - Marc Rehmsmeier
- Computational Biology Unit, Department of Informatics, University of Bergen, P.O. Box 7803, N-5020 Bergen, Norway.,Integrated Research Institute (IRI) for the Life Sciences and Department of Biology, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany
| |
Collapse
|
29
|
Abstract
As the process that silences gene expression ensues during development, the stage is set for the activity of Polycomb-repressive complex 2 (PRC2) to maintain these repressed gene profiles. PRC2 catalyzes a specific histone posttranslational modification (hPTM) that fosters chromatin compaction. PRC2 also facilitates the inheritance of this hPTM through its self-contained "write and read" activities, key to preserving cellular identity during cell division. As these changes in gene expression occur without changes in DNA sequence and are inherited, the process is epigenetic in scope. Mutants of mammalian PRC2 or of its histone substrate contribute to the cancer process and other diseases, and research into these aberrant pathways is yielding viable candidates for therapeutic targeting. The effectiveness of PRC2 hinges on its being recruited to the proper chromatin sites; however, resolving the determinants to this process in the mammalian case was not straightforward and thus piqued the interest of many in the field. Here, we chronicle the latest advances toward exposing mammalian PRC2 and its high maintenance.
Collapse
Affiliation(s)
- Jia-Ray Yu
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York 10016, USA
- Howard Hughes Medical Institute, Chevy Chase, Maryland 20815, USA
| | - Chul-Hwan Lee
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York 10016, USA
- Howard Hughes Medical Institute, Chevy Chase, Maryland 20815, USA
| | - Ozgur Oksuz
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York 10016, USA
- Howard Hughes Medical Institute, Chevy Chase, Maryland 20815, USA
| | - James M Stafford
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York 10016, USA
- Howard Hughes Medical Institute, Chevy Chase, Maryland 20815, USA
| | - Danny Reinberg
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York 10016, USA
- Howard Hughes Medical Institute, Chevy Chase, Maryland 20815, USA
| |
Collapse
|
30
|
Polycomb Assemblies Multitask to Regulate Transcription. EPIGENOMES 2019; 3:epigenomes3020012. [PMID: 34968234 PMCID: PMC8594731 DOI: 10.3390/epigenomes3020012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 06/14/2019] [Accepted: 06/16/2019] [Indexed: 02/06/2023] Open
Abstract
The Polycomb system is made of an evolutionary ancient group of proteins, present throughout plants and animals. Known initially from developmental studies with the fly Drosophila melanogaster, they were associated with stable sustainment of gene repression and maintenance of cell identity. Acting as multiprotein assemblies with an ability to modify chromatin, through chemical additions to histones and organization of topological domains, they have been involved subsequently in control of developmental transitions and in cell homeostasis. Recent work has unveiled an association of Polycomb components with transcriptionally active loci and the promotion of gene expression, in clear contrast with conventional recognition as repressors. Focusing on mammalian models, I review here advances concerning roles in transcriptional control. Among new findings highlighted is the regulation of their catalytic properties, recruiting to targets, and activities in chromatin organization and compartmentalization. The need for a more integrated approach to the study of the Polycomb system, given its fundamental complexity and its adaptation to cell context, is discussed.
Collapse
|
31
|
Chen K, Lu Y, Shi K, Stovall DB, Li D, Sui G. Functional analysis of YY1 zinc fingers through cysteine mutagenesis. FEBS Lett 2019; 593:1392-1402. [PMID: 31127623 DOI: 10.1002/1873-3468.13431] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 05/06/2019] [Accepted: 05/06/2019] [Indexed: 11/08/2022]
Abstract
As a transcription factor, Yin Yang 1 (YY1) either activates or represses gene expression depending on its recruited cofactors. The YY1 C-terminal consists of four zinc fingers (ZF) that are responsible for its DNA binding. However, the contribution of each YY1 ZF to its functions have not been fully elucidated. In this study, we used alanines to replace YY1 cysteines that are crucial to ZFs in binding to DNA. We characterized these YY1 mutants for their DNA binding, transcriptional activity, and functional role in maintaining MDA-MB-231 cell proliferation. We demonstrated that ZFs 2 and 3 are essential to the general biological activity of YY1. ZF 1 showed relatively low importance, while ZF 4 is virtually dispensable for YY1 function.
Collapse
Affiliation(s)
- Kuida Chen
- College of Life Science, Northeast Forestry University, Harbin, China
| | - Yao Lu
- College of Life Science, Northeast Forestry University, Harbin, China
| | - Ke Shi
- College of Life Science, Northeast Forestry University, Harbin, China
| | - Daniel B Stovall
- School of Math and Science, North Carolina Wesleyan College, Rocky Mount, NC, USA
| | - Dangdang Li
- College of Life Science, Northeast Forestry University, Harbin, China
| | - Guangchao Sui
- College of Life Science, Northeast Forestry University, Harbin, China
| |
Collapse
|
32
|
Bracken AP, Brien GL, Verrijzer CP. Dangerous liaisons: interplay between SWI/SNF, NuRD, and Polycomb in chromatin regulation and cancer. Genes Dev 2019; 33:936-959. [PMID: 31123059 PMCID: PMC6672049 DOI: 10.1101/gad.326066.119] [Citation(s) in RCA: 105] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In this review, Bracken et al. discuss the functional organization and biochemical activities of remodelers and Polycomb and explore how they work together to control cell differentiation and the maintenance of cell identity. They also discuss how mutations in the genes encoding these various chromatin regulators contribute to oncogenesis by disrupting the chromatin equilibrium. Changes in chromatin structure mediated by ATP-dependent nucleosome remodelers and histone modifying enzymes are integral to the process of gene regulation. Here, we review the roles of the SWI/SNF (switch/sucrose nonfermenting) and NuRD (nucleosome remodeling and deacetylase) and the Polycomb system in chromatin regulation and cancer. First, we discuss the basic molecular mechanism of nucleosome remodeling, and how this controls gene transcription. Next, we provide an overview of the functional organization and biochemical activities of SWI/SNF, NuRD, and Polycomb complexes. We describe how, in metazoans, the balance of these activities is central to the proper regulation of gene expression and cellular identity during development. Whereas SWI/SNF counteracts Polycomb, NuRD facilitates Polycomb repression on chromatin. Finally, we discuss how disruptions of this regulatory equilibrium contribute to oncogenesis, and how new insights into the biological functions of remodelers and Polycombs are opening avenues for therapeutic interventions on a broad range of cancer types.
Collapse
Affiliation(s)
- Adrian P Bracken
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Gerard L Brien
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - C Peter Verrijzer
- Department of Biochemistry, Erasmus University Medical Center, 3000 DR Rotterdam, the Netherlands
| |
Collapse
|
33
|
Agrawal P, Chung P, Heberlein U, Kent C. Enabling cell-type-specific behavioral epigenetics in Drosophila: a modified high-yield INTACT method reveals the impact of social environment on the epigenetic landscape in dopaminergic neurons. BMC Biol 2019; 17:30. [PMID: 30967153 PMCID: PMC6456965 DOI: 10.1186/s12915-019-0646-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 03/07/2019] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Epigenetic mechanisms play fundamental roles in brain function and behavior and stressors such as social isolation can alter animal behavior via epigenetic mechanisms. However, due to cellular heterogeneity, identifying cell-type-specific epigenetic changes in the brain is challenging. Here, we report the first use of a modified isolation of nuclei tagged in specific cell type (INTACT) method in behavioral epigenetics of Drosophila melanogaster, a method we call mini-INTACT. RESULTS Using ChIP-seq on mini-INTACT purified dopaminergic nuclei, we identified epigenetic signatures in socially isolated and socially enriched Drosophila males. Social experience altered the epigenetic landscape in clusters of genes involved in transcription and neural function. Some of these alterations could be predicted by expression changes of four transcription factors and the prevalence of their binding sites in several clusters. These transcription factors were previously identified as activity-regulated genes, and their knockdown in dopaminergic neurons reduced the effects of social experience on sleep. CONCLUSIONS Our work enables the use of Drosophila as a model for cell-type-specific behavioral epigenetics and establishes that social environment shifts the epigenetic landscape in dopaminergic neurons. Four activity-related transcription factors are required in dopaminergic neurons for the effects of social environment on sleep.
Collapse
Affiliation(s)
- Pavan Agrawal
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
| | - Phuong Chung
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Ulrike Heberlein
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Clement Kent
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
- Department of Biology, York University, Toronto, Canada.
| |
Collapse
|
34
|
Alhaj Abed J, Ghotbi E, Ye P, Frolov A, Benes J, Jones RS. De novo recruitment of Polycomb-group proteins in Drosophila embryos. Development 2018; 145:dev.165027. [PMID: 30389849 DOI: 10.1242/dev.165027] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 10/29/2018] [Indexed: 12/24/2022]
Abstract
Polycomb-group (PcG)-mediated transcriptional repression of target genes can be delineated into two phases. First, following initial repression of target genes by gene-specific transcription factors, PcG proteins recognize the repressed state and assume control of the genes' repression. Second, once the silenced state is established, PcG proteins may maintain repression through an indefinite number of cell cycles. Little is understood about how PcG proteins initially recognize the repressed state of target genes and the steps leading to de novo establishment of PcG-mediated repression. We describe a genetic system in which a Drosophila PcG target gene, giant (gt), is ubiquitously repressed during early embryogenesis by a maternally expressed transcription factor, and show the temporal recruitment of components of three PcG protein complexes: PhoRC, PRC1 and PRC2. We show that de novo PcG recruitment follows a temporal hierarchy in which PhoRC stably localizes at the target gene at least 1 h before stable recruitment of PRC2 and concurrent trimethylation of histone H3 at lysine 27 (H3K27me3). The presence of PRC2 and increased levels of H3K27me3 are found to precede stable binding by PRC1.
Collapse
Affiliation(s)
- Jumana Alhaj Abed
- Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275-0376, USA
| | - Elnaz Ghotbi
- Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275-0376, USA
| | - Piao Ye
- Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275-0376, USA
| | - Alexander Frolov
- Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275-0376, USA
| | - Judith Benes
- Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275-0376, USA
| | - Richard S Jones
- Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275-0376, USA
| |
Collapse
|
35
|
Epigenetic and non-epigenetic functions of the RYBP protein in development and disease. Mech Ageing Dev 2018; 174:111-120. [DOI: 10.1016/j.mad.2018.03.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 03/22/2018] [Accepted: 03/26/2018] [Indexed: 12/30/2022]
|
36
|
Nakagawa T, Yoneda M, Higashi M, Ohkuma Y, Ito T. Enhancer function regulated by combinations of transcription factors and cofactors. Genes Cells 2018; 23:808-821. [PMID: 30092612 DOI: 10.1111/gtc.12634] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 07/23/2018] [Accepted: 07/24/2018] [Indexed: 12/11/2022]
Abstract
Regulation of the expression of diverse genes is essential for making possible the complexity of higher organisms, and the temporal and spatial regulation of gene expression allows for the alteration of cell types and growth patterns. A critical component of this regulation is the DNA sequence-specific binding of transcription factors (TFs). However, most TFs do not independently participate in gene transcriptional regulation, because they lack an effector function. Instead, TFs are thought to work by recruiting cofactors, including Mediator complex (Mediator), chromatin-remodeling complexes (CRCs), and histone-modifying complexes (HMCs). Mediator associates with the majority of transcribed genes and acts as an integrator of multiple signals. On the other hand, CRCs and HMCs are selectively recruited by TFs. Although all the pairings between TFs and CRCs or HMCs are not fully known, there are a growing number of established TF-CRC and TF-HMC combinations. In this review, we focused on the most important of these pairings and discuss how they control gene expression.
Collapse
Affiliation(s)
- Takeya Nakagawa
- Department of Biochemistry, Nagasaki University School of Medicine, Nagasaki, Japan
| | - Mitsuhiro Yoneda
- Department of Biochemistry, Nagasaki University School of Medicine, Nagasaki, Japan
| | - Miki Higashi
- Department of Biochemistry, Nagasaki University School of Medicine, Nagasaki, Japan
| | - Yoshiaki Ohkuma
- Department of Biochemistry, Nagasaki University School of Medicine, Nagasaki, Japan
| | - Takashi Ito
- Department of Biochemistry, Nagasaki University School of Medicine, Nagasaki, Japan
| |
Collapse
|
37
|
Kyrchanova O, Kurbidaeva A, Sabirov M, Postika N, Wolle D, Aoki T, Maksimenko O, Mogila V, Schedl P, Georgiev P. The bithorax complex iab-7 Polycomb response element has a novel role in the functioning of the Fab-7 chromatin boundary. PLoS Genet 2018; 14:e1007442. [PMID: 30110328 PMCID: PMC6110506 DOI: 10.1371/journal.pgen.1007442] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 08/27/2018] [Accepted: 07/30/2018] [Indexed: 12/22/2022] Open
Abstract
Expression of the three bithorax complex homeotic genes is orchestrated by nine parasegment-specific regulatory domains. Autonomy of each domain is conferred by boundary elements (insulators). Here, we have used an in situ replacement strategy to reanalyze the sequences required for the functioning of one of the best-characterized fly boundaries, Fab-7. It was initially identified by a deletion, Fab-71, that transformed parasegment (PS) 11 into a duplicate copy of PS12. Fab-71 deleted four nuclease hypersensitive sites, HS*, HS1, HS2, and HS3, located between the iab-6 and iab-7 regulatory domains. Transgenic and P-element excision experiments mapped the boundary to HS*+HS1+HS2, while HS3 was shown to be the iab-7 Polycomb response element (PRE). Recent replacement experiments showed that HS1 is both necessary and sufficient for boundary activity when HS3 is also present in the replacement construct. Surprisingly, while HS1+HS3 combination has full boundary activity, we discovered that HS1 alone has only minimal function. Moreover, when combined with HS3, only the distal half of HS1, dHS1, is needed. A ~1,000 kD multiprotein complex containing the GAF protein, called the LBC, binds to the dHS1 sequence and we show that mutations in dHS1, that disrupt LBC binding in nuclear extracts, eliminate boundary activity and GAF binding in vivo. HS3 has binding sites for GAF and Pho proteins that are required for PRE silencing. In contrast, HS3 boundary activity only requires the GAF binding sites. LBC binding with HS3 in nuclear extracts, and GAF association in vivo, depend upon the HS3 GAF sites, but not the Pho sites. Consistent with a role for the LBC in HS3 boundary activity, the boundary function of the dHS1+HS3mPho combination is lost when the flies are heterozygous for a mutation in the GAF gene. Taken together, these results reveal a novel function for the iab-7 PREs in chromosome architecture. Polycomb group proteins (PcG) are important epigenetic regulators of developmental genes in all higher eukaryotes. In Drosophila, these proteins are bound to specific regulatory DNA elements called Polycomb group Response Elements (PREs). Drosophila PREs are made up of binding sites for a complex array of DNA binding proteins, including GAF and Pho. In the regulatory region of the bithorax complex (BX-C), the boundary/insulator elements organize the autonomous regulatory domains, and their active or repressed states are regulated by PREs. Here, we studied functional properties of sequences that constitute the Fab-7 boundary and the adjacent iab-7 PRE. It was previously thought that the sole function of the iab-7 PRE is to recruit PcG proteins in parasegments anterior to PS12 and silence the iab-7 domain. However, we found that the iab-7 PRE also functions as a component of the Fab-7 boundary. The boundary activity of the iab-7 PRE sequence depends upon a large complex called the LBC. We show that it is possible to reconstitute a fully functional boundary by combining the LBC binding sequences in HS1 with the iab-7 PRE. Moreover, its boundary function is independent of its PcG silencing activity.
Collapse
Affiliation(s)
- Olga Kyrchanova
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Amina Kurbidaeva
- Laboratory of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
- Department of Molecular Biology, Princeton University, Princeton, NJ, United States of America
| | - Marat Sabirov
- Group of Molecular Organization of Genome, Institute of Gene Biology, Russian Acsademy of Sciences, Moscow, Russia
| | - Nikolay Postika
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Daniel Wolle
- Department of Molecular Biology, Princeton University, Princeton, NJ, United States of America
| | - Tsutomu Aoki
- Department of Molecular Biology, Princeton University, Princeton, NJ, United States of America
| | - Oksana Maksimenko
- Group of Molecular Organization of Genome, Institute of Gene Biology, Russian Acsademy of Sciences, Moscow, Russia
| | - Vladic Mogila
- Laboratory of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Paul Schedl
- Laboratory of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
- Department of Molecular Biology, Princeton University, Princeton, NJ, United States of America
- * E-mail: (PS); (PG)
| | - Pavel Georgiev
- Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
- * E-mail: (PS); (PG)
| |
Collapse
|
38
|
Daraiseh SI, Kassardjian A, Alexander KE, Rizkallah R, Hurt MM. c-Abl phosphorylation of Yin Yang 1's conserved tyrosine 254 in the spacer region modulates its transcriptional activity. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1173-1186. [PMID: 29807053 DOI: 10.1016/j.bbamcr.2018.05.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 05/02/2018] [Accepted: 05/24/2018] [Indexed: 12/31/2022]
Abstract
Yin Yang 1 (YY1) is a multifunctional transcription factor that can activate or repress transcription depending on the promotor and/or the co-factors recruited. YY1 is phosphorylated in various signaling pathways and is critical for different biological functions including embryogenesis, apoptosis, proliferation, cell-cycle regulation and tumorigenesis. Here we report that YY1 is a substrate for c-Abl kinase phosphorylation at conserved residue Y254 in the spacer region. Pharmacological inhibition of c-Abl kinase by imatinib, nilotinib and GZD824, knock-down of c-Abl using siRNA, and the use of c-Abl kinase-dead drastically reduces tyrosine phosphorylation of YY1. Both radioactive and non-radioactive in vitro kinase assays, as well as co-immunoprecipitation in different cell lines, show that the target of c-Abl phosphorylation is tyrosine residue 254. c-Abl phosphorylation has little effect on YY1 DNA binding ability or cellular localization in asynchronous cells. However, functional studies reveal that c-Abl mediated phosphorylation of YY1 regulates YY1's transcriptional ability in vivo. In conclusion, we demonstrate the novel role of c-Abl kinase in regulation of YY1's transcriptional activity, linking YY1 regulation with c-Abl tyrosine kinase signaling pathways.
Collapse
Affiliation(s)
- Susan I Daraiseh
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, USA
| | - Ari Kassardjian
- David Geffen School of Medicine, Department of Pathology and Laboratory Medicine at UCLA, Los Angeles, CA, USA
| | - Karen E Alexander
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, USA
| | - Raed Rizkallah
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, USA
| | - Myra M Hurt
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, FL, USA.
| |
Collapse
|
39
|
Wang J, Wu X, Wei C, Huang X, Ma Q, Huang X, Faiola F, Guallar D, Fidalgo M, Huang T, Peng D, Chen L, Yu H, Li X, Sun J, Liu X, Cai X, Chen X, Wang L, Ren J, Wang J, Ding J. YY1 Positively Regulates Transcription by Targeting Promoters and Super-Enhancers through the BAF Complex in Embryonic Stem Cells. Stem Cell Reports 2018; 10:1324-1339. [PMID: 29503092 PMCID: PMC5998734 DOI: 10.1016/j.stemcr.2018.02.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 02/07/2018] [Accepted: 02/08/2018] [Indexed: 12/20/2022] Open
Abstract
Yin Yang 1 (YY1) regulates early embryogenesis and adult tissue formation. However, the role of YY1 in stem cell regulation remains unclear. YY1 has a Polycomb group (PcG) protein-dependent role in mammalian cells. The PcG-independent functions of YY1 are also reported, although their underlying mechanism is still undefined. This paper reports the role of YY1 and BAF complex in the OCT4-mediated pluripotency network in mouse embryonic stem cells (mESCs). The interaction between YY1 and BAF complex promotes mESC proliferation and pluripotency. Knockdown of Yy1 or Smarca4, the core component of the BAF complex, downregulates pluripotency markers and upregulates several differentiation markers. Moreover, YY1 enriches at both promoter and super-enhancer regions to stimulate transcription. Thus, this study elucidates the role of YY1 in regulating pluripotency through its interaction with OCT4 and the BAF complex and the role of BAF complex in integrating YY1 into the core pluripotency network. YY1 is integrated into the core pluripotency network through the BAF complex YY1 and the BAF complex promote ESC proliferation YY1 activates gene expression through the BAF complex to maintain pluripotency YY1 is enriched at the ESC-specific super-enhancers to promote gene expression
Collapse
Affiliation(s)
- Jia Wang
- Program in Stem Cell and Regenerative Medicine, The Third Affiliated Hospital of Sun Yat-Sen University, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China; Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-Sen University, Guangzhou 510080, China; Department of Cell Biology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - Xingui Wu
- Program in Stem Cell and Regenerative Medicine, The Third Affiliated Hospital of Sun Yat-Sen University, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China; Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-Sen University, Guangzhou 510080, China; Department of Cell Biology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - Chao Wei
- Program in Stem Cell and Regenerative Medicine, The Third Affiliated Hospital of Sun Yat-Sen University, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China; Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-Sen University, Guangzhou 510080, China; Department of Cell Biology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - Xin Huang
- The Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Qian Ma
- Program in Stem Cell and Regenerative Medicine, The Third Affiliated Hospital of Sun Yat-Sen University, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China; Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-Sen University, Guangzhou 510080, China; Department of Cell Biology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - Xiaona Huang
- Program in Stem Cell and Regenerative Medicine, The Third Affiliated Hospital of Sun Yat-Sen University, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China; Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-Sen University, Guangzhou 510080, China; Department of Cell Biology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - Francesco Faiola
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Diana Guallar
- Centro de Investigaciónen Medicina Molecular e EnfermidadesCronicas, Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain
| | - Miguel Fidalgo
- Centro de Investigaciónen Medicina Molecular e EnfermidadesCronicas, Universidade de Santiago de Compostela, Santiago de Compostela 15782, Spain
| | - Tingyuan Huang
- Guangzhou Center for Disease Control and Prevention, Guangzhou 510440, China
| | - Di Peng
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, Guangdong 510275, China
| | - Li Chen
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, Guangdong 510275, China
| | - Haopeng Yu
- Program in Stem Cell and Regenerative Medicine, The Third Affiliated Hospital of Sun Yat-Sen University, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China; Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-Sen University, Guangzhou 510080, China; Department of Cell Biology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - Xingyu Li
- Program in Stem Cell and Regenerative Medicine, The Third Affiliated Hospital of Sun Yat-Sen University, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China; Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-Sen University, Guangzhou 510080, China; Department of Cell Biology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - Junyi Sun
- Program in Stem Cell and Regenerative Medicine, The Third Affiliated Hospital of Sun Yat-Sen University, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China; Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-Sen University, Guangzhou 510080, China; Department of Cell Biology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - Xinyi Liu
- Program in Stem Cell and Regenerative Medicine, The Third Affiliated Hospital of Sun Yat-Sen University, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China; Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-Sen University, Guangzhou 510080, China; Department of Cell Biology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - Xiaoxia Cai
- Program in Stem Cell and Regenerative Medicine, The Third Affiliated Hospital of Sun Yat-Sen University, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China; Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-Sen University, Guangzhou 510080, China; Department of Cell Biology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - Xiao Chen
- Program in Stem Cell and Regenerative Medicine, The Third Affiliated Hospital of Sun Yat-Sen University, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China; Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-Sen University, Guangzhou 510080, China; Department of Cell Biology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - Ling Wang
- Program in Stem Cell and Regenerative Medicine, The Third Affiliated Hospital of Sun Yat-Sen University, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China; Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-Sen University, Guangzhou 510080, China; Department of Cell Biology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - Jian Ren
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, Guangdong 510275, China
| | - Jianlong Wang
- The Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; The Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
| | - Junjun Ding
- Program in Stem Cell and Regenerative Medicine, The Third Affiliated Hospital of Sun Yat-Sen University, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China; Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-Sen University, Guangzhou 510080, China; Department of Cell Biology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China.
| |
Collapse
|
40
|
Global changes of H3K27me3 domains and Polycomb group protein distribution in the absence of recruiters Spps or Pho. Proc Natl Acad Sci U S A 2018; 115:E1839-E1848. [PMID: 29432187 DOI: 10.1073/pnas.1716299115] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Polycomb group (PcG) proteins maintain the silenced state of key developmental genes in animals, but how these proteins are recruited to specific regions of the genome is still poorly understood. In Drosophila, PcG proteins are recruited to Polycomb response elements (PREs) that include combinations of sites for sequence specific DNA binding "PcG recruiters," including Pho, Cg, and Spps. To understand their roles in PcG recruitment, we compared Pho-, Cg-, and Spps-binding sites against H3K27me3 and key PcG proteins by ChIP-seq in wild-type and mutant third instar larvae. H3K27me3 in canonical Polycomb domains is decreased after the reduction of any recruiter. Reduction of Spps and Pho, but not Cg, causes the redistribution of H3K27me3 to heterochromatin. Regions with dramatically depleted H3K27me3 after Spps knockout are usually accompanied by decreased Pho binding, suggesting their cooperative binding. PcG recruiters, the PRC2 component E(z), and the PRC1 components Psc and Ph cobind thousands of active genes outside of H3K27me3 domains. This study demonstrates the importance of distinct PcG recruiters for the establishment of unique Polycomb domains. Different PcG recruiters can act both cooperatively and independently at specific PcG target genes, highlighting the complexity and diversity of PcG recruitment mechanisms.
Collapse
|
41
|
|
42
|
Pereira A, Paro R. Pho dynamically interacts with Spt5 to facilitate transcriptional switches at the hsp70 locus. Epigenetics Chromatin 2017; 10:57. [PMID: 29208012 PMCID: PMC5718073 DOI: 10.1186/s13072-017-0166-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 11/29/2017] [Indexed: 11/10/2022] Open
Abstract
Background Numerous target genes of the Polycomb group (PcG) are transiently activated by a stimulus and subsequently repressed. However, mechanisms by which PcG proteins regulate such target genes remain elusive. Results We employed the heat shock-responsive hsp70 locus in Drosophila to study the chromatin dynamics of PRC1 and its interplay with known regulators of the locus before, during and after heat shock. We detected mutually exclusive binding patterns for HSF and PRC1 at the hsp70 locus. We found that Pleiohomeotic (Pho), a DNA-binding PcG member, dynamically interacts with Spt5, an elongation factor. The dynamic interaction switch between Pho and Spt5 is triggered by the recruitment of HSF to chromatin. Mutation in the protein–protein interaction domain (REPO domain) of Pho interferes with the dynamics of its interaction with Spt5. The transcriptional kinetics of the heat shock response is negatively affected by a mutation in the REPO domain of Pho. Conclusions We propose that a dynamic interaction switch between PcG proteins and an elongation factor enables stress-inducible genes to efficiently switch between ON/OFF states in the presence/absence of the activating stimulus. Electronic supplementary material The online version of this article (10.1186/s13072-017-0166-9) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Allwyn Pereira
- Department of Biosystems Science and Engineering, ETH Zurich, 4058, Basel, Switzerland
| | - Renato Paro
- Department of Biosystems Science and Engineering, ETH Zurich, 4058, Basel, Switzerland. .,Faculty of Sciences, University of Basel, 4056, Basel, Switzerland.
| |
Collapse
|
43
|
Niehaus EM, Studt L, von Bargen KW, Kummer W, Humpf HU, Reuter G, Tudzynski B. Sound of silence: the beauvericin cluster in Fusarium fujikuroi is controlled by cluster-specific and global regulators mediated by H3K27 modification. Environ Microbiol 2017; 18:4282-4302. [PMID: 27750383 DOI: 10.1111/1462-2920.13576] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 10/11/2016] [Indexed: 01/25/2023]
Abstract
In this study, we compared the secondary metabolite profile of Fusarium fujikuroi and the histone deacetylase mutant ΔHDA1. We identified a novel peak in ΔHDA1, which was identified as beauvericin (BEA). Going in line with a 1000-fold increased BEA production, the respective non-ribosomal peptide synthetase (NRPS)-encoding gene (BEA1), as well as two adjacent genes (BEA2-BEA3), were significantly up-regulated in ΔHDA1 compared to the wild type. A special role was revealed for the ABC transporter Bea3: deletion of the encoding gene resulted in significant up-regulation of BEA1 and BEA2 and drastically elevated product yields. Furthermore, mutation of a conserved sequence motif in the promoter of BEA1 released BEA repression and resulted in elevated product levels. Candidate transcription factors (TFs) that could bind to this motif are the cluster-specific TF Bea4 as well as a homolog of the global mammalian Kruppel-like TF Yin Yang 1 (Yy1), both acting as repressors of BEA biosynthesis. In addition to Hda1, BEA biosynthesis is repressed by the activity of the H3K27 methyltransferase Kmt6. Consistently, Western blot analyses revealed a genome-wide enrichment of H3K27 acetylation (H3K27ac) in the ΔHDA1 and KMT6 knock-down mutants. Subsequent chromatin immunoprecipitation (ChIP) experiments showed elevated H3K27ac modification levels at the BEA cluster.
Collapse
Affiliation(s)
- Eva-Maria Niehaus
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Schlossplatz 8, Münster, D-48143
| | - Lena Studt
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Schlossplatz 8, Münster, D-48143
| | - Katharina W von Bargen
- Institut für Lebensmittelchemie, Westfälische Wilhelms-Universität Münster, Corrensstr. 45, Münster, D-48149
| | - Wiebke Kummer
- Institut für Genetik, Martin Luther Universität Halle-Wittenberg, Weinbergweg 10, Halle (Saale), D-06120
| | - Hans-Ulrich Humpf
- Institut für Lebensmittelchemie, Westfälische Wilhelms-Universität Münster, Corrensstr. 45, Münster, D-48149
| | - Gunter Reuter
- Institut für Genetik, Martin Luther Universität Halle-Wittenberg, Weinbergweg 10, Halle (Saale), D-06120
| | - Bettina Tudzynski
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Schlossplatz 8, Münster, D-48143
| |
Collapse
|
44
|
Kassis JA, Kennison JA, Tamkun JW. Polycomb and Trithorax Group Genes in Drosophila. Genetics 2017; 206:1699-1725. [PMID: 28778878 PMCID: PMC5560782 DOI: 10.1534/genetics.115.185116] [Citation(s) in RCA: 142] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 05/15/2017] [Indexed: 01/08/2023] Open
Abstract
Polycomb group (PcG) and Trithorax group (TrxG) genes encode important regulators of development and differentiation in metazoans. These two groups of genes were discovered in Drosophila by their opposing effects on homeotic gene (Hox) expression. PcG genes collectively behave as genetic repressors of Hox genes, while the TrxG genes are necessary for HOX gene expression or function. Biochemical studies showed that many PcG proteins are present in two protein complexes, Polycomb repressive complexes 1 and 2, which repress transcription via chromatin modifications. TrxG proteins activate transcription via a variety of mechanisms. Here we summarize the large body of genetic and biochemical experiments in Drosophila on these two important groups of genes.
Collapse
Affiliation(s)
- Judith A Kassis
- Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892
| | - James A Kennison
- Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892
| | - John W Tamkun
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, California 95064
| |
Collapse
|
45
|
Sex combs reduced (Scr) regulatory region of Drosophila revisited. Mol Genet Genomics 2017; 292:773-787. [DOI: 10.1007/s00438-017-1309-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 03/08/2017] [Indexed: 10/19/2022]
|
46
|
Three-Dimensional Genome Organization and Function in Drosophila. Genetics 2017; 205:5-24. [PMID: 28049701 PMCID: PMC5223523 DOI: 10.1534/genetics.115.185132] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 10/15/2016] [Indexed: 12/18/2022] Open
Abstract
Understanding how the metazoan genome is used during development and cell differentiation is one of the major challenges in the postgenomic era. Early studies in Drosophila suggested that three-dimensional (3D) chromosome organization plays important regulatory roles in this process and recent technological advances started to reveal connections at the molecular level. Here we will consider general features of the architectural organization of the Drosophila genome, providing historical perspective and insights from recent work. We will compare the linear and spatial segmentation of the fly genome and focus on the two key regulators of genome architecture: insulator components and Polycomb group proteins. With its unique set of genetic tools and a compact, well annotated genome, Drosophila is poised to remain a model system of choice for rapid progress in understanding principles of genome organization and to serve as a proving ground for development of 3D genome-engineering techniques.
Collapse
|
47
|
Erceg J, Pakozdi T, Marco-Ferreres R, Ghavi-Helm Y, Girardot C, Bracken AP, Furlong EEM. Dual functionality of cis-regulatory elements as developmental enhancers and Polycomb response elements. Genes Dev 2017; 31:590-602. [PMID: 28381411 PMCID: PMC5393054 DOI: 10.1101/gad.292870.116] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 03/03/2017] [Indexed: 11/24/2022]
Abstract
Here, Erceg et al. studied the occupancy of the Drosophila PhoRC during embryogenesis and revealed extensive co-occupancy at developmental enhancers. By using an established in vivo assay for Polycomb response element (PRE) activity, they show that a subset of characterized developmental enhancers can function as PREs and silence transcription in a Polycomb-dependent manner, thereby suggesting that reuse of the same elements by the PcG system may help fine-tune gene expression and ensure the timely maintenance of cell identities. Developmental gene expression is tightly regulated through enhancer elements, which initiate dynamic spatio–temporal expression, and Polycomb response elements (PREs), which maintain stable gene silencing. These two cis-regulatory functions are thought to operate through distinct dedicated elements. By examining the occupancy of the Drosophila pleiohomeotic repressive complex (PhoRC) during embryogenesis, we revealed extensive co-occupancy at developmental enhancers. Using an established in vivo assay for PRE activity, we demonstrated that a subset of characterized developmental enhancers can function as PREs, silencing transcription in a Polycomb-dependent manner. Conversely, some classic Drosophila PREs can function as developmental enhancers in vivo, activating spatio–temporal expression. This study therefore uncovers elements with dual function: activating transcription in some cells (enhancers) while stably maintaining transcriptional silencing in others (PREs). Given that enhancers initiate spatio–temporal gene expression, reuse of the same elements by the Polycomb group (PcG) system may help fine-tune gene expression and ensure the timely maintenance of cell identities.
Collapse
Affiliation(s)
- Jelena Erceg
- Genome Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg D69117, Germany
| | - Tibor Pakozdi
- Genome Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg D69117, Germany
| | - Raquel Marco-Ferreres
- Genome Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg D69117, Germany
| | - Yad Ghavi-Helm
- Genome Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg D69117, Germany
| | - Charles Girardot
- Genome Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg D69117, Germany
| | - Adrian P Bracken
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Eileen E M Furlong
- Genome Biology Unit, European Molecular Biology Laboratory (EMBL), Heidelberg D69117, Germany
| |
Collapse
|
48
|
Molecular basis of PRC1 targeting to Polycomb response elements by PhoRC. Genes Dev 2017; 30:1116-27. [PMID: 27151979 PMCID: PMC4863741 DOI: 10.1101/gad.279141.116] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 04/13/2016] [Indexed: 12/11/2022]
Abstract
Here, Frey et al. report the structural basis by which the Drosophila Pho-repressive complex (PhoRC), the only Polycomb group protein complex with sequence-specific DNA-binding activity, binds to Polycomb-repressive complex 1 (PRC1) and thereby recruits it to Polycomb response elements in target genes. Polycomb group (PcG) protein complexes repress transcription by modifying target gene chromatin. In Drosophila, this repression requires association of PcG protein complexes with cis-regulatory Polycomb response elements (PREs), but the interactions permitting formation of these assemblies are poorly understood. We show that the Sfmbt subunit of the DNA-binding Pho-repressive complex (PhoRC) and the Scm subunit of the canonical Polycomb-repressive complex 1 (PRC1) directly bind each other through their SAM domains. The 1.9 Å crystal structure of the Scm-SAM:Sfmbt-SAM complex reveals the recognition mechanism and shows that Sfmbt-SAM lacks the polymerization capacity of the SAM domains of Scm and its PRC1 partner subunit, Ph. Functional analyses in Drosophila demonstrate that Sfmbt-SAM and Scm-SAM are essential for repression and that PhoRC DNA binding is critical to initiate PRC1 association with PREs. Together, this suggests that PRE-tethered Sfmbt-SAM nucleates PRC1 recruitment and that Scm-SAM/Ph-SAM-mediated polymerization then results in the formation of PRC1-compacted chromatin.
Collapse
|
49
|
Chetverina DA, Elizar’ev PV, Lomaev DV, Georgiev PG, Erokhin MM. Control of the gene activity by polycomb and trithorax group proteins in Drosophila. RUSS J GENET+ 2017. [DOI: 10.1134/s1022795417020028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
50
|
Polycomb complexes PRC1 and their function in hematopoiesis. Exp Hematol 2017; 48:12-31. [PMID: 28087428 DOI: 10.1016/j.exphem.2016.12.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 12/19/2016] [Accepted: 12/20/2016] [Indexed: 12/31/2022]
Abstract
Hematopoiesis, the process by which blood cells are continuously produced, is one of the best studied differentiation pathways. Hematological diseases are associated with reiterated mutations in genes encoding important gene expression regulators, including chromatin regulators. Among them, the Polycomb group (PcG) of proteins is an essential system of gene silencing involved in the maintenance of cell identities during differentiation. PcG proteins assemble into two major types of Polycomb repressive complexes (PRCs) endowed with distinct histone-tail-modifying activities. PRC1 complexes are histone H2A E3 ubiquitin ligases and PRC2 trimethylates histone H3. Established conceptions about their activities, mostly derived from work in embryonic stem cells, are being modified by new findings in differentiated cells. Here, we focus on PRC1 complexes, reviewing recent evidence on their intricate architecture, the diverse mechanisms of their recruitment to targets, and the different ways in which they engage in transcriptional control. We also discuss hematopoietic PRC1 gain- and loss-of-function mouse strains, including those that model leukemic and lymphoma diseases, in the belief that these genetic analyses provide the ultimate test for molecular mechanisms driving normal hematopoiesis and hematological malignancies.
Collapse
|