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Zhang X, Xia F, Zhang X, Blumenthal RM, Cheng X. C2H2 Zinc Finger Transcription Factors Associated with Hemoglobinopathies. J Mol Biol 2024; 436:168343. [PMID: 37924864 PMCID: PMC11185177 DOI: 10.1016/j.jmb.2023.168343] [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: 09/04/2023] [Revised: 10/23/2023] [Accepted: 10/30/2023] [Indexed: 11/06/2023]
Abstract
In humans, specific aberrations in β-globin results in sickle cell disease and β-thalassemia, symptoms of which can be ameliorated by increased expression of fetal globin (HbF). Two recent CRISPR-Cas9 screens, centered on ∼1500 annotated sequence-specific DNA binding proteins and performed in a human erythroid cell line that expresses adult hemoglobin, uncovered four groups of candidate regulators of HbF gene expression. They are (1) members of the nucleosome remodeling and deacetylase (NuRD) complex proteins that are already known for HbF control; (2) seven C2H2 zinc finger (ZF) proteins, including some (ZBTB7A and BCL11A) already known for directly silencing the fetal γ-globin genes in adult human erythroid cells; (3) a few other transcription factors of different structural classes that might indirectly influence HbF gene expression; and (4) DNA methyltransferase 1 (DNMT1) that maintains the DNA methylation marks that attract the MBD2-associated NuRD complex to DNA as well as associated histone H3 lysine 9 methylation. Here we briefly discuss the effects of these regulators, particularly C2H2 ZFs, in inducing HbF expression for treating β-hemoglobin disorders, together with recent advances in developing safe and effective small-molecule therapeutics for the regulation of this well-conserved hemoglobin switch.
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Affiliation(s)
- Xing Zhang
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
| | - Fangfang Xia
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Xiaotian Zhang
- Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center Houston, McGovern Medical School, Houston, TX 77030, USA
| | - Robert M Blumenthal
- Department of Medical Microbiology and Immunology, and Program in Bioinformatics, The University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - Xiaodong Cheng
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
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2
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Chambers C, Cermakova K, Chan YS, Kurtz K, Wohlan K, Lewis AH, Wang C, Pham A, Dejmek M, Sala M, Loeza Cabrera M, Aguilar R, Nencka R, Lacorazza HD, Rau RE, Hodges HC. SWI/SNF Blockade Disrupts PU.1-Directed Enhancer Programs in Normal Hematopoietic Cells and Acute Myeloid Leukemia. Cancer Res 2023; 83:983-996. [PMID: 36662812 PMCID: PMC10071820 DOI: 10.1158/0008-5472.can-22-2129] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 11/09/2022] [Accepted: 01/18/2023] [Indexed: 01/21/2023]
Abstract
In acute myeloid leukemia (AML), SWI/SNF chromatin remodeling complexes sustain leukemic identity by driving high levels of MYC. Previous studies have implicated the hematopoietic transcription factor PU.1 (SPI1) as an important target of SWI/SNF inhibition, but PU.1 is widely regarded to have pioneer-like activity. As a result, many questions have remained regarding the interplay between PU.1 and SWI/SNF in AML as well as normal hematopoiesis. Here we found that PU.1 binds to most of its targets in a SWI/SNF-independent manner and recruits SWI/SNF to promote accessibility for other AML core regulatory factors, including RUNX1, LMO2, and MEIS1. SWI/SNF inhibition in AML cells reduced DNA accessibility and binding of these factors at PU.1 sites and redistributed PU.1 to promoters. Analysis of nontumor hematopoietic cells revealed that similar effects also impair PU.1-dependent B-cell and monocyte populations. Nevertheless, SWI/SNF inhibition induced profound therapeutic response in an immunocompetent AML mouse model as well as in primary human AML samples. In vivo, SWI/SNF inhibition promoted leukemic differentiation and reduced the leukemic stem cell burden in bone marrow but also induced leukopenia. These results reveal a variable therapeutic window for SWI/SNF blockade in AML and highlight important off-tumor effects of such therapies in immunocompetent settings. SIGNIFICANCE Disruption of PU.1-directed enhancer programs upon SWI/SNF inhibition causes differentiation of AML cells and induces leukopenia of PU.1-dependent B cells and monocytes, revealing the on- and off-tumor effects of SWI/SNF blockade.
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Affiliation(s)
- Courtney Chambers
- Department of Molecular and Cellular Biology, Center for Precision Environmental Health, Baylor College of Medicine, Houston, Texas
- Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas
- Translational Biology and Molecular Medicine Graduate Program, Baylor College of Medicine, Houston, Texas
| | - Katerina Cermakova
- Department of Molecular and Cellular Biology, Center for Precision Environmental Health, Baylor College of Medicine, Houston, Texas
- Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas
| | - Yuen San Chan
- Department of Molecular and Cellular Biology, Center for Precision Environmental Health, Baylor College of Medicine, Houston, Texas
- Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas
| | - Kristen Kurtz
- Department of Pediatrics, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas
| | - Katharina Wohlan
- Department of Molecular and Cellular Biology, Center for Precision Environmental Health, Baylor College of Medicine, Houston, Texas
| | - Andrew Henry Lewis
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas
| | - Christiana Wang
- Genetics and Genomics Graduate Program, Baylor College of Medicine, Houston, Texas
| | - Anh Pham
- Department of Bioengineering, Rice University, Houston, Texas
| | - Milan Dejmek
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic
| | - Michal Sala
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic
| | - Mario Loeza Cabrera
- Department of Molecular and Cellular Biology, Center for Precision Environmental Health, Baylor College of Medicine, Houston, Texas
- Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas
| | - Rogelio Aguilar
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, Texas
| | - Radim Nencka
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic
| | - H. Daniel Lacorazza
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, Texas
| | - Rachel E. Rau
- Department of Pediatrics, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas
- Stem Cells and Regenerative Medicine Center, Baylor College of Medicine, Houston, Texas
| | - H. Courtney Hodges
- Department of Molecular and Cellular Biology, Center for Precision Environmental Health, Baylor College of Medicine, Houston, Texas
- Department of Bioengineering, Rice University, Houston, Texas
- Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer Center, Houston, Texas
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3
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Wang Z, Wang P, Li Y, Peng H, Zhu Y, Mohandas N, Liu J. Interplay between cofactors and transcription factors in hematopoiesis and hematological malignancies. Signal Transduct Target Ther 2021; 6:24. [PMID: 33468999 PMCID: PMC7815747 DOI: 10.1038/s41392-020-00422-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/16/2020] [Accepted: 10/26/2020] [Indexed: 02/07/2023] Open
Abstract
Hematopoiesis requires finely tuned regulation of gene expression at each stage of development. The regulation of gene transcription involves not only individual transcription factors (TFs) but also transcription complexes (TCs) composed of transcription factor(s) and multisubunit cofactors. In their normal compositions, TCs orchestrate lineage-specific patterns of gene expression and ensure the production of the correct proportions of individual cell lineages during hematopoiesis. The integration of posttranslational and conformational modifications in the chromatin landscape, nucleosomes, histones and interacting components via the cofactor–TF interplay is critical to optimal TF activity. Mutations or translocations of cofactor genes are expected to alter cofactor–TF interactions, which may be causative for the pathogenesis of various hematologic disorders. Blocking TF oncogenic activity in hematologic disorders through targeting cofactors in aberrant complexes has been an exciting therapeutic strategy. In this review, we summarize the current knowledge regarding the models and functions of cofactor–TF interplay in physiological hematopoiesis and highlight their implications in the etiology of hematological malignancies. This review presents a deep insight into the physiological and pathological implications of transcription machinery in the blood system.
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Affiliation(s)
- Zi Wang
- Department of Hematology, Institute of Molecular Hematology, The Second Xiangya Hospital, Central South University, 410011, ChangSha, Hunan, China. .,Molecular Biology Research Center and Hunan Province Key Laboratory of Basic and Applied Hematology, School of Life Sciences, Central South University, 410078, Changsha, Hunan, China.
| | - Pan Wang
- Molecular Biology Research Center and Hunan Province Key Laboratory of Basic and Applied Hematology, School of Life Sciences, Central South University, 410078, Changsha, Hunan, China
| | - Yanan Li
- Molecular Biology Research Center and Hunan Province Key Laboratory of Basic and Applied Hematology, School of Life Sciences, Central South University, 410078, Changsha, Hunan, China
| | - Hongling Peng
- Department of Hematology, Institute of Molecular Hematology, The Second Xiangya Hospital, Central South University, 410011, ChangSha, Hunan, China
| | - Yu Zhu
- Molecular Biology Research Center and Hunan Province Key Laboratory of Basic and Applied Hematology, School of Life Sciences, Central South University, 410078, Changsha, Hunan, China
| | - Narla Mohandas
- Red Cell Physiology Laboratory, New York Blood Center, New York, NY, USA
| | - Jing Liu
- Molecular Biology Research Center and Hunan Province Key Laboratory of Basic and Applied Hematology, School of Life Sciences, Central South University, 410078, Changsha, Hunan, China.
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Identification of a Novel Enhancer/Chromatin Opening Element Associated with High-Level γ-Globin Gene Expression. Mol Cell Biol 2018; 38:MCB.00197-18. [PMID: 30012865 PMCID: PMC6146835 DOI: 10.1128/mcb.00197-18] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 07/10/2018] [Indexed: 01/05/2023] Open
Abstract
The organization of the five β-type globin genes on chromosome 11 reflects the timing of expression during erythroid cell development, with the embryonic ε-globin gene being located at the 5′ end, followed by the two fetal γ-globin genes, and with the adult β- and δ-globin genes being located at the 3′ end. Here, we functionally characterized a DNase I-hypersensitive site (HS) located 4 kb upstream of the Gγ-globin gene (HBG-4kb HS). The organization of the five β-type globin genes on chromosome 11 reflects the timing of expression during erythroid cell development, with the embryonic ε-globin gene being located at the 5′ end, followed by the two fetal γ-globin genes, and with the adult β- and δ-globin genes being located at the 3′ end. Here, we functionally characterized a DNase I-hypersensitive site (HS) located 4 kb upstream of the Gγ-globin gene (HBG-4kb HS). This site is occupied by transcription factors USF1, USF2, EGR1, MafK, and NF-E2 in the human erythroleukemia cell line K562 and exhibits histone modifications typical for enhancers. We generated a synthetic zinc finger (ZF) DNA-binding domain targeting the HBG-4kb HS (HBG-4kb ZF). The HBG-4kb ZF interacted with the target site in vitro and in the context of cells with a high affinity and specificity. Direct delivery of the HBG-4kb ZF to K562 and primary human erythroid cells caused a reduction in γ-globin gene expression which was associated with decreased binding of transcription factors and active histone marks at and downstream of the HS. The data demonstrate that the HBG-4kb HS is important for fetal globin production and suggest that it may act by opening chromatin in a directional manner.
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5
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Iarovaia OV, Kovina AP, Petrova NV, Razin SV, Ioudinkova ES, Vassetzky YS, Ulianov SV. Genetic and Epigenetic Mechanisms of β-Globin Gene Switching. BIOCHEMISTRY (MOSCOW) 2018; 83:381-392. [PMID: 29626925 DOI: 10.1134/s0006297918040090] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Vertebrates have multiple forms of hemoglobin that differ in the composition of their polypeptide chains. During ontogenesis, the composition of these subunits changes. Genes encoding different α- and β-polypeptide chains are located in two multigene clusters on different chromosomes. Each cluster contains several genes that are expressed at different stages of ontogenesis. The phenomenon of stage-specific transcription of globin genes is referred to as globin gene switching. Mechanisms of expression switching, stage-specific activation, and repression of transcription of α- and β-globin genes are of interest from both theoretical and practical points of view. Alteration of balanced expression of globin genes, which usually occurs due to damage to adult β-globin genes, leads to development of severe diseases - hemoglobinopathies. In most cases, reactivation of the fetal hemoglobin gene in patients with β-thalassemia and sickle cell disease can reduce negative consequences of irreversible alterations of expression of the β-globin genes. This review focuses on the current state of research on genetic and epigenetic mechanisms underlying stage-specific switching of β-globin genes.
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Affiliation(s)
- O V Iarovaia
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia.
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6
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Abstract
Naturally occurring, large deletions in the β-globin locus result in hereditary persistence of fetal hemoglobin, a condition that mitigates the clinical severity of sickle cell disease (SCD) and β-thalassemia. We designed a clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein 9 (Cas9) (CRISPR/Cas9) strategy to disrupt a 13.6-kb genomic region encompassing the δ- and β-globin genes and a putative γ-δ intergenic fetal hemoglobin (HbF) silencer. Disruption of just the putative HbF silencer results in a mild increase in γ-globin expression, whereas deletion or inversion of a 13.6-kb region causes a robust reactivation of HbF synthesis in adult erythroblasts that is associated with epigenetic modifications and changes in chromatin contacts within the β-globin locus. In primary SCD patient-derived hematopoietic stem/progenitor cells, targeting the 13.6-kb region results in a high proportion of γ-globin expression in erythroblasts, increased HbF synthesis, and amelioration of the sickling cell phenotype. Overall, this study provides clues for a potential CRISPR/Cas9 genome editing approach to the therapy of β-hemoglobinopathies.
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Kokavec J, Zikmund T, Savvulidi F, Kulvait V, Edelmann W, Skoultchi AI, Stopka T. The ISWI ATPase Smarca5 (Snf2h) Is Required for Proliferation and Differentiation of Hematopoietic Stem and Progenitor Cells. Stem Cells 2017; 35:1614-1623. [PMID: 28276606 DOI: 10.1002/stem.2604] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Revised: 12/14/2016] [Accepted: 01/09/2017] [Indexed: 12/17/2022]
Abstract
The imitation switch nuclear ATPase Smarca5 (Snf2h) is one of the most conserved chromatin remodeling factors. It exists in a variety of oligosubunit complexes that move DNA with respect to the histone octamer to generate regularly spaced nucleosomal arrays. Smarca5 interacts with different accessory proteins and represents a molecular motor for DNA replication, repair, and transcription. We deleted Smarca5 at the onset of definitive hematopoiesis (Vav1-iCre) and observed that animals die during late fetal development due to anemia. Hematopoietic stem and progenitor cells accumulated but their maturation toward erythroid and myeloid lineages was inhibited. Proerythroblasts were dysplastic while basophilic erythroblasts were blocked in G2/M and depleted. Smarca5 deficiency led to increased p53 levels, its activation at two residues, one associated with DNA damage (S15Ph °s ) second with CBP/p300 (K376Ac ), and finally activation of the p53 targets. We also deleted Smarca5 in committed erythroid cells (Epor-iCre) and observed that animals were anemic postnatally. Furthermore, 4-hydroxytamoxifen-mediated deletion of Smarca5 in the ex vivo cultures confirmed its requirement for erythroid cell proliferation. Thus, Smarca5 plays indispensable roles during early hematopoiesis and erythropoiesis. Stem Cells 2017;35:1614-1623.
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Affiliation(s)
- Juraj Kokavec
- BIOCEV, First Faculty of Medicine, Charles University, Czech Republic.,Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Tomas Zikmund
- BIOCEV, First Faculty of Medicine, Charles University, Czech Republic
| | - Filipp Savvulidi
- BIOCEV, First Faculty of Medicine, Charles University, Czech Republic
| | - Vojtech Kulvait
- BIOCEV, First Faculty of Medicine, Charles University, Czech Republic
| | - Winfried Edelmann
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Arthur I Skoultchi
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Tomas Stopka
- BIOCEV, First Faculty of Medicine, Charles University, Czech Republic
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8
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Lee WS, McColl B, Maksimovic J, Vadolas J. Epigenetic interplay at the β-globin locus. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2017; 1860:393-404. [DOI: 10.1016/j.bbagrm.2017.01.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 01/28/2017] [Accepted: 01/30/2017] [Indexed: 02/02/2023]
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9
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Cavazzana M, Antoniani C, Miccio A. Gene Therapy for β-Hemoglobinopathies. Mol Ther 2017; 25:1142-1154. [PMID: 28377044 DOI: 10.1016/j.ymthe.2017.03.024] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 03/15/2017] [Accepted: 03/15/2017] [Indexed: 01/09/2023] Open
Abstract
β-Thalassemia and sickle cell disease (SCD) are the world's two most widely disseminated hereditary hemoglobinopathies. β-Thalassemia originated in the Mediterranean, Middle Eastern, and Asian regions, and SCD originated in central Africa. However, subsequent population migration means that these two diseases are now global and thus constitute a growing health problem in many countries. Despite remarkable improvements in medical care for patients with β-hemoglobinopathies, there is still only one definitive treatment option: allogeneic hematopoietic stem cell (HSC) transplantation. The development of gene therapy for β-hemoglobinopathies has been justified by (1) the limited availability of human leukocyte antigen (HLA)-identical donors, (2) the narrow window of application of HSC transplantation to the youngest patients, and (3) recent advances in HSC-based gene therapy. The huge ongoing efforts in translational medicine and the high number of related publications show that gene therapy has the potential to become the treatment of choice for patients who lack either an HLA genoidentical sibling or an alternative, medically acceptable donor. In this dynamic scientific context, we first summarize the main steps toward clinical translation of this therapeutic approach and then discuss novel lentiviral- and genome editing-based treatment strategies for β-hemoglobinopathies.
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Affiliation(s)
- Marina Cavazzana
- Biotherapy Department, Necker Children's Hospital, Assistance Publique-Hôpitaux de Paris, 75015 Paris, France; Biotherapy Clinical Investigation Center, Assistance Publique-Hôpitaux de Paris, INSERM, Groupe Hospitalier Universitaire Ouest, 75015 Paris, France; INSERM UMR 1163, Laboratory of Human Lymphohematopoiesis, 75015 Paris, France; Paris Descartes, Sorbonne Paris Cité University, Imagine Institute, 75015 Paris, France.
| | - Chiara Antoniani
- Paris Descartes, Sorbonne Paris Cité University, Imagine Institute, 75015 Paris, France; INSERM UMR 1163, Laboratory of Chromatin and Gene Regulation, 75015 Paris, France
| | - Annarita Miccio
- Paris Descartes, Sorbonne Paris Cité University, Imagine Institute, 75015 Paris, France; INSERM UMR 1163, Laboratory of Chromatin and Gene Regulation, 75015 Paris, France.
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10
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Chen C, Wu M, Zhang W, Lu W, Zhang M, Zhang Z, Zhang X, Yuan Z. MicroRNA-939 restricts Hepatitis B virus by targeting Jmjd3-mediated and C/EBPα-coordinated chromatin remodeling. Sci Rep 2016; 6:35974. [PMID: 27779233 PMCID: PMC5078794 DOI: 10.1038/srep35974] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 10/10/2016] [Indexed: 12/18/2022] Open
Abstract
Multi-layered mechanisms of virus host interaction exist for chronic hepatitis B virus (HBV) infection, which have been typically manifested at the microRNA level. Our previous study suggested that miRNA-939 (miR-939) may play a potential role in regulating HBV replication. Here we further investigated the mechanism by which miR-939 regulates HBV life cycle. We found that miR-939 inhibited the abundance of viral RNAs without direct miRNA-mRNA base pairing, but via host factors. Expression profiling and functional validation identified Jmjd3 as a target responsible for miR-939 induced anti-HBV effect. Jmjd3 appeared to enhance the transcription efficiency of HBV enhancer II/core promoter (En II) in a C/EBPα-dependent manner. However, the demethylase activity of Jmjd3 was not required in this process. Rather, Jmjd3’s transactivation activity depended on its interaction with C/EBPα. This coordinated action further recruited the Brm containing SWI/SNF chromatin remodeling complex which promoted the transcription of HBV RNAs. Taken together, we propose that the miR-939-Jmjd3 axis perturbs the accessibility of En II promoter to essential nuclear factors (C/EBPα and SWI/SNF complex) therefore leading to compromised viral RNA synthesis and hence restricted viral multiplication.
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Affiliation(s)
- Cuncun Chen
- Institute of Medical Microbiology and Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai, China.,Key Laboratory of Medical Molecular Virology, Ministry of Education and Health, Shanghai Medical College of Fudan University, Shanghai, China
| | - Min Wu
- Research Units, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Wen Zhang
- Institute of Medical Microbiology and Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai, China.,Key Laboratory of Medical Molecular Virology, Ministry of Education and Health, Shanghai Medical College of Fudan University, Shanghai, China
| | - Wei Lu
- Department of Hepatology, Shanghai Public Health Clinical Center, Shanghai, China
| | - Min Zhang
- Department of Clinical Laboratory, Shanghai Public Health Clinical Center, Shanghai, China
| | - Zhanqing Zhang
- Department of Hepatology, Shanghai Public Health Clinical Center, Shanghai, China
| | - Xiaonan Zhang
- Research Units, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Zhenghong Yuan
- Institute of Medical Microbiology and Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai, China.,Key Laboratory of Medical Molecular Virology, Ministry of Education and Health, Shanghai Medical College of Fudan University, Shanghai, China
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11
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Sarnowska E, Gratkowska DM, Sacharowski SP, Cwiek P, Tohge T, Fernie AR, Siedlecki JA, Koncz C, Sarnowski TJ. The Role of SWI/SNF Chromatin Remodeling Complexes in Hormone Crosstalk. TRENDS IN PLANT SCIENCE 2016; 21:594-608. [PMID: 26920655 DOI: 10.1016/j.tplants.2016.01.017] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 12/14/2015] [Accepted: 01/21/2016] [Indexed: 05/20/2023]
Abstract
SWI/SNF-type ATP-dependent chromatin remodeling complexes (CRCs) are evolutionarily conserved multiprotein machineries controlling DNA accessibility by regulating chromatin structure. We summarize here recent advances highlighting the role of SWI/SNF in the regulation of hormone signaling pathways and their crosstalk in Arabidopsis thaliana. We discuss the functional interdependences of SWI/SNF complexes and key elements regulating developmental and hormone signaling pathways by indicating intriguing similarities and differences in plants and humans, and summarize proposed mechanisms of SWI/SNF action on target loci. We postulate that, given their viability, several plant SWI/SNF mutants may serve as an attractive model for searching for conserved functions of SWI/SNF CRCs in hormone signaling, cell cycle control, and other regulatory pathways.
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Affiliation(s)
| | | | | | - Pawel Cwiek
- Institute of Biochemistry and Biophysics PAS, Pawinskiego 5A, 02-106 Warsaw, Poland
| | - Takayuki Tohge
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany
| | - Alisdair R Fernie
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany
| | | | - Csaba Koncz
- Max-Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829 Köln, Germany; Institute of Plant Biology, Biological Research Center of Hungarian Academy, Temesvári Körút 62, 6724 Szeged, Hungary
| | - Tomasz J Sarnowski
- Institute of Biochemistry and Biophysics PAS, Pawinskiego 5A, 02-106 Warsaw, Poland.
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12
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DeVilbiss AW, Tanimura N, McIver SC, Katsumura KR, Johnson KD, Bresnick EH. Navigating Transcriptional Coregulator Ensembles to Establish Genetic Networks: A GATA Factor Perspective. Curr Top Dev Biol 2016; 118:205-44. [PMID: 27137658 DOI: 10.1016/bs.ctdb.2016.01.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Complex developmental programs require orchestration of intrinsic and extrinsic signals to control cell proliferation, differentiation, and survival. Master regulatory transcription factors are vital components of the machinery that transduce these stimuli into cellular responses. This is exemplified by the GATA family of transcription factors that establish cell type-specific genetic networks and control the development and homeostasis of systems including blood, vascular, adipose, and cardiac. Dysregulated GATA factor activity/expression underlies anemia, immunodeficiency, myelodysplastic syndrome, and leukemia. Parameters governing the capacity of a GATA factor expressed in multiple cell types to generate cell type-specific transcriptomes include selective coregulator usage and target gene-specific chromatin states. As knowledge of GATA-1 mechanisms in erythroid cells constitutes a solid foundation, we will focus predominantly on GATA-1, while highlighting principles that can be extrapolated to other master regulators. GATA-1 interacts with ubiquitous and lineage-restricted transcription factors, chromatin modifying/remodeling enzymes, and other coregulators to activate or repress transcription and to maintain preexisting transcriptional states. Major unresolved issues include: how does a GATA factor selectively utilize diverse coregulators; do distinct epigenetic landscapes and nuclear microenvironments of target genes dictate coregulator requirements; and do gene cohorts controlled by a common coregulator ensemble function in common pathways. This review will consider these issues in the context of GATA factor-regulated hematopoiesis and from a broader perspective.
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Affiliation(s)
- A W DeVilbiss
- UW-Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; UW-Madison Blood Research Program, Madison, WI, United States
| | - N Tanimura
- UW-Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; UW-Madison Blood Research Program, Madison, WI, United States
| | - S C McIver
- UW-Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; UW-Madison Blood Research Program, Madison, WI, United States
| | - K R Katsumura
- UW-Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; UW-Madison Blood Research Program, Madison, WI, United States
| | - K D Johnson
- UW-Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; UW-Madison Blood Research Program, Madison, WI, United States
| | - E H Bresnick
- UW-Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States; UW-Madison Blood Research Program, Madison, WI, United States.
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13
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Thompson KW, Marquez SB, Lu L, Reisman D. Induction of functional Brm protein from Brm knockout mice. Oncoscience 2015; 2:349-61. [PMID: 26097869 PMCID: PMC4468321 DOI: 10.18632/oncoscience.153] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Accepted: 04/08/2015] [Indexed: 12/18/2022] Open
Abstract
Once the knockout of the Brm gene was found to be nontumorigenic in mice, the study of BRM's involvement in cancer seemed less important compared with that of its homolog, Brg1. This has likely contributed to the disparity that has been observed in the publication ratio between BRG1 and BRM. We show that a previously published Brm knockout mouse is an incomplete knockout whereby a truncated isoform of Brm is detected in normal tissue and in tumors. We show that this truncated Brm isoform has functionality comparable to wild type Brm. By immunohistochemistry (IHC), this truncated Brm is undetectable in normal lung tissue and is minimal to very low in Brmnull tumors. However, it is significant in a subset (~40%) of Brg1/Brm double knockout (DKO) tumors that robustly express this truncated BRM, which in part stems from an increase in Brm mRNA levels. Thus, it is likely that this mutant mouse model does not accurately reflect the role that Brm plays in cancer development. We suggest that the construction of a completely new mouse Brm knockout, where Brm is functionally absent, is needed to determine whether or not Brm is actually tumorigenic and if Brm might be a tumor suppressor.
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Affiliation(s)
- Kenneth W. Thompson
- Division of Hematology and Oncology, Department of Medicine, University of Florida, Gainesville, Florida, USA
| | - Stefanie B. Marquez
- Division of Hematology and Oncology, Department of Medicine, University of Florida, Gainesville, Florida, USA
| | - Li Lu
- Department of Pathology, University of Florida, Gainesville, Florida, USA
| | - David Reisman
- Division of Hematology and Oncology, Department of Medicine, University of Florida, Gainesville, Florida, USA
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14
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Gorzkiewicz A, Walczewska A. Functions of the Ikaros transcription factor and the role of IKZF1 gene defects in hematological malignancies. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.achaem.2014.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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15
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Tacheny A, Dieu M, Arnould T, Renard P. Mass spectrometry-based identification of proteins interacting with nucleic acids. J Proteomics 2013; 94:89-109. [PMID: 24060998 DOI: 10.1016/j.jprot.2013.09.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 08/19/2013] [Accepted: 09/13/2013] [Indexed: 01/02/2023]
Abstract
The identification of the regulatory proteins that control DNA transcription as well as RNA stability and translation represents a key step in the comprehension of gene expression regulation. Those proteins can be purified by DNA- or RNA-affinity chromatography, followed by identification by mass spectrometry. Although very simple in the concept, this represents a real technological challenge due to the low abundance of regulatory proteins compared to the highly abundant proteins binding to nucleic acids in a nonsequence-specific manner. Here we review the different strategies that have been set up to reach this purpose, discussing the key parameters that should be considered to increase the chances of success. Typically, two categories of biological questions can be distinguished: the identification of proteins that specifically interact with a precisely defined binding site, mostly addressed by quantitative mass spectrometry, and the identification in a non-comparative manner of the protein complexes recruited by a poorly characterized long regulatory region of nucleic acids. Finally, beside the numerous studies devoted to in vitro-assembled nucleic acid-protein complexes, the scarce data reported on proteomic analyses of in vivo-assembled complexes are described, with a special emphasis on the associated challenges.
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Affiliation(s)
- A Tacheny
- Laboratory of Biochemistry and Cell Biology (URBC), NAmur Research Institute for LIfe Sciences (NARILIS), University of Namur, 61 rue de Bruxelles, 5000 Namur, Belgium
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16
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Direct protein interactions are responsible for Ikaros-GATA and Ikaros-Cdk9 cooperativeness in hematopoietic cells. Mol Cell Biol 2013; 33:3064-76. [PMID: 23732910 DOI: 10.1128/mcb.00296-13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ikaros (Ik) is a critical regulator of hematopoietic gene expression. Here, we established that the Ik interactions with GATA transcription factors and cyclin-dependent kinase 9 (Cdk9), a component of the positive transcription elongation factor b (P-TEFb), are required for transcriptional activation of Ik target genes. A detailed dissection of Ik-GATA and Ik-Cdk9 protein interactions indicated that the C-terminal zinc finger domain of Ik interacts directly with the C-terminal zinc fingers of GATA1, GATA2, and GATA3, whereas the N-terminal zinc finger domain of Ik is required for interaction with the kinase and T-loop domains of Cdk9. The relevance of these interactions was demonstrated in vivo in COS-7 and primary hematopoietic cells, in which Ik facilitated Cdk9 and GATA protein recruitment to gene promoters and transcriptional activation. Moreover, the oncogenic isoform Ik6 did not efficiently interact with Cdk9 or GATA proteins in vivo and perturbed Cdk9/P-TEFb recruitment to Ik target genes, thereby affecting transcription elongation. Finally, characterization of a novel nuclear Ik isoform revealed that Ik exon 6 is dispensable for interactions with Mi2 and GATA proteins but is essential for the Cdk9 interaction. Thus, Ik is central to the Ik-GATA-Cdk9 regulatory network, which is broadly utilized for gene regulation in hematopoietic cells.
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17
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Hu G, Schones DE, Cui K, Ybarra R, Northrup D, Tang Q, Gattinoni L, Restifo NP, Huang S, Zhao K. Regulation of nucleosome landscape and transcription factor targeting at tissue-specific enhancers by BRG1. Genome Res 2011; 21:1650-8. [PMID: 21795385 DOI: 10.1101/gr.121145.111] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Enhancers of transcription activate transcription via binding of sequence-specific transcription factors to their target sites in chromatin. In this report, we identify GATA1-bound distal sites genome-wide and find a global reorganization of the nucleosomes at these potential enhancers during differentiation of hematopoietic stem cells (HSCs) to erythrocytes. We show that the catalytic subunit BRG1 of BAF complexes localizes to these distal sites during differentiation and generates a longer nucleosome linker region surrounding the GATA1 sites by shifting the flanking nucleosomes away. Intriguingly, we find that the nucleosome shifting specifically facilitates binding of TAL1 but not GATA1 and is linked to subsequent transcriptional regulation of target genes.
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Affiliation(s)
- Gangqing Hu
- Laboratory of Molecular Immunology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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18
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Bottardi S, Zmiri FA, Bourgoin V, Ross J, Mavoungou L, Milot E. Ikaros interacts with P-TEFb and cooperates with GATA-1 to enhance transcription elongation. Nucleic Acids Res 2011; 39:3505-19. [PMID: 21245044 PMCID: PMC3089448 DOI: 10.1093/nar/gkq1271] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Ikaros is associated with both gene transcriptional activation and repression in lymphocytes. Ikaros acts also as repressor of human γ-globin (huγ-) gene transcription in fetal and adult erythroid cells. Whether and eventually, how Ikaros can function as a transcriptional activator in erythroid cells remains poorly understood. Results presented herein demonstrate that Ikaros is a developmental-specific activator of huγ-gene expression in yolk sac erythroid cells. Molecular analysis in primary cells revealed that Ikaros interacts with Gata-1 and favors Brg1 recruitment to the human β-globin Locus Control Region and the huγ-promoters, supporting long-range chromatin interactions between these regions. Additionally, we demonstrate that Ikaros contributes to transcription initiation and elongation of the huγ-genes, since it is not only required for TBP and RNA Polymerase II (Pol II) assembly at the huγ-promoters but also for conversion of Pol II into the elongation-competent phosphorylated form. In agreement with the latter, we show that Ikaros interacts with Cyclin-dependent kinase 9 (Cdk9), which contributes to efficient transcription elongation by phosphorylating the C-terminal domain of the large subunit of Pol II on Serine 2, and favours Cdk9 recruitment to huγ-promoters. Our results show that Ikaros exerts dual functionality during gene activation, by promoting efficient transcription initiation and elongation.
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Affiliation(s)
- Stefania Bottardi
- Maisonneuve-Rosemont Hospital Research Center, Maisonneuve-Rosemont Hospital and Faculty of Medicine, University of Montreal, 5415 boulevard l'Assomption, Montreal, Quebec, Canada H1T 2M4
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19
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Bakshi R, Hassan MQ, Pratap J, Lian JB, Montecino MA, van Wijnen AJ, Stein JL, Imbalzano AN, Stein GS. The human SWI/SNF complex associates with RUNX1 to control transcription of hematopoietic target genes. J Cell Physiol 2010; 225:569-76. [PMID: 20506188 DOI: 10.1002/jcp.22240] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The acute myeloid leukemia 1 (AML1, RUNX1) transcription factor is a key regulator of hematopoietic differentiation that forms multi-protein complexes with co-regulatory proteins. These complexes are assembled at target gene promoters in nuclear microenvironments to mediate phenotypic gene expression and chromatin-related epigenetic modifications. Here, immunofluorescence microscopy and biochemical assays are used to show that RUNX1 associates with the human ATP-dependent SWI/SNF chromatin remodeling complex. The SWI/SNF subunits BRG1 and INI1 bind in vivo to RUNX1 target gene promoters (e.g., GMCSF, IL3, MCSF-R, MIP, and p21). These interactions correlate with histone modifications characteristic of active chromatin, including acetylated H4 and dimethylated H3 lysine 4. Downregulation of RUNX1 by RNA interference diminishes the binding of BRG1 and INI1 at selected target genes. Taken together, our findings indicate that RUNX1 interacts with the human SWI/SNF complex to control hematopoietic-specific gene expression.
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Affiliation(s)
- Rachit Bakshi
- Department of Cell Biology and Cancer Center, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
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20
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Jawaid K, Wahlberg K, Thein SL, Best S. Binding patterns of BCL11A in the globin and GATA1 loci and characterization of the BCL11A fetal hemoglobin locus. Blood Cells Mol Dis 2010; 45:140-6. [DOI: 10.1016/j.bcmd.2010.05.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Accepted: 05/07/2010] [Indexed: 01/12/2023]
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21
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Sankaran VG, Xu J, Orkin SH. Advances in the understanding of haemoglobin switching. Br J Haematol 2010; 149:181-94. [PMID: 20201948 DOI: 10.1111/j.1365-2141.2010.08105.x] [Citation(s) in RCA: 152] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The study of haemoglobin switching has represented a focus in haematology due in large part to the clinical relevance of the fetal to adult haemoglobin switch for developing targeted approaches to ameliorate the severity of the beta-haemoglobinopathies. Additionally, the process by which this switch occurs represents an important paradigm for developmental gene regulation. In this review, we provide an overview of both the embryonic primitive to definitive switch in haemoglobin expression, as well as the fetal to adult switch that is unique to humans and old world monkeys. We discuss the nature of these switches and models of their regulation. The factors that have been suggested to regulate this process are then discussed. With the increased understanding and discovery of molecular regulators of haemoglobin switching, such as BCL11A, new avenues of research may lead ultimately to novel therapeutic, mechanism-based approaches to fetal haemoglobin reactivation in patients.
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Affiliation(s)
- Vijay G Sankaran
- Division of Hematology/Oncology, Children's Hospital Boston, Harvard Medical School, Boston, MA, USA
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22
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De Andrade T, Moreira L, Duarte A, Lanaro C, De Albuquerque D, Saad S, Costa F. Expression of new red cell-related genes in erythroid differentiation. Biochem Genet 2009; 48:164-71. [PMID: 19941055 DOI: 10.1007/s10528-009-9310-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2008] [Accepted: 10/22/2009] [Indexed: 10/20/2022]
Abstract
Using a suppression subtractive hybridization method, we have previously identified genes differentially expressed in erythroid cells heterozygous for large deletions in beta-like globin cluster. Herein, we investigated the expression of four newly detected red cell-related genes in erythroid differentiation. ARID1B and TSPYL1, genes with chromatin remodeling properties, presented similar patterns of expression with an upregulation after erythropoietin (EPO) addition, similar to previous data found in reticulocytes. ZHX2, a transcriptional repressor, was downregulated, and a redoxin-related gene, SH3BGRL2, had higher levels of expression on differentiation. These are the first investigations of these newly described genes in erythroid differentiation and demonstrate that the expression of these genes is affected by EPO stimulation. These genes may participate in globin regulation and may be important in the normal physiology of erythrocytes.
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Affiliation(s)
- Tiago De Andrade
- Federal University of Alagoas, Campus Arapiraca, Arapiraca, AL, Brazil.
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23
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Perrine SP, Mankidy R, Boosalis MS, Bieker JJ, Faller DV. Erythroid Kruppel-like factor (EKLF) is recruited to the gamma-globin gene promoter as a co-activator and is required for gamma-globin gene induction by short-chain fatty acid derivatives. Eur J Haematol 2009; 82:466-76. [PMID: 19220418 DOI: 10.1111/j.1600-0609.2009.01234.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVES The erythroid Kruppel-like factor (EKLF) is an essential transcription factor for beta-type globin gene switching, and specifically activates transcription of the adult beta-globin gene promoter. We sought to determine if EKLF is also required for activation of the gamma-globin gene by short-chain fatty acid (SCFA) derivatives, which are now entering clinical trials. METHODS The functional and physical interaction of EKLF and co-regulatory molecules with the endogenous human globin gene promoters was studied in primary human erythroid progenitors and cell lines, using chromatin immunoprecipitation (ChIP) assays and genetic manipulation of the levels of EKLF and co-regulators. RESULTS AND CONCLUSIONS Knockdown of EKLF prevents SCFA-induced expression of the gamma-globin promoter in a stably expressed microLCRbeta(pr)R(luc) (A)gamma(pr)F(luc) cassette, and prevents induction of the endogenous gamma-globin gene in primary human erythroid progenitors. EKLF is actively recruited to endogenous gamma-globin gene promoters after exposure of primary human erythroid progenitors, and murine hematopoietic cell lines, to SCFA derivatives. The core ATPase BRG1 subunit of the human SWI/WNF complex, a ubiquitous multimeric complex that regulates gene expression by remodeling nucleosomal structure, is also required for gamma-globin gene induction by SCFA derivatives. BRG1 is actively recruited to the endogenous gamma-globin promoter of primary human erythroid progenitors by exposure to SCFA derivatives, and this recruitment is dependent upon the presence of EKLF. These findings demonstrate that EKLF, and the co-activator BRG1, previously demonstrated to be required for definitive or adult erythropoietic patterns of globin gene expression, are co-opted by SCFA derivatives to activate the fetal globin genes.
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Affiliation(s)
- Susan P Perrine
- Cancer Center, Boston University School of Medicine, Boston, MA 02118, USA
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24
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Ikaros and GATA-1 combinatorial effect is required for silencing of human gamma-globin genes. Mol Cell Biol 2008; 29:1526-37. [PMID: 19114560 DOI: 10.1128/mcb.01523-08] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
During development and erythropoiesis, globin gene expression is finely modulated through an important network of transcription factors and chromatin modifying activities. In this report we provide in vivo evidence that endogenous Ikaros is recruited to the human beta-globin locus and targets the histone deacetylase HDAC1 and the chromatin remodeling protein Mi-2 to the human gamma-gene promoters, thereby contributing to gamma-globin gene silencing at the time of the gamma- to beta-globin gene transcriptional switch. We show for the first time that Ikaros interacts with GATA-1 and enhances the binding of the latter to different regulatory regions across the locus. Consistent with these results, we show that the combinatorial effect of Ikaros and GATA-1 impairs close proximity between the locus control region and the human gamma-globin genes. Since the absence of Ikaros also affects GATA-1 recruitment to GATA-2 promoter, we propose that the combinatorial effect of Ikaros and GATA-1 is not restricted to globin gene regulation.
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25
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Ko M, Sohn DH, Chung H, Seong RH. Chromatin remodeling, development and disease. Mutat Res 2008; 647:59-67. [PMID: 18786551 DOI: 10.1016/j.mrfmmm.2008.08.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2008] [Revised: 07/30/2008] [Accepted: 08/07/2008] [Indexed: 05/26/2023]
Abstract
Development is a stepwise process in which multi-potent progenitor cells undergo lineage commitment, differentiation, proliferation and maturation to produce mature cells with restricted developmental potentials. This process is directed by spatiotemporally distinct gene expression programs that allow cells to stringently orchestrate intricate transcriptional activation or silencing events. In eukaryotes, chromatin structure contributes to developmental progression as a blueprint for coordinated gene expression by actively participating in the regulation of gene expression. Changes in higher order chromatin structure or covalent modification of its components are considered to be critical events in dictating lineage-specific gene expression during development. Mammalian cells utilize multi-subunit nuclear complexes to alter chromatin structure. Histone-modifying complex catalyzes covalent modifications of histone tails including acetylation, methylation, phosphorylation and ubiquitination. ATP-dependent chromatin remodeling complex, which disrupts histone-DNA contacts and induces nucleosome mobilization, requires energy from ATP hydrolysis for its catalytic activity. Here, we discuss the diverse functions of ATP-dependent chromatin remodeling complexes during mammalian development. In particular, the roles of these complexes during embryonic and hematopoietic development are reviewed in depth. In addition, pathological conditions such as tumor development that are induced by mutation of several key subunits of the chromatin remodeling complex are discussed, together with possible mechanisms that underlie tumor suppression by the complex.
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Affiliation(s)
- Myunggon Ko
- Department of Biological Sciences, Institute of Molecular Biology and Genetics, Seoul National University, Seoul 151-742, Republic of Korea
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26
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Fetal hemoglobin chemical inducers for treatment of hemoglobinopathies. Ann Hematol 2008; 88:505-28. [PMID: 19011856 DOI: 10.1007/s00277-008-0637-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2008] [Accepted: 10/27/2008] [Indexed: 12/29/2022]
Abstract
The switch from fetal ((G)gamma and (A)gamma) to adult (beta and delta) globin gene expression occurs at birth, leading to the gradual replacement of HbF with HbA. Genetic regulation of this switch has been studied for decades, and the molecular mechanisms underlying this developmental change in gene expression have been in part elucidated. The understanding of the developmental regulation of gamma-globin gene expression was paralleled by the identification of a series of chemical compounds able to reactivate HbF synthesis in vitro and in vivo in adult erythroid cells. Reactivation of HbF expression is an important therapeutic option in patients with hemoglobin disorders, such as sickle cell anemia and beta-thalassemia. These HbF inducers can be grouped in several classes based on their chemical structures and mechanisms of action. Clinical studies with some of these agents have shown that they were effective, in a part of patients, in ameliorating the clinical condition. The increase in HbF in response to these drugs varies among patients with beta-thalassemia and sickle cell disease due to individual genetic determinants.
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27
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Ni Z, Abou El Hassan M, Xu Z, Yu T, Bremner R. The chromatin-remodeling enzyme BRG1 coordinates CIITA induction through many interdependent distal enhancers. Nat Immunol 2008; 9:785-93. [PMID: 18500344 DOI: 10.1038/ni.1619] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2007] [Accepted: 04/21/2008] [Indexed: 01/22/2023]
Abstract
The chromatin-remodeling enzyme BRG1 is critical for interferon-gamma (IFN-gamma)-mediated gene induction. Promoter-proximal elements are sufficient to mediate BRG1 dependency at some IFN-gamma targets. In contrast, we show here that at CIITA, which encodes the 'master regulator' of induction of major histocompatibility complex class II, distal elements conferred BRG1 dependency. At the uninduced locus, many sites formed BRG1-independent loops. One loop juxtaposed a far downstream element adjacent to a far upstream site. Notably, BRG1 was recruited to the latter site, which triggered the appearance of a histone 'mark' linked to activation. This subtle change was crucial, as subsequent IFN-gamma-induced recruitment of the transcription factors STAT1, IRF1 and p300, as well as histone modifications, accessibility and additional loops, showed BRG1 dependency. Like BRG1, each remote element was critical for the induction of CIITA expression. Thus, BRG1 regulates CIITA through many interdependent remote enhancers, not through the promoter alone.
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Affiliation(s)
- Zuyao Ni
- Genetics and Development Division, Toronto Western Research Institute, University Health Network, Toronto, Ontario M5T 2S8, Canada
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28
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Keys JR, Tallack MR, Zhan Y, Papathanasiou P, Goodnow CC, Gaensler KM, Crossley M, Dekker J, Perkins AC. A mechanism for Ikaros regulation of human globin gene switching. Br J Haematol 2008; 141:398-406. [PMID: 18318763 DOI: 10.1111/j.1365-2141.2008.07065.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The human beta globin locus consists of an upstream LCR and functional genes arranged sequentially in the order of their expression during development: 5'-HBE1, HBG2, HBG1, HBD, HBB-3'. Haemoglobin switching entails the successive recruitment of these genes into an active chromatin hub (ACH). Here we show that the transcription factor Ikaros plays a major role in the formation of the beta-globin ACH, and in haemoglobin switching. In Plastic mice, where the DNA-binding region of Ikaros is disrupted by a point mutation, there is concomitant marked down-regulation of HBB, and up-regulation of HBG expression. We show for the first time Ikaros and its family member Eos, bind to critical cis elements implicated in haemoglobin switching and deletional hereditary persistence of fetal haemoglobin (HPFH). Chromatin conformation capture (3C) data demonstrated that Ikaros facilitates long-distance DNA looping between the LCR and a region upstream of HBD. This study provides new insights into the mechanism of stage-specific assembly of the beta-globin ACH, and HPFH.
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Affiliation(s)
- Janelle R Keys
- Institute for Molecular Bioscience, Queensland Bioscience Precinct, University of Queensland, Queensland, Australia
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29
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Abstract
Transcriptional networks orchestrate fundamental biological processes, including hematopoiesis, in which hematopoietic stem cells progressively differentiate into specific progenitors cells, which in turn give rise to the diverse blood cell types. Whereas transcription factors recruit coregulators to chromatin, leading to targeted chromatin modification and recruitment of the transcriptional machinery, many questions remain unanswered regarding the underlying molecular mechanisms. Furthermore, how diverse cell type-specific transcription factors function cooperatively or antagonistically in distinct cellular contexts is poorly understood, especially since genes in higher eukaryotes commonly encompass broad chromosomal regions (100 kb and more) and are littered with dispersed regulatory sequences. In this article, we describe an important set of transcription factors and coregulators that control erythropoiesis and highlight emerging transcriptional mechanisms and principles. It is not our intent to comprehensively survey all factors implicated in the transcriptional control of erythropoiesis, but rather to underscore specific mechanisms, which have potential to be broadly relevant to transcriptional control in diverse systems.
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30
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Svasti S, Paksua S, Nuchprayoon I, Winichagoon P, Fucharoen S. Characterization of a novel deletion causing (deltabeta)0-thalassemia in a Thai family. Am J Hematol 2007; 82:155-61. [PMID: 17034028 DOI: 10.1002/ajh.20781] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A novel deletion of the human beta-globin gene cluster associated with the increased level of fetal hemoglobin (Hb F) in adult life has been demonstrated in a Thai family. A Thai girl who was mistakenly diagnosed as beta-thalassemia/HbE is found to be the compound heterozygote of this mutation and Hb E. The heterozygous father had mild hypochromic and microcytic red blood cells and a high level of Hb F (23.2%). Polymorphic restriction sites in the beta-globin gene cluster identified the homozygous alleles, which localized the deletion region between the psibeta-globin and the 3' beta-globin genes. DNA polymerase that can amplify a long DNA template was employed to examine DNA fragment encompassing this deletion. A 11.3 kilobases (kb) of DNA deletion, beginning approximately 3.1 kb 5' to the delta-globin gene and end in the intron 2 of the beta-globin gene was detected. DNA analysis revealed that this is a case of (deltabeta)(0)-thalassemia with a novel mutation, which can lead to a mild form of beta-thalassemia upon interaction with Hb E.
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Affiliation(s)
- Saovaros Svasti
- Thalassemia Research Center, Institute of Science and Technology for Research and Development, Mahidol University, Salaya, Nakornpathom, Thailand
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31
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Xu Z, Meng X, Cai Y, Koury M, Brandt S. Recruitment of the SWI/SNF protein Brg1 by a multiprotein complex effects transcriptional repression in murine erythroid progenitors. Biochem J 2006; 399:297-304. [PMID: 16800816 PMCID: PMC1609906 DOI: 10.1042/bj20060873] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
SWI/SNF complexes are involved in both activation and repression of transcription. While one of two homologous ATPases, Brg1 [Brm (Brahma)-related gene 1] or Brm, is required for their chromatin remodelling function, less is known about how these complexes are recruited to DNA. We recently established that a DNA-binding complex containing TAL1/SCL, E47, GATA-1, LMO2 and Ldb1 stimulates P4.2 (protein 4.2) transcription in erythroid progenitors via two E box-GATA elements in the gene's proximal promoter. We show here that the SWI/SNF protein Brg1 is also associated with this complex and that both the E box and GATA DNA-binding sites in these elements are required for Brg1 recruitment. Further, Brg1 occupancy of the P4.2 promoter decreased with terminal erythroid differentiation in association with increased P4.2 transcription, while enforced expression of Brg1 in murine erythroleukaemia cells reduced P4.2 gene expression. Overexpression of Brg1 was associated with increased occupancy of the P4.2 promoter by the nuclear co-repressor mSin3A and HDAC2 (histone deacetylase 2) and with reduced histone H3 and H4 acetylation. Finally, a specific HDAC inhibitor attenuated Brg1-directed repression of P4.2 promoter activity in transfected cells. These results provide insight into the mechanism by which SWI/SNF proteins are recruited to promoters and suggest that transcription of P4.2, and most likely other genes, is actively repressed until the terminal differentiation of erythroid progenitors.
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Affiliation(s)
- Zhixiong Xu
- *Department of Medicine, Vanderbilt University, Nashville, TN 37232, U.S.A
- †VA Tennessee Valley Healthcare System, Nashville, TN 37212, U.S.A
| | - Xianzhang Meng
- *Department of Medicine, Vanderbilt University, Nashville, TN 37232, U.S.A
| | - Ying Cai
- *Department of Medicine, Vanderbilt University, Nashville, TN 37232, U.S.A
| | - Mark J. Koury
- *Department of Medicine, Vanderbilt University, Nashville, TN 37232, U.S.A
- †VA Tennessee Valley Healthcare System, Nashville, TN 37212, U.S.A
| | - Stephen J. Brandt
- *Department of Medicine, Vanderbilt University, Nashville, TN 37232, U.S.A
- †VA Tennessee Valley Healthcare System, Nashville, TN 37212, U.S.A
- ‡Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, U.S.A
- §Department of Cancer Biology, Vanderbilt University, Nashville, TN 37232, U.S.A
- ∥Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, TN 37232, U.S.A
- To whom correspondence should be addressed, at Division of Hematology–Oncology, Room 777, Preston Research Building, Vanderbilt University Medical Center, Nashville, TN 37232, U.S.A. (email )
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Dostie J, Richmond TA, Arnaout RA, Selzer RR, Lee WL, Honan TA, Rubio ED, Krumm A, Lamb J, Nusbaum C, Green RD, Dekker J. Chromosome Conformation Capture Carbon Copy (5C): a massively parallel solution for mapping interactions between genomic elements. Genes Dev 2006; 16:1299-309. [PMID: 16954542 PMCID: PMC1581439 DOI: 10.1101/gr.5571506] [Citation(s) in RCA: 823] [Impact Index Per Article: 45.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2006] [Accepted: 07/25/2006] [Indexed: 01/12/2023]
Abstract
Physical interactions between genetic elements located throughout the genome play important roles in gene regulation and can be identified with the Chromosome Conformation Capture (3C) methodology. 3C converts physical chromatin interactions into specific ligation products, which are quantified individually by PCR. Here we present a high-throughput 3C approach, 3C-Carbon Copy (5C), that employs microarrays or quantitative DNA sequencing using 454-technology as detection methods. We applied 5C to analyze a 400-kb region containing the human beta-globin locus and a 100-kb conserved gene desert region. We validated 5C by detection of several previously identified looping interactions in the beta-globin locus. We also identified a new looping interaction in K562 cells between the beta-globin Locus Control Region and the gamma-beta-globin intergenic region. Interestingly, this region has been implicated in the control of developmental globin gene switching. 5C should be widely applicable for large-scale mapping of cis- and trans- interaction networks of genomic elements and for the study of higher-order chromosome structure.
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Affiliation(s)
- Josée Dostie
- Program in Gene Function and Expression and Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605-0103, USA
| | | | - Ramy A. Arnaout
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02141-2023, USA
- Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts 02115-6110, USA
- Program for Evolutionary Dynamics, Harvard University, Cambridge, Massachusetts 02138-3758, USA
| | | | - William L. Lee
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02141-2023, USA
| | - Tracey A. Honan
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02141-2023, USA
| | - Eric D. Rubio
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington 98104, USA
| | - Anton Krumm
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington 98104, USA
| | - Justin Lamb
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02141-2023, USA
| | - Chad Nusbaum
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02141-2023, USA
| | | | - Job Dekker
- Program in Gene Function and Expression and Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605-0103, USA
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de Andrade TG, Peterson KR, Cunha AF, Moreira LS, Fattori A, Saad STO, Costa FF. Identification of novel candidate genes for globin regulation in erythroid cells containing large deletions of the human β-globin gene cluster. Blood Cells Mol Dis 2006; 37:82-90. [PMID: 16952470 DOI: 10.1016/j.bcmd.2006.07.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2006] [Revised: 07/01/2006] [Accepted: 07/11/2006] [Indexed: 10/24/2022]
Abstract
The genetic mechanisms underlying the continued expression of the gamma-globin genes during the adult stage in deletional hereditary persistence of fetal hemoglobin (HPFH) and deltabeta-thalassemias are not completely understood. Herein, we investigated the possible involvement of transcription factors, using the suppression subtractive hybridization (SSH) method as an initial screen to identify differentially expressed transcripts in reticulocytes from a normal and a HPFH-2 subject. Some of the detectable transcripts may participate in globin gene regulation. Quantitative real-time PCR (qRT-PCR) experiments confirmed the downregulation of ZHX2, a transcriptional repressor, in two HPFH-2 subjects and in a carrier of the Sicilian deltabeta-thalassemia trait. The chromatin remodeling factors ARID1B and TSPYL1 had a very similar pattern of expression with an incremental increase in HPFH and decreased expression in deltabeta-thalassemia. These differences suggest a mechanism to explain the heterocellular and pancellular distribution of fetal hemoglobin in deltabeta-thalassemia and deletional HPFH, respectively. Interestingly, alpha-globin mRNA levels were decreased, similar to beta-globin in all reticulocyte samples analyzed.
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Affiliation(s)
- Tiago Gomes de Andrade
- Institute of Medical and Biological Sciences, Federal University of Alagoas, Maceió, AL, Brazil.
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34
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Bank A, O'Neill D, Lopez R, Pulte D, Ward M, Mantha S, Richardson C. Role of intergenic human gamma-delta-globin sequences in human hemoglobin switching and reactivation of fetal hemoglobin in adult erythroid cells. Ann N Y Acad Sci 2006; 1054:48-54. [PMID: 16339651 DOI: 10.1196/annals.1345.057] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The details of the molecular events regulating normal human hemoglobin switching and reactivation of fetal hemoglobin in adult hematopoietic cells are unclear. The potential role of sequences between the human gamma- and delta-globin genes (intergenic gamma-delta sequences) in this process has been in question until the recent finding that two patients homozygous for the Corfu deletion, involving the loss of 7.2 kb of the intergenic gamma-delta region upstream of the delta gene, have 88% and 90% fetal hemoglobin, only mild anemia, and no transfusion requirements. These results provide the first strong evidence in humans that the gamma-delta intergenic sequences alone have a role in the reactivation of fetal hemoglobin in adult-type cells, and perhaps are involved in normal hemoglobin switching as well. The polypyrimidine (PYR) complex is a hematopoietic cell-specific and stage-specific chromatin remodeling complex that binds upstream of the human delta-globin gene within the Corfu deletion. Deletion of the PYR binding site has been shown to delay human gamma-to-beta globin switching. The PYR complex is present in adult human hematopoietic cells and absent in fetal-embryonic cells: properties of a globin-switching complex. Taken together, the data from patients with the Corfu deletion and the PYR complex results suggest that intergenic gamma-delta sequences are involved in human gamma-to-beta globin switching and reactivation of fetal hemoglobin in adult cells.
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Affiliation(s)
- Arthur Bank
- Department of Medicine, Columbia University, 701 West 168th St., Rm. 1604, New York, NY 10032, USA.
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35
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de la Serna IL, Ohkawa Y, Imbalzano AN. Chromatin remodelling in mammalian differentiation: lessons from ATP-dependent remodellers. Nat Rev Genet 2006; 7:461-73. [PMID: 16708073 DOI: 10.1038/nrg1882] [Citation(s) in RCA: 281] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The initiation of cellular differentiation involves alterations in gene expression that depend on chromatin changes, at the level of both higher-order structures and individual genes. Consistent with this, chromatin-remodelling enzymes have key roles in differentiation and development. The functions of ATP-dependent chromatin-remodelling enzymes have been studied in several mammalian differentiation pathways, revealing cell-type-specific and gene-specific roles for these proteins that add another layer of precision to the regulation of differentiation. Recent studies have also revealed a role for ATP-dependent remodelling in regulating the balance between proliferation and differentiation, and have uncovered intriguing links between chromatin remodelling and other cellular processes during differentiation, including recombination, genome organization and the cell cycle.
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Affiliation(s)
- Ivana L de la Serna
- Department of Biochemistry and Cancer Biology, Medical University of Ohio, 3035 Arlington Avenue, Toledo, Ohio 43606, USA
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36
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Simone C. SWI/SNF: the crossroads where extracellular signaling pathways meet chromatin. J Cell Physiol 2006; 207:309-14. [PMID: 16155938 DOI: 10.1002/jcp.20514] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The coordinated expression of the genome in response to extracellular cues is ensured by enzymatic cascades signaling to the nucleus. These pathways generate chromatin modifications at specific loci controlling the transcription of signal-dependent and tissue-specific genes. The SWI/SNF chromatin remodeling complex offers the ideal surface for integrating these signals in the execution of diverse or even opposite biological programs.
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Affiliation(s)
- Cristiano Simone
- Department of Biomedicine in Childhood, Division of Medical Genetics, University of Bari, Bari, Italy.
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37
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Inayoshi Y, Miyake K, Machida Y, Kaneoka H, Terajima M, Dohda T, Takahashi M, Iijima S. Mammalian Chromatin Remodeling Complex SWI/SNF Is Essential for Enhanced Expression of the Albumin Gene during Liver Development. ACTA ACUST UNITED AC 2006; 139:177-88. [PMID: 16452305 DOI: 10.1093/jb/mvj015] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The chromatin remodeling complex SWI/SNF is known to regulate the transcription of several genes by controlling chromatin structure in an ATP-dependent manner. SWI/SNF contains the Swi2p/Snf2p like ATPases BRG1 or BRM exclusively. We found that the expression of BRM gradually increases and that of BRG1 decreases as liver cells differentiate. Chromatin immunoprecipitation assays revealed that the ATPase subunits of SWI/SNF and tumor suppressor retinoblastoma (RB) family proteins bind to the promoter region of the albumin gene in hepatocytes, and that the replacement of BRG1 with BRM and pRB with p130 at this site occurs over the course of differentiation. Small interfering RNA experiments showed that blocking the expression of BRG1 and BRM in fetal and adult hepatocytes, respectively, causes a reduction in albumin expression. In luciferase reporter assays with a pREP4-based reporter plasmid that forms a chromatin structure, BRG1 showed activity stimulating the expression of the albumin promoter mediated by CCAAT/enhancer-binding protein alpha (C/EBPalpha). This enhancement was facilitated by the RB family members pRB and p130. ATPase assays showed that both pRB and C/EBPalpha proteins directly stimulate the ATPase activity of BRG1. Our findings suggest that the mechanism by which the activity of transcription factors is enhanced by RB family members and SWI/SNF includes an increase in the ATPase activity of the chromatin remodeling complex.
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Affiliation(s)
- Yujin Inayoshi
- Department of Biotechnology, Graduate School of Engineering, Japan
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38
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Pulte D, Lopez RA, Baker ST, Ward M, Ritchie E, Richardson CA, O'Neill DW, Bank A. Ikaros increases normal apoptosis in adult erythroid cells. Am J Hematol 2006; 81:12-8. [PMID: 16369973 DOI: 10.1002/ajh.20507] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Ikaros is a critical transcriptional regulator of hematopoietic cell differentiation. In addition to its effects on the lymphoid system and hematopoietic stem-cell compartment, we have previously shown that Ikaros is also required for normal erythroid development. In this report, we compare Ikaros-dependent gene expression in erythroid cells of mice lacking the Ikaros protein with that of normal mice in purified adult bone-marrow erythroid cells (BMRC). Gene expression, measured by Affymetrix microarray analysis, indicates that in the BMRC of Ikaros-null mice, there is significant up-regulation of SMADs 6 and 7, serine protease inhibitor 3, and immediate-early protein 3 (IER3), all proteins that play a modulating role in apoptosis. We investigate the role of Ikaros in oxidative stress-induced apoptosis using Annexin-V staining and FACS analysis. We find a decrease in apoptosis in the BMRC of Ikaros-null mice compared to normal mice. This effect is also seen in nonerythroid cells but is stronger in BMRC. We conclude that normal Ikaros function increases normal apoptosis in erythroid cells. The data also suggest that Ikaros plays a role in apoptosis-mediated events in other normal hematopoietic cell lineages.
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Affiliation(s)
- Dianne Pulte
- Department of Medicine, Columbia University, New York, NY, USA
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39
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Bresnick EH, Johnson KD, Kim SI, Im H. Establishment and regulation of chromatin domains: mechanistic insights from studies of hemoglobin synthesis. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 2006; 81:435-71. [PMID: 16891178 DOI: 10.1016/s0079-6603(06)81011-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Emery H Bresnick
- Department of Pharmacology, University of Wisconsin Medical School, 383 Medical Sciences Center, Madison, Wisconsin 53706, USA
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40
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Bultman SJ, Gebuhr TC, Magnuson T. A Brg1 mutation that uncouples ATPase activity from chromatin remodeling reveals an essential role for SWI/SNF-related complexes in beta-globin expression and erythroid development. Genes Dev 2005; 19:2849-61. [PMID: 16287714 PMCID: PMC1315392 DOI: 10.1101/gad.1364105] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2005] [Accepted: 09/29/2005] [Indexed: 11/25/2022]
Abstract
The Brg1 catalytic subunit of SWI/SNF-related complexes has been implicated in many developmental and physiological processes, but null homozygotes die as blastocysts prior to implantation. To circumvent this early embryonic lethality, we performed an ENU mutagenesis screen and generated a Brg1 hypomorph mutation in the ATPase domain. The mutant Brg1 protein is stable, assembles into SWI/SNF-related complexes, and exhibits normal ATPase activity but is unable to establish DNase I hypersensitivity sites characteristic of open chromatin. Mutant embryos develop normally until midgestation but then exhibit a distinct block in the development of the erythroid lineage, leading to anemia and death. The mutant Brg1 protein is recruited to the beta-globin locus, but chromatin remodeling and transcription are perturbed. Histone acetylation and DNA methylation are also affected. To our knowledge, Brg1 is the first chromatin-modifying factor shown to be required for beta-globin regulation and erythropoiesis in vivo. Not only does this mutation establish a role for Brg1 during organogenesis, it also demonstrates that ATPase activity can be uncoupled from chromatin remodeling.
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Affiliation(s)
- Scott J Bultman
- Department of Genetics, University of North Carolina, Chapel Hill, North Carolina 27599-7264, USA.
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41
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Mahajan MC, Narlikar GJ, Boyapaty G, Kingston RE, Weissman SM. Heterogeneous nuclear ribonucleoprotein C1/C2, MeCP1, and SWI/SNF form a chromatin remodeling complex at the beta-globin locus control region. Proc Natl Acad Sci U S A 2005; 102:15012-7. [PMID: 16217013 PMCID: PMC1257739 DOI: 10.1073/pnas.0507596102] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Locus control regions (LCRs) are regulatory DNA sequences that are situated many kilobases away from their cognate promoters. LCRs protect transgenes from position effect variegation and heterochromatinization and also promote copy-number dependence of the levels of transgene expression. In this work, we describe the biochemical purification of a previously undescribed LCR-associated remodeling complex (LARC) that consists of heterogeneous nuclear ribonucleoprotein C1/C2, nucleosome remodeling SWI/SNF, and nucleosome remodeling and deacetylating (NuRD)/MeCP1 as a single homogeneous complex. LARC binds to the hypersensitive 2 (HS2)-Maf recognition element (MARE) DNA in a sequence-specific manner and remodels nucleosomes. Heterogeneous nuclear ribonucleoprotein C1/C2, previously known as a general RNA binding protein, provides a sequence-specific DNA recognition element for LARC, and the LARC DNA-recognition sequence is essential for the enhancement of transcription by HS2. Independently of the initiation of transcription, LARC becomes associated with beta-like globin promoters.
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Affiliation(s)
- Milind C Mahajan
- Department of Genetics, The Anlyan Center, Yale University School of Medicine, New Haven, CT 06511, USA
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42
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Inayoshi Y, Kaneoka H, Machida Y, Terajima M, Dohda T, Miyake K, Iijima S. Repression of GR-Mediated Expression of the Tryptophan Oxygenase Gene by the SWI/SNF Complex during Liver Development. ACTA ACUST UNITED AC 2005; 138:457-65. [PMID: 16272140 DOI: 10.1093/jb/mvi147] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The chromatin remodeling complex, SWI/SNF, is known to regulate the transcription of several genes by altering the chromatin structure in an ATP-dependent manner. SWI/SNF exclusively contains BRG1 or BRM as an ATPase subunit. In the present study, we studied the role of SWI/SNF containing BRM or BRG1 in the expression of the liver-specific tryptophan oxygenase (TO) and tyrosine aminotransferase genes. Chromatin remodeling factors significantly repressed the expression of these genes induced by glucocorticoid receptor and dexamethasone. Since the repression was not reversed by trichostatin A treatment, it seemed to be independent of the well-known histone deacetylase pathway. Knock-down of BRG1 by small interfering RNA reversed the repression in primary fetal hepatocytes. These results support a model in which SWI/SNF containing BRG1 represses late stage-specific TO gene expression at an early stage of liver development.
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Affiliation(s)
- Yujin Inayoshi
- Department of Biotechnology, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
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43
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Abstract
The human globin genes are among the most extensively characterized in the human genome, yet the details of the molecular events regulating normal human hemoglobin switching and the potential reactivation of fetal hemoglobin in adult hematopoietic cells remain elusive. Recent discoveries demonstrate physical interactions between the beta locus control region and the downstream structural gamma- and beta-globin genes, and with transcription factors and chromatin remodeling complexes. These interactions all play roles in globin gene expression and globin switching at the human beta-globin locus. If the molecular events in hemoglobin switching were better understood and fetal hemoglobin could be more fully reactivated in adult cells, the insights obtained might lead to new approaches to the therapy of sickle cell disease and beta thalassemia by identifying specific new targets for molecular therapies.
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Affiliation(s)
- Arthur Bank
- Department of Medicine, Columbia University, New York, NY, USA.
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44
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Bank A. Understanding globin regulation in beta-thalassemia: it's as simple as alpha, beta, gamma, delta. J Clin Invest 2005; 115:1470-3. [PMID: 15931385 PMCID: PMC1137010 DOI: 10.1172/jci25398] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
A vast excess of alpha-globin production and inadequate gamma-globin compensation lead to the development of severe anemia in human beta-thalassemia. Newly identified modifiers of alpha- and gamma-globin synthesis and insights into the mechanisms of globin regulation provide the tools for potential new approaches to treating this and other red blood cell disorders. In the study by Han and colleagues in this issue of the JCI, the activity of a heme-regulated protein, HRI, is shown to modulate the accumulation of excess alpha-globin chains in murine beta-thalassemia and to decrease the severity of the disease.
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Affiliation(s)
- Arthur Bank
- Department of Medicine, Columbia University College of Physicians and Surgeons, Armand Hammer Health Science Center, New York, New York 10032, USA.
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45
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Vradii D, Wagner S, Doan DN, Nickerson JA, Montecino M, Lian JB, Stein JL, van Wijnen AJ, Imbalzano AN, Stein GS. Brg1, the ATPase subunit of the SWI/SNF chromatin remodeling complex, is required for myeloid differentiation to granulocytes. J Cell Physiol 2005; 206:112-8. [PMID: 15965950 DOI: 10.1002/jcp.20432] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Many mammalian SWI/SNF complexes use Brahma-related gene 1 (Brg1) as a catalytic subunit to remodel nucleosomes for transcription regulation. In several mesenchymal cells and tissues, expression of a defective Brg1 protein negates the normal activity of the SWI/SNF complex and delays or blocks differentiation. To investigate the role of SWI/SNF complexes during myelopoiesis, we stably expressed a dominant negative (dn) Brg1 mutant in the myeloid lineage. Forced expression of dnBrg1 in IL-3-dependent murine 32Dcl3 myeloid progenitor cells results in a profound delay in the granulocyte-colony stimulating factor (G-CSF) induced granulocytic maturation. These cells also exhibit a significant decrease in the expression of both CD11b and Gr-1 surface receptors, which are normally upregulated during granulopoiesis, and show sustained expression of myeloperoxidase, which is synthesized primarily during the promyelocytic (blast) stage of myeloid development. Thus, dnBrg1 expression causes a developmental block at the promyelocytic/metamyelocytic stage of myeloid differentiation. Our findings indicate that the normal chromatin remodeling function of Brg1 is necessary for the G-CSF dependent differentiation of myeloid cells towards the granulocytic lineage. This dependency on Brg1 may reflect a stringent requirement for chromatin remodeling at a critical stage of hematopoietic cell maturation.
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Affiliation(s)
- Diana Vradii
- Department of Cell Biology and Cancer Center, University of Massachusetts Medical School, Worcester, Massachusetts 01655-0106, USA
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46
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Hill DA, de la Serna IL, Veal TM, Imbalzano AN. BRCA1 interacts with dominant negative SWI/SNF enzymes without affecting homologous recombination or radiation-induced gene activation of p21 or Mdm2. J Cell Biochem 2005; 91:987-98. [PMID: 15034933 DOI: 10.1002/jcb.20003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BRCA1 is a tumor suppressor gene linked to familial breast and ovarian cancer. The BRCA1 protein has been implicated in a diverse set of cellular functions, including activation of gene expression by the p53 tumor suppressor and control of homologous recombination (HR) during DNA repair. Prior reports have demonstrated that BRCA1 can exist in cells in a complex with the BRG1-based SWI/SNF ATP-dependent chromatin remodeling enzymes and that SWI/SNF components contribute to p53-mediated gene activation. To investigate the link between SWI/SNF function and BRCA1 mediated effects on p53-mediated gene activation and on mechanisms of homologous recombination, we have utilized mammalian cells that inducibly express an ATPase-deficient, dominant negative SWI/SNF enzymes. Mutant SWI/SNF ATPases retain the ability to interact with BRCA1 in cells. We report that expression of dominant negative SWI/SNF enzymes does not affect p53-mediated induction of the p21 cyclin dependent kinase inhibitor or the Mdm2 E3 ubiquitin ligase that regulates p53 in cells exposed to UV or gamma irradiation. Similarly, integration of a reporter that monitors homologous recombination by gene conversion into these cells demonstrated no change in the recombination rate in the absence of functional SWI/SNF enzyme. We conclude that the SWI/SNF chromatin remodeling enzymes may contribute to but are not required for these processes.
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Affiliation(s)
- David A Hill
- Department of Cell Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA
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47
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Chakalova L, Osborne CS, Dai YF, Goyenechea B, Metaxotou-Mavromati A, Kattamis A, Kattamis C, Fraser P. The Corfu deltabeta thalassemia deletion disrupts gamma-globin gene silencing and reveals post-transcriptional regulation of HbF expression. Blood 2004; 105:2154-60. [PMID: 15536151 DOI: 10.1182/blood-2003-11-4069] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The 7.2 kilobase (kb) Corfu deltabeta thalassemia mutation is the smallest known deletion encompassing a region upstream of the human delta gene that has been suggested to account for the vastly different phenotypes in hereditary persistence of fetal hemoglobin (HPFH) versus beta thalassemia. Fetal hemoglobin (HbF) expression in Corfu heterozygotes and homozygotes is paradoxically dissimilar, suggesting conflicting theories as to the function of the region on globin gene regulation. Here, we measure gamma- and beta-globin gene transcription, steady-state mRNA, and hemoglobin expression levels in primary erythroid cells cultured from several patients with Corfu deltabeta thalassemia. We show through RNA fluorescence in situ hybridization that the Corfu deletion results in high-level transcription of the fetal gamma genes in cis with a concomitant reduction in transcription of the downstream beta gene. Surprisingly, we find that elevated gamma gene transcription does not always result in a corresponding accumulation of gamma mRNA or fetal hemoglobin, indicating a post-transcriptional regulation of gamma gene expression. The data suggest that efficient gamma mRNA accumulation and HbF expression are blocked until beta mRNA levels fall below a critical threshold. These results explain the Corfu paradox and show that the deleted region harbors a critical element that functions in the developmentally regulated transcription of the beta-globin genes.
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Affiliation(s)
- Lyubomira Chakalova
- Laboratory of Chromatin and Gene Expression, The Babraham Institute, Babraham Research Campus, Cambridge, CB2 4AT, United Kingdom
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48
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Wilsker D, Patsialou A, Zumbrun SD, Kim S, Chen Y, Dallas PB, Moran E. The DNA-binding properties of the ARID-containing subunits of yeast and mammalian SWI/SNF complexes. Nucleic Acids Res 2004; 32:1345-53. [PMID: 14982958 PMCID: PMC390273 DOI: 10.1093/nar/gkh277] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
SWI/SNF complexes are ATP-dependent chromatin remodeling complexes that are highly conserved from yeast to human. From yeast to human the complexes contain a subunit with an ARID (A-T-rich interaction domain) DNA-binding domain. In yeast this subunit is SWI1 and in human there are two closely related alternative subunits, p270 and ARID1B. We describe here a comparison of the DNA-binding properties of the yeast and human SWI/SNF ARID-containing subunits. We have determined that SWI1 is an unusual member of the ARID family in both its ARID sequence and in the fact that its DNA-binding affinity is weaker than that of other ARID family members, including its human counterparts, p270 and ARID1B. Sequence analysis and substitution mutagenesis reveals that the weak DNA-binding affinity of the SWI1 ARID is an intrinsic feature of its sequence, arising from specific variations in the major groove interaction site. In addition, this work confirms the finding that p270 binds DNA without regard to sequence specificity, excluding the possibility that the intrinsic role of the ARID is to recruit SWI/SNF complexes to specific promoter sequences. These results emphasize that care must be taken when comparing yeast and higher eukaryotic SWI/SNF complexes in terms of DNA-binding mechanisms.
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Affiliation(s)
- Deborah Wilsker
- Fels Institute for Cancer Research, Temple University School of Medicine, Philadelphia, PA, USA
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Zheng P, Patel B, McMenamin M, Paprocki AM, Schramm RD, Nagl NG, Wilsker D, Wang X, Moran E, Latham KE. Expression of genes encoding chromatin regulatory factors in developing rhesus monkey oocytes and preimplantation stage embryos: possible roles in genome activation. Biol Reprod 2004; 70:1419-27. [PMID: 14724134 DOI: 10.1095/biolreprod.103.023796] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
One of the most critical events of preimplantation development is the successful activation of gene transcription. Both the timing and the array of genes activated must be controlled. The ability to regulate gene transcription appears to be reduced just prior to the time of the major genome activation event, and changes in chromatin structure appear essential for establishing this ability. Major molecules that modulate chromatin structure are the linker and core histones, enzymes that modify histones, and a wide variety of other factors that associate with DNA and mediate either repressive or activating changes. Among the latter are chromatin accessibility complexes, SWI/SNF complexes, and the YY1 protein and its associated factors. Detailed information about the expression and regulation of these factors in preimplantation stage embryos has not been published for any species. In order to ascertain which of these factors may participate in chromatin remodeling, genome activation, and DNA replication during early primate embryogenesis, we determined the temporal expression patterns of mRNA encoding these factors. Our data identify the predominant members of these different functional classes of factors expressed in oocytes and embryos, and reveal patterns of expression distinct from those patterns seen in somatic cells. Among each of four classes of mRNAs examined, some mRNAs were expressed predominantly in the oocyte, with these largely giving way to others expressed stage specifically in the embryo. This transition may be part of a global mechanism underlying the transition from maternal to embryonic control of development, wherein the oocyte program is silenced and an embryonic pattern of gene expression becomes established. Possible roles for these mRNAs in chromatin remodeling, genome activation, DNA replication, cell lineage determination, and nuclear reprogramming are discussed.
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Affiliation(s)
- Ping Zheng
- The Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
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Perani M, Ingram CJE, Cooper CS, Garrett MD, Goodwin GH. Conserved SNH domain of the proto-oncoprotein SYT interacts with components of the human chromatin remodelling complexes, while the QPGY repeat domain forms homo-oligomers. Oncogene 2003; 22:8156-67. [PMID: 14603256 DOI: 10.1038/sj.onc.1207031] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Many studies have now established that the SWI/SNF chromatin remodelling complexes are involved in activation and repression of a variety of genes. In mammalian cells, these complexes contain the BRM and BRG1 helicase-like proteins that are thought to be responsible for nucleosome remodelling. The proto-oncoprotein SYT, involved in the unique translocation t(X;18) found in synovial sarcoma, is known to interact with human BRM (hBRM), thus providing a link between chromatin remodelling factors and human cancer. In this work, we address how SYT interacts with hBRM and BRG1. We demonstrate that the conserved N-terminal SNH domain of SYT, which is also present in the oncoproteins SYT-SSX, binds to both hBRM and BRG1. We have also found that in vivo the C-terminus transactivation QPGY region of SYT can interact with itself. This results in an amplified interaction with hBRM and highlights a possible regulatory function of this domain in cells.
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Affiliation(s)
- Michela Perani
- Section of Molecular Carcinogenesis-BLB, Institute of Cancer Research, 15, Cotswold Road, Sutton, Surrey SM 5NG, UK.
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