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Planutis A, Xue L, Trainor CD, Dangeti M, Gillinder K, Siatecka M, Nebor D, Peters LL, Perkins AC, Bieker JJ. Neomorphic effects of the neonatal anemia (Nan-Eklf) mutation contribute to deficits throughout development. Development 2017; 144:430-440. [PMID: 28143845 DOI: 10.1242/dev.145656] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 12/18/2016] [Indexed: 12/20/2022]
Abstract
Transcription factor control of cell-specific downstream targets can be significantly altered when the controlling factor is mutated. We show that the semi-dominant neonatal anemia (Nan) mutation in the EKLF/KLF1 transcription factor leads to ectopic expression of proteins that are not normally expressed in the red blood cell, leading to systemic effects that exacerbate the intrinsic anemia in the adult and alter correct development in the early embryo. Even when expressed as a heterozygote, the Nan-EKLF protein accomplishes this by direct binding and aberrant activation of genes encoding secreted factors that exert a negative effect on erythropoiesis and iron use. Our data form the basis for a novel mechanism of physiological deficiency that is relevant to human dyserythropoietic anemia and likely other disease states.
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Affiliation(s)
- Antanas Planutis
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Li Xue
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Cecelia D Trainor
- Laboratory of Molecular Biology, NIDDK, NIH, Bethesda, MD 20892, USA
| | - Mohan Dangeti
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Kevin Gillinder
- Mater Research Institute, University of Queensland, Woolloongabba QLD 4102, Queensland, Australia
| | - Miroslawa Siatecka
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA.,Department of Genetics, University of Adam Mickiewicz, Poznan 61-614, Poland
| | | | | | - Andrew C Perkins
- Mater Research Institute, University of Queensland, Woolloongabba QLD 4102, Queensland, Australia.,Princess Alexandra Hospital, Brisbane QLD 4102, Queensland, Australia
| | - James J Bieker
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA .,Black Family Stem Cell Institute, Mount Sinai School of Medicine, New York, NY 10029, USA.,Tisch Cancer Institute, Mount Sinai School of Medicine, New York, NY 10029, USA.,Mindich Child Health and Development Institute, Mount Sinai School of Medicine, New York, NY 10029, USA
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Lohmann F, Dangeti M, Soni S, Chen X, Planutis A, Baron MH, Choi K, Bieker JJ. The DEK Oncoprotein Is a Critical Component of the EKLF/KLF1 Enhancer in Erythroid Cells. Mol Cell Biol 2015; 35:3726-38. [PMID: 26303528 PMCID: PMC4589598 DOI: 10.1128/mcb.00382-15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Revised: 05/06/2015] [Accepted: 08/17/2015] [Indexed: 02/07/2023] Open
Abstract
Understanding how transcriptional regulators are themselves controlled is important in attaining a complete picture of the intracellular effects that follow signaling cascades during early development and cell-restricted differentiation. We have addressed this issue by focusing on the regulation of EKLF/KLF1, a zinc finger transcription factor that plays a necessary role in the global regulation of erythroid gene expression. Using biochemical affinity purification, we have identified the DEK oncoprotein as a critical factor that interacts with an essential upstream enhancer element of the EKLF promoter and exerts a positive effect on EKLF levels. This element also binds a core set of erythroid transcription factors, suggesting that DEK is part of a tissue-restricted enhanceosome that contains BMP4-dependent and -independent components. Together with local enrichment of properly coded histones and an open chromatin domain, optimal transcriptional activation of the EKLF locus can be established.
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Affiliation(s)
- Felix Lohmann
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, New York, USA
| | - Mohan Dangeti
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, New York, USA
| | - Shefali Soni
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, New York, USA
| | - Xiaoyong Chen
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, New York, USA
| | - Antanas Planutis
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, New York, USA
| | - Margaret H Baron
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, New York, USA Black Family Stem Cell Institute, Mount Sinai School of Medicine, New York, New York, USA Tisch Cancer Institute, Mount Sinai School of Medicine, New York, New York, USA Department of Medicine, Mount Sinai School of Medicine, New York, New York, USA
| | - Kyunghee Choi
- Department of Pathology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - James J Bieker
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, New York, USA Black Family Stem Cell Institute, Mount Sinai School of Medicine, New York, New York, USA Tisch Cancer Institute, Mount Sinai School of Medicine, New York, New York, USA
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Xue L, Galdass M, Gnanapragasam MN, Manwani D, Bieker JJ. Extrinsic and intrinsic control by EKLF (KLF1) within a specialized erythroid niche. Development 2014; 141:2245-54. [PMID: 24866116 DOI: 10.1242/dev.103960] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The erythroblastic island provides an important nutritional and survival support niche for efficient erythropoietic differentiation. Island integrity is reliant on adhesive interactions between erythroid and macrophage cells. We show that erythroblastic islands can be formed from single progenitor cells present in differentiating embryoid bodies, and that these correspond to erythro-myeloid progenitors (EMPs) that first appear in the yolk sac of the early developing embryo. Erythroid Krüppel-like factor (EKLF; KLF1), a crucial zinc finger transcription factor, is expressed in the EMPs, and plays an extrinsic role in erythroid maturation by being expressed in the supportive macrophage of the erythroblastic island and regulating relevant genes important for island integrity within these cells. Together with its well-established intrinsic contributions to erythropoiesis, EKLF thus plays a coordinating role between two different cell types whose interaction provides the optimal environment to generate a mature red blood cell.
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Affiliation(s)
- Li Xue
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Mariann Galdass
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Merlin Nithya Gnanapragasam
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - Deepa Manwani
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
| | - James J Bieker
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
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Neutralizing the function of a β-globin-associated cis-regulatory DNA element using an artificial zinc finger DNA-binding domain. Proc Natl Acad Sci U S A 2012; 109:17948-53. [PMID: 23074246 DOI: 10.1073/pnas.1207677109] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Gene expression is primarily regulated by cis-regulatory DNA elements and trans-interacting proteins. Transcription factors bind in a DNA sequence-specific manner and recruit activities that modulate the association and activity of transcription complexes at specific genes. Often, transcription factors belong to families of related proteins that interact with similar DNA sequences. Furthermore, genes are regulated by multiple, sometimes redundant, cis-regulatory elements. Thus, the analysis of the role of a specific DNA regulatory sequence and the interacting proteins in the context of intact cells is challenging. In this study, we designed and functionally characterized an artificial DNA-binding domain that neutralizes the function of a cis-regulatory DNA element associated with adult β-globin gene expression. The zinc finger DNA-binding domain (ZF-DBD), comprising six ZFs, interacted specifically with a CACCC site located 90 bp upstream of the transcription start site (-90 β-ZF-DBD), which is normally occupied by KLF1, a major regulator of adult β-globin gene expression. Stable expression of the -90 β-ZF-DBD in mouse erythroleukemia cells reduced the binding of KLF1 with the β-globin gene, but not with locus control region element HS2, and led to reduced transcription. Transient transgenic embryos expressing the -90 β-ZF-DBD developed normally but revealed reduced expression of the adult β-globin gene. These results demonstrate that artificial DNA-binding proteins lacking effector domains are useful tools for studying and modulating the function of cis-regulatory DNA elements.
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Recombinant erythroid Kruppel-like factor fused to GATA1 up-regulates delta- and gamma-globin expression in erythroid cells. Blood 2011; 117:3045-52. [PMID: 21220744 DOI: 10.1182/blood-2010-07-294751] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The β-hemoglobinopathies sickle cell disease and β-thalassemia are among the most common human genetic disorders worldwide. Hemoglobin A2 (HbA2, α₂δ₂) and fetal hemoglobin (HbF, α₂γ₂) both inhibit the polymerization of hemoglobin S, which results in erythrocyte sickling. Expression of erythroid Kruppel-like factor (EKLF) and GATA1 is critical for transitioning hemoglobin from HbF to hemoglobin A (HbA, α₂β₂) and HbA2. The lower levels of δ-globin expression compared with β-globin expression seen in adulthood are likely due to the absence of an EKLF-binding motif in the δ-globin proximal promoter. In an effort to up-regulate δ-globin to increase HbA2 expression, we created a series of EKLF-GATA1 fusion constructs composed of the transactivation domain of EKLF and the DNA-binding domain of GATA1, and then tested their effects on hemoglobin expression. EKLF-GATA1 fusion proteins activated δ-, γ-, and β-globin promoters in K562 cells, and significantly up-regulated δ- and γ-globin RNA transcript and protein expression in K562 and/or CD34(+) cells. The binding of EKLF-GATA1 fusion proteins at the GATA1 consensus site in the δ-globin promoter was confirmed by chromatin immunoprecipitation assay. Our studies demonstrate that EKLF-GATA1 fusion proteins can enhance δ-globin expression through interaction with the δ-globin promoter, and may represent a new genetic therapeutic approach to β-hemoglobinopathies.
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Severe anemia in the Nan mutant mouse caused by sequence-selective disruption of erythroid Kruppel-like factor. Proc Natl Acad Sci U S A 2010; 107:15151-6. [PMID: 20696915 DOI: 10.1073/pnas.1004996107] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Studies of mouse models of anemia have long provided fundamental insights into red blood cell formation and function. Here we show that the semidominant mouse mutation Nan ("neonatal anemia") carries a single amino acid change (E339D) within the second zinc finger of the erythroid Krüppel-like factor (EKLF), a critical erythroid regulatory transcription factor. The mutation alters the DNA-binding specificity of EKLF so that it no longer binds promoters of a subset of its DNA targets. Remarkably, even when mutant Nan and wild-type EKLF alleles are expressed at equivalent levels, the mutant form selectively interferes with expression of EKLF target genes whose promoter elements it no longer binds. This interference yields a distorted genetic output and selective protein deficiencies that differ from those seen in EKLF-heterozygous and EKLF-null red blood cells and presents a unique and unexpected mechanism of inherited disease.
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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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Lohmann F, Bieker JJ. Activation of Eklf expression during hematopoiesis by Gata2 and Smad5 prior to erythroid commitment. Development 2008; 135:2071-82. [PMID: 18448565 DOI: 10.1242/dev.018200] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The hierarchical progression of stem and progenitor cells to their more-committed progeny is mediated through cell-to-cell signaling pathways and intracellular transcription factor activity. However, the mechanisms that govern the genetic networks underlying lineage fate decisions and differentiation programs remain poorly understood. Here we show how integration of Bmp4 signaling and Gata factor activity controls the progression of hematopoiesis, as exemplified by the regulation of Eklf during establishment of the erythroid lineage. Utilizing transgenic reporter assays in differentiating mouse embryonic stem cells as well as in the murine fetal liver, we demonstrate that Eklf expression is initiated prior to erythroid commitment during hematopoiesis. Applying phylogenetic footprinting and in vivo binding studies in combination with newly developed loss-of-function technology in embryoid bodies, we find that Gata2 and Smad5 cooperate to induce Eklf in a progenitor population, followed by a switch to Gata1-controlled regulation of Eklf transcription upon erythroid commitment. This stage- and lineage-dependent control of Eklf expression defines a novel role for Eklf as a regulator of lineage fate decisions during hematopoiesis.
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Affiliation(s)
- Felix Lohmann
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, Box 1020, 1 Gustave Levy Place, New York, NY 10029, USA
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Frontelo P, Manwani D, Galdass M, Karsunky H, Lohmann F, Gallagher PG, Bieker JJ. Novel role for EKLF in megakaryocyte lineage commitment. Blood 2007; 110:3871-80. [PMID: 17715392 PMCID: PMC2190608 DOI: 10.1182/blood-2007-03-082065] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Megakaryocytes and erythroid cells are thought to derive from a common progenitor during hematopoietic differentiation. Although a number of transcriptional regulators are important for this process, they do not explain the bipotential result. We now show by gain- and loss-of-function studies that erythroid Krüppel-like factor (EKLF), a transcription factor whose role in erythroid gene regulation is well established, plays an unexpected directive role in the megakaryocyte lineage. EKLF inhibits the formation of megakaryocytes while at the same time stimulating erythroid differentiation. Quantitative examination of expression during hematopoiesis shows that, unlike genes whose presence is required for establishment of both lineages, EKLF is uniquely down-regulated in megakaryocytes after formation of the megakaryocyte-erythroid progenitor. Expression profiling and molecular analyses support these observations and suggest that megakaryocytic inhibition is achieved, at least in part, by EKLF repression of Fli-1 message levels.
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