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Jin H, Zhang W, Liu H, Bao Y. Genome-wide identification and characteristic analysis of ETS gene family in blood clam Tegillarca granosa. BMC Genomics 2023; 24:700. [PMID: 37990147 PMCID: PMC10664356 DOI: 10.1186/s12864-023-09731-5] [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: 07/18/2023] [Accepted: 10/11/2023] [Indexed: 11/23/2023] Open
Abstract
BACKGROUND ETS transcription factors, known as the E26 transformation-specific factors, assume a critical role in the regulation of various vital biological processes in animals, including cell differentiation, the cell cycle, and cell apoptosis. However, their characterization in mollusks is currently lacking. RESULTS The current study focused on a comprehensive analysis of the ETS genes in blood clam Tegillarca granosa and other mollusk genomes. Our phylogenetic analysis revealed the absence of the SPI and ETV subfamilies in mollusks compared to humans. Additionally, several ETS genes in mollusks were found to lack the PNT domain, potentially resulting in a diminished ability of ETS proteins to bind target genes. Interestingly, the bivalve ETS1 genes exhibited significantly high expression levels during the multicellular proliferation stage and in gill tissues. Furthermore, qRT-PCR results showed that Tg-ETS-14 (ETS1) is upregulated in the high total hemocyte counts (THC) population of T. granosa, suggesting it plays a significant role in stimulating hemocyte proliferation. CONCLUSION Our study significantly contributes to the comprehension of the evolutionary aspects concerning the ETS gene family, while also providing valuable insights into its role in fostering hemocyte proliferation across mollusks.
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Affiliation(s)
- Hongyu Jin
- School of Marine Sciences, Ningbo University, Ningbo, 315000, China
- Zhejiang Key Laboratory of Aquatic Germplasm Resources, College of Biological & Environmental Sciences, Zhejiang Wanli University, Zhejiang, 315100, China
| | - Weiwei Zhang
- School of Marine Sciences, Ningbo University, Ningbo, 315000, China
| | - Hongxing Liu
- Zhejiang Key Laboratory of Aquatic Germplasm Resources, College of Biological & Environmental Sciences, Zhejiang Wanli University, Zhejiang, 315100, China.
| | - Yongbo Bao
- Zhejiang Key Laboratory of Aquatic Germplasm Resources, College of Biological & Environmental Sciences, Zhejiang Wanli University, Zhejiang, 315100, China.
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Peluso S, Douglas A, Hill A, De Angelis C, Moore BL, Grimes G, Petrovich G, Essafi A, Hill RE. Fibroblast growth factors (FGFs) prime the limb specific Shh enhancer for chromatin changes that balance histone acetylation mediated by E26 transformation-specific (ETS) factors. eLife 2017; 6:28590. [PMID: 28949289 PMCID: PMC5659820 DOI: 10.7554/elife.28590] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 09/25/2017] [Indexed: 01/12/2023] Open
Abstract
Sonic hedgehog (Shh) expression in the limb bud organizing centre called the zone of polarizing activity is regulated by the ZRS enhancer. Here, we examine in mouse and in a mouse limb-derived cell line the dynamic events that activate and restrict the spatial activity of the ZRS. Fibroblast growth factor (FGF) signalling in the distal limb primes the ZRS at early embryonic stages maintaining a poised, but inactive state broadly across the distal limb mesenchyme. The E26 transformation-specific transcription factor, ETV4, which is induced by FGF signalling and acts as a repressor of ZRS activity, interacts with the histone deacetylase HDAC2 and ensures that the poised ZRS remains transcriptionally inactive. Conversely, GABPα, an activator of the ZRS, recruits p300, which is associated with histone acetylation (H3K27ac) indicative of an active enhancer. Hence, the primed but inactive state of the ZRS is induced by FGF signalling and in combination with balanced histone modification events establishes the restricted, active enhancer responsible for patterning the limb bud during development. As an animal embryo develops, specific genes need to be switched on and off at the right time and place to ensure that the embryo’s tissues and organs form properly. Proteins called transcription factors control the activity of individual genes by binding to regions of DNA known as enhancers. Changes in the way DNA is packaged inside cells can affect the ability of transcription factors to access the enhancers, and therefore also influence when particular genes are switched on or off. Sonic hedgehog (or Shh for short) is a gene that helps to control various aspects of development including the formation of the limbs and brain. The limb forms from a structure in the embryo referred to as the limb bud. An enhancer called ZRS regulates the precise position within the limb bud where the Shh gene is active in a region designated as the “zone of polarizing activity”. Yet, it was not known how the enhancer is controlled to ensure this pattern is achieved. Peluso et al. investigated the events that lead to ZRS becoming active in mice embryos. The experiments show that the ZRS enhancer exists in three different states in cells across the limb bud: poised, active and inactive. The enhancer is poised in a broad region of the limb bud in cells that are potentially able to switch on the Shh gene. Proteins called fibroblast growth factors drive the enhancer to enter this poised state by altering the way the DNA containing the enhancer is packaged in the cell. Specific transcription factors are able to bind to the poised enhancer and it is the balance between these different transcription factors that activates the enhancer in the zone of polarizing activity. Furthermore in the region of the limb bud where the fibroblast growth factors are not present the ZRS is inactive. These findings show that fibroblast growth factors, in combination with other changes to the ZRS enhancer, restrict the area in which the enhancer is active to a particular region of the limb bud. Differences in enhancer elements are known to underlie a range of inherited characteristics and may influence whether an individual develops many common diseases. In the future, investigating how cells control the activity of enhancers may provide clues to identifying new targets for drugs to treat some of these diseases.
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Affiliation(s)
- Silvia Peluso
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Adam Douglas
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Alison Hill
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Carlo De Angelis
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Benjamin L Moore
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Graeme Grimes
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Giulia Petrovich
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Abdelkader Essafi
- School of Cellular and Molecular Medicine, Faculty of Biomedical Sciences, University of Bristol, Bristol, United Kingdom
| | - Robert E Hill
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
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Liu M, Gao W, van Velkinburgh JC, Wu Y, Ni B, Tian Y. Role of Ets Proteins in Development, Differentiation, and Function of T-Cell Subsets. Med Res Rev 2015; 36:193-220. [PMID: 26301869 DOI: 10.1002/med.21361] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 07/12/2015] [Accepted: 07/23/2015] [Indexed: 12/18/2022]
Abstract
Through positive selection, double-positive cells in the thymus differentiate into CD4(+) or CD8(+) T single-positive cells that subsequently develop into different types of effective T cells, such as T-helper and cytotoxic T lymphocyte cells, that play distinctive roles in the immune system. Development, differentiation, and function of thymocytes and CD4(+) and CD8(+) T cells are controlled by a multitude of secreted and intracellular factors, ranging from cytokine signaling modules to transcription factors and epigenetic modifiers. Members of the E26 transformation specific (Ets) family of transcription factors, in particular, are potent regulators of these CD4(+) or CD8(+) T-cell processes. In this review, we summarize and discuss the functions and underlying mechanisms of the Ets family members that have been characterized as involved in these processes. Ongoing research of these factors is expected to identify practical applications for the Ets family members as novel therapeutic targets for inflammation-related diseases.
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Affiliation(s)
- Mian Liu
- Institute of Immunology, PLA, Third Military Medical University, Chongqing, 400038, P.R. China.,Battalion 10 of Cadet Brigade, Third Military Medical University, Chongqing, 400038, P.R. China
| | - Weiwu Gao
- Institute of Immunology, PLA, Third Military Medical University, Chongqing, 400038, P.R. China
| | | | - Yuzhang Wu
- Institute of Immunology, PLA, Third Military Medical University, Chongqing, 400038, P.R. China
| | - Bing Ni
- Institute of Immunology, PLA, Third Military Medical University, Chongqing, 400038, P.R. China
| | - Yi Tian
- Institute of Immunology, PLA, Third Military Medical University, Chongqing, 400038, P.R. China
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4
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Testoni M, Chung EYL, Priebe V, Bertoni F. The transcription factor ETS1 in lymphomas: friend or foe? Leuk Lymphoma 2015; 56:1975-80. [PMID: 25363344 DOI: 10.3109/10428194.2014.981670] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
ETS1 is a member of the ETS family of transcription factors, which contains many cancer genes. ETS1 gene is mapped at 11q24.3, a chromosomal region that is often the site of genomic rearrangements in hematological cancers. ETS1 is expressed in a variety of cells, including B and T lymphocytes. ETS1 is important in various biological processes such as development, differentiation, proliferation, apoptosis, migration and tissue remodeling. It acts as an oncogene controlling invasive and angiogenic behavior of malignant cells in multiple human cancers. In particular, ETS1 deregulation has been reported in diffuse large B-cell lymphoma, in Burkitt lymphoma and in Hodgkin lymphoma. Here, we summarize the function of ETS1 in normal cells, with a particular emphasis on lymphocytes, and its possible role as an oncogene or tumor suppressor gene in the different mature B cell lymphomas.
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Affiliation(s)
- Monica Testoni
- Lymphoma and Genomics Research Program, IOR Institute of Oncology Research , Bellinzona , Switzerland
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5
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Wolf L, Harrison W, Huang J, Xie Q, Xiao N, Sun J, Kong L, Lachke SA, Kuracha MR, Govindarajan V, Brindle PK, Ashery-Padan R, Beebe DC, Overbeek PA, Cvekl A. Histone posttranslational modifications and cell fate determination: lens induction requires the lysine acetyltransferases CBP and p300. Nucleic Acids Res 2013; 41:10199-214. [PMID: 24038357 PMCID: PMC3905850 DOI: 10.1093/nar/gkt824] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Lens induction is a classical embryologic model to study cell fate determination. It has been proposed earlier that specific changes in core histone modifications accompany the process of cell fate specification and determination. The lysine acetyltransferases CBP and p300 function as principal enzymes that modify core histones to facilitate specific gene expression. Herein, we performed conditional inactivation of both CBP and p300 in the ectodermal cells that give rise to the lens placode. Inactivation of both CBP and p300 resulted in the dramatic discontinuation of all aspects of lens specification and organogenesis, resulting in aphakia. The CBP/p300−/− ectodermal cells are viable and not prone to apoptosis. These cells showed reduced expression of Six3 and Sox2, while expression of Pax6 was not upregulated, indicating discontinuation of lens induction. Consequently, expression of αB- and αA-crystallins was not initiated. Mutant ectoderm exhibited markedly reduced levels of histone H3 K18 and K27 acetylation, subtly increased H3 K27me3 and unaltered overall levels of H3 K9ac and H3 K4me3. Our data demonstrate that CBP and p300 are required to establish lens cell-type identity during lens induction, and suggest that posttranslational histone modifications are integral to normal cell fate determination in the mammalian lens.
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Affiliation(s)
- Louise Wolf
- Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY10461, USA, Department of Genetics, Albert Einstein College of Medicine, Bronx, NY10461, USA, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA, Departments of Ophthalmology and Visual Sciences, Washington University Saint Louis, Saint Louis, MO 63110, USA, Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA, Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE 19716, USA, Department of Surgery, Creighton University, Omaha, NE 68178, USA, Department of Biochemistry, St. Jude Children's Research Hospital, Memphis, TN 38105, USA and Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine and Sagol School of Neuroscience, Tel Aviv University, Israel 69978
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6
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Yu S, Jing X, Colgan JD, Zhao DM, Xue HH. Targeting tetramer-forming GABPβ isoforms impairs self-renewal of hematopoietic and leukemic stem cells. Cell Stem Cell 2013; 11:207-19. [PMID: 22862946 DOI: 10.1016/j.stem.2012.05.021] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 02/26/2012] [Accepted: 05/03/2012] [Indexed: 11/27/2022]
Abstract
Hematopoietic stem cells (HSCs) and leukemic stem cells (LSCs) are both capable of self-renewal, with HSCs sustaining multiple blood lineage differentiation and LSCs indefinitely propagating leukemia. The GABP complex, consisting of DNA binding GABPα subunit and transactivation GABPβ subunit, critically regulates HSC multipotency and self-renewal via controlling an essential gene regulatory module. Two GABPβ isoforms, GABPβ1L and GABPβ2, contribute to assembly of GABPα(2)β(2) tetramer. We demonstrate that GABPβ1L/β2 deficiency specifically impairs HSC quiescence and survival, with little impact on cell cycle or apoptosis in differentiated blood cells. The HSC-specific effect is mechanistically ascribed to perturbed integrity of the GABP-controlled gene regulatory module in HSCs. Targeting GABPβ1L/β2 also impairs LSC self-renewal in p210(BCR-ABL)-induced chronic myelogenous leukemia (CML) and exhibits synergistic effects with tyrosine kinase inhibitor imatinib therapy in inhibiting CML propagation. These findings identify the tetramer-forming GABPβ isoforms as specific HSC regulators and potential therapeutic targets in treating LSC-based hematological malignancy.
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Affiliation(s)
- Shuyang Yu
- Department of Microbiology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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Zhu H, Vadigepalli R, Rafferty R, Gonye GE, Weaver DR, Schwaber JS. Integrative gene regulatory network analysis reveals light-induced regional gene expression phase shift programs in the mouse suprachiasmatic nucleus. PLoS One 2012; 7:e37833. [PMID: 22662235 PMCID: PMC3360606 DOI: 10.1371/journal.pone.0037833] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Accepted: 04/27/2012] [Indexed: 01/05/2023] Open
Abstract
We use the multigenic pattern of gene expression across suprachiasmatic nuclei (SCN) regions and time to understand the dynamics within the SCN in response to a circadian phase-resetting light pulse. Global gene expression studies of the SCN indicate that circadian functions like phase resetting are complex multigenic processes. While the molecular dynamics of phase resetting are not well understood, it is clear they involve a “functional gene expression program”, e.g., the coordinated behavior of functionally related genes in space and time. In the present study we selected a set of 89 of these functionally related genes in order to further understand this multigenic program. By use of high-throughput qPCR we studied 52 small samples taken by anatomically precise laser capture from within the core and shell SCN regions, and taken at time points with and without phase resetting light exposure. The results show striking regional differences in light response to be present in the mouse SCN. By using network-based analyses, we are able to establish a highly specific multigenic correlation between genes expressed in response to light at night and genes normally activated during the day. The light pulse triggers a complex and highly coordinated network of gene regulation. The largest differences marking neuroanatomical location are in transmitter receptors, and the largest time-dependent differences occur in clock-related genes. Nighttime phase resetting appears to recruit transcriptional regulatory processes normally active in the day. This program, or mechanism, causes the pattern of core region gene expression to transiently shift to become more like that of the shell region.
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Affiliation(s)
- Haisun Zhu
- Daniel Baugh Institute, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Rajanikanth Vadigepalli
- Daniel Baugh Institute, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Rachel Rafferty
- Daniel Baugh Institute, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Gregory E. Gonye
- Daniel Baugh Institute, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - David R. Weaver
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - James S. Schwaber
- Daniel Baugh Institute, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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8
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Hollenhorst PC, McIntosh LP, Graves BJ. Genomic and biochemical insights into the specificity of ETS transcription factors. Annu Rev Biochem 2011; 80:437-71. [PMID: 21548782 DOI: 10.1146/annurev.biochem.79.081507.103945] [Citation(s) in RCA: 369] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
ETS proteins are a group of evolutionarily related, DNA-binding transcriptional factors. These proteins direct gene expression in diverse normal and disease states by binding to specific promoters and enhancers and facilitating assembly of other components of the transcriptional machinery. The highly conserved DNA-binding ETS domain defines the family and is responsible for specific recognition of a common sequence motif, 5'-GGA(A/T)-3'. Attaining specificity for biological regulation in such a family is thus a conundrum. We present the current knowledge of routes to functional diversity and DNA binding specificity, including divergent properties of the conserved ETS and PNT domains, the involvement of flanking structured and unstructured regions appended to these dynamic domains, posttranslational modifications, and protein partnerships with other DNA-binding proteins and coregulators. The review emphasizes recent advances from biochemical and biophysical approaches, as well as insights from genomic studies that detect ETS-factor occupancy in living cells.
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Affiliation(s)
- Peter C Hollenhorst
- Medical Sciences, Indiana University School of Medicine, Bloomington, Indiana 47405, USA.
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Verschoor ML, Wilson LA, Singh G. Mechanisms associated with mitochondrial-generated reactive oxygen species in cancer. Can J Physiol Pharmacol 2011; 88:204-19. [PMID: 20393586 DOI: 10.1139/y09-135] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The mitochondria are unique cellular organelles that contain their own genome and, in conjunction with the nucleus, are able to transcribe and translate genes encoding components of the electron transport chain (ETC). To do so, the mitochondria must communicate with the nucleus via the production of reactive oxygen species (ROS) such as hydrogen peroxide (H2O2), which are produced as a byproduct of aerobic respiration within the mitochondria. Mitochondrial signaling is proposed to be altered in cancer cells, where the mitochondria are frequently found to harbor mutations within their genome and display altered functional characteristics leading to increased glycolysis. As signaling molecules, ROS oxidize and inhibit MAPK phosphatases resulting in enhanced proliferation and survival, an effect particularly advantageous to cancer cells. In terms of transcriptional regulation, ROS affect the phosphorylation, activation, oxidation, and DNA binding of transcription factors such as AP-1, NF-kappaB, p53, and HIF-1alpha, leading to changes in target gene expression. Increased ROS production by defective cancer cell mitochondria also results in the upregulation of the transcription factor Ets-1, a factor that has been increasingly associated with aggressive cancers.
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Affiliation(s)
- Meghan L Verschoor
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON L8N 3Z5, Canada
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10
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Amino acid residues in the β3 strand and subsequent loop of the conserved ETS domain that mediate basic leucine zipper (bZIP) recruitment and potentially distinguish functional attributes of Ets proteins. Biochem J 2010; 430:129-39. [DOI: 10.1042/bj20091742] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Ets family members share a conserved DNA-binding ETS domain, and serve a variety of roles in development, differentiation and oncogenesis. Besides DNA binding, the ETS domain also participates in protein–protein interactions with other structurally unrelated transcription factors. Although this mechanism appears to confer tissue- or development stage-specific functions on individual Ets proteins, the biological significance of many of these interactions remains to be evaluated, because their molecular basis has been elusive. We previously demonstrated a direct interaction between the ETS domain of the widely expressed GABPα (GA-binding protein α) and the granulocyte inducer C/EBPα (CCAAT/enhancer-binding protein α), and suggested its involvement in co-operative transcriptional activation of myeloid-specific genes, such as human FCAR encoding FcαR [Fc receptor for IgA (CD89)]. By deletion analysis, we identified helix α3 and the β3/β4 region as the C/EBPα-interacting region. Domain-swapping of individual sub-domains with those of other Ets proteins allowed us to highlight β-strand 3 and the subsequent loop, which when exchanged by those of Elf-1 (E74-like factor 1) reduced the ability to recruit C/EBPα. Further analysis identified a four-amino acid swap mutation of this region (I387L/C388A/K393Q/F395L) that reduces both physical interaction and co-operative transcriptional activation with C/EBPα without affecting its transactivation capacity by itself. Moreover, re-ChIP (re-chromatin immunoprecipitation) analysis demonstrated that GABPα recruits C/EBPα to the FCAR promoter, depending on these residues. The identified amino acid residues could confer the specificity of the action on the Ets proteins in diverse biological processes through mediating the recruitment of its partner factor.
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Ras signaling requires dynamic properties of Ets1 for phosphorylation-enhanced binding to coactivator CBP. Proc Natl Acad Sci U S A 2010; 107:10026-31. [PMID: 20534573 DOI: 10.1073/pnas.0915137107] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Ras/MAPK signaling is often aberrantly activated in human cancers. The downstream effectors are transcription factors, including those encoded by the ETS gene family. Using cell-based assays and biophysical measurements, we have determined the mechanism by which Ras/MAPK signaling affects the function of Ets1 via phosphorylation of Thr38 and Ser41. These ERK2 phosphoacceptors lie within the unstructured N-terminal region of Ets1, immediately adjacent to the PNT domain. NMR spectroscopic analyses demonstrated that the PNT domain is a four-helix bundle (H2-H5), resembling the SAM domain, appended with two additional helices (H0-H1). Phosphorylation shifted a conformational equilibrium, displacing the dynamic helix H0 from the core bundle. The affinity of Ets1 for the TAZ1 (or CH1) domain of the coactivator CBP was enhanced 34-fold by phosphorylation, and this binding was sensitive to ionic strength. NMR-monitored titration experiments mapped the interaction surfaces of the TAZ1 domain and Ets1, the latter encompassing both the phosphoacceptors and PNT domain. Charge complementarity of these surfaces indicate that electrostatic forces act in concert with a conformational equilibrium to mediate phosphorylation effects. We conclude that the dynamic helical elements of Ets1, appended to a conserved structural core, constitute a phospho-switch that directs Ras/MAPK signaling to downstream changes in gene expression. This detailed structural and mechanistic information will guide strategies for targeting ETS proteins in human disease.
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Lucas ME, Crider KS, Powell DR, Kapoor-Vazirani P, Vertino PM. Methylation-sensitive regulation of TMS1/ASC by the Ets factor, GA-binding protein-alpha. J Biol Chem 2009; 284:14698-709. [PMID: 19324871 DOI: 10.1074/jbc.m901104200] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Epigenetic silencing involving the aberrant DNA methylation of promoter-associated CpG islands is one mechanism leading to the inactivation of tumor suppressor genes in human cancers. However, the molecular mechanisms underlying this event remains poorly understood. TMS1/ASC is a novel proapoptotic signaling factor that is subject to epigenetic silencing in human breast and other cancers. The TMS1 promoter is embedded within a CpG island that is unmethylated in normal cells and is spanned by three DNase I-hypersensitive sites (HS). Silencing of TMS1 in cancer cells is accompanied by local alterations in histone modification, remodeling of the HS, and hypermethylation of DNA. In this study, we probed the functional significance of the CpG island-specific HS. We identified a methylation-sensitive complex that bound a 55-bp intronic element corresponding to HS2. Affinity chromatography and mass spectrometry identified a component of this complex to be the GA-binding protein (GABP) alpha. Supershift analysis indicated that the GABPalpha binding partner, GABPbeta1, was also present in the complex. The HS2 element conferred a 3-fold enhancement in TMS1 promoter activity, which was dependent on both intact tandem ets binding sites and the presence of GABPalpha/beta1 in trans. GABPalpha was selectively enriched at HS2 in human cells, and its occupancy was inversely correlated with CpG island methylation. Down-regulation of GABPalpha led to a concomitant decrease in TMS1 expression. These data indicate that the intronic HS2 element acts in cis to maintain transcriptional competency at the TMS1 locus and that this activity is mediated by the ets transcription factor, GABPalpha.
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Affiliation(s)
- Mary E Lucas
- Graduate Program in Genetics and Molecular Biology, the Winship Cancer Institute, Emory University, Atlanta, Georgia 30322, USA
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Izumi T, Fujii R, Izumi T, Nakazawa M, Yagishita N, Tsuchimochi K, Yamano Y, Sato T, Fujita H, Aratani S, Araya N, Azakami K, Hasegawa D, Kasaoka S, Tsuruta R, Yokouti M, Ijiri K, Beppu M, Maruyama I, Nishioka K, Maekawa T, Komiya S, Nakajima T. Activation of synoviolin promoter in rheumatoid synovial cells by a novel transcription complex of interleukin enhancer binding factor 3 and GA binding protein α. ACTA ACUST UNITED AC 2009; 60:63-72. [DOI: 10.1002/art.24178] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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