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Kala M, Babok S, Mikhailava N, Piirsoo M, Piirsoo A. The POU-HD TFs impede the replication efficiency of several human papillomavirus genomes. Virol J 2024; 21:54. [PMID: 38444021 PMCID: PMC10916165 DOI: 10.1186/s12985-024-02334-w] [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: 12/07/2023] [Accepted: 02/28/2024] [Indexed: 03/07/2024] Open
Abstract
Human papillomavirus (HPV) is a double-stranded DNA virus that infects cutaneous and mucosal epithelial cells. HPV replication initiates at the origin (ori), located within a noncoding region near the major early promoter. Only two viral proteins, E1 and E2, are essential for replication, with the host cell contributing other necessary factors. However, the role of host cell proteins in regulating HPV replication remains poorly understood. While several binding sites for cellular transcription factors (TFs), such as POU-HD proteins, have been mapped in the regulatory region, their functional importance is unclear. Some POU-HD TFs have been shown to influence replication in a system where E1 and E2 are provided exogenously. In this study, we investigated the impact of several POU-HD TFs on the replication of the HPV5, HPV11, and HPV18 genomes in U2OS cells and human primary keratinocytes. We demonstrated that OCT1, OCT6, BRN5A, and SKN1A are expressed in HPV host cells and that their overexpression inhibits HPV genome replication, whereas knocking down OCT1 had a positive effect. Using the replication-deficient HPV18-E1- genome, we demonstrated that OCT1-mediated inhibition of HPV replication involves modulation of HPV early promoters controlling E1 and E2 expression. Moreover, using Oct6 mutants deficient either in DNA binding or transcriptional regulation, we showed that the inhibition of HPV18 replication is solely dependent on Oct6's DNA binding activity. Our study highlights the complex regulatory roles of POU-HD factors in the HPV replication.
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Affiliation(s)
- Martin Kala
- Institute of Technology, University of Tartu, Tartu, Estonia
| | - Sofiya Babok
- Institute of Technology, University of Tartu, Tartu, Estonia
| | - Nika Mikhailava
- Institute of Technology, University of Tartu, Tartu, Estonia
| | - Marko Piirsoo
- Institute of Technology, University of Tartu, Tartu, Estonia
| | - Alla Piirsoo
- Institute of Technology, University of Tartu, Tartu, Estonia.
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Ober-Reynolds B, Wang C, Ko JM, Rios EJ, Aasi SZ, Davis MM, Oro AE, Greenleaf WJ. Integrated single-cell chromatin and transcriptomic analyses of human scalp identify gene-regulatory programs and critical cell types for hair and skin diseases. Nat Genet 2023; 55:1288-1300. [PMID: 37500727 PMCID: PMC11190942 DOI: 10.1038/s41588-023-01445-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 06/17/2023] [Indexed: 07/29/2023]
Abstract
Genome-wide association studies have identified many loci associated with hair and skin disease, but identification of causal variants requires deciphering of gene-regulatory networks in relevant cell types. We generated matched single-cell chromatin profiles and transcriptomes from scalp tissue from healthy controls and patients with alopecia areata, identifying diverse cell types of the hair follicle niche. By interrogating these datasets at multiple levels of cellular resolution, we infer 50-100% more enhancer-gene links than previous approaches and show that aggregate enhancer accessibility for highly regulated genes predicts expression. We use these gene-regulatory maps to prioritize cell types, genes and causal variants implicated in the pathobiology of androgenetic alopecia (AGA), eczema and other complex traits. AGA genome-wide association studies signals are enriched in dermal papilla regulatory regions, supporting the role of these cells as drivers of AGA pathogenesis. Finally, we train machine learning models to nominate single-nucleotide polymorphisms that affect gene expression through disruption of transcription factor binding, predicting candidate functional single-nucleotide polymorphism for AGA and eczema.
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Affiliation(s)
| | - Chen Wang
- Department of Dermatology, School of Medicine, Stanford University, Stanford, CA, USA
- Division of Dermatology, Department of Medicine, Santa Clara Valley Medical Center, San Jose, CA, USA
- Institute of Immunity, Transplantation and Infection, School of Medicine, Stanford University, Stanford, CA, USA
| | - Justin M Ko
- Department of Dermatology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Eon J Rios
- Department of Dermatology, School of Medicine, Stanford University, Stanford, CA, USA
- Division of Dermatology, Department of Medicine, Santa Clara Valley Medical Center, San Jose, CA, USA
| | - Sumaira Z Aasi
- Department of Dermatology, School of Medicine, Stanford University, Stanford, CA, USA
| | - Mark M Davis
- Institute of Immunity, Transplantation and Infection, School of Medicine, Stanford University, Stanford, CA, USA
- Department of Microbiology and Immunology, School of Medicine, Stanford University, Stanford, CA, USA
- Howard Hughes Medical Institute, School of Medicine, Stanford University, Stanford, CA, USA
| | - Anthony E Oro
- Department of Dermatology, School of Medicine, Stanford University, Stanford, CA, USA
- Program in Epithelial Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - William J Greenleaf
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA.
- Department of Applied Physics, Stanford University, Stanford, CA, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, USA.
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3
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DeVore SB, Stevens ML, He H, Biagini JM, Kroner JW, Martin LJ, Hershey GKK. Novel role for caspase recruitment domain family member 14 and its genetic variant rs11652075 in skin filaggrin homeostasis. J Allergy Clin Immunol 2022; 149:708-717. [PMID: 34271060 PMCID: PMC9119145 DOI: 10.1016/j.jaci.2021.07.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 06/29/2021] [Accepted: 07/01/2021] [Indexed: 02/03/2023]
Abstract
BACKGROUND Low epidermal filaggrin (FLG) is a risk factor for atopic dermatitis (AD) and allergic comorbidity. FLG mutations do not fully explain the variation in epidermal FLG levels, highlighting that other genetic loci may also regulate FLG expression. OBJECTIVE We sought to identify genetic loci that regulate FLG expression and elucidate their functional and mechanistic consequences. METHODS A genome-wide association study of quantified skin FLG expression in lesional and baseline non(never)-lesional skin of children with AD in the Mechanisms of Progression of Atopic Dermatitis to Asthma in Children cohort was conducted. Clustered regularly interspaced short palindromic repeat approaches were used to create isogenic human keratinocytes differing only at the identified variant rs11652075, and caspase recruitment domain family member 14 (CARD14)-deficient keratinocytes for subsequent mechanistic studies. RESULTS The genome-wide association study identified the CARD14 rs11652075 variant to be associated with FLG expression in non(never)-lesional skin of children with AD. Rs11652075 is a CARD14 expression quantitative trait locus in human skin and primary human keratinocytes. The T variant destroys a functional cytosine-phosphate-guanine site, resulting in reduced cytosine-phosphate-guanine methylation at this site (but not neighboring sites) in TT and CT compared with CC primary human keratinocytes and Mechanisms of Progression of Atopic Dermatitis to Asthma in Children children's skin samples, and rs11652075 increases CARD14 expression in an allele-specific fashion. Furthermore, studies in clustered regularly interspaced short palindromic repeat-generated CC and TT isogenic keratinocytes, as well as CARD14-haplosufficient and deficient keratinocytes, reveal that IL-17A regulates FLG expression via CARD14, and that the underlying mechanisms are dependent on the rs11652075 genotype. CONCLUSIONS Our study identifies CARD14 as a novel regulator of FLG expression in the skin of children with AD. Furthermore, CARD14 regulates skin FLG homeostasis in an rs11652075-dependent fashion.
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Affiliation(s)
- Stanley B. DeVore
- Department of Pediatrics, University of Cincinnati College of Medicine, 3230 Eden Avenue, Cincinnati, Ohio 45267, USA.,Division of Asthma Research, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA
| | - Mariana L. Stevens
- Division of Asthma Research, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA
| | - Hua He
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA
| | - Jocelyn M. Biagini
- Department of Pediatrics, University of Cincinnati College of Medicine, 3230 Eden Avenue, Cincinnati, Ohio 45267, USA.,Division of Asthma Research, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA
| | - John W. Kroner
- Division of Asthma Research, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA
| | - Lisa J. Martin
- Department of Pediatrics, University of Cincinnati College of Medicine, 3230 Eden Avenue, Cincinnati, Ohio 45267, USA.,Division of Human Genetics, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA
| | - Gurjit K. Khurana Hershey
- Department of Pediatrics, University of Cincinnati College of Medicine, 3230 Eden Avenue, Cincinnati, Ohio 45267, USA.,Division of Asthma Research, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, Ohio 45229, USA.,Corresponding Author Information Gurjit Khurana Hershey, MD, PhD, 3333 Burnet Avenue, MLC 7037, Cincinnati, OH 45229, USA, Phone 513-636-7054, Fax 513-636-1657,
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Siekmann TE, Gerber MM, Toland AE. Variants in an Hdac9 intronic enhancer plasmid impact Twist1 expression in vitro. Mamm Genome 2015; 27:99-110. [PMID: 26721262 DOI: 10.1007/s00335-015-9618-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 12/15/2015] [Indexed: 12/24/2022]
Abstract
Skin tumor susceptibility 5 (Skts5) was previously mapped to mouse chromosome 12 through linkage analysis of skin tumor susceptible Mus musculus (NIH/Ola-S) and skin tumor resistant outbred Mus spretus (SPRET/Out-R) mice. Hdac9 was identified as a potential candidate for Skts5 based on conserved non-synonymous sequence variants and expression analyses. Studies by others identified an enhancer in human HDAC9 that correlated with TWIST1 expression. We identified 45 sequence variants between NIH/Ola-S and SPRET/Out-R mice from the orthologous region of the human HDAC9 enhancer. Variants mapping to intron 18 differentially affected luciferase expression in vitro. NIH/Ola-S clones showed an approximate 1.7-fold increased luciferase expression relative to vector alone or the equivalent clones from SPRET/Out-R-R. Furthermore, cells transfected with a portion of the NIH/Ola-S intron induced 2.2-fold increases in Twist1 expression, but the same region from SPRET/Out-R mice resulted in no up-regulation of Twist1. In silico transcription factor analyses identified multiple transcription factors predicted to differentially bind NIH/Ola-S and SPRET/Out-R polymorphic sites. Chromatin immunoprecipitation studies of two transcription factors, Gata3 and Oct1, demonstrated differential binding between NIH/Ola-S and SPRET/Out-R plasmids that corroborated the in silico predictions. Together these studies provide evidence that the murine orthologous region to a human HDAC9 enhancer also acts as a transcriptional enhancer for mouse Twist1. As ectopic sequence variants between NIH/Ola-S and SPRET/Out-R differentially impacted luciferase expression, correlated with Twist1 expression in vitro, and affected Gata3 and Oct1 binding, these variants may explain part of the observed differences in skin tumor susceptibility at Skts5 between NIH/Ola-S and SPRET/Out-R.
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Affiliation(s)
- Tyler E Siekmann
- Biomedical Sciences Program, The Ohio State University College of Medicine, Columbus, OH, 43210, USA
| | - Madelyn M Gerber
- Biomedical Sciences Graduate Program, The Ohio State University College of Medicine, Columbus, OH, 43210, USA
| | - Amanda Ewart Toland
- Department of Molecular Virology, Immunology and Medical Genetics and the Division of Human Genetics, Department of Internal Medicine, The Ohio State University Comprehensive Cancer Center, The Ohio State University, 998 Biomedical Research Tower, 460 W. 12th Avenue, Columbus, OH, 43210, USA.
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5
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Seltmann J, Roesner LM, von Hesler FW, Wittmann M, Werfel T. IL-33 impacts on the skin barrier by downregulating the expression of filaggrin. J Allergy Clin Immunol 2015; 135:1659-61.e4. [DOI: 10.1016/j.jaci.2015.01.048] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 12/02/2014] [Accepted: 01/09/2015] [Indexed: 02/08/2023]
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Neumann C, Bigliardi-Qi M, Widmann C, Bigliardi PL. The δ-opioid receptor affects epidermal homeostasis via ERK-dependent inhibition of transcription factor POU2F3. J Invest Dermatol 2014; 135:471-480. [PMID: 25178105 PMCID: PMC4291683 DOI: 10.1038/jid.2014.370] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 08/14/2014] [Accepted: 08/18/2014] [Indexed: 12/02/2022]
Abstract
Neuropeptides and their receptors are present in human skin, and their importance for cutaneous homeostasis and during wound healing is increasingly appreciated. However, there is currently a lack of understanding of the molecular mechanisms by which their signaling modulates keratinocyte function. Here, we show that δ-opioid receptor (DOPr) activation inhibits proliferation of human keratinocytes, resulting in decreased epidermal thickness in an organotypic skin model. DOPr signaling markedly delayed induction of keratin intermediate filament (KRT10) during in vitro differentiation and abolished its induction in the organotypic skin model. This was accompanied by deregulation of involucrin (IVL), loricrin, and filaggrin. Analysis of the transcription factor POU2F3, which is involved in regulation of KRT10, IVL, and profilaggrin expression, revealed a DOPr-mediated extracellular signal-regulated kinase (ERK)-dependent downregulation of this factor. We propose that DOPr signaling specifically activates the ERK 1/2 mitogen-activated protein kinase pathway to regulate keratinocyte functions. Complementing our earlier studies in DOPr-deficient mice, these data suggest that DOPr activation in human keratinocytes profoundly influences epidermal morphogenesis and homeostasis.
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Affiliation(s)
- Christine Neumann
- Experimental Dermatology Laboratory, Institute of Medical Biology, A*STAR, Singapore; Doctoral School Faculty of Biology and Medicine, University of Lausanne, Dorigny, Switzerland; These authors contributed equally to this work
| | - Mei Bigliardi-Qi
- Experimental Dermatology Laboratory, Institute of Medical Biology, A*STAR, Singapore.
| | - Christian Widmann
- Department of Physiology, University of Lausanne, Lausanne, Switzerland
| | - Paul L Bigliardi
- Experimental Dermatology Laboratory, Institute of Medical Biology, A*STAR, Singapore; Division of Rheumatology, University Medicine Cluster, National University Hospital, Singapore.
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Kawachi Y, Ishitsuka Y, Maruyama H, Fujisawa Y, Furuta J, Nakamura Y, Ishii Y, Ichikawa E, Otsuka F. The POU domain transcription factors Oct-6 and Oct-11 negatively regulate loricrin gene expression in keratinocytes: association with AP-1 and Sp1/Sp3. Arch Dermatol Res 2013; 305:371-8. [PMID: 23341029 DOI: 10.1007/s00403-013-1317-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Revised: 01/07/2013] [Accepted: 01/08/2013] [Indexed: 11/30/2022]
Abstract
Loricrin is a major component of the epidermal cornified cell envelope, and is expressed only in terminally differentiated keratinocytes. This cell differentiation-specific expression pattern suggests specific regulatory mechanisms for activation and suppression of loricrin gene transcription in differentiated keratinocytes. Here, we identified a regulatory element in the proximal promoter region of the loricrin gene involved in suppression of its expression in keratinocytes. A database search indicated that this sequence contained a POU transcription factor binding motif. Electrophoretic mobility shift assay revealed that Oct-1, Oct-6, and Oct-11 actually bind to the motif. Constructs with point mutations in the POU-binding motif showed increased reporter activity, indicating that the POU factors negatively regulate loricrin gene transcription. Cotransfection experiments suggested that Oct-6 and Oct-11 suppress loricrin gene transcription in a cooperative manner with AP-1 and Sp1. Furthermore, in vitro experiments indicated that the Oct-6 and Oct-11 can physically associate with both AP-1 factors and Sp1/Sp3. These findings indicate that Oct-6 and Oct-11 contribute to the regulation of loricrin gene transcription via interaction with AP-1 factors and Sp1/Sp3.
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Affiliation(s)
- Yasuhiro Kawachi
- Department of Dermatology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
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IL-31 regulates differentiation and filaggrin expression in human organotypic skin models. J Allergy Clin Immunol 2012; 129:426-33, 433.e1-8. [DOI: 10.1016/j.jaci.2011.10.042] [Citation(s) in RCA: 151] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Revised: 10/17/2011] [Accepted: 10/28/2011] [Indexed: 10/14/2022]
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Burgess STG, McNeilly TN, Watkins CA, Nisbet AJ, Huntley JF. Host transcription factors in the immediate pro-inflammatory response to the parasitic mite Psoroptes ovis. PLoS One 2011; 6:e24402. [PMID: 21915322 PMCID: PMC3168495 DOI: 10.1371/journal.pone.0024402] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Accepted: 08/08/2011] [Indexed: 12/18/2022] Open
Abstract
Background Sheep scab, caused by infestation with the ectoparasitic mite Psoroptes ovis, results in the rapid development of cutaneous inflammation and leads to the crusted skin lesions characteristic of the disease. We described previously the global host transcriptional response to infestation with P. ovis, elucidating elements of the inflammatory processes which lead to the development of a rapid and profound immune response. However, the mechanisms by which this response is instigated remain unclear. To identify novel methods of intervention a better understanding of the early events involved in triggering the immune response is essential. The objective of this study was to gain a clearer understanding of the mechanisms and signaling pathways involved in the instigation of the immediate pro-inflammatory response. Results Through a combination of transcription factor binding site enrichment and pathway analysis we identified key roles for a number of transcription factors in the instigation of cutaneous inflammation. In particular, defined roles were elucidated for the transcription factors NF-kB and AP-1 in the orchestration of the early pro-inflammatory response, with these factors being implicated in the activation of a suite of inflammatory mediators. Conclusions Interrogation of the host temporal response to P. ovis infestation has enabled the further identification of the mechanisms underlying the development of the immediate host pro-inflammatory response. This response involves key regulatory roles for the transcription factors NF-kB and AP-1. Pathway analysis demonstrated that the activation of these transcription factors may be triggered following a host LPS-type response, potentially involving TLR4-signalling and also lead to the intriguing possibility that this could be triggered by a P. ovis allergen.
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Affiliation(s)
- Stewart T G Burgess
- Moredun Research Institute, Pentlands Science Park, Edinburgh, Scotland, United Kingdom.
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Yu X, Espinoza-Lewis RA, Sun C, Lin L, He F, Xiong W, Yang J, Wang A, Chen Y. Overexpression of constitutively active BMP-receptor-IB in mouse skin causes an ichthyosis-vulgaris-like disease. Cell Tissue Res 2010; 342:401-10. [PMID: 21079999 DOI: 10.1007/s00441-010-1077-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Accepted: 10/07/2010] [Indexed: 01/31/2023]
Abstract
The skin is the outer layer of protection against the environment. The development and formation of the skin is regulated by several genetic cascades including the bone morphogenetic protein (BMP) signaling pathway, which has been suggested to play an important role during embryonic organ development. Several skin defects and diseases are caused by genetic mutations or disorders. Ichthyosis is a common genetic skin disorder characterized by dry scaly skin. Loss-of-function mutations in the filaggrin (FLG) gene have been identified as the cause of the ichthyosis vulgaris (IV) phenotype; however, the direct regulation of filaggrin expression in vivo is unknown. We present evidence that BMP signaling regulates filaggrin expression in the epidermis. Mice expressing a constitutively active form of BMP-receptor-IB in the developing epidermis exhibit a phenotype resembling IV in humans, including dry flaky skin, compact hyperkeratosis, and an attenuated granular layer associated with a significantly downregulated expression of filaggrin. Regulation of filaggrin expression by BMP signaling has been further confirmed by the application of exogenous BMP2 in skin explants and by a transgenic model overexpressing Noggin in the epidermis. Our results demonstrate that aberrant BMP signaling in the epidermis causes overproliferation and hyperkeratinization, leading to an IV-like skin disease.
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Affiliation(s)
- Xueyan Yu
- Section of Oral Biology, The Ohio State University College of Dentistry, Columbus, OH 43210, USA
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Shi G, Sohn KC, Choi DK, Kim YJ, Kim SJ, Ou BS, Piao YJ, Lee YH, Yoon TJ, Lee Y, Seo YJ, Kim CD, Lee JH. Brn2 is a transcription factor regulating keratinocyte differentiation with a possible role in the pathogenesis of lichen planus. PLoS One 2010; 5:e13216. [PMID: 20967260 PMCID: PMC2953493 DOI: 10.1371/journal.pone.0013216] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Accepted: 09/10/2010] [Indexed: 11/18/2022] Open
Abstract
Terminal differentiation of skin keratinocytes is a vertically directed multi-step process that is tightly controlled by the sequential expression of a variety of genes. In this study, we investigated the role of the POU domain-containing transcription factor Brn2 in keratinocyte differentiation. Immunohistochemical analysis showed that Brn2 is expressed primarily in the upper granular layer. Consistent with its epidermal localization, Brn2 expression was highly induced at 14 days after calcium treatment of cultured normal human epidermal keratinocytes. When Brn2 was overexpressed by adenoviral transduction, Brn2 led to increased expression of the differentiation-related genes involucrin, filaggrin, and loricrin in addition to inhibition of their proliferation. Chromatin immunoprecipitation demonstrated that Brn2 bound to the promoter regions of these differentiation-related genes. We injected the purified Brn2 adenovirus into rat skin, which led to a thickened epidermis with increased amounts of differentiation related markers. The histopathologic features of adenovirus-Brn2 injected skin tissues looked similar to the features of lichen planus, a human skin disease showing chronic inflammation and well-differentiated epidermal changes. Moreover, Brn2 is shown to be expressed in almost all cell nuclei of the thickened epidermis of lichen planus, and Brn2 also attracts T lymphocytes. Our results demonstrate that Brn2 is probably a transcriptional factor playing an important role in keratinocyte differentiation and probably also in the pathogenesis of lichen planus lesions.
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Affiliation(s)
- Ge Shi
- Department of Dermatology and Research Institute for Medical Sciences, School of Medicine, Chungnam National University, Daejeon, Korea
- Department of Dermatology, The First Affiliated Hospital, Guangxi Traditional Chinese Medical University, Nanning, China
| | - Kyung-Cheol Sohn
- Department of Dermatology and Research Institute for Medical Sciences, School of Medicine, Chungnam National University, Daejeon, Korea
| | - Dae-Kyoung Choi
- Department of Dermatology and Research Institute for Medical Sciences, School of Medicine, Chungnam National University, Daejeon, Korea
| | - Yu-Jin Kim
- Department of Dermatology and Research Institute for Medical Sciences, School of Medicine, Chungnam National University, Daejeon, Korea
| | - Seong-Jin Kim
- Department of Dermatology, School of Medicine, Chonnam National University, Gwangju, Korea
| | - Bai-Sheng Ou
- Department of Dermatology, The First Affiliated Hospital, Guangxi Traditional Chinese Medical University, Nanning, China
| | - Yong-Jun Piao
- Department of Dermatology, First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Young Ho Lee
- Department of Anatomy, School of Medicine, Chungnam National University, Daejeon, Korea
| | - Tae-Jin Yoon
- Department of Dermatology and Institute of Health Sciences, School of Medicine, Gyeongsang National University, Jinju, Korea
| | - Young Lee
- Department of Dermatology and Research Institute for Medical Sciences, School of Medicine, Chungnam National University, Daejeon, Korea
| | - Young-Joon Seo
- Department of Dermatology and Research Institute for Medical Sciences, School of Medicine, Chungnam National University, Daejeon, Korea
| | - Chang Deok Kim
- Department of Dermatology and Research Institute for Medical Sciences, School of Medicine, Chungnam National University, Daejeon, Korea
| | - Jeung-Hoon Lee
- Department of Dermatology and Research Institute for Medical Sciences, School of Medicine, Chungnam National University, Daejeon, Korea
- * E-mail:
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Skn-1a/Oct-11 and ΔNp63α exert antagonizing effects on human keratin expression. Biochem Biophys Res Commun 2010; 401:568-73. [PMID: 20888799 DOI: 10.1016/j.bbrc.2010.09.102] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2010] [Accepted: 09/24/2010] [Indexed: 12/30/2022]
Abstract
The formation of a stratified epidermis requires a carefully controlled balance between keratinocyte proliferation and differentiation. Here, we report the reciprocal effect on keratin expression of ΔNp63, pivotal in normal epidermal morphogenesis and maintenance, and Skn-1a/Oct-11, a POU transcription factor that triggers and regulates the differentiation of keratinocytes. The expression of Skn-1a markedly downregulated ΔNp63-driven K14 expression in luciferase reporter assays. The extent of downregulation was comparable to the inhibition of Skn-1a-mediated K10 expression upon expression of ΔNp63. ΔNp63, mutated in the protein-protein interaction domain (SAM domain; mutated in human ectodermal dysplasia syndrome), was significantly less effecting in downregulating K10, raising the possibility of a direct interaction among Skn-1a and ΔNp63. Immunolocalization in human skin biopsies revealed that the expression of the two transcription factors is partially overlapping. Co-immunoprecipitation experiments did not, however, demonstrate a direct interaction between ΔNp63 and Skn-1a, suggesting that the antagonistic effects of Skn-1a and p63 on keratin promoter transactivation is probably through competition for overlapping binding sites on target gene promoter or through an indirect interaction.
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Human papillomavirus type 8 E2 protein unravels JunB/Fra-1 as an activator of the beta4-integrin gene in human keratinocytes. J Virol 2009; 84:1376-86. [PMID: 19923172 DOI: 10.1128/jvi.01220-09] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The papillomavirus life cycle parallels keratinocyte differentiation in stratifying epithelia. We have previously shown that the human papillomavirus type 8 (HPV8) E2 protein downregulates beta4-integrin expression in normal human keratinocytes, which may trigger subsequent differentiation steps. Here, we demonstrate that the DNA binding domain of HPV8 E2 is sufficient to displace a cellular factor from the beta4-integrin promoter. We identified the E2-displaceable factor as activator protein 1 (AP-1), a heteromeric transcription factor with differentiation-specific expression in the epithelium. beta4-Integrin-positive epithelial cells displayed strong AP-1 binding activity. Both AP-1 binding activity and beta4-integrin expression were coregulated during keratinocyte differentiation suggesting the involvement of AP-1 in beta4-integrin expression. In normal human keratinocytes the AP-1 complex was composed of JunB and Fra-1 subunits. Chromatin immunoprecipitation assays confirmed that JunB/Fra-1 proteins interact in vivo with the beta4-integrin promoter and that JunB/Fra-1 promoter occupancy is reduced during keratinocyte differentiation as well as in HPV8 E2 positive keratinocytes. Ectopic expression of the tethered JunB/Fra-1 heterodimer in normal human keratinocytes activated the beta4-integrin promoter, while coexpression of HPV8 E2 reverted the JunB/Fra-1 effect. In summary, we identified a novel mechanism of human beta4-integrin regulation that is specifically targeted by the HPV8 E2 protein mimicking transcriptional conditions of differentiation. This may explain the early steps of how HPV8 commits its host cells to the differentiation process required for the viral life cycle.
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Sandilands A, Sutherland C, Irvine AD, McLean WHI. Filaggrin in the frontline: role in skin barrier function and disease. J Cell Sci 2009; 122:1285-94. [PMID: 19386895 DOI: 10.1242/jcs.033969] [Citation(s) in RCA: 544] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Recently, loss-of-function mutations in FLG, the human gene encoding profilaggrin and filaggrin, have been identified as the cause of the common skin condition ichthyosis vulgaris (which is characterised by dry, scaly skin). These mutations, which are carried by up to 10% of people, also represent a strong genetic predisposing factor for atopic eczema, asthma and allergies. Profilaggrin is the major component of the keratohyalin granules within epidermal granular cells. During epidermal terminal differentiation, the approximately 400 kDa profilaggrin polyprotein is dephosphorylated and rapidly cleaved by serine proteases to form monomeric filaggrin (37 kDa), which binds to and condenses the keratin cytoskeleton and thereby contributes to the cell compaction process that is required for squame biogenesis. Within the squames, filaggrin is citrullinated, which promotes its unfolding and further degradation into hygroscopic amino acids, which constitute one element of natural moisturising factor. Loss of profilaggrin or filaggrin leads to a poorly formed stratum corneum (ichthyosis), which is also prone to water loss (xerosis). Recent human genetic studies strongly suggest that perturbation of skin barrier function as a result of reduction or complete loss of filaggrin expression leads to enhanced percutaneous transfer of allergens. Filaggrin is therefore in the frontline of defence, and protects the body from the entry of foreign environmental substances that can otherwise trigger aberrant immune responses.
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Affiliation(s)
- Aileen Sandilands
- Epithelial Genetics Group, Division of Molecular Medicine, Colleges of Life Sciences and Medicine, Dentistry and Nursing, University of Dundee, Dundee DD1 5EH, UK
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15
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Ruiz S, Tafalla C, Cuesta A, Estepa A, Coll JM. In vitro search for alternative promoters to the human immediate early cytomegalovirus (IE-cMV) to express the G gene of viral haemorrhagic septicemia virus (VHSV) in fish epithelial cells. Vaccine 2009; 26:6620-9. [PMID: 18840493 DOI: 10.1016/j.vaccine.2008.09.048] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2008] [Revised: 09/06/2008] [Accepted: 09/15/2008] [Indexed: 11/18/2022]
Abstract
Present DNA vaccines against fish rhabdoviruses require intramuscular injection (fish-to-fish vaccination) of their G-protein gene under the control of the human immediate early cytomegalovirus (IE-CMV) promoter, while immersion delivery (mass DNA vaccination), for instance, by using fish epithelial-specific promoters, would be more practical for aquaculture. To find fish epithelial-specific promoters alternative to the IE-CMV, a comparative study of the effectiveness of different fish promoters constitutively expressing the G gene of the viral haemorrhagic septicemia virus (VHSV) in the epithelial papulosum cyprini (EPC) cell line was performed. The study included MCV1.4 (an alternative IE-CMV promoter version), AE6 (a version of the carp beta-actin promoter), long terminal repeats (LTR) of zebrafish or walleye retroviruses, trout Mx1, carp myosin-heavy-chain and flatfish pleurocidin promoters and salmonid sleeping beauty (SB)/medaka Tol2 transposon repeats. The G-protein expression in transfected EPC cells was studied by estimating the number of cells expressing the G-protein in their membrane and the average expression level per cell. In addition, in an attempt to reduce their sizes, some regions of the MCV1.4 and AE6 promoters were deleted and expression levels compared to those observed for full-length promoters. Since both zebrafish LTR and carp AE6 promoters were the most effective regulatory sequences for expressing the VHSV G-protein in EPC cells, these sequences might be candidates for new DNA vaccine vectors for fish epithelial tissues avoiding the IE-CMV promoter. Furthermore, known transcription factor binding sites (TFBS) common to most of the fish G-expressing promoters, might enable the future design of fully synthetic or hybrid promoters with improved efficacy of VHSV G-protein expression in epithelial fish cells.
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Affiliation(s)
- S Ruiz
- INIA, SGIT, Dept Biotecnología, Crt. Coruña Km 7, Madrid, Spain
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16
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Zhang X, Jin G, Wang L, Hu W, Tian M, Qin J, Huang H. Brn-4 is upregulated in the deafferented hippocampus and promotes neuronal differentiation of neural progenitors in vitro. Hippocampus 2009; 19:176-86. [PMID: 18831054 DOI: 10.1002/hipo.20498] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Fimbria-fornix (FF), the septo-hippocampal pathway, was transected to model Alzheimer's disease (AD), which is characterized by loss of cholinergic afferent fibers in hippocampus. Various alternations may happen in the deafferented hippocampus. In this study, we determined the expression of Brn-4 in hippocampus after FF lesion. RT-PCR and Western blot showed that mRNA transcription and protein of Brn-4 increased significantly and reached to the peak at day 14 after FF lesion. Hybridization and immunohistochemistry indicated that Brn-4 signals in hippocampus and dentate gyrus (DG) of the deafferented side were significantly stronger than the normal side. More Brn-4 positive cells were identified in the DG of deafferented hippocampus. In the pyramidal and granular cells, Brn-4 positive cells were all NeuN positive neurons, whereas in the neurogenic area, subgranular zone (SGZ), only a part of Brn-4 positive cells were NeuN positive, and these Brn-4/NeuN double positive neurons in SGZ and hilus of DG increased significantly after the trauma induced by FF lesion. In vitro Brn-4 antibody attenuated the role of extract from deafferented hippocampus in promoting differentiation of hippocampal progenitors into MAP-2 positive neurons. This study demonstrated that after FF lesion, Brn-4 in the deafferented hippocampus was upregulated and might play an important role in inducing local progenitors to differentiate into neurons, which may compensate for the loss of cholinergic afferent fibers or other dysfunctions.
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Affiliation(s)
- Xinhua Zhang
- Department of Anatomy and Neurobiology, The Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong, PR China
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17
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Beck IM, Müller M, Mentlein R, Sadowski T, Mueller MS, Paus R, Sedlacek R. Matrix metalloproteinase-19 expression in keratinocytes is repressed by transcription factors Tst-1 and Skn-1a: implications for keratinocyte differentiation. J Invest Dermatol 2006; 127:1107-14. [PMID: 17195013 DOI: 10.1038/sj.jid.5700674] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Matrix metalloproteinase-19 (MMP-19), unlike other members of the MMP family, is expressed in basal keratinocytes of intact epidermis whereas keratinocytes in suprabasal and higher epidermal layers express this enzyme only during cutaneous disorders. As the activity of MMP-19 effects proliferation, migration, and adhesion of keratinocytes we examined whether transcription factors involved in keratinocyte differentiation repress the expression of MMP-19. Using luciferase reporter assays, POU transcription factors Tst-1 (Oct-6) and Skn-1a (Oct-11) markedly downregulated the activity of MMP-19 promoter in COS-7 cells and HaCaT keratinocytes. Tst-1 alone was able to inhibit 85% of the promoter activity. Skn-1a exhibited a weak inhibitory effect although it synergistically increased effects of Tst-1. HaCaT cells stably transfected with Tst-1 showed a strong decrease of activity of MMP-19 promoter that correlated with suppression of MMP-19, cytokeratin 14 and 5, decreased cell proliferation, and altered expression of involucrin and loricrin. The expression of MMP-9 was also significantly reduced in Tst-1 expressing keratinocytes. MMP-2 was substantially affected during its activation whereas the expression of MMP-28 was unchanged. Our results suggest that Tst-1 and Skn-1a regulate expression of MMPs in keratinocytes and effect both the expression and activation of these proteolytic enzymes.
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Affiliation(s)
- Inken M Beck
- Institute of Biochemistry, University of Kiel, Kiel, Germany
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18
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Markova NG, Karaman-Jurukovska N, Pinkas-Sarafova A, Marekov LN, Simon M. Inhibition of histone deacetylation promotes abnormal epidermal differentiation and specifically suppresses the expression of the late differentiation marker profilaggrin. J Invest Dermatol 2006; 127:1126-39. [PMID: 17195011 DOI: 10.1038/sj.jid.5700684] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Reversible protein acetylation modulates higher-order chromatin structure and transcription activity of the genome. The reversible acetylation is executed by the intrinsic acetylase and deacetylase activities of co-regulators associated with the regulatory regions. Compounds capable of inhibiting deacetylase activity are a powerful tool for dissecting the role of protein acetylation in gene function. The ability of the deacetylase inhibitors to preferentially affect the homeostasis of transformed cells has also prompted studies for their clinical application. We present evidence that deacetylase inhibition with trichostatin A (TSA) affects the normal epidermal tissue architecture and pattern of expression by a mechanism(s) that does not correlate directly with the hyperacetylated histone status. While promoting abnormal differentiation, TSA specifically represses transcription initiation of the differentiation marker profilaggrin. Multiple factors, among which we have identified decreased Sp1 binding, a local decrease in acetylation activity, and enhanced synthesis and recruitment of a repressor histone demethylase, alter the chromatin configuration over the promoter, ultimately blocking its activation by c-jun. As compromised profilaggrin production leads to epidermal and consequently allergic disorders, our findings emphasize the need for a detailed investigation of the role deacetylase inhibitors may play in the maintenance of epidermal homeostasis in order to optimize their clinical applicability.
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Affiliation(s)
- Nelli G Markova
- Department of Oral Biology and Pathology, The Living Skin Bank, School of Dental Medicine, SUNY Stony Brook, Stony Brook, New York 11794-8702, USA.
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19
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Markova NG, Pinkas-Sarafova A, Simon M. A Metabolic Enzyme of the Short-Chain Dehydrogenase/Reductase Superfamily May Moonlight in the Nucleus as a Repressor of Promoter Activity. J Invest Dermatol 2006; 126:2019-31. [PMID: 16691198 DOI: 10.1038/sj.jid.5700347] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Transcriptional repression often depends on the action of recruited co-repressor complexes with intrinsic enzymatic activities. The composition of these complexes depends on the nicotine amide dinucleotide co-factors and is thus directly reflective of the metabolic state of the cells. This study provides evidence that an enzyme, hRoDH-E2, with cytoplasmic phosphorylated and reduced forms of NAD-dependent retinol dehydrogenase activity may function in the nucleus as a transcriptional repressor. By using the promoter of the epidermal late differentiation marker profilaggrin as a model, we show that both in vivo and in vitro the protein is recruited over the promoter. hRoDH-E2 represses profilaggrin promoter activity by altering the function of other activators, such as Sp1. The repressive function is associated with the ability of nuclear hRoDH-E2 to modulate the acetylation/deacetylation activity in the vicinity of transcription initiation site. These findings add hRoDH-E2 to the small group of metabolic enzymes, which, by being recruited over promoter regions, could directly link the cytoplasmic and nuclear functions within the cell.
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Affiliation(s)
- Nelli G Markova
- Living Skin Bank, Department of Oral Biology and Pathology, School of Dental Medicine, SUNY Stony Brook, New York 11794, USA.
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20
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Lefort K, Dotto GP. Notch signaling in the integrated control of keratinocyte growth/differentiation and tumor suppression. Semin Cancer Biol 2005; 14:374-86. [PMID: 15288263 DOI: 10.1016/j.semcancer.2004.04.017] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Oncogenesis is closely linked to abnormalities in cell differentiation. Notch signaling provides an important form of intercellular communication involved in cell fate determination, stem cell potential and differentiation. Here we review the role of this pathway in the integrated growth/differentiation control of the keratinocyte cell type, and the maintenance of normal skin homeostasis. In parallel with the pro-differentiation function of Notch1 in keratinocytes, we discuss recent evidence pointing to a tumor suppressor function of this gene in both mouse skin and human cervical carcinogenesis. The possibility that Notch signaling elicits signals with a duality of growth positive and negative function will be discussed.
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Affiliation(s)
- Karine Lefort
- Department of Biochemistry, Lausanne University, Chemin des Boveresses 155, CH-1066 Epalinges, Switzerland
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21
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Kam KY, Jeong KH, Norwitz ER, Jorgensen EM, Kaiser UB. Oct-1 and nuclear factor Y bind to the SURG-1 element to direct basal and gonadotropin-releasing hormone (GnRH)-stimulated mouse GnRH receptor gene transcription. Mol Endocrinol 2004; 19:148-62. [PMID: 15388790 DOI: 10.1210/me.2004-0025] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The cis-regulatory element localized to position -292/-285 of the mouse GnRH receptor (mGnRHR) gene promoter, designated Sequence Underlying Responsiveness to GnRH 1 (SURG-1), has been shown previously to contribute to stimulation of mGnRHR gene expression by GnRH. We have identified three specific protein-DNA complexes on the SURG-1 element by EMSA using nuclear extracts from the gonadotrope-derived alphaT3-1 and LbetaT2 cell lines. Serial mutagenesis and supershift assays identified nuclear factor Y (NF-Y) binding to -288/-284 and Oct-1 binding to a TAAT sequence at -290/-287. Binding of these two transcription factors was confirmed in vivo by chromatin immunoprecipitation assay and increased in response to GnRH stimulation. To define the functional significance of these sequences in the regulation of mGnRHR gene transcription, transient transfection assays were performed in alphaT3-1 cells using a 1.2-kb mGnRHR (-1164/+62) gene promoter-luciferase reporter construct with selective mutations of the Oct-1, NF-Y, and/or the previously characterized activating protein 1 (AP-1) binding site (-274/-268). Individual mutations in the Oct-1, NF-Y, and AP-1 sites decreased both basal expression and stimulation by GnRH agonist, and the combined mutation of the Oct-1 and AP-1 binding sites further reduced basal transcriptional activity and abolished GnRH stimulation. Overexpression of NF-YA increased GnRHR promoter activity, whereas expression of a dominant negative NF-YA mutant decreased activity, further supporting a role of NF-Y in regulation of mGnRHR gene transcription. In addition, knockdown of Oct-1 by small interfering RNA confirmed that Oct-1 is important for mGnRHR gene expression. In conclusion, NF-Y and Oct-1 bind to the SURG-1 element to direct basal and GnRH-stimulated expression of the mGnRHR gene.
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Affiliation(s)
- Kyung-Yoon Kam
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 221 Longwood Avenue, Boston, Massachusetts 02115, USA
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22
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Popa C, Dahler AL, Serewko-Auret MM, Wong CF, Smith L, Barnes LM, Strutton GM, Saunders NA. AP-2 transcription factor family member expression, activity, and regulation in human epidermal keratinocytes in vitro. Differentiation 2004; 72:185-97. [PMID: 15270775 DOI: 10.1111/j.1432-0436.2004.07205001.x] [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: 11/28/2022]
Abstract
The AP-2 transcription factor family is presumed to play an important role in the regulation of the keratinocyte squamous differentiation program; however, limited functional data are available to support this. In the present study, the activity and regulation of AP-2 were examined in differentiating human epidermal keratinocytes. We report that (1) AP-2 transcriptional activity decreases in differentiated keratinocytes but remains unchanged in differentiation-insensitive squamous cell carcinoma cell lines, (2) diminished AP-2 transcriptional activity is associated with a loss of specific DNA-bound AP-2 complexes, and (3) there is an increase in the ability of cytoplasmic extracts, derived from differentiated keratinocytes, to phosphorylate AP-2 alpha and AP-2 beta when cells differentiate. In contrast, extracts from differentiation-insensitive squamous cell carcinoma cells are unable to phosphorylate AP-2 proteins. Finally, the phosphorylation of recombinant AP-2 alpha by cytosolic extracts from differentiated keratinocytes is associated with decreased AP-2 DNA-binding activity. Combined, these data indicate that AP-2 trans-activation and DNA-binding activity decrease as keratinocytes differentiate, and that this decreased activity is associated with an enhanced ability to phosphorylate AP-2 alpha and beta.
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Affiliation(s)
- Claudia Popa
- Epithelial Pathobiology Group, Cancer Biology Program, Centre for Immunology and Cancer Research, University of Queensland, Building 1, R Wing, Level 4, Princess Alexandra Hospital, Brisbane, Queensland, Australia
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23
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Enomoto Y, Enomoto K, Kitamura T, Kanda T. Keratinocyte-specific POU transcription factor hSkn-1a represses the growth of cervical cancer cell lines. Oncogene 2004; 23:5014-22. [PMID: 15077167 DOI: 10.1038/sj.onc.1207653] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The POU transcription factor human Skn-1a (hSkn-1a) specifically promotes the proliferation of keratinocytes and enhances their differentiation. We examined the effects of hSkn-1a on cervical cancer cell lines of epithelial origin, in which the differentiation program is interrupted. From HeLa/Tet-On, a clone that can be induced to make hSkn-1a by doxycycline (HeLa/hSkn-1a) was prepared and characterized. Shortly after the induction, the cells expressed cytokeratin 10 (K10), a major marker protein in differentiating keratinocytes. While maintained for several days in the presence of doxycycline, the HeLa/hSkn-1a cells showed a slightly prolonged time of population doubling, the occasional appearance of flat cells with lowered DNA synthesis, and a low level of apoptotic DNA fragmentation. In SiHa and HeLa S3 cultures, K10 mRNA and apoptotic DNA fragmentation were detected at 48 h after infection with an adenoviral vector capable of expressing hSkn-1a. A colony inhibition assay showed that the growth of HeLa S3, SiHa, CaSki, and C-33A cells was repressed, as seen from the decreased number and average size of the drug-resistant colonies at 2 or 3 weeks after transfection with a plasmid that can express hSkn-1a and neomycin resistance gene. These results suggest that the expression of hSkn-1a represses the growth of the cervical cancer cells through the partial resumption of the differentiation pathway followed by slow suppression of cell replication and apoptosis.
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Affiliation(s)
- Yutaka Enomoto
- 1Division of Molecular Genetics, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
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24
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Gangnuss S, Cowin AJ, Daehn IS, Hatzirodos N, Rothnagel JA, Varelias A, Rayner TE. Regulation of MAPK Activation, AP-1 Transcription Factor Expression and Keratinocyte Differentiation in Wounded Fetal Skin. J Invest Dermatol 2004; 122:791-804. [PMID: 15086567 DOI: 10.1111/j.0022-202x.2004.22319.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Fetal epithelium retains the ability to re-epithelialize a wound in organotypic culture in a manner not dependent on the presence of underlying dermal substrata. This capacity is lost late in the third trimester of gestation or after embryonic day 17 (E(17)) in the rat such that embryonic day 19 (E(19)) wounds do not re-epithelialize. Moreover, wounds created in E(17) fetuses in utero heal in a regenerative, scar-free fashion. To investigate the molecular events regulating re-epithelialization in fetal skin, the wound-induced expression profile and tissue localization of activator protein 1 (AP-1) transcription factors c-Fos and c-Jun was characterised in E(17) and E(19) skin using organotypic fetal cultures. The involvement of mitogen-activated protein kinase (MAPK) signaling in mediating wound-induced transcription factor expression and wound re-epithelialization was assessed, with the effect of wounding on the expression of keratinocyte differentiation markers determined. Our results show that expression of AP-1 transcription factors was induced immediately by wounding and localized predominantly to the epidermis in E(17) and E(19) skin. c-fos and c-jun induction was transient in E(17) skin with MAPK-dependent c-fos expression necessary for the re-epithelialization of an excisional wound in organotypic culture. In E(19) skin, AP-1 expression persisted beyond 12 h post-wounding, and marked upregulation of the keratinocyte differentiation markers keratin 10 and loricrin was observed. No such changes in the expression of keratin 10 or loricrin occurred in E(17) skin. These findings indicate that re-epithelialization in fetal skin is regulated by wound-induced AP-1 transcription factor expression via MAPK and the differentiation status of keratinocytes.
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Affiliation(s)
- Samantha Gangnuss
- Wound Healing and Injury Research Centre, The University of Adelaide Department of Surgery, The Queen Elizabeth Hospital, Woodville, South Australia
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25
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Cabral A, Fischer DF, Vermeij WP, Backendorf C. Distinct functional interactions of human Skn-1 isoforms with Ese-1 during keratinocyte terminal differentiation. J Biol Chem 2003; 278:17792-9. [PMID: 12624109 DOI: 10.1074/jbc.m300508200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Among the three major POU proteins expressed in human skin, Oct-1, Tst-1/Oct-6, and Skn-1/Oct-11, only the latter induced SPRR2A, a marker of keratinocyte terminal differentiation. In this study, we have identified three Skn-1 isoforms, which encode proteins with various N termini, generated by alternative promoter usage. These isotypes showed distinct expression patterns in various skin samples, internal squamous epithelia, and cultured human keratinocytes. Skn-1a and Skn-1d1 bound the SPRR2A octamer site with comparable affinity and functioned as transcriptional activators. Skn-1d2 did not affect SPRR2A expression. Skn-1a, the largest protein, functionally cooperated with Ese-1/Elf-3, an epithelial-specific transcription factor, previously implicated in SPRR2A induction. This cooperativity, which depended on an N-terminal pointed-like domain in Skn-1a, was not found for Skn-1d1. Actually, Skn-1d1 counteracted the cooperativity between Skn-1a and Ese-1. Apparently, the human Skn-1 locus encodes multifunctional protein isotypes, subjected to biochemical cross-talk, which are likely to play a major role in the fine-tuning of keratinocyte terminal differentiation.
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Affiliation(s)
- Adriana Cabral
- Laboratory of Molecular Genetics, Leiden Institute of Chemistry, Leiden University, P. O. Box 9502, 2300 RA Leiden, The Netherlands
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26
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Enomoto K, Enomoto Y, Ishii Y, Araie M, Kanda T. Genes up- or down-regulated by expression of keratinocyte-specific POU transcription factor hSkn-1a. Biochem Biophys Res Commun 2003; 303:580-5. [PMID: 12659859 DOI: 10.1016/s0006-291x(03)00395-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The keratinocyte-specific POU transcription factor hSkn-1a is believed to trigger and regulate the differentiation of keratinocytes. To find genes regulated by hSkn-1a, we compared mRNAs in a HeLa clone (HeLa/hSkn-1a) that contains an inducible hSkn-1a gene between before and after the induction. RNA was screened for binding to DNA microarrays and candidate RNAs were further examined by two PCR methods. Quantitative RT-PCR showed that hSkn-1a up-regulated Cx43 and ARHH genes, besides the two genes of differentiation markers K10 and TG1, and down-regulated Mx2 and RALGDS genes in the HeLa cells. To know whether this finding is applicable to keratinocyte differentiation, we examined in human primary keratinocyte cultures the mRNAs for those six genes, along with the hSkn-1a gene, before and after the cells achieved confluence. Quantitative RT-PCR showed that in the differentiating confluent cells mRNAs increased for hSkn-1a, K10, TG1, Cx43, ARHH, and RALGDS, but decreased for Mx2. Thus, it appears that in keratinocyte differentiation Cx43, ARHH, and RALGDS genes were newly identified as up-regulated by hSkn-1a and Mx2 gene, as down-regulated. To study how hSkn-1a regulates those genes we cloned and sequenced putative transcriptional control regions for Cx43, ARHH, and Mx2 genes, in which several hSkn-1a-binding sequences were located. Expression of the luciferase gene from the isolated ARHH promoter was enhanced by the induction of hSkn-1a in HeLa/hSkn-1a and deletion or substitution mutation of the hSkn-1a-binding sequences reduced the expression, suggesting that hSkn-1a activates ARHH gene by binding to its promoter.
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Affiliation(s)
- Kikuko Enomoto
- Division of Molecular Genetics, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
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27
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Zhang D, Karunaratne S, Kessler M, Mahony D, Rothnagel JA. Characterization of mouse profilaggrin: evidence for nuclear engulfment and translocation of the profilaggrin B-domain during epidermal differentiation. J Invest Dermatol 2002; 119:905-12. [PMID: 12406337 DOI: 10.1046/j.1523-1747.2002.00133.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Filaggrin is a keratin filament associated protein that is expressed in granular layer keratinocytes and derived by sequential proteolysis from a polyprotein precursor termed profilaggrin. Depending on the species, each profilaggrin molecule contains between 10 and 20 filaggrin subunits organized as tandem repeats with a calcium-binding domain at the N- terminal end. We now report the characterization of the complete mouse gene. The structural organization of the mouse gene is identical to the human profilaggrin gene and consists of three exons with a 4 kb intron within the 5' noncoding region and a 1.7 kb intron separating the sequences encoding the calcium-binding EF-hand motifs. A processed pseudogene was found embedded within the second intron. The third and largest exon encodes the second EF-hand, a basic domain (designated the B-domain) followed by 12 filaggrin repeats and a unique C-terminal tail domain. A polyclonal antibody raised against the conceptually translated sequence of the B-domain specifically stained keratohyalin granules and colocalized with a filaggrin antibody in granular layer cells. In upper granular layer cells, B-domain containing keratohyalin granules were in close apposition to the nucleus and, in some cells, appeared to be completely engulfed by the nucleus. In transition layer cells, B-domain staining was evident in the nucleus whereas filaggrin staining remained cytoplasmic. Nuclear staining of the B-domain was also observed in primary mouse keratinocytes induced to differentiate. This study has also revealed significant sequence homology between the mouse and human promoter sequences and in the calcium-binding domain but the remainder of the protein-coding region shows substantial divergence.
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Affiliation(s)
- Dan Zhang
- Department of Biochemistry and Molecular Biology and the Center for Functional and Applied Genomics, University of Queensland, Brisbane, Australia
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28
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Yates S, Rayner TE. Transcription factor activation in response to cutaneous injury: role of AP-1 in reepithelialization. Wound Repair Regen 2002; 10:5-15. [PMID: 11983002 DOI: 10.1046/j.1524-475x.2002.10902.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Reepithelialization is the process responsible for restoring an intact epidermis following cutaneous injury. A change in the activity of keratinocytes is required for reepithelialization to occur, and this is likely to be regulated by the altered expression of effector genes, mediated by transcription factors. The injury itself provides a stimulus for transcription factor activation either directly due to mechanical stress, or via paracrine mechanisms such as the release of growth factors from damaged cells. Members of the activator protein-1 family, in particular c-fos and c-jun, have been the most widely studied wound-induced transcription factors. The signal transduction pathways linking cellular injury to activator protein-1 stimulation appear to involve an increase in intracellular Ca2+ and activation of mitogen-activated protein kinases. Given that a number of genes involved in the reepithelialization of wounds are regulated by activator protein-1, a distinct role for this transcription factor in reepithelialization is beginning to emerge. This article reviews the evidence for activator protein-1 involvement in reepithelialization, with particular focus on the activation of this transcription factor in response to wounding, the second messenger/kinase pathways involved, and the modulation of downstream genes that have the capacity to regulate keratinocyte function.
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Affiliation(s)
- Samantha Yates
- Co-operative Research Centre for Tissue Growth and Repair, The University of Adelaide Department of Surgery, The Queen Elizabeth Hospital, Woodville, Australia
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Kukimoto I, Kanda T. Displacement of YY1 by differentiation-specific transcription factor hSkn-1a activates the P(670) promoter of human papillomavirus type 16. J Virol 2001; 75:9302-11. [PMID: 11533193 PMCID: PMC114498 DOI: 10.1128/jvi.75.19.9302-9311.2001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transcription from human papillomavirus type 16 (HPV16) P(670), a promoter in the E7 open reading frame, is repressed in undifferentiated keratinocytes but becomes activated upon differentiation. We showed that the transient luciferase expression driven by P(670) was markedly enhanced in HeLa cells cotransfected with an expression plasmid for human Skn-1a (hSkn-1a), a transcription factor specific to differentiating keratinocytes. The hSkn-1a POU domain alone, which mediates sequence-specific DNA binding, was sufficient to activate the expression of luciferase. Electrophoretic mobility shift assay revealed the presence of two binding sites, sites 1 and 2, upstream of P(670), which were shared by hSkn-1a and YY1. Site 1 bound more strongly to hSkn-1a than site 2 did. YY1 complexing with a short DNA fragment having site 1 was displaced by hSkn-1a, indicating that hSkn-1a's affinity with site 1 was stronger than YY1's. Disrupting the binding sites by nucleotide substitutions raised the basal expression level of luciferase and decreased the enhancing effect of hSkn-1a. In HeLa cells transfected with circular HPV16 DNA along with the expression plasmid for hSkn-1a, the transcript from P(670) was detectable, which indicates that the results obtained with the reporter plasmids are likely to have mimicked the regulation of P(670) in authentic HPV16 DNA. The data strongly suggest that the transcription from P(670) is repressed primarily by YY1 binding to the two sites, and the displacement of YY1 by hSkn-1a releases P(670) from the repression.
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Affiliation(s)
- I Kukimoto
- Division of Molecular Genetics, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan
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Sugihara TM, Kudryavtseva EI, Kumar V, Horridge JJ, Andersen B. The POU domain factor Skin-1a represses the keratin 14 promoter independent of DNA binding. A possible role for interactions between Skn-1a and CREB-binding protein/p300. J Biol Chem 2001; 276:33036-44. [PMID: 11429405 DOI: 10.1074/jbc.m103000200] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The genes encoding keratin 5 and 14 are highly expressed in the basal cell layer keratinocytes of the epidermis, but both genes are silenced when keratinocytes move into the suprabasal compartment. The POU homeodomain factors Skn-1a and Tst-1, which are expressed in epidermis, may play a role in the suprabasal repression of the keratin 5 and 14 genes because keratin 14 mRNA expression persists in suprabasal cells in Skn-1/Tst-1 double knockout mice. In transfection experiments, both Skn-1a and Tst-1 repress the keratin 14 promoter, with the POU domain being sufficient for repression. The region of the keratin 14 gene sufficient and required for repression by Skn-1a is a 100-base pair sequence lacking POU-binding sites adjacent to the transcription start site. DNA-binding defective mutants of Skn-1a and Tst-1 are as effective at mediating repression as the wild type proteins, suggesting that protein-protein interactions rather than direct DNA binding are important for repression. We also show that CREB-binding protein (CBP)/p300 co-activators are strong activators of keratin 14 gene expression, acting through sequences close to the keratin 14 promoter. Further, CBP interacts directly with the POU domain of Skn-1a, and increasing concentrations of CBP can overcome Skn-1a-mediated repression, suggesting that POU domain factors may repress keratin 14 gene expression by interfering with the activity of co-activators such as CBP/p300.
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Affiliation(s)
- T M Sugihara
- Department of Medicine, Division of Endocrinology and Metabolism, University of California, San Diego, La Jolla, California 92093-0648, USA
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Chinenov Y, Kerppola TK. Close encounters of many kinds: Fos-Jun interactions that mediate transcription regulatory specificity. Oncogene 2001; 20:2438-52. [PMID: 11402339 DOI: 10.1038/sj.onc.1204385] [Citation(s) in RCA: 519] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Fos and Jun family proteins regulate the expression of a myriad of genes in a variety of tissues and cell types. This functional versatility emerges from their interactions with related bZIP proteins and with structurally unrelated transcription factors. These interactions at composite regulatory elements produce nucleoprotein complexes with high sequence-specificity and regulatory selectivity. Several general principles including binding cooperativity and conformational adaptability have emerged from studies of regulatory complexes containing Fos-Jun family proteins. The structural properties of Fos-Jun family proteins including opposite orientations of heterodimer binding and the ability to bend DNA can contribute to the assembly and functions of such complexes. The cooperative recruitment of transcription factors, coactivators and chromatin remodeling factors to promoter and enhancer regions generates multiprotein transcription regulatory complexes with cell- and stimulus-specific transcriptional activities. The gene-specific architecture of these complexes can mediate the selective control of transcriptional activity.
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Affiliation(s)
- Y Chinenov
- Howard Hughes Medical Institute, University of Michigan Medical School Ann Arbor, Michigan, MI 48109-0650, USA
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Abstract
Ets is a family of transcription factors present in species ranging from sponges to human. All family members contain an approximately 85 amino acid DNA binding domain, designated the Ets domain. Ets proteins bind to specific purine-rich DNA sequences with a core motif of GGAA/T, and transcriptionally regulate a number of viral and cellular genes. Thus, Ets proteins are an important family of transcription factors that control the expression of genes that are critical for several biological processes, including cellular proliferation, differentiation, development, transformation, and apoptosis. Here, we tabulate genes that are regulated by Ets factors and describe past, present and future strategies for the identification and validation of Ets target genes. Through definition of authentic target genes, we will begin to understand the mechanisms by which Ets factors control normal and abnormal cellular processes.
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Affiliation(s)
- V I Sementchenko
- Center for Molecular and Structural Biology, Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, SC 29403, USA
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