1
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Turi KN, Shankar J, Anderson LJ, Rajan D, Gaston K, Gebretsadik T, Das SR, Stone C, Larkin EK, Rosas-Salazar C, Brunwasser SM, Moore ML, Peebles RS, Hartert TV. Infant Viral Respiratory Infection Nasal Immune-Response Patterns and Their Association with Subsequent Childhood Recurrent Wheeze. Am J Respir Crit Care Med 2018; 198:1064-1073. [PMID: 29733679 PMCID: PMC6221572 DOI: 10.1164/rccm.201711-2348oc] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 05/07/2018] [Indexed: 02/06/2023] Open
Abstract
RATIONALE Recurrent wheeze and asthma are thought to result from alterations in early life immune development following respiratory syncytial virus (RSV) infection. However, prior studies of the nasal immune response to infection have assessed only individual cytokines, which does not capture the whole spectrum of response to infection. OBJECTIVES To identify nasal immune phenotypes in response to RSV infection and their association with recurrent wheeze. METHODS A birth cohort of term healthy infants born June to December were recruited and followed to capture the first infant RSV infection. Nasal wash samples were collected during acute respiratory infection, viruses were identified by RT-PCR, and immune-response analytes were assayed using a multianalyte bead-based panel. Immune-response clusters were identified using machine learning, and association with recurrent wheeze at age 1 and 2 years was assessed using logistic regression. MEASUREMENTS AND MAIN RESULTS We identified two novel and distinct immune-response clusters to RSV and human rhinovirus. In RSV-infected infants, a nasal immune-response cluster characterized by lower non-IFN antiviral immune-response mediators, and higher type-2 and type-17 cytokines was significantly associated with first and second year recurrent wheeze. In comparison, we did not observe this in infants with human rhinovirus acute respiratory infection. Based on network analysis, type-2 and type-17 cytokines were central to the immune response to RSV, whereas growth factors and chemokines were central to the immune response to human rhinovirus. CONCLUSIONS Distinct immune-response clusters during infant RSV infection and their association with risk of recurrent wheeze provide insights into the risk factors for and mechanisms of asthma development.
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Affiliation(s)
- Kedir N. Turi
- Division of Allergy, Pulmonary, and Critical Care Medicine and
| | - Jyoti Shankar
- Infectious Disease Group, J. Craig Venter Institute, Rockville, Maryland; and
| | | | - Devi Rajan
- Department of Pediatrics, Emory University, Atlanta, Georgia
| | - Kelsey Gaston
- Department of Pediatrics, Emory University, Atlanta, Georgia
| | | | - Suman R. Das
- Division of Infectious Diseases, Department of Medicine
- Infectious Disease Group, J. Craig Venter Institute, Rockville, Maryland; and
| | - Cosby Stone
- Division of Allergy, Pulmonary, and Critical Care Medicine and
| | - Emma K. Larkin
- Division of Allergy, Pulmonary, and Critical Care Medicine and
| | | | | | - Martin L. Moore
- Department of Pediatrics, Emory University, Atlanta, Georgia
| | | | - Tina V. Hartert
- Division of Allergy, Pulmonary, and Critical Care Medicine and
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2
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Jayaraman P, Lee K, Kitchen P, Clark D, Lertsuwan J, Sawasdichai A, Oltean S, Satayavivad J, Afford SS, Gaston K. PO-120 Proline rich homeodomain protein is required for cholangiocarcinoma tumour growth. ESMO Open 2018. [DOI: 10.1136/esmoopen-2018-eacr25.161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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3
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Assis Junior EMD, Jayaraman P, Gaston K. PO-180 Transforming growth factor beta 1activates cell migration through the down-regulation of PRH/HHEX expression. ESMO Open 2018. [DOI: 10.1136/esmoopen-2018-eacr25.219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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4
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Wadey KS, Brown BA, Sala-Newby GB, Jayaraman PS, Gaston K, George SJ. Protein kinase CK2 inhibition suppresses neointima formation via a proline-rich homeodomain-dependent mechanism. Vascul Pharmacol 2017; 99:34-44. [PMID: 28927755 PMCID: PMC5718878 DOI: 10.1016/j.vph.2017.09.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 09/05/2017] [Accepted: 09/14/2017] [Indexed: 11/19/2022]
Abstract
Neointimal hyperplasia is a product of VSMC replication and consequent accumulation within the blood vessel wall. In this study, we determined whether inhibition of protein kinase CK2 and the resultant stabilisation of proline-rich homeodomain (PRH) could suppress VSMC proliferation. Both silencing and pharmacological inhibition of CK2 with K66 antagonised replication of isolated VSMCs. SiRNA-induced knockdown as well as ectopic overexpression of proline-rich homeodomain indicated that PRH disrupts cell cycle progression. Mutation of CK2 phosphorylation sites Ser163 and Ser177 within the PRH homeodomain enabled prolonged cell cycle arrest by PRH. Concomitant knockdown of PRH and inhibition of CK2 with K66 indicated that the anti-proliferative action of K66 required the presence of PRH. Both K66 and adenovirus-mediated gene transfer of S163C:S177C PRH impaired neointima formation in human saphenous vein organ cultures. Importantly, neither intervention had notable effects on cell cycle progression, cell survival or migration in cultured endothelial cells.
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MESH Headings
- Animals
- Casein Kinase II/antagonists & inhibitors
- Casein Kinase II/genetics
- Casein Kinase II/metabolism
- Cell Cycle Checkpoints/drug effects
- Cell Proliferation/drug effects
- Cells, Cultured
- Homeodomain Proteins/genetics
- Homeodomain Proteins/metabolism
- Human Umbilical Vein Endothelial Cells/drug effects
- Human Umbilical Vein Endothelial Cells/enzymology
- Humans
- Hyperplasia
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/enzymology
- Muscle, Smooth, Vascular/pathology
- Mutation
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/enzymology
- Myocytes, Smooth Muscle/pathology
- Neointima
- Phosphorylation
- Proline-Rich Protein Domains
- Protein Kinase Inhibitors/pharmacology
- RNA Interference
- Rats
- Saphenous Vein/drug effects
- Saphenous Vein/enzymology
- Saphenous Vein/pathology
- Signal Transduction/drug effects
- Tissue Culture Techniques
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Transfection
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Affiliation(s)
- K S Wadey
- School of Clinical Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK; Department of Biochemistry, University of Bristol, Bristol BS8 1TD, UK
| | - B A Brown
- School of Clinical Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - G B Sala-Newby
- School of Clinical Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK
| | - P-S Jayaraman
- Division of Immunity and Infection, College of Medicine, University Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - K Gaston
- Department of Biochemistry, University of Bristol, Bristol BS8 1TD, UK
| | - S J George
- School of Clinical Sciences, University of Bristol, Research Floor Level 7, Bristol Royal Infirmary, Bristol BS2 8HW, UK.
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5
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Abstract
90 participants from 8 training environments provided self-assessments and peer-assessments of Kirton Adaption-Innovation scores after receiving a briefing on the topic. Correlations gave confirmatory support for the convergent validity of the instrument; however, the results indicated a more complex pattern of correlations of self-assessments and peer-assessments with actual inventory scores than has been suggested in earlier studies. The nature of the decision-making process appears to be an overlooked factor associated with the effectiveness of peer-assessments.
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6
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de Assis EM, Siddiqui YH, Kershaw R, Humphreys E, Chaudhri S, Jayaraman P, Gaston K. Protein kinase CK2 regulates prostate cancer cell migration and proliferation through phosphorylation of PRH/HHEX. Eur J Cancer 2016. [DOI: 10.1016/s0959-8049(16)61340-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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7
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Wadey K, Jayaraman PS, Gaston K, George S. Proline-rich homeodomain and protein kinase CK2 as mediators of vascular smooth muscle cell proliferation and pathophysiological neointima formation. Atherosclerosis 2016. [DOI: 10.1016/j.atherosclerosis.2015.10.086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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8
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Wadey K, Jayaraman PS, Gaston K, George S. Elevation of PRH and inhibition of CK2 retards smooth muscle cell proliferation. Atherosclerosis 2014. [DOI: 10.1016/j.atherosclerosis.2013.11.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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9
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Kershaw RM, Siddiqui YH, Roberts D, Jayaraman PS, Gaston K. PRH/HHex inhibits the migration of breast and prostate epithelial cells through direct transcriptional regulation of Endoglin. Oncogene 2013; 33:5592-600. [PMID: 24240683 DOI: 10.1038/onc.2013.496] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 09/19/2013] [Accepted: 10/11/2013] [Indexed: 12/16/2022]
Abstract
PRH/HHex (proline-rich homeodomain protein) is a transcription factor that controls cell proliferation and cell differentiation in a variety of tissues. Aberrant subcellular localisation of PRH is associated with breast cancer and thyroid cancer. Further, in blast crisis chronic myeloid leukaemia, and a subset of acute myeloid leukaemias, PRH is aberrantly localised and its activity is downregulated. Here we show that PRH is involved in the regulation of cell migration and cancer cell invasion. We show for the first time that PRH is expressed in prostate cells and that a decrease in PRH protein levels increases the migration of normal prostate epithelial cells. We show that a decrease in PRH protein levels also increases the migration of normal breast epithelial cells. Conversely, PRH overexpression inhibits cell migration and cell invasion by PC3 and DU145 prostate cancer cells and MDA-MB-231 breast cancer cells. Previous work has shown that the transforming growth factor-β co-receptor Endoglin inhibits the migration of prostate and breast cancer cells. Here we show that PRH can bind to the Endoglin promoter in immortalised prostate and breast cells. PRH overexpression in these cells results in increased Endoglin protein expression, whereas PRH knockdown results in decreased Endoglin protein expression. Moreover, we demonstrate that Endoglin overexpression abrogates the increased migration shown by PRH knockdown cells. Our data suggest that PRH controls the migration of multiple epithelial cell lineages in part at least through the direct transcriptional regulation of Endoglin. We discuss these results in terms of the functions of PRH in normal cells and the mislocalisation of PRH seen in multiple cancer cell types.
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Affiliation(s)
- R M Kershaw
- Division of Immunity and Infection, School of Medicine, University of Birmingham, Edgbaston, Birmingham, UK
| | - Y H Siddiqui
- School of Biochemistry, University Walk, University of Bristol, Bristol, UK
| | - D Roberts
- Division of Immunity and Infection, School of Medicine, University of Birmingham, Edgbaston, Birmingham, UK
| | - P-S Jayaraman
- Division of Immunity and Infection, School of Medicine, University of Birmingham, Edgbaston, Birmingham, UK
| | - K Gaston
- School of Biochemistry, University Walk, University of Bristol, Bristol, UK
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10
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Wadey K, Sawasdichai A, Jayaraman PS, Gaston K, George S. Identification of prh as a novel inhibitor of smooth muscle cell proliferation. Atherosclerosis 2012. [DOI: 10.1016/j.atherosclerosis.2012.10.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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11
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Esco MR, Williford HN, Olson MS, Russell AR, Gaston K. The Relationship Between Selected Anthropometric Variables, Vo2Max, and Heart Rate Recovery. J Strength Cond Res 2011. [DOI: 10.1097/01.jsc.0000395703.59589.73] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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12
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Williford HN, Gaston K, Esco MR, Olson MS. The Acute Physiological Responses Of Youth To an Interactive Video Game. Med Sci Sports Exerc 2010. [DOI: 10.1249/01.mss.0000385355.55431.47] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Abstract
The human papillomavirus (HPV) E6 and E7 oncogenes have direct effects on host cell proliferation. The viral E2 protein regulates transcription of E6 and E7 and thereby has an indirect effect on cell proliferation. In HPV-induced tumours, misappropriate random integration of the viral genome into the host chromosome often leads to disruption of the E2 gene and the loss of E2 expression. This results in cessation of the virus life cycle and the deregulation of E6 and E7 and is an important step in tumourigenesis. However, prior to these integration events, E2 can interact directly with the E6 and E7 proteins and modulate their activities. E2 also interacts with a variety of host proteins, including the p53 tumour suppressor protein. Here we outline evidence that suggests a role for E2 in the regulation of cell proliferation, and we discuss the importance of this regulation in viral infection and cervical tumourigenesis.
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Affiliation(s)
- N Abdul Hamid
- Department of Biochemistry, School of Medical Sciences, University of Bristol, Bristol, BS8 1TD, United Kingdom
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14
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Davis J, Kamat A, Grossman H, Gaston K, Dinney C. POD-7.13: Robotic-Assisted Laparoscopic Surgery for Invasive Bladder Cancer: Can the Lymph Node Dissection Match the Benchmarks of Open Surgery? Urology 2008. [DOI: 10.1016/j.urology.2008.08.166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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15
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Abstract
For many, if not most genes, the initiation of transcription is the principle point at which their expression is regulated. Transcription factors, some of which bind to specific DNA sequences, generally either activate or repress promoter activity and thereby control transcription initiation. Recent work has revealed in molecular detail some of the mechanisms used by transcription factors to bring about transcriptional repression. Some transcriptional repressor proteins counteract the activity of positively acting transcription factors. Other repressors inhibit the basal transcription machinery. In addition, the repression of transcription is often intimately associated with chromatin re-organisation. Many transcriptional repressor proteins interact either directly or indirectly with proteins that remodel chromatin or can themselves influence chromatin structure. This review discusses the mechanisms by which transcriptional repression is achieved and the role that chromatin re-organisation plays in this process.
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Affiliation(s)
- K Gaston
- Department of Biochemistry, School of Medical Sciences, University of Bristol, Bristol BS8 1TD, United Kingdom
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16
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Rees LEN, Wood NAP, Gillespie KM, Lai KN, Gaston K, Mathieson PW. The interleukin-10-1082 G/A polymorphism: allele frequency in different populations and functional significance. Cell Mol Life Sci 2002; 59:560-9. [PMID: 11964134 DOI: 10.1007/s00018-002-8448-0] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Genotypic variation in the human interleukin-10 (IL-10) promoter may account for marked inter-individual variation in IL-10 production and may influence susceptibility to autoimmune diseases. The G/A polymorphism at position -1082 has been linked to high/low IL-10 producer status. We directly tested the functional significance of this polymorphism using DNA-binding assays and reporter gene assays, examined allele frequencies in two geographically distinct populations and assessed intra- and inter-individual variation in IL-10 production in vitro according to genotype. Functional analyses showed that the -1082 region contains a putative ETS-like transcription factor-binding site, and nuclear factors from a monocyte cell line bind to this region. Transient transfection studies in an Epstein-Barr virus-transformed B cell line indicated that the -1082 A allele confers a two fold increase in transcriptional activity of the IL-10 promoter compared to the G allele. There was marked inter-individual variation in IL-10 production by peripheral blood mononuclear cells in vitro, with no consistent effect of genotype.
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Affiliation(s)
- L E N Rees
- Academic Renal Unit, Southmead Hospital, Bristol, United Kingdom
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17
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Davidson EJ, Brown MD, Burt DJ, Parish JL, Gaston K, Kitchener HC, Stacey SN, Stern PL. Human T cell responses to HPV 16 E2 generated with monocyte-derived dendritic cells. Int J Cancer 2001; 94:807-12. [PMID: 11745482 DOI: 10.1002/ijc.1558] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Persistent infection with human papillomavirus (HPV) type 16 has been implicated in the etiology of cervical cancer. The E2 protein is required early in viral infection and therefore may serve as a useful immune target for a vaccine aimed at prevention or therapy of premalignant lesions. Dendritic cells (DC) prepared from monocytes and pulsed with bacterially produced HPV 16 E2 C-terminus protein were used to stimulate autologous T cells over several rounds of stimulation. T cells were tested for gamma-interferon release by ELISPOT and for cytotoxic activity by (51)chromium release assays. To generate E2-expressing target cells for cytotoxicity assays, we constructed a recombinant vaccinia virus encoding HPV 16 E2, which was used to infect autologous Epstein-Barr virus-transformed lymphoblastoid cell lines (LCL). The results show that DC pulsed with E2 C-terminus protein induce gamma-interferon-releasing T cells as demonstrated by ELISPOT. Furthermore, we demonstrate E2-specific lysis of vaccinia-E2 infected autologous LCL by CD8+ cytotoxic T lymphocytes (CTL). E2-specific CTL did not lyse untreated autologous LCL or LCL infected with wild-type vaccinia and showed low levels of cytotoxicity against natural killer cell-sensitive K562 cells. In addition, T cells stimulated with DC in the absence of E2 failed to demonstrate lysis of vaccinia-E2-labeled targets. Phenotypically, CTL populations were CD3+/CD8+. These results will facilitate the study of naturally occurring T-cell responses to HPV E2 in patients with cervical intraepithelial neoplasia and the development of immunotherapeutic strategies designed to treat this and other HPV-associated diseases.
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Affiliation(s)
- E J Davidson
- CRC Immunology Group, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Manchester, United Kingdom
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18
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Abstract
Human papillomaviruses (HPVs) have been linked to a variety of human diseases, most notably cancer of the cervix, a disease responsible for at least 200,000 deaths per year worldwide. Over 100 different types of HPV have been identified and these can be divided into two groups. Low-risk HPV types are the causative agent of benign warts. High-risk HPV types are associated with cancer. This review focuses on the role of high-risk HPV types in cervical tumorigenesis. Recent work has uncovered new cellular partners for many of the HPV early proteins and thrown light on many of the pathways and processes in which these viral proteins intervene. At the same time, structural and biochemical studies are revealing the molecular details of viral protein function. Several of these new avenues of research have the potential to lead to new approaches to the treatment and prevention of cervical cancer.
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Affiliation(s)
- G Dell
- Department of Biochemistry, School of Medical Sciences, University of Bristol, United Kingdom
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19
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Abstract
The human Surf-1 and Surf-2 genes are divergently transcribed and share a single bi-directional promoter. The addition of serum growth factors to serum-starved cells activates transcription in the Surf-1 direction, but has no effect on transcription in the Surf-2 direction. Mutations that block the binding of YY1 to a site immediately downstream of the major Surf-1 transcription start point abolish this response to serum factors. Here we show that over-expression of mitogen-activated protein (MAP) kinase phosphatase MKP-1, an inhibitor of the MAP kinase cascade, also blocks the response the Surf-1 promoter to serum factors. YY1 has previously been shown to interact with several transcription factors including Myc. We show that although the Surf-1/Surf-2 promoter does not contain Myc binding sites (E-boxes), Myc over-expression, or the activation of a Myc-oestrogen receptor fusion protein, activates transcription in the Surf-1 direction and that this response to Myc requires a functional YY1 binding site. Our data suggest that the MAP kinase cascade is required for the stimulation of Surf-1 promoter activity and that the Myc-YY1 interaction mediates this response.
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Affiliation(s)
- E G Vernon
- Department of Biochemistry, School of Medical Sciences, University of Bristol, University Walk, Bristol BS8 1TD, UK
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20
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Webster K, Parish J, Pandya M, Stern PL, Clarke AR, Gaston K. The human papillomavirus (HPV) 16 E2 protein induces apoptosis in the absence of other HPV proteins and via a p53-dependent pathway. J Biol Chem 2000; 275:87-94. [PMID: 10617590 DOI: 10.1074/jbc.275.1.87] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The human papillomavirus (HPV) E2 protein regulates viral gene expression and is also required for viral replication. HPV-transformed cells often contain chromosomally integrated copies of the HPV genome in which the viral E2 gene is disrupted. We have shown previously that re-expression of the HPV 16 E2 protein in HPV 16-transformed cells results in cell death via apoptosis. Here we show that the HPV 16 E2 protein can induce apoptosis in both HPV-transformed and non-HPV-transformed cell lines. E2-induced apoptosis is abrogated by a trans-dominant negative mutant of p53 or by overexpression of the HPV 16 E6 protein, but is increased by overexpression of wild-type p53. We show that mutations that block the DNA binding activity of E2 do not impair the ability of this protein to induce apoptosis. In contrast, removal of both N-terminal domains from the E2 dimer completely blocks E2-induced cell death. Heterodimers formed between wild-type E2 and N-terminally deleted E2 proteins also fail to induce cell death. Our data suggest that neither the DNA binding activity of E2 nor other HPV proteins are required for the induction of apoptosis by E2 and that E2-induced cell death occurs via a p53-dependent pathway.
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Affiliation(s)
- K Webster
- Department of Biochemistry, School of Medical Sciences, University of Bristol, Bristol BS8 1TD, United Kingdom
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21
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Abstract
The human papillomavirus 16 E2 protein binds to four specific DNA sequences present within the HPV 16 genome and regulates viral gene expression and DNA replication. However, the E2 protein can also bind tightly to non-specific DNA sequences. Here, we show that in binding reactions which contain an excess of non-specific DNA, magnesium ions enhance the binding of E2 to its specific sites. In contrast, in the absence of non-specific DNA, magnesium ions have no effect on the binding of E2 to specific sites. Although these data suggest that magnesium ions decrease the binding of E2 to non-specific DNA, gel retardation assays show that these ions have no effect on the binding of E2 to short non-specific DNA fragments and have only a minor effect on the binding of E2 to long non-specific DNA fragments. We also show that the binding of E2 to long fragments of non-specific DNA is highly cooperative. The E2-non-specific DNA complexes formed in the absence of magnesium ions are highly stable. However, the addition of specific DNA to E2-non-specific DNA complexes formed in the presence of magnesium ions rapidly results in the formation of E2-specific DNA complexes. Our data suggest that magnesium ions facilitate the transfer of E2 from non-specific binding sites to specific binding sites, and help to explain how E2 is able to direct human papillomavirus transcription and DNA replication in intact cells.
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Affiliation(s)
- H Lewis
- Department of Biochemistry School of Medical Sciences, University of Bristol, Bristol, BS8 1TD, UK
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22
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Sanchez-Perez AM, Soriano S, Clarke AR, Gaston K. Disruption of the human papillomavirus type 16 E2 gene protects cervical carcinoma cells from E2F-induced apoptosis. J Gen Virol 1997; 78 ( Pt 11):3009-18. [PMID: 9367388 DOI: 10.1099/0022-1317-78-11-3009] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Human papillomavirus type 16 (HPV-16) is a DNA tumour virus that has been implicated in the development of cervical cancer. In non-transformed HPV-infected cells, the HPV E2 protein regulates transcription of the viral E6 and E7 oncogenes. Malignant transformation is usually accompanied by disruption of the E2 gene and consequent deregulated expression of E6 and E7. Here we show that re-introduction of the HPV-16 E2 protein into an HPV-16-transformed cervical carcinoma cell line results in a decrease in growth rate and, in the absence of serum growth factors, cell death via apoptosis. E2 expression increases E6/E7 mRNA levels. This brings about an increase in E7 protein levels, which in turn leads to an increase in free E2F, a condition that has previously been shown to induce apoptotic cell death. Despite the increase in E6 mRNA there is no detectable E6 protein in these cells and E2 expression does not reduce the activity of a p53-responsive promoter. Our data suggest that disruption of the E2 gene produces HPV-transformed cells that are less liable to undergo apoptosis and, therefore, more likely to form cervical tumours.
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Affiliation(s)
- A M Sanchez-Perez
- Department of Biochemistry, School of Medical Sciences, University of Bristol, UK
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23
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Cole EG, Gaston K. A functional YY1 binding site is necessary and sufficient to activate Surf-1 promoter activity in response to serum growth factors. Nucleic Acids Res 1997; 25:3705-11. [PMID: 9278494 PMCID: PMC146936 DOI: 10.1093/nar/25.18.3705] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The human Surf-1 and Surf-2 housekeeping genes are divergently transcribed and share a bi-directional, TATA-less promoter. Housekeeping promoters typically contain complex arrays of transcription factor binding sites and several studies have suggested that many of these sites might be functionally redundant. The Surf-1/Surf-2 promoter region contains four factor binding sites; members of the ETS family of transcription factors bind to two of these sites whilst YY1 binds to a third site immediately downstream of the major Surf-1 transcription start point. Here we show that Sp1 binds to the fourth transcription factor binding site. Although YY1 and Sp1 have previously been shown to interact both in vitro and in vivo, these proteins function independently at the Surf-1/Surf-2 promoter. The binding of Sp1 alone is sufficient to bring about full promoter activity in the Surf-2 direction. In contrast, both Sp1 and ETS proteins are required to bring about full promoter activity in the Surf-1 direction. The YY1 binding site is not required for basal transcription in either direction. The YY1 binding site is, however, both necessary and sufficient to confer growth factor inducibility on transcription in the Surf-1 direction. Our data suggest that functionally redundant transcription factor binding sites might not be a general feature of housekeeping promoters.
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Affiliation(s)
- E G Cole
- Department of Biochemistry, School of Medical Sciences, University of Bristol, Bristol BS8 1TD, UK
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Thain A, Webster K, Emery D, Clarke AR, Gaston K. DNA binding and bending by the human papillomavirus type 16 E2 protein. Recognition of an extended binding site. J Biol Chem 1997; 272:8236-42. [PMID: 9079642 DOI: 10.1074/jbc.272.13.8236] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The human papillomavirus (HPV) 16 E2 protein (hE2) binds to four sites present upstream of the P97 promoter and regulates transcription of the viral E6 and E7 oncogenes. We have determined the relative binding constants for the interaction of the full-length hE2 protein with these sites. Our results show that hE2 binds tightly to site 4, less tightly to sites 1 and 2, and weakly to site 3. Similar results have previously been obtained using a C-terminal fragment of the hE2 protein suggesting that the C-terminal domain is the sole determinant of DNA binding affinity and specificity. Using circular permutation assays we show that binding of the hE2 protein induces the formation of a significant DNA bend and that the hE2-induced DNA bend angle is the same at both tight and weak hE2-binding sites. An alignment of the four hE2-binding sites from the HPV 16 genome suggests that this protein recognizes an extended binding site when compared with the bovine papillomavirus E2 protein. Here we show that the hE2 protein binds tightly to sites containing an A:T or a G:C base pair at position 7 of its binding site but weakly to sites containing either C:G or T:A at this position. Using site-directed mutagenesis we demonstrate that an arginine at position 304 of the hE2 protein is responsible for the recognition of specific base pairs at this position.
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Affiliation(s)
- A Thain
- Department of Biochemistry, Centre for Molecular Recognition, School of Medical Sciences, University of Bristol, Bristol BS8 1TD, United Kingdom
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Thain A, Jenkins O, Clarke AR, Gaston K. CpG methylation directly inhibits binding of the human papillomavirus type 16 E2 protein to specific DNA sequences. J Virol 1996; 70:7233-5. [PMID: 8794373 PMCID: PMC190779 DOI: 10.1128/jvi.70.10.7233-7235.1996] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
CpG methylation of the human papillomavirus upstream regulatory region has previously been shown to reduce virus promoter activity. Here, we demonstrate that methylation of the CpG dinucleotides contained within the binding site of the human papillomavirus type 16 E2 protein has a direct effect on the interaction of this protein with DNA. Methylation of both CpG dinucleotides within the E2 site abolishes the binding of E2.
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Affiliation(s)
- A Thain
- Department of Biochemistry, School of Medical Sciences, University of Bristol, United Kingdom
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Affiliation(s)
- A Thain
- Dept of Biochemistry, University of Bristol, UK
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Abstract
The divergently transcribed Surf-1 and Surf-2 genes are separated by a bi-directional, TATA-less promoter which contains three important factor-binding sites, Su1, Su2 and Su3. The transcription initiation factor YY1 binds to the Su1 site and stimulates transcription in the direction of Surf-1 and, to a lesser extent, Surf-2. Members of the ETS family of transcription factors bind to the Su2 and Su3 sites. Here we show that in transient transfection assays, transcription in both the Surf-1 and the Surf-2 direction is severely reduced by CpG methylation. Although the Su1 site contains three CpG dinucleotides, the binding of YY1 is not affected by CpG methylation. In contrast, the binding of two ETS factors (ETS-2 and PEA-3) to the Su2 site (which also contains three CpG dinucleotides) is totally abolished by CpG methylation. Finally, we show that methylation of a single C within the Su2 site is sufficient to prevent ETS factor binding.
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Affiliation(s)
- K Gaston
- Department of Biochemistry, School of Medical Sciences, University of Bristol, UK
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Gaston K, Fried M. CpG methylation has differential effects on the binding of YY1 and ETS proteins to the bi-directional promoter of the Surf-1 and Surf-2 genes. Nucleic Acids Res 1995; 23:901-9. [PMID: 7731802 PMCID: PMC306783 DOI: 10.1093/nar/23.6.901] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The divergently transcribed Surf-1 and Surf-2 housekeeping genes are separated by a bi-directional, TATA-less promoter which lies within a CpG-rich island. Here we show that CpG methylation severely reduces transcription in the direction of both Surf-1 and Surf-2. Previous work has identified three promoter elements (Su1, Su2 and Su3) which are conserved between the human and mouse Surf-1/Surf-2 promoters. These elements bind transcription factors present in human and mouse cell nuclear extracts in vitro and mutations which prevent factor binding also reduce promoter activity in vivo. Transcription initiation factor YY1 binds to the Su1 site and stimulates transcription in the direction of Surf-1 and, to a lesser extent, Surf-2. Here we show that members of the ETS family of transcription factors bind to the Su2 site. Although the Su1 factor binding site contains three CpG dinucleotides, the binding of YY1 is not affected by CpG methylation. In contrast, CpG methylation abolishes the binding of ETS proteins to the Su2 site; methylation of a single cytosine, at position 3 of the consensus ETS site, is sufficient to prevent factor binding. This direct effect on the binding of ETS proteins is, however, not in itself sufficient to explain the repression of this promoter by CpG methylation. A mutation of the Su2 site which removes the sequence CpG, but which does not prevent ETS factor binding, fails to relieve this promoter from repression by CpG methylation.
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Affiliation(s)
- K Gaston
- Department of Biochemistry, School of Medical Sciences, University of Bristol, UK
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Lennard A, Gaston K, Fried M. The Surf-1 and Surf-2 genes and their essential bidirectional promoter elements are conserved between mouse and human. DNA Cell Biol 1994; 13:1117-26. [PMID: 7702754 DOI: 10.1089/dna.1994.13.1117] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The organization of the Surfeit locus and the juxtaposition of at least five of the Surfeit genes (Surf-1 to -5) are conserved between mouse and human (Williams et al., 1988; Yon et al., 1993). In the mouse, the heterogeneous transcription start sites of the divergent Surf-1 and Surf-2 genes are separated by a maximum of only 73 bp (Williams and Fried, 1986). This region contains a bidirectional promoter composed of three major factor binding sites required for the efficient expression of both the Surf-1 and Surf-2 genes (Lennard and Fried, 1991). Here we report the isolation and characterization of the human Surf-1 and Surf-2 genes and their intergenic region. Although the major Surf-1 and Surf-2 transcription start sites are separated by 97 bp in the human and there are multiple differences in the mouse and human sequence between and around the transcriptional start sites, there is high conservation of the sequence specifying the three major factor binding sites of the bidirectional promoter. The three factor binding sites (HSu1, 2, and 3) present within the human promoter bind nuclear factors, of which the binding of HSu1 and HSu2 are competed by oligonucleotides carrying the corresponding mouse factor binding sites. The HSu3 site binds factors that are similar but apparently not direct homologs of those that bind to the equivalent mouse sequences. Human Surf-1 and Surf-2 cDNAs have been cloned and sequenced. The putative human Surf-1 and Surf-2 proteins are 77% and 69% identical to the corresponding mouse proteins.
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Affiliation(s)
- A Lennard
- Eukaryotic Gene Organisation and Expression Laboratory, Imperial Cancer Research Fund, London, UK
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Abstract
The Surfeit locus is an unusual cluster of at least 6 housekeeping genes whose organisation is conserved between birds and mammals. We have previously shown that the divergently transcribed Surf-1 and Surf-2 genes are separated by a bi-directional, TATA-less promoter. In mouse, the Surf-1/Surf-2 promoter contains three important factor binding sites: Su1, Su2, and Su3. These sites are conserved between the mouse and human Surf-1/Surf-2 promoters, bind nuclear factors in vitro, and are required for accurate and efficient expression of Surf-1 and Surf-2 in vivo. Using gel retardation assays, methylation interference experiments, and specific antibodies we demonstrate that the Su1 binding factor is the initiator protein YY1. Over-expression of YY1 results in a major stimulation of transcription in the Surf-1 direction and a minor stimulation of transcription in the Surf-2 direction.
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Affiliation(s)
- K Gaston
- Department of Biochemistry, University of Bristol, School of Medical Sciences, UK
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Gaston K. Estimating extinction rates: Joseph Banks' legacy. Trends Ecol Evol 1994; 9:80-2. [DOI: 10.1016/0169-5347(94)90198-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Gaston K, Fried M. The isolation of transcription factors from lambda gt11 cDNA expression libraries: human steroid 5 alpha-reductase 1 has sequence-specific DNA binding activity. Nucleic Acids Res 1992; 20:6297-301. [PMID: 1475191 PMCID: PMC334519 DOI: 10.1093/nar/20.23.6297] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The Surf-1/Surf-2 bi-directional promoter contains binding sites for at least three transcription factors (Su1, Su2, and Su3). By screening a lambda gt11 HeLa cell cDNA expression library with a concatenated Su2 factor binding site, we isolated a cDNA which encodes a protein with sequence-specific DNA binding activity. Gel retardation assays showed that the cloned factor binds specifically to the Su2 factor binding site present in the human Surf-1/Surf-2 promoter but not to an Su2 site containing mutated base pairs. Co-transfection experiments demonstrated that the cloned cDNA had little or no effect on the expression of a reporter gene under the control of multiple Su2 factor binding sites. Similarly a fusion protein in which the acidic activation domain of HSV VP16 was linked to the cloned factor had no effect, implying that the factor does not function as a DNA binding protein in vivo. DNA sequence analysis revealed that the cloned cDNA is identical to that of human steroid 5 alpha-reductase 1, an enzyme which converts testosterone to dihydrotestosterone. These results are discussed with respect to other putative transcription factors which have been isolated from cDNA expression libraries on the basis of their sequence-specific DNA binding activity.
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Affiliation(s)
- K Gaston
- Eukaryotic Gene Organisation and Expression Laboratory, Imperial Cancer Research Fund, London, UK
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Abstract
Protein-induced DNA bending is of importance in the formation of complex nucleoprotein assemblies such as those involved in the initiation of DNA replication or transcription initiation. We have compared the DNA bending characteristics of the Escherichia coli cyclic AMP receptor protein (CRP or CAP), an archetypal DNA bending protein, to those of TFIID, the eukaryotic TATA-element binding transcription factor. By altering the helical phasing between a CRP binding site and the E. coli melR promoter we have mapped a DNA sequence-directed bend in the downstream region of the promoter. This intrinsic DNA bend may be important in the regulation of the melR promoter by CRP in vivo. Gel retardation assays and DNAse I footprinting show that human TFIID binds to the melR promoter - 10 region. Taking advantage of this fact, and using the CRP-induced DNA bend as a standard, we have employed phase sensitive detection to show that the DNA bend angle induced by TFIID is far less than that induced by CRP. Further evidence to support this conclusion comes from a comparison of the relative mobilities of CRP-DNA and TFIID-DNA complexes. These results place limits on the role of any DNA bending induced by TFIID alone in the initiation of transcription.
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Affiliation(s)
- K Gaston
- Eukaryotic Gene Organisation and Expression Laboratory, Imperial Cancer Research Fund, Lincoln's Inn Fields, London, UK
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Bell A, Gaston K, Williams R, Chapman K, Kolb A, Buc H, Minchin S, Williams J, Busby S. Mutations that alter the ability of the Escherichia coli cyclic AMP receptor protein to activate transcription. Nucleic Acids Res 1990; 18:7243-50. [PMID: 2259621 PMCID: PMC332859 DOI: 10.1093/nar/18.24.7243] [Citation(s) in RCA: 155] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The effects of a number of mutations in the E. coli cyclic AMP receptor protein (CRP) have been determined by monitoring the in vivo expression and in vitro open complex formation at two semi-synthetic promoters that are totally CRP-dependent. At one promoter the CRP-binding site is centered around 41.5 base pairs upstream from the transcription start whilst at the other promoter it is 61.5 base pairs upstream. The CRP mutation E171K reduces expression from both promoters whilst H159L renders CRP totally inactive: neither mutation stops CRP binding at either promoter. The mutations K52N and K52Q reverse the effect of H159L and 'reeducate' CRP to activate transcription. CRP carrying both H159L and K52N activates transcription from the promoter with the CRP site at -41.5 better than wild type CRP. In sharp contrast, this doubly changed CRP is totally inactive with respect to the activation of transcription from the promoter carrying the CRP site at -61.5. Our results suggest that CRP can use different contacts and/or conformations during transcription activation at promoters with different architectures.
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Affiliation(s)
- A Bell
- School of Biochemistry, University of Birmingham, UK
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Abstract
The cyclic AMP receptor protein-cAMP complex (CRP-cAMP) binds at a variety of distances upstream of several E. coli promoters and activates transcription. We have constructed a model system in which a consensus CRP binding site is placed at different distances upstream of the melR promoter. CRP-cAMP activates transcription from melR when bound at a number of positions, all of which lie on the same face of the DNA helix. The two distances at which transcription is strongly activated correspond exactly to those at which CRP-cAMP binds upstream of the well-studied galP1 and lac promoters. Footprinting of the synthetic promoters reveals that RNA polymerase makes identical contacts with their -10 regions even though CRP-cAMP binds at a different distance in each case. Kinetic analysis in vitro indicates that CRP-cAMP activates transcription from these promoters in similar but distinct ways. A model is proposed to explain this two-position activation.
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Affiliation(s)
- K Gaston
- Unité de Physicochimie des Macromolécules Biologiques, URA 1149 du CNRS, Institut Pasteur, Paris, France
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Gaston K, Kolb A, Busby S. Binding of the Escherichia coli cyclic AMP receptor protein to DNA fragments containing consensus nucleotide sequences. Biochem J 1989; 261:649-53. [PMID: 2673223 PMCID: PMC1138872 DOI: 10.1042/bj2610649] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Binding of the Escherichia coli CRP protein to DNA fragments carrying nucleotide sequences closely corresponding to the consensus is very tight with a dissociation time of over 2 h in our conditions. The concentration of cyclic AMP required for this binding is below the physiological range of intracellular cyclic AMP concentrations. Changes in nucleotide sequence at positions that are not well-conserved between different naturally-occurring CRP sites allow a more rapid dissociation of CRP-DNA complexes. There is an inverse correlation between the stability of CRP binding to sites in vitro and the repression by glucose of expression dependent on these sites in vivo: expression that is dependent on the tighter binding sites cannot be repressed by the inclusion of glucose in the growth medium.
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Affiliation(s)
- K Gaston
- School of Biochemistry, University of Birmingham, U.K
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Abstract
Expression of the melR gene is required for melibiose-dependent stimulation of transcription initiation at the promoter of the melAB operon. Using the S1 nuclease method we have located the melR transcription start point. Transcription from the melR promoter is dependent on cAMP-CRP: specific nucleotide sequences downstream of bp -59 with respect to the melR transcription start are sufficient for full promoter activity. Nucleotide sequence homologies suggest that the cAMP-CRP binding site is located from bp -52 to -31, in exactly the same position as at the galP1 promoter. Using DNase I footprinting we show that cAMP-CRP and RNA polymerase together bind tightly to the melR promoter sequence, creating a strong footprint from bp -70 to +20. Alone, cAMP-CRP binding is hardly detectable, whereas RNA polymerase alone creates a weak footprint centred around the -10 hexamer sequence. When the melR gene is expressed from a cAMP-CRP-independent promoter, melibiose-dependent transcription from the melAB promoter becomes independent of cAMP-CRP, showing that the melR promoter is the primary site of control by cAMP-CRP in the mel regulon.
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Affiliation(s)
- C Webster
- Department of Biochemistry, University of Birmingham, U.K
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Gaston K, Chan B, Kolb A, Fox J, Busby S. Alterations in the binding site of the cyclic AMP receptor protein at the Escherichia coli galactose operon regulatory region. Biochem J 1988; 253:809-18. [PMID: 2845937 PMCID: PMC1149375 DOI: 10.1042/bj2530809] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Gene manipulation techniques have been used to alter the binding site for the cyclic AMP-cyclic AMP receptor protein complex (cAMP-CRP) at the regulatory region of the Escherichia coli galactose (gal) operon. The effects of these changes on CRP-dependent stimulation of expression from the galP1 promoter in vivo have been measured, and gel binding assays have been used to measure the affinity of cAMP-CRP for the modified sites. Firstly we have deleted progressively longer sequences from upstream of the gal CRP site in order to locate the functional limit of the site. A deletion to -49, removing the first base that corresponds to the consensus sequence for a CRP binding site, is sufficient to reduce CRP binding and block CRP-dependent stimulation of P1. Secondly, we used synthetic oligonucleotides to invert the asymmetric nucleotide sequence at the gal CRP binding site or to make the sequence symmetric. Inversion of the site has little effect on CRP binding, the architecture of open complexes at P1 revealed by DNAase I footprinting, or the stimulation of transcription from P1. Making the site symmetric increases the affinity for CRP by over 50-fold and leads to increased transcription from P1, whilst hardly altering the DNAase I footprint of open complexes. Our results confirm that the strength of binding of CRP depends on the nature of the site and show that it is this that principally accounts for differences in CRP-dependent stimulation of transcription.
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Affiliation(s)
- K Gaston
- Department of Biochemistry, University of Birmingham, U.K
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