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Firlej V, Bocquet B, Desbiens X, de Launoit Y, Chotteau-Lelièvre A. Pea3 Transcription Factor Cooperates with USF-1 in Regulation of the Murine bax Transcription without Binding to an Ets-binding Site. J Biol Chem 2005; 280:887-98. [PMID: 15466854 DOI: 10.1074/jbc.m408017200] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Pea3 transcription factor (which belongs to the PEA3 group) from the Ets family has been shown to be involved in mammary embryogenesis and oncogenesis. However, except for proteinases, only few of its target genes have been reported. In the present report, we identified bax as a Pea3 up-regulated gene. We provide evidence of this regulation by using Pea3 overexpression and Pea3 silencing in a mammary cell line. Both Pea3 and Erm, another member of the PEA3 group, are able to transactivate bax promoter fragments. Although the minimal Pea3-regulated bax promoter does not contain an Ets-binding site, two functional upstream stimulatory factor-regulated E boxes are present. We further demonstrate the ability of Pea3 and USF-1 to cooperate for the transactivation of the bax promoter, mutation of the E boxes dramatically reducing the Pea3 transactivation potential. Although Pea3 did not directly bind to the minimal bax promoter, we provide evidence that USF-1 could form a ternary complex with Pea3 and DNA. Taken together, our results suggest that Pea3 may regulate bax transcription via the interaction with USF-1 but without binding to DNA.
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Affiliation(s)
- Virginie Firlej
- Laboratoire de Biologie du Développement UPRES-EA1033, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq, France
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2
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Park CW, Park YM, Lee GT, Lee Y, Woo S, Cha JY, Ahn CW, Cha BS, Kim KS, Ahn YH, Lee HC. Targeting of therapeutic gene expression to the liver by using liver-type pyruvate kinase proximal promoter and the SV40 viral enhancer active in multiple cell types. Biochem Biophys Res Commun 2004; 314:131-7. [PMID: 14715256 DOI: 10.1016/j.bbrc.2003.12.064] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
To achieve the liver-directed expression in sufficient amounts of therapeutic genes for successful and safe gene therapy, natural liver-specific promoters can be used to direct the expression of therapeutic genes in the liver, whereas strong viral enhancers were used to obtain sufficient amounts of expressed therapeutic gene products. However, very often use of either the former or the latter does not guarantee both potent and liver-specific therapeutic gene expression. Here we conglomerate them and thus create a potent tissue-specific promoter by characterizing and using the liver-type pyruvate kinase proximal promoter (LPKPP) harboring its TATA box and a HNF-1alpha binding site. Alone it hardly activated its reporter gene expression in non-hepatocytes or hepatocytes. However, in the presence of the SV40 viral enhancer (SV40VE), which is active in multiple cell types, it was able to potently activate its reporter gene expression specifically in hepatocytes. The tissue-specific activation of the LPKPP by the viral enhancer was attributed to HNF-1alpha binding to the LPKPP. Taken together, these results support the idea that the constitutively active SV40VE could be used to activate the LPKPP in a tissue-specific manner in the presence of HNF-1alpha. To our knowledge, this is the first study to utilize HNF-1alpha and its binding site, in the context of the LPKPP, to generate a basal promoter that is transcriptionally activated potently in a tissue-specific manner by a viral enhancer that is active in multiple cell types.
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Affiliation(s)
- Cheol Won Park
- Institute of Endocrine Research, College of Medicine, Yonsei University, Seoul, South Korea
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3
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Naiki T, Nagaki M, Shidoji Y, Kojima H, Imose M, Kato T, Ohishi N, Yagi K, Moriwaki H. Analysis of gene expression profile induced by hepatocyte nuclear factor 4alpha in hepatoma cells using an oligonucleotide microarray. J Biol Chem 2002; 277:14011-9. [PMID: 11834723 DOI: 10.1074/jbc.m105403200] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Hepatocyte nuclear factor 4alpha (HNF-4alpha), a liver-specific transcription factor, plays a significant role in many liver-specific functions, including lipid, glucose, drug, and ammonia metabolism, and also in embryonal liver development. However, its functions and regulation are not yet clearly understood. In this study, we constructed an adenovirus vector carrying rat HNF-4alpha cDNA and transfected the adenovirus to human hepatoma cells, HuH-7, to enforce expression of the exogenous HNF-4alpha gene. We analyzed HNF-4alpha-induced genes using cDNA microarray technology, which included over 9000 genes. As a result, 62 genes showed a greater than 2.0-fold change in expression level after the viral transfection. Fifty-six genes were consistently induced by HNF-4alpha overexpression, and six genes were repressed. To assess HNF-4alpha function, we attempted to classify the genes, which had been classified by their encoding protein functions in a previous report. We could classify 45 genes. The rest of the HNF-4alpha-sensitive genes were unclassified (4 genes) or not identified (13 genes). Among the classified genes, almost half of the induced genes (26 of 40) were related to metabolism genes and particularly to lipid metabolism-related genes. This cDNA microarray analysis showed that HNF-4alpha is one of the central liver metabolism regulators.
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Affiliation(s)
- Takafumi Naiki
- First Department of Internal Medicine and the Department of Neurology and Psychiatry, Gifu University School of Medicine, Gifu, Japan
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4
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El Bahi S, Caliot E, Bens M, Bogdanova A, Kernéis S, Kahn A, Vandewalle A, Pringault E. Lymphoepithelial interactions trigger specific regulation of gene expression in the M cell-containing follicle-associated epithelium of Peyer's patches. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 168:3713-20. [PMID: 11937521 DOI: 10.4049/jimmunol.168.8.3713] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In the intestine, the follicle-associated epithelium (FAE) of Peyer's patches (PP) performs Ag sampling as the first step in developing immune responses. Depending on the species, this epithelium contains 10-50% of M cells, which act as regulated gates in epithelial barriers that can be used opportunistically by pathogens to invade their host. However, the mechanisms involved in the differentiation and uptake processes of M cells are not known, in part because their limited number in the intestinal mucosa has hampered molecular and biochemical studies. In this work we provide evidence that PP lymphocytes can themselves modulate gene expression in PP in vivo and in an in vitro model of FAE. Transgenic mice carrying a reporter gene under the control of a modified L-pyruvate kinase promoter (SVPK) exhibit strong transgene expression in PP and FAE, but not in the adjacent villous cells. We used the mouse intestinal epithelial cell line m-IC(cl2) transfected with the SVPK promoter fused to beta-galactosidase to investigate the direct effect of PP lymphocytes on SVPK promoter activity. beta-Galactosidase expression was 4.4-fold higher in transfected m-IC(cl2) cells when they were cultured with PP lymphocytes. Conversely, green fluorescent protein expression was 1.8-fold lower in stably transfected differentiated intestinal Caco-2(cl1) cells with the sucrase isomaltase promoter fused to green fluorescent protein cDNA when they were cultured with PP lymphocytes, indicating that the in vivo FAE down-regulation of sucrase isomaltase promoter is transcriptionally regulated.
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Affiliation(s)
- Sophia El Bahi
- Laboratoire des Interactions Lympho-Epithéliales, Département de Biologie Cellulaire et Infection, Institut Pasteur, Paris, France
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5
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Krones A, Jungermann K, Kietzmann T. Cross-talk between the signals hypoxia and glucose at the glucose response element of the L-type pyruvate kinase gene. Endocrinology 2001; 142:2707-18. [PMID: 11356723 DOI: 10.1210/endo.142.6.8200] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The signals oxygen and glucose play an important role in metabolism, angiogenesis, tumorigenesis, and embryonic development. Little is known about an interaction of these two signals. We demonstrate here the cross-talk between oxygen and glucose in the regulation of L-type pyruvate kinase (L-PK) gene expression in the liver. In the liver the periportal to perivenous drop in O(2) tension was proposed to be an endocrine key regulator for the zonated gene expression. In primary rat hepatocyte cultures the expression of the L-PK gene on mRNA and on protein level was induced by venous pO(2), whereas its glucose-dependent induction occurred predominantly under arterial pO(2). It was shown by transient transfection of L-PK promoter luciferase and glucose response element (Glc(PK)RE) SV40 promoter luciferase gene constructs that the modulation by O(2) of the glucose-dependent induction occurred at the Glc(PK)RE in the L-PK gene promoter. The reduction of the glucose-dependent induction of the L-PK gene expression under venous pO(2) appeared to be mediated via an interference between hypoxia inducible factor-1 (HIF-1) and upstream stimulating factor at the Glc(PK)RE. The glucose response element also functioned as an hypoxia response element which was confirmed in cotransfection assays with Glc(PK)RE luciferase gene constructs and HIF-1alpha expression vectors. Furthermore, it was found by gel shift and supershift assay that HIF-1alpha and USF-1 or USF-2 could bind to the Glc(PK)RE. Our findings implicate that the cross-talk between oxygen and glucose might have a fundamental role in the regulation of several physiological and pathophysiological processes.
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Affiliation(s)
- A Krones
- Institut für Biochemie und Molekulare Zellbiologie, Georg-August-Universität, Humboldtallee 23, D-37073 Göttingen, Germany
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6
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Samoylenko A, Roth U, Jungermann K, Kietzmann T. The upstream stimulatory factor-2a inhibits plasminogen activator inhibitor-1 gene expression by binding to a promoter element adjacent to the hypoxia-inducible factor-1 binding site. Blood 2001; 97:2657-66. [PMID: 11313255 DOI: 10.1182/blood.v97.9.2657] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Plasminogen activator inhibitor-1 (PAI-1) expression is induced by hypoxia (8% O(2)) via the PAI-1 promoter region -175/-159 containing a hypoxia response element (HRE-2) binding the hypoxia-inducible factor-1 (HIF-1) and an adjacent response element (HRE-1) binding a so far unknown factor. The aim of the present study was to identify this factor and to investigate its role in the regulation of PAI-1 expression. It was found by supershift assays that the upstream stimulatory factor-2a (USF-2a) bound mainly to the HRE-1 of the PAI-1 promoter and to a lesser extent to HRE-2. Overexpression of USF-2a inhibited PAI-1 messenger RNA and protein expression and activated L-type pyruvate kinase expression in primary rat hepatocytes under normoxia and hypoxia. Luciferase (Luc) gene constructs driven by 766 and 276 base pairs of the 5'-flanking region of the PAI-1 gene were transfected into primary hepatocytes together with expression vectors encoding wild-type USF-2a and a USF-2a mutant lacking DNA binding and dimerization activity (DeltaHU2a). Cotransfection of the wild-type USF-2a vector reduced Luc activity by about 8-fold, whereas cotransfection of DeltaHU2a did not influence Luc activity. Mutation of the HRE-1 (-175/-168) in the PAI-1 promoter Luc constructs decreased USF-dependent inhibition of Luc activity. Mutation of the HRE-2 (-165/-158) was less effective. Cotransfection of a HIF-1alpha vector could compete for the binding of USF at HRE-2. These results indicated that the balance between 2 transcriptional factors, HIF-1 and USF-2a, which can bind adjacent HRE sites, appears to be involved in the regulation of PAI-1 expression in many clinical conditions.
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Affiliation(s)
- A Samoylenko
- Institut für Biochemie und Molekulare Zellbiologie, Humboldtallee 23, Göttingen, Germany
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7
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Lou DQ, Tannour M, Selig L, Thomas D, Kahn A, Vasseur-Cognet M. Chicken ovalbumin upstream promoter-transcription factor II, a new partner of the glucose response element of the L-type pyruvate kinase gene, acts as an inhibitor of the glucose response. J Biol Chem 1999; 274:28385-94. [PMID: 10497199 DOI: 10.1074/jbc.274.40.28385] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Transcription of the L-type pyruvate kinase (L-PK) gene is induced by glucose in the presence of insulin and repressed by glucagon via cyclic AMP. The DNA regulatory sequence responsible for mediating glucose and cyclic AMP responses, called glucose response element (GlRE), consists of two degenerated E boxes spaced by 5 base pairs and is able to bind basic helix-loop-helix/leucine zipper proteins, in particular the upstream stimulatory factors (USFs). From ex vivo and in vivo experiments, it appears that USFs are required for correct response of the L-PK gene to glucose, but their expression and binding activity are not known to be regulated by glucose. A genetic screen in yeast has allowed us to identify a novel transcriptional factor binding to the GlRE, i.e. the chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII). Binding of COUP-TFII to the GlRE was confirmed by electrophoretic mobility shift assays, and COUP-TFII-containing complexes were detectable in liver nuclear extracts. Neither abundance nor binding activity of COUP-TFII appeared to be significantly regulated by diets. In footprinting experiments, two COUP-TFII-binding sites overlapping the E boxes were detected. Overexpression of COUP-TFII abrogated the USF-dependent transactivation of an artificial GlRE-dependent promoter in COS cells and the glucose responsiveness of the L-PK promoter in hepatocytes in primary culture. In addition, a mutated GlRE with increased affinity for USF and very low affinity for COUP-TFII conferred a dramatically decreased glucose responsiveness on the L-PK promoter in hepatocytes in primary culture by increasing activity of the reporter gene in low glucose condition. We propose that COUP-TFII could be a negative regulatory component of the glucose sensor complex assembled on the GlRE of the L-PK gene and most likely of other glucose-responsive genes as well.
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Affiliation(s)
- D Q Lou
- Institut Cochin de Génétique Moléculaire, U129 INSERM, Université René Descartes, 75014 Paris, France
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8
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Gregori C, Porteu A, Lopez S, Kahn A, Pichard AL. Characterization of the aldolase B intronic enhancer. J Biol Chem 1998; 273:25237-43. [PMID: 9737987 DOI: 10.1074/jbc.273.39.25237] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The aldolase B gene is transcribed at a high level in the liver, kidney, and small intestine. This high level of gene expression results from cooperation between a weak but liver-specific promoter and an intronic activator. A deletional study of this activator present in the first intron allowed us to ascribe the maximal enhancer function to a 400-base pair (bp) fragment (+1916 to + 2329). This enhancer is highly liver-specific and enhances the activity of heterologous minimal promoters in a position and distance-independent fashion in transiently transfected Hep G2 hepatoma cells. The aldolase B enhancer is composed of two domains, a 200-bp module (Ba) inactive by itself but which synergizes with another 200-bp module (Bb) that alone retains 25% of the total enhancer activity. The Bb sequence is 76% homologous between human and rat genes and contains several binding sites for liver-enriched nuclear factors. By electrophoretic mobility shift assays, we demonstrated that elements 5 and 7 bind hepatic nuclear factor 1 (HNF1), whereas element 2 binds hepatic nuclear factor 4 (HNF4). A functional analysis of the enhancer whose elements have been mutated demonstrated that mutation of any of the HNF1 sites totally suppressed enhancer activity, whereas mutation of the HNF4-binding site reduced it by 80%.
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Affiliation(s)
- C Gregori
- Institut Cochin de Génétique Moléculaire, U.129 INSERM, 24, rue du Faubourg Saint Jacques, 75014 Paris, France
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9
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Rudoni S, Martinenghi S, Severini GM, Monti LD, Pozza G, Bordignon C, Falqui L. Glucose-induced activity of liver-type pyruvate kinase promoter in primary rat hepatocytes. Transplant Proc 1998; 30:584-5. [PMID: 9532186 DOI: 10.1016/s0041-1345(97)01414-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- S Rudoni
- Telethon Institute for Gene Therapy (TIGET), Milan, Italy
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10
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Gilbert E, Morel A, Tulliez M, Maunoury R, Terzi F, Miquerol L, Kahn A. In vivo effects of activated H-ras oncogene expressed in the liver and in urogenital tissues. Int J Cancer 1997; 73:749-56. [PMID: 9398057 DOI: 10.1002/(sici)1097-0215(19971127)73:5<749::aid-ijc23>3.0.co;2-#] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Transgenic mouse technology provides a direct genetic approach to in vivo carcinogenesis. In order to determine the oncogenic potential of an activated ras gene in liver, kidney and intestine, we created transgenic mice expressing the human H-ras oncogene under control of the L-type pyruvate-kinase gene. This gene is expressed in hepatocytes, enterocytes, proximal tubular cells of the kidney and endocrine pancreatic cells. Depending on lines, we observed hepatocarcinoma, polycystic kidney disease and an unexpected epididymis hyperplasia. These transgenic mice are an interesting model of polycystic kidney disease, and complete our study of the tissue-specificity of oncogene action.
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MESH Headings
- Animals
- Carcinoma, Hepatocellular/genetics
- Carcinoma, Hepatocellular/metabolism
- Carcinoma, Hepatocellular/pathology
- Epididymis/pathology
- Female
- Gene Expression Regulation, Neoplastic
- Genes, ras/genetics
- Humans
- Hyperplasia/genetics
- Hyperplasia/pathology
- Kidney Function Tests
- Liver/metabolism
- Liver Function Tests
- Liver Neoplasms, Experimental/genetics
- Liver Neoplasms, Experimental/metabolism
- Liver Neoplasms, Experimental/pathology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Inbred DBA
- Mice, Transgenic/genetics
- Oncogene Protein p21(ras)/biosynthesis
- Oncogene Protein p21(ras)/genetics
- Polycystic Kidney Diseases/genetics
- Polycystic Kidney Diseases/metabolism
- Polycystic Kidney Diseases/pathology
- Urogenital System/metabolism
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Affiliation(s)
- E Gilbert
- Institut Cochin de Génétique Moléculaire, Unité 129 de l'INSERM, Paris, France
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11
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Kennedy HJ, Viollet B, Rafiq I, Kahn A, Rutter GA. Upstream stimulatory factor-2 (USF2) activity is required for glucose stimulation of L-pyruvate kinase promoter activity in single living islet beta-cells. J Biol Chem 1997; 272:20636-40. [PMID: 9252379 DOI: 10.1074/jbc.272.33.20636] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Elevated glucose concentrations stimulate L-pyruvate kinase (L-PK) gene transcription in liver and islet beta-cells. A glucose response element termed the L4 box (two noncanonical E-boxes located -165 and -154 base pairs upstream of the transcriptional start point) has previously been defined within the proximal promoter region of the gene. However, the identity of the transacting factor(s) which binds to this site remains unclear. We have used photon counting digital imaging of firefly luciferase activity to monitor promoter activity continuously in single living islet beta and derived INS-1 cells, and to analyze the molecular basis of the regulation by glucose. L-PK promoter activity, normalized to cytomegalovirus promoter activity using the distinct Renilla reniformis luciferase, was >/=6-fold higher in cells cultured at 16 mM glucose or above compared with cells cultured at 3 mM glucose. Microinjection of antibodies against the ubiquitous transcription factor USF2 inhibited L-PK promoter activity in beta- and INS-1 cells incubated at 30 mM glucose by 71-87%. Anti-USF2 antibodies had a much smaller effect on promoter activity in INS-1 cells cultured at 3 mM glucose, and on the activity of a modified promoter construct lacking an L4 box. These data support the view that glucose enhances L-PK gene transcription in beta-cells by modifying the transactivational capacity of USF2 bound to the upstream L4 box.
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Affiliation(s)
- H J Kennedy
- Department of Biochemistry, School of Medical Sciences, University Walk, University of Bristol, Bristol BS8 1TD, United Kingdom
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12
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Hilliard CM, Fletcher S, Yeoh GC. Calcium phosphate transfection and cell-specific expression of heterologous genes in primary fetal rat hepatocytes. Int J Biochem Cell Biol 1996; 28:639-50. [PMID: 8673728 DOI: 10.1016/1357-2725(96)00007-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
In order to study transcriptional regulation of hepatic genes during development, a method for transfer of fusion genes to primary cultures of fetal hepatocytes was required. The aim of this study was to assess currently available transfection methods and optimize the best method for use with cultured fetal hepatocytes. The Rous sarcoma virus 5' long terminal repeat controlling transcription of the beta-galactosidase reporter gene (pRSV lac Z II) was used to assess electroporation, lipofection, DEAE-dextran and calcium phosphate transfection in cultured primary fetal hepatocytes. The success of transfection was determined by histochemical detection and quantitation of beta-galactosidase activity. Results showed that calcium phosphate transfection was optimal for fetal hepatocytes with respect to beta-galactosidase activity and cell survival. For maximum transfection of cells, 10 micrograms/ml DNA, HEPES buffered saline transfection buffer at pH 7.05 and a 24 hr expression period for the reporter gene were employed. Glycerol shock did not increase transfection efficiency significantly. The method was simplified by adding calcium chloride solution to DNA diluted in transfection buffer and the resulting co-precipitate added directly to the medium covering the cells. Transfection 24 hr after initial culture and a precipitate incubation time of 20 hr were optimal. The suitability of this method was confirmed with a liver-specific promoter controlling beta-galactosidase and chloramphenicol acetyltransferase expression. In conclusion this study shows that a modified calcium phosphate transfection method is most effective for transferring DNA to primary cultured fetal hepatocytes. It is concluded that this method is appropriate for use with fetal hepatocytes and will facilitate studies of gene regulation during liver development.
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Affiliation(s)
- C M Hilliard
- Department of Biochemistry, University of Western Australia, Nedlands, Australia
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13
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Doiron B, Cuif MH, Chen R, Kahn A. Transcriptional glucose signaling through the glucose response element is mediated by the pentose phosphate pathway. J Biol Chem 1996; 271:5321-4. [PMID: 8621383 DOI: 10.1074/jbc.271.10.5321] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Glucose catabolism induces the expression of the L-type pyruvate kinase (L-PK) gene through the glucose response element (GIRE). The metabolic pathway used by glucose after its phosphorylation to glucose 6-phosphate by glucokinase to induce L-PK gene expression in hepatocytes remains unknown. The sugar alcohol xylitol is metabolized to xylulose 5-phosphate, an intermediate of the nonoxidative branch of the pentose phosphate pathway. In this study, we demonstrated that xylitol at low concentration (O.5 mM) induced the expression of the L-PK/CAT construct in glucose-responsive mhAT3F hepatoma cells at the same level as 20 mM glucose, while it did not affect intracellular concentration of glucose 6-phosphate significantly. The effect of xylitol on the induction of the L-PK gene expression was noncumulative with that of glucose since 20 mM glucose plus 5 mM xylitol induced the expression of the L-PK/CAT construct similarly to 20 mM glucose alone. In hepatocytes in primary culture, 5 mM xylitol induced accumulation of the L-PK mRNA even in the absence of insulin. Furthermore, the response to xylitol as well as glucose required the presence of a functional GIRE. It can be assumed from these results that glucose induces the expression of the L-PK gene through the nonoxidative branch of the pentose phosphate pathway. The effect of xylitol at low concentration suggests that the glucose signal to the transcriptional machinery is mediated by xylulose 5-phosphate.
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Affiliation(s)
- B Doiron
- Institut Cochin de Génétique Moléculaire, INSERM, Unité 129, 24 rue du Faubourg Saint Jacques, 75014 Paris, France
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14
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Odagiri H, Wang J, German MS. Function of the human insulin promoter in primary cultured islet cells. J Biol Chem 1996; 271:1909-15. [PMID: 8567638 DOI: 10.1074/jbc.271.4.1909] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Pancreatic islet beta cells regulate the rate of insulin gene transcription in response to a number of nutrients, the most potent of which is glucose. To test for its regulation by glucose, the promoter sequence was isolated from the human insulin gene. When linked to chloramphenicol acetyltransferase and transfected into primary islet cultures, the human insulin promoter is activated by glucose. In parallel islet transfections, glucose also activates the L-pyruvate kinase and islet amyloid chain ketoacid dehydrogenase E1a promoter, but it does not affect the beta cell glucose kinase promoter. Using deletion and substitution mutations of the proximal human insulin promoter, we mapped a metabolic response element to the E box, E1, at -100 base pairs relative to the transcription start site. Although the isolated E1 element responds to glucose, inclusion of either of two AT-rich sequences, A1 or A2/C1 on either side of E1, results in dramatic synergistic activation. Inclusion of A2/C1 also increases the response to glucose. The A2-E1-A1 region alone, however, does not explain all of the activity of the human insulin promoter in cultured islets, and other transcriptionally important elements likely to contribute to the glucose response as well.
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Affiliation(s)
- H Odagiri
- Hormone Research Institute, University of California at San Francisco 94143-0534, USA
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15
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Viollet B, Lefrançois-Martinez AM, Henrion A, Kahn A, Raymondjean M, Martinez A. Immunochemical characterization and transacting properties of upstream stimulatory factor isoforms. J Biol Chem 1996; 271:1405-15. [PMID: 8576131 DOI: 10.1074/jbc.271.3.1405] [Citation(s) in RCA: 164] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The ubiquitous upstream stimulatory factor (USF) transcription factors encoded by two distinct genes (USF1 and USF2) exist under the form of various dimers able to bind E-boxes. We report the molecular cloning and functional characterization of USF2 isoforms, corresponding to a 44-kDa subunit, USF2a, and a new 38-kDa subunit, USF2b, generated by differential splicing. Using specific anti-USF antibodies, we define the different binding complexes in various nuclear extracts. In vivo, the USF1/USF2a heterodimer represents over 66% of the USF binding activity whereas the USF1 and USF2a homodimers represent less than 10%, which strongly suggests an in vivo preferential association in heterodimers. In particular, an USF1/USF2b heterodimer accounted for almost 15% of the USF species in some cells. The preferential heterodimerization of USF subunits was reproduced ex vivo, while the in vitro association of cotranslated subunits, or recombinant USF proteins, appeared to be random. In transiently transfected HeLa or hepatoma cells, USF2a and USF1 homodimers transactivated a minimal promoter with similar efficiency, whereas USF2b, which lacks an internal 67-amino acid domain, was a poor transactivator. Additionally, USF2b was an efficient as USF1 and USF2a homodimers in transactivating the liver-specific pyruvate kinase gene promoter.
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Affiliation(s)
- B Viollet
- Institut Cochin de Génétique Moléculaire, U129 INSERM, Université René Descartes, Paris, France
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16
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Chen R, Doiron B, Kahn A. Glucose responsiveness of a reporter gene transduced into hepatocytic cells using a retroviral vector. FEBS Lett 1995; 365:223-6. [PMID: 7781783 DOI: 10.1016/0014-5793(95)00472-l] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
An MMLV-based retroviral vector containing the chloramphenicol acetyl transferase reporter gene under the control of a glucose-dependent internal promoter derived from the L-type pyruvate kinase gene was constructed. After transfection into psi-CRIP packaging cells, clones producing recombinant retrovirus were selected. These retroviruses were used to infect cultured established hepatocytic cells whose endogenous L-type pyruvate kinase gene is transcriptionally regulated by glucose. In the infected cells, the reporter gene was as responsive to glucose as the endogenous L-type pyruvate kinase gene, and the glucose gene activation was time- and concentration-dependent. The possibility to confer a glucose responsiveness on a transgene carried by a retroviral vector provides a powerful tool in the prospect of gene therapy for diabetes mellitus.
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Affiliation(s)
- R Chen
- Institut Cochin de Génétique Moléculaire, Paris, France
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17
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Lefrançois-Martinez AM, Martinez A, Antoine B, Raymondjean M, Kahn A. Upstream stimulatory factor proteins are major components of the glucose response complex of the L-type pyruvate kinase gene promoter. J Biol Chem 1995; 270:2640-3. [PMID: 7852331 DOI: 10.1074/jbc.270.6.2640] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
L-type pyruvate kinase (L-PK) gene transcription is induced by glucose through its glucose response element (GlRE) composed of two degenerated E boxes able to bind in vitro ubiquitous upstream stimulator factor (USF) proteins. Here we demonstrate in vivo, by transient transfections in hepatoma cells, that (i) native USF proteins synthesized from expression vectors can act as transactivators of the L-PK promoter via the GlRE, stimulating transcription without glucose and, therefore, decreasing the glucose responsiveness of the promoter; (ii) expression of the truncated USF proteins, able to bind the GlRE but devoid of the NH2-terminal activation domain, represses the activation of the L-PK promoter by glucose; and (iii) a similar repression of the glucose effect is observed upon expression of mutant USF proteins devoid of the basic DNA binding domain, able to dimerize with endogenous USF but not to bind the GlRE. We conclude that USF proteins are components of the transcriptional glucose response complex assembled on the L-PK gene promoter.
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Affiliation(s)
- A M Lefrançois-Martinez
- Institut Cochin de génétique Moléculaire, U.129 INSERM, Université René Descartes, Paris, France
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18
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Blakeley S, Gottlob-McHugh S, Wan J, Crews L, Miki B, Ko K, Dennis DT. Molecular characterization of plastid pyruvate kinase from castor and tobacco. PLANT MOLECULAR BIOLOGY 1995; 27:79-89. [PMID: 7865798 DOI: 10.1007/bf00019180] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Clones encoding two different forms of plastid pyruvate kinase (PKp; EC 2.7.1.40) have been isolated from both castor and tobacco seed cDNA libraries. One form, designated PKpA, from castor was described in a previous report, and the tobacco homologue of PKpA has now been isolated. In addition, a second cDNA, designated PKpG, has been identified and sequenced in both species. Western blot analysis, using antibodies raised against protein overexpressed from these clones, indicates that they encode the two predominant polypeptides of plastid pyruvate kinase from developing castor endosperm. In castor, both PKpA and PKpG are encoded by single genes. In the allotetraploid Nicotiana tabacum, there are two copies of each, one derived from each of the progenitors of this species. The expression of the genes for PKpA and PKpG was examined in various tissues from both castor and tobacco. In castor, both forms are expressed in developing and germinating endosperm and in the root but neither is expressed in the leaf. In tobacco, both forms are expressed in developing seeds but in mature tissues, PKpA is most abundant in roots and PKpG in leaves.
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Affiliation(s)
- S Blakeley
- Department of Biology, Queens University, Kingston, Ontario, Canada
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19
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Expression of the L-type pyruvate kinase gene and the hepatocyte nuclear factor 4 transcription factor in exocrine and endocrine pancreas. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)37059-x] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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20
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Thomas M, Makeh I, Briand P, Kahn A, Skala H. Determinants of the brain-specific expression of the rat aldolase C gene: ex vivo and in vivo analysis. EUROPEAN JOURNAL OF BIOCHEMISTRY 1993; 218:143-51. [PMID: 8243460 DOI: 10.1111/j.1432-1033.1993.tb18360.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A 115-bp promoter fragment of the aldolase C gene is sufficient for conferring neural cell specificity on a reporter gene, in cultured PC12 cells and in transgenic mice. In vitro DNase I protection experiments detected two footprints on the promoter, termed boxes A/A', and B. The 5' A/A' box contains overlapping Sp1 and Krox20/Krox24 binding sites; it binds Sp1 in fibroblasts (box A') and a different complex in brain (box A). Any deletion or mutation of this box that impairs protein recognition also suppresses promoter activity. The replacement of box A/A' by a Sp1 consensus binding site results in the loss of the brain specificity of expression in transgenic mice. Further 3', box B is composed of a 5' direct repeat and a 3' GC box consisting of overlapping Sp1 and Krox20/Krox24 binding sites. Mutation of the direct repeat subregion appears to be more deleterious for the promoter activity than mutation of the G+C-rich subregion.
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Affiliation(s)
- M Thomas
- Institut Cochin de Génétique Moléculaire, Laboratoire de Génétique et Pathologie Moléculaires, INSERM U129, Paris, France
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21
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The pyruvate kinase gene as a model for studies of glucose-dependent regulation of gene expression in the endocrine pancreatic beta-cell type. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(20)80468-2] [Citation(s) in RCA: 85] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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22
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Abstract
The pattern of expression of homeodomain proteins often exceeds their apparent domain of activity. Tissue-specific proteins that modulate the in vivo activity of homeodomain proteins have been proposed to account for this functional restriction. The first identified example of such an accessory protein is DCoH, which confers transcriptional activity to the hepatocyte nuclear factor 1 and provides a model of how other accessory factors might modulate the function of homeodomain proteins.
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Affiliation(s)
- L P Hansen
- Beckman Center for Molecular and Genetic Medicine, Stanford University Medical School, CA 94305
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23
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Cartier N, Lacave R, Vallet V, Hagege J, Hellio R, Robine S, Pringault E, Cluzeaud F, Briand P, Kahn A. Establishment of renal proximal tubule cell lines by targeted oncogenesis in transgenic mice using the L-pyruvate kinase-SV40 (T) antigen hybrid gene. J Cell Sci 1993; 104 ( Pt 3):695-704. [PMID: 8100235 DOI: 10.1242/jcs.104.3.695] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Targeted oncogenesis allowed us to obtain two cell lines which have been derived from the proximal tubule of kidney from transgenic mice harbouring the simian virus (SV40) large T and small t antigens placed under the control of the 5′ regulatory sequence from the rat L-type pyruvate kinase (L-PK) gene. The cell lines (PKSV-PCT and PKSV-PR cells) were derived from early (PCT) and late (Pars Recta, PR) microdissected proximal tubules grown in D-glucose-enriched medium. In such conditions of culture, both cell lines exhibited L-PK transcripts, a stable expression of SV40-encoded nuclear large T antigen, a prolonged life span but failed to induce tumors when injected sub-cutaneously into athymic (nu-nu) mice. Confluent cells, grown on plastic support or porous filters, were organized as monolayers of polarized cuboid cells with well developed apical microvilli and formed domes. Both cell lines exhibited morphological features of proximal tubule cells with villin located in the apical brush-border and substantial amounts of hydrolase activity. By immunofluorescence studies using specific antibodies, aminopeptidase N appeared restricted to the apical microvillar domain, whereas the H2 histocompatibility antigen was distributed in the cytoplasm and lateral membranes. These results demonstrate that the proximal morphological phenotype has been fully preserved in these cultured cells derived from tissue-specific targeted oncogenesis in transgenic mice.
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Affiliation(s)
- N Cartier
- Institut Cochin de Génétique Moléculaire, Institut National de la Santé et de la Recherche Médicale (INSERM), Faculté Cochin, Paris, France
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24
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25
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Ciliberto G, Colantuoni V, De Francesco R, De Simone V, Monaci P, Nicosia A, Ramji DP, Toniatti C, Cortese R. Transcriptional Control of Gene Expression in Hepatic Cells. Gene Expr 1993. [DOI: 10.1007/978-1-4684-6811-3_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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26
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Puzenat N, Vaulont S, Kahn A, Raymondjean M. Combinatorial crosstalk of transacting factors binding to the L-type pyruvate kinase promoter elements analysed in vitro. Biochem Biophys Res Commun 1992; 189:1119-28. [PMID: 1472022 DOI: 10.1016/0006-291x(92)92320-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Five Dnase 1 footprints, termed boxes L1 to L5, have been characterized in the 280 bp upstream from the cap site of the L-type pyruvate kinase (L-PK) gene. They bind from 3' to 5', the factors HNF1, HNF4, MLTF, and a non-identified protein referred to as L5 binding factor (L5-BF). These elements, individually or variably combined, were tested by cell-free transcription. The L1 box stimulates both L-PK and TK promoters, but in the context of L-PK promoter, it cooperates with the L3 element to reach a high level of transcriptional activation. The L3 and L4 elements exhibit weaker influences, increased by homologous or heterologous interactions. The L5 box behaves as a promoter-dependent negative regulatory element.
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Affiliation(s)
- N Puzenat
- ICGM, Laboratoire de recherches en genetique et pathologie moleculaires, INSERM U.129, université Paris 5, CHU Cochin, France
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27
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Abstract
Numerous liver specific genes are transcriptionally activated by the binding to their promoter or enhancer of Hepatic Nuclear Factor 1 (HNF1). HNF1 contains a variant homeo-domain and binds to DNA as either a homodimer or a heterodimer with the vHNF1 protein. Surprisingly, HNF1 is not restricted to hepatocytes but is expressed in epithelial cells of several endoderm derived organs and in mesoderm derived kidney tubules. Hence, HNF1 alone can not account for the differentiated state of the hepatic cells. In fact, several other liver-enriched transcription factors have been cloned. The hepatic phenotype could result from the combinatorial expression of these regulators. Possible involvement of these trans-acting factors in liver organogenesis and hepatic differentiation is discussed.
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Affiliation(s)
- F Tronche
- Département des Biotechnologies, Institut Pasteur, France
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28
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Boquet D, Vaulont S, Tremp G, Ripoche MA, Daegelen D, Jami J, Kahn A, Raymondjean M. DNase-I hypersensitivity analysis of the L-type pyruvate kinase gene in rats and transgenic mice. EUROPEAN JOURNAL OF BIOCHEMISTRY 1992; 207:13-21. [PMID: 1378399 DOI: 10.1111/j.1432-1033.1992.tb17013.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The rat L-type pyruvate kinase gene possesses two promoters located 500 bp apart. The L' promoter is specific to erythroid cells. The L promoter is specific to liver and is regulated by diet and hormones; positively by glucose and insulin and negatively by glucagon via cAMP. The DNA elements involved in this tissue-specific and hormone-regulated gene expression are located within 3.2 kbp of 5' flanking region as previously demonstrated by transgenic mice analysis [Tremp, G. L., Boquet, D., Ripoche, M. A., Cognet, M., Yu-Chun, L., Jami, J., Kahn, A. and Daegelen, D. (1989) J. Biol. Chem. 264, 19,904-19,910]. Moreover, we have observed in these mice that gene expression was dependent on the transgene copy number and independent of the integration site. We present here DNase-I-hypersensitivity analysis of the endogenous rat L-type pyruvate kinase gene and of two transgene constructs in relation to development, tissue differentiation, nutritional and hormonal status. In rats, two groups of proximal sites were detected on the endogenous gene; hypersensitive site (HSS) HSS-1 in adult liver and HSS-A in fetal liver (a major erythropoietic tissue). Both groups are probably related to the transcriptional initiation complexes at either the L or L' promoter. Two other distal groups were detected; HSS-2 at -3 kbp (with respect to the liver-specific cap site) in adult liver and HSS-B around -4 kbp in fetal liver. These sites are thought to correspond to activating sequences; in adult liver, deletion of a fragment encompassing HSS-2 provokes a dramatic reduction of transcription starting at the L promoter of the transgene. In adult liver, HSS-1 appears to be a transcription-associated site, being greatly weakened in fasted rats, while HSS-2 is transcription independent. The pattern of DNase-I hypersensitivity is similar for the rat endogenous gene and for the complete rat transgene; the liver-specific HSS-1 and HSS-2 are present and the intensity of the sites is correlated to the number of integrated copies. Interestingly, HSS-1 is still detectable and its intensity remains proportional to the number of integrated copies in a truncated transgene with HSS-2 deletion, while this transgene is very weakly (but nevertheless tissue-specifically) expressed. These results strongly suggest that each transgene copy possesses a complete set of specific nucleoprotein complexes and that, with or without HSS-2, the DNA is in a potentially active configuration.
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Affiliation(s)
- D Boquet
- Institut Cochin de Génétique moléculaire, Institut National de la Santé et de la Recherche Médicale Unité 129, Paris, France
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29
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Antoine B, Levrat F, Vallet V, Berbar T, Cartier N, Dubois N, Briand P, Kahn A. Gene expression in hepatocyte-like lines established by targeted carcinogenesis in transgenic mice. Exp Cell Res 1992; 200:175-85. [PMID: 1373387 DOI: 10.1016/s0014-4827(05)80086-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
New hepatocyte-like cell lines (mhAT) were derived from the liver of a transgenic mouse expressing SV40 early genes under the direction of the liver-specific antithrombin III gene promoter (ATIII-TSV40). Their differentiated phenotypes were improved and stabilized by the use of liver-specific growth media (arginine-free, glucose-free, or low-fructose/glucose-free medium). The best differentiated lines display a very high level of albumin, transferrin, and L-type pyruvate kinase (L-PK) gene expression that is comparable to that observed in the mouse liver. Abundance of the aldolase B and phosphoenolpyruvate carboxykinase (PEPCK) transcripts varied from 5 to 35% of the in vivo concentrations while abundance of the alpha-fetoprotein and phenylalanine hydroxylase transcripts remained very low. Hormonal (cAMP and insulin) and nutritional (glucose) gene controls of PEPCK and L-PK were, at least partially, conserved. mhAT cells are readily transfectable by the calcium phosphate coprecipitation technique and exhibit a liver-specific pattern of expression of exogenous genes. Thus, mhAT cells seem suitable for the analysis of the regulatory regions involved in the tissue-specific transcription of genes. This work demonstrates, therefore, the great efficiency of targeted carcinogenesis in transgenic mice to create new differentiated cell lines. The availability of various lines of liver-specific cells with different phenotypes will constitute useful tools to establish correlations between expression of trans-acting factors and control of the phenotype.
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Affiliation(s)
- B Antoine
- Institut Cochin de Génétique Moléculaire, laboratoire de recherche en génétique et pathologie moléculaires (INSERM U129), Paris, France
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