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Miquerol L, Cluzeaud F, Porteu A, Alexandre Y, Vandewalle A, Kahn A. Tissue specificity of L-pyruvate kinase transgenes results from the combinatorial effect of proximal promoter and distal activator regions. Gene Expr 2018; 5:315-30. [PMID: 8836739 PMCID: PMC6138020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The L-type pyruvate kinase (L-PK) gene is regulated by diet and hormones and expressed at high levels in the hepatocytes, enterocytes, and proximal tubular cells of the kidney and at low levels in the endocrine pancreatic cells. Two regulatory regions have been shown to be important in transgenic mice to confer on a reporter gene a similar tissue-specific and diet-responsive expression: a proximal promoter fragment, with binding sites for the tissue-specific hepatocyte nuclear factors 1 and 4, and presence of the glucose-response element (GIRE) and a distal activator corresponding to a liver-specific hypersensitive site at -3000 bp with respect to the cap site. Although the proximal promoter is able to confer by itself tissue-specific expression on a reporter gene, its activity in vivo is strongly stimulated by the distal activator. To determine the possible role of the distal region on diet responsiveness and tissue specificity of the L-PK gene expression, we have created lines of transgenic mice in which the gene for SV40 T antigen (Tag) was directed by composite regulatory sequences consisting of the L-PK promoter and different enhancers: either the SV40 early enhancer (SV) or the H enhancer of the aldolase A gene (H). The induction of the composite H-PK/Tag and SV-PK/Tag transgenes by a carbohydrate-rich diet in the liver was similar to that of the endogenous L-PK gene. This suggests that in fasted mice the L-PK promoter, and especially the GIRE, is able to silence the activating influence of a strong viral enhancer such as the SV40 enhancer. The H-PK/Tag mice expressed the transgene similarly to the endogenous gene, except in the pancreas, where expression was practically undetectable. Consistently, whereas L-PK/Tag mice develop insulinomas, H-PK/Tag mice develop only hepatomas. In contrast, the transgene expression was partly aberrant in SV-PK/Tag mice. In addition to a normal activation of the transgene in the liver, a strong expression was also detected in the kidney medulla, whereas the transgene was practically silent in enterocytes. Finally, the effect of the distal region (-2070 to -3200) on an ubiquitous promoter was tested by ligating the distal L-PK gene fragment in front of a thymidine kinase/CAT transgene. Such a transgene was constantly expressed in the pancreas and, strikingly, in the brain. It appears, therefore, that the L-PK distal activator exhibits, by itself, a certain neuropancreatic specificity required in combination with the proximal promoter for L-PK gene expression in pancreas endocrine cells.
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Affiliation(s)
- L Miquerol
- Institut Cochin de Génétique Moléculaire, INSERM U 129, Université René Descartes, Paris, France
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Grahn RA, Grahn JC, Penedo MC, Helps CR, Lyons LA. Erythrocyte pyruvate kinase deficiency mutation identified in multiple breeds of domestic cats. BMC Vet Res 2012; 8:207. [PMID: 23110753 PMCID: PMC3534511 DOI: 10.1186/1746-6148-8-207] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Accepted: 10/22/2012] [Indexed: 11/29/2022] Open
Abstract
Background Erythrocyte pyruvate kinase deficiency (PK deficiency) is an inherited hemolytic anemia that has been documented in the Abyssinian and Somali breeds as well as random bred domestic shorthair cats. The disease results from mutations in PKLR, the gene encoding the regulatory glycolytic enzyme pyruvate kinase (PK). Multiple isozymes are produced by tissue-specific differential processing of PKLR mRNA. Perturbation of PK decreases erythrocyte longevity resulting in anemia. Additional signs include: severe lethargy, weakness, weight loss, jaundice, and abdominal enlargement. In domestic cats, PK deficiency has an autosomal recessive mode of inheritance with high variability in onset and severity of clinical symptoms. Results Sequence analysis of PKLR revealed an intron 5 single nucleotide polymorphism (SNP) at position 304 concordant with the disease phenotype in Abyssinian and Somali cats. Located 53 nucleotides upstream of the exon 6 splice site, cats with this SNP produce liver and blood processed mRNA with a 13 bp deletion at the 3’ end of exon 5. The frame-shift mutation creates a stop codon at amino acid position 248 in exon 6. The frequency of the intronic SNP in 14,179 American and European cats representing 38 breeds, 76 western random bred cats and 111 cats of unknown breed is 6.31% and 9.35% when restricted to the 15 groups carrying the concordant SNP. Conclusions PK testing is recommended for Bengals, Egyptian Maus, La Perms, Maine Coon cats, Norwegian Forest cats, Savannahs, Siberians, and Singapuras, in addition to Abyssinians and Somalis as well an any new breeds using the afore mentioned breeds in out crossing or development programs.
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Affiliation(s)
- Robert A Grahn
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
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Di Stefano M, Galassi L, Magni G. Unique expression pattern of human nicotinamide mononucleotide adenylyltransferase isozymes in red blood cells. Blood Cells Mol Dis 2010; 45:33-9. [PMID: 20457531 DOI: 10.1016/j.bcmd.2010.04.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2010] [Revised: 04/09/2010] [Accepted: 04/09/2010] [Indexed: 10/19/2022]
Abstract
Nicotinamide mononucleotide adenylyltransferase (NMNAT) catalyzes the formation of nicotinamide adenine dinucleotide (NAD). In humans, three isozymes have been identified: NMNAT1, which is widely expressed in all tissues, NMNAT2 and NMNAT3, which show a tissue-specific expression and whose mRNA levels are generally lower compared to NMNAT1. In the present study we determined the individual NMNAT isozymes activity in human red blood cells (RBCs) by using a biochemical discrimination assay based on the distinctive catalytic properties of the three proteins. We found that isozyme 3 predominates over isozyme 1, whereas isozyme 2 is absent. This high prevalence of NMNAT3 is cell-aging independent and was also confirmed by analyzing the mRNA and protein levels. RBC represent the first human cell type with a remarkable predominance of NMNAT3, and this unique expression pattern is discussed in light of the catalytic properties of the isozymes and in consideration of the biochemical microenvironment of RBC.
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Affiliation(s)
- M Di Stefano
- Dipartimento di Patologia Molecolare e Terapie Innovative, sezione di Biochimica, Università Politecnica delle Marche, Via Ranieri 69, 60131 Ancona, Italy
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Zanotto E, Shah ZH, Jacobs HT. The bidirectional promoter of two genes for the mitochondrial translational apparatus in mouse is regulated by an array of CCAAT boxes interacting with the transcription factor NF-Y. Nucleic Acids Res 2006; 35:664-77. [PMID: 17179180 PMCID: PMC1802594 DOI: 10.1093/nar/gkl1037] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The genes for mitoribosomal protein S12 (Mrps12) and mitochondrial seryl-tRNA ligase (Sarsm and Sars2) are oppositely transcribed from a conserved promoter region of <200 bp in both human and mouse. Using a dual reporter vector we identified an array of 4 CCAAT box elements required for efficient transcription of the two genes in cultured mouse 3T3 cells, and for enforcing directionality in favour of Mrps12. Electrophoretic mobility shift assay (EMSA) and in vivo footprinting confirmed the importance of these promoter elements as sites of protein-binding, and EMSA supershift and chromatin immunoprecipitation (ChIP) assays identified NF-Y as the key transcription factor involved, revealing a common pattern of protein–DNA interactions in all tissues tested (liver, brain, heart, kidney and 3T3 cells). The inherently bidirectional activity of NF-Y makes it an especially suitable factor to govern promoters of this class, whose expression is linked to cell proliferation.
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Affiliation(s)
- Ernesto Zanotto
- Institute of Medical Technology & Tampere University Hospital, FI-33014 University of TampereFinland
| | - Zahid H. Shah
- Institute of Medical Technology & Tampere University Hospital, FI-33014 University of TampereFinland
| | - Howard T. Jacobs
- Institute of Medical Technology & Tampere University Hospital, FI-33014 University of TampereFinland
- Institute of Biomedical and Life Sciences, University of GlasgowGlasgow G12 8QQ, Scotland, UK
- To whom correspondence should be addressed. Tel: +35 8335517731; Fax: +35 832157710;
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van Wijk R, van Solinge WW, Nerlov C, Beutler E, Gelbart T, Rijksen G, Nielsen FC. Disruption of a novel regulatory element in the erythroid-specific promoter of the human PKLR gene causes severe pyruvate kinase deficiency. Blood 2003; 101:1596-602. [PMID: 12393511 DOI: 10.1182/blood-2002-07-2321] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We established the molecular basis for pyruvate kinase (PK) deficiency in a white male patient with severe nonspherocytic hemolytic anemia. The paternal allele exhibited the common PKLR cDNA sequence (c.) 1529G>A mutation, known to be associated with PK deficiency. On the maternal allele, 3 in cis mutations were identified in the erythroid-specific promoter region of the gene: one deletion of thymine -248 and 2 single nucleotide substitutions, nucleotide (nt) -324T>A and nt -83G>C. Analysis of the patient's RNA demonstrated the presence of only the 1529A allele, indicating severely reduced transcription from the allele linked to the mutated promoter region. Transfection of promoter constructs into erythroleukemic K562 cells showed that the most upstream -324T>A and -248delT mutations were nonfunctional polymorphisms. In contrast, the -83G>C mutation strongly reduced promoter activity. Site-directed mutagenesis of the promoter region revealed the presence of a putative regulatory element (PKR-RE1) whose core binding motif, CTCTG, is located between nt -87 and nt -83. Electrophoretic mobility shift assay using K562 nuclear extracts indicated binding of an as-yet-unidentified trans-acting factor. This novel element mediates the effects of factors necessary for regulation of pyruvate kinase gene expression during red cell differentiation and maturation.
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Affiliation(s)
- Richard van Wijk
- Department of Clinical Chemistry, University Medical Center Utrecht, The Netherlands
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Shimizu S, Matsuoka Y, Shinohara Y, Yoneda Y, Tsujimoto Y. Essential role of voltage-dependent anion channel in various forms of apoptosis in mammalian cells. J Cell Biol 2001; 152:237-50. [PMID: 11266442 PMCID: PMC2199613 DOI: 10.1083/jcb.152.2.237] [Citation(s) in RCA: 271] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Through direct interaction with the voltage-dependent anion channel (VDAC), proapoptotic members of the Bcl-2 family such as Bax and Bak induce apoptogenic cytochrome c release in isolated mitochondria, whereas BH3-only proteins such as Bid and Bik do not directly target the VDAC to induce cytochrome c release. To investigate the biological significance of the VDAC for apoptosis in mammalian cells, we produced two kinds of anti-VDAC antibodies that inhibited VDAC activity. In isolated mitochondria, these antibodies prevented Bax-induced cytochrome c release and loss of the mitochondrial membrane potential (Deltapsi), but not Bid-induced cytochrome c release. When microinjected into cells, these anti-VDAC antibodies, but not control antibodies, also prevented Bax-induced cytochrome c release and apoptosis, whereas the antibodies did not prevent Bid-induced apoptosis, indicating that the VDAC is essential for Bax-induced, but not Bid-induced, apoptogenic mitochondrial changes and apoptotic cell death. In addition, microinjection of these anti-VDAC antibodies significantly inhibited etoposide-, paclitaxel-, and staurosporine-induced apoptosis. Furthermore, we used these antibodies to show that Bax- and Bak-induced lysis of red blood cells was also mediated by the VDAC on plasma membrane. Taken together, our data provide evidence that the VDAC plays an essential role in apoptogenic cytochrome c release and apoptosis in mammalian cells.
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Affiliation(s)
- Shigeomi Shimizu
- Osaka University Graduate School of Medicine, Biomedical Research Center, Department of Medical Genetics, Osaka 565-0871, Japan
- Core Research for Evolutional Science and Technology of Japan Science and Technology Corp., Osaka 565-0871, Japan
| | - Yosuke Matsuoka
- Department of Cell Biology and Neuroscience, Osaka 565-0871, Japan
- Core Research for Evolutional Science and Technology of Japan Science and Technology Corp., Osaka 565-0871, Japan
| | - Yasuo Shinohara
- University of Tokushima, Faculty of Pharmaceutical Sciences, Tokushima 770-8505, Japan
| | - Yoshihiro Yoneda
- Department of Cell Biology and Neuroscience, Osaka 565-0871, Japan
- Core Research for Evolutional Science and Technology of Japan Science and Technology Corp., Osaka 565-0871, Japan
| | - Yoshihide Tsujimoto
- Osaka University Graduate School of Medicine, Biomedical Research Center, Department of Medical Genetics, Osaka 565-0871, Japan
- Core Research for Evolutional Science and Technology of Japan Science and Technology Corp., Osaka 565-0871, Japan
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Yamada K, Tanaka T, Noguchi T. Characterization and purification of carbohydrate response element-binding protein of the rat L-type pyruvate kinase gene promoter. Biochem Biophys Res Commun 1999; 257:44-9. [PMID: 10092507 DOI: 10.1006/bbrc.1999.0410] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The L-III transcriptional regulatory element of the rat pyruvate kinase L gene is located between -170 and -150 base pairs upstream of the hepatocyte-specific transcription initiation site. As the L-III element is not only necessary for cell type-specific expression but also for transcriptional stimulation by carbohydrates, it is also referred to as a carbohydrate-response element. Electrophoretic mobility shift assays using rat liver nuclear extract showed that L-III element-binding protein (L-IIIBP) was observed as multiple bands. These bands disappeared when the nuclear extract was preincubated at 60 degrees C for 5 min and were competed with unlabeled L-III oligonucleotide but not with unlabeled adenovirus major late promoter E box oligonucleotide. In addition, these bands were not affected in the presence of antiserum against upstream stimulating factor (USF). Thus, we conclude that L-IIIBP is different from USF. Then, heat-labile L-IIIBP was purified from rat liver nuclear extracts. Purified L-IIIBP exhibited two bands on sodium dodecyl sulfate/polyacrylamide gel electrophoresis by silver staining. Ultraviolet crosslinking experiment showed that both bands had binding activity to the L-III oligonucleotide.
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Affiliation(s)
- K Yamada
- Department of Biochemistry, Fukui Medical University, Shimoaizuki, Matsuoka, Fukui, 910-1193, Japan
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Affiliation(s)
- K Yamada
- Department of Biochemistry, Fukui Medical University, Shimoaizuki, Matsuoka, Fukui, 910-1193, Japan
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Ruzzo A, Andreoni F, Magnani M. Structure of the human hexokinase type I gene and nucleotide sequence of the 5' flanking region. Biochem J 1998; 331 ( Pt 2):607-13. [PMID: 9531504 PMCID: PMC1219395 DOI: 10.1042/bj3310607] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
This study reports the precise intron/exon boundaries and intron/exon composition of the human hexokinase type I gene. A yeast artificial chromosome containing the hexokinase type I gene was isolated from the yeast artificial chromosome library of the Centre d'Etude du Polymorphisme Humaine. A cosmid sublibrary was created and direct sequencing of the individual cosmids was used to provide the exon/intron organization. The human hexokinase type I gene was found to be composed of 18 exons ranging in size from 63 to 305 bp. Intron 1 is at least 15 kb in length, whereas intron 2 spans at least 10 kb. Overall, the length of the 17 introns ranges from 104 to greater than 15 kb. The entire coding region is contained in at least 75 kb of the gene. The structure of the gene reveals a remarkable conservation of the size of the exons compared with glucokinase and hexokinase type II. Isolation of the 5' flanking region of the gene revealed a 75-90% identity with the rat sequence. Direct evidence of an alternative red-blood-cell-specific exon 1 located upstream of the 5' flanking region of the gene is also provided.
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Affiliation(s)
- A Ruzzo
- 'G.Fornaini' Institute of Biological Chemistry, University of Urbino, Via Saffi 2, 61029 Urbino, Italy
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Abstract
AbstractA unique cDNA for hexokinase (HK) was identified from poly(A)+ RNA of human reticulocytes by anchored polymerase chain reaction. This appeared to represent the cDNA for the red blood cell (RBC)–specific HK isozyme (HKR ) described in our previous study (Murakami et al: Blood 75:770, 1990). Its nucleotide sequence was identical to HKI cDNA except for the 5′ extreme end. It lacked the first 62 nucleotides of the HKI coding region: instead, it contained a unique sequence of 60 nucleotides at the beginning of the coding sequence as well as another unique sequence upstream of the putative translation initiation site. It lacked the porin-binding domain which facilitates binding to the mitochondria, thus explaining the exclusive cytoplasmic localization of HKR . It was the major cDNA derived from reticulocytes, consistent with the observation that HKR activity is predominant in reticulocytes. Northern blot analysis showed that it was expressed in the reticulocytes and in the K562 erythroleukemic cell line, but not in a lymphocytic cell line. In the extract of K562 cells, HKR activity co-eluted with the HKR of human RBCs on a MonoQ column (Pharmacia, Piscataway, NJ) chromatography, using a salt gradient elution. The separate genetic control of the RBC-specific HK isozyme explains the clinical reports of two types of HK deficiency, one in which the HK activity was reduced exclusively in the RBC (HKR defect) and another with general decrease of HK activity in several tissues (HKI defect).
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Crossley M, Whitelaw E, Perkins A, Williams G, Fujiwara Y, Orkin SH. Isolation and characterization of the cDNA encoding BKLF/TEF-2, a major CACCC-box-binding protein in erythroid cells and selected other cells. Mol Cell Biol 1996; 16:1695-705. [PMID: 8657145 PMCID: PMC231156 DOI: 10.1128/mcb.16.4.1695] [Citation(s) in RCA: 189] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
CACCC boxes are among the critical sequences present in regulatory elements of genes expressed in erythroid cells, as well as in selected other cell types. While an erythroid cell-specific CACCC-box-binding protein, EKLF, has been shown to be required in vivo for proper expression of the adult beta-globin gene, it is dispensable for the regulation of several other globin and nonglobin erythroid cell-expressed genes. In the work described here, we searched for additional CACCC-box transcription factors that might be active in murine erythroid cells. We identified a major gel shift activity (termed BKLF), present in yolk sac and fetal liver erythroid cells, that could be distinguished from EKLF by specific antisera. Through relaxed-stringency hybridization, we obtained the cDNA encoding BKLF, a highly basic, novel zinc finger protein that is related to EKLF and other Krüppel-like members in its DNA-binding domain but unrelated elsewhere. BKLF, which is widely but not ubiquitously expressed in cell lines, is highly expressed in the midbrain region of embryonic mice and appears to correspond to the gel shift activity TEF-2, a transcriptional activator implicated in regulation of the simian virus 40 enhancer and other CACCC-box-containing regulatory elements. Because BKLF binds with high affinity and preferentially over Sp1 to many CACCC sequences of erythroid cell expressed genes, it is likely to participate in the control of many genes whose expression appears independent of the action of EKLF.
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Affiliation(s)
- M Crossley
- Division of Hematology-Oncology, Children's Hospital, Dana Farber Cancer Institute, Boston, Massachusetts 02115, USA
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Salminen M, López S, Maire P, Kahn A, Daegelen D. Fast-muscle-specific DNA-protein interactions occurring in vivo at the human aldolase A M promoter are necessary for correct promoter activity in transgenic mice. Mol Cell Biol 1996; 16:76-85. [PMID: 8524331 PMCID: PMC230980 DOI: 10.1128/mcb.16.1.76] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The human aldolase A tissue-specific M promoter (pM) has served as a model system for identifying pathways that lead to fast-muscle-specialized expression. The current study has delimited the sequences necessary and sufficient for fast-muscle-specific expression in transgenic mice to a short 209-bp fragment extending from bp -164 to +45 relative to the pM transcription start site. Genomic footprinting methods showed that in this proximal region, the same elements that bind muscle nuclear proteins in vitro are involved in DNA-protein interactions in intact muscle nuclei of transgenic mice. Furthermore, these experiments provided the first evidence that different DNA-binding activities exist between slow and fast muscles in vivo. Fast-muscle-specific interactions occur at an element named M1 and at a muscle-specific DNase I-hypersensitive site that was previously detected by in vitro methods. The formation of the muscle-specific DNase I-hypersensitive site reflects binding of proteins to a close element, named M2, which contains a binding site for nuclear factors of the NF1 family. Mutational analysis performed with transgenic mice confirmed the importance of the M1 element for high-level fast-muscle-specific pM activity and suggested that the M2/NF1 element is differently required for correct pM expression in distinct fast muscles. In addition, two other protein binding sites, the MEF3 motif and the USF site, seem to act as stage-specific activators and/or as participants in the establishment of an active chromatin configuration at pM.
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Affiliation(s)
- M Salminen
- Institut Cochin de Génétique Moléculaire, Institut National de la Santé et de la Recherche Médicale U129, Université René Descartes, Paris, France
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Porcher C, Picat C, Daegelen D, Beaumont C, Grandchamp B. Functional analysis of DNase-I hypersensitive sites at the mouse porphobilinogen deaminase gene locus. Different requirements for position-independent expression from its two promoters. J Biol Chem 1995; 270:17368-74. [PMID: 7615541 DOI: 10.1074/jbc.270.29.17368] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Porphobilinogen deaminase (EC 4.3.1.8; PBG-D) is the third enzyme of the heme biosynthetic pathway. In both human and mouse, the gene encoding PBG-D possesses two promoters, lying in close proximity. We have previously reported the mapping of six nuclear DNase-I hypersensitive sites at the PBG-D locus which could contribute to the regulation of the gene. In the present study, and in order to define all the elements necessary for a high level of expression and an integration site independence, we studied the pattern and the level of expression of a cloned PBG-D gene following integration into a host genome. The longest construct that we tested (12.5 kilobases) contained sufficient regulatory elements to promote expression levels similar to that of the endogenous gene, both in transgenic mice and in transfected cells. The overall contribution of individual DNase-I hypersensitive sites to the expression of the gene was then studied using a series of mutants that were stably transfected into mouse erythroleukemia cells. Two regions seem to play a critical role in the erythroid-specific expression of the PBG-D gene: the proximal promoter and a region situated at -1000 relative to the initiation site. Study of individual clones of mouse erythroleukemia cells revealed that the erythroid-specific expression of the gene was submitted to position effects in the absence of the upstream region, although the housekeeping transcription is not sensitive to such effects. The tandem arrangement of the housekeeping and tissue-specific promoters of the PBG-D gene raises some questions about the functioning of these two overlapping transcriptional units in erythroid cells. Previous data have suggested that in erythroid cells most of the transcripts initiated at the upstream promoter stop downstream of the first ubiquitous exon, between the two promoters. Here, we show that the deletion of a constitutive DNase-I hypersensitive site that is located in the region of the elongation block results in opposite effects on the steady state levels of housekeeping and tissue-specific RNA. This finding is consistent with the hypothesis that this region promotes premature termination of the housekeeping transcripts therefore preventing promoter interference.
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Affiliation(s)
- C Porcher
- INSERM U409, Faculté de Médecine Xavier Bichat, Paris, France
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Lacronique V, Lopez S, Miquerol L, Porteu A, Kahn A, Raymondjean M. Identification and functional characterization of an erythroid-specific enhancer in the L-type pyruvate kinase gene. J Biol Chem 1995; 270:14989-97. [PMID: 7797480 DOI: 10.1074/jbc.270.25.14989] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The rat L-type pyruvate kinase gene is transcribed either from promoter L in the liver or promoter L' in erythroid cells. We have now cloned and functionally characterized an erythroid-specific enhancer, mapped in the fetal liver as hypersensitive site B (HSSB) at 3.7 kilobases upstream from the promoter L'. Protein-DNA interactions were examined in the 200-base pair core of the site by in vivo footprinting experiments. In the fetal liver, footprints were revealed at multiple GATA and CACC/GT motifs, whose association is the hallmark of erythroid-specific regulatory sequences. Functional analysis of the HSSB element in transgenic mice revealed properties of a cell-restricted enhancer. Indeed, this element was able to activate the linked ubiquitous herpes simplex virus thymidine kinase promoter in erythroid tissues. The activation was also observed in a variety of nonerythroid tissues known to synthesize GATA-binding factors. In the context of L'-PK transgenes, HSSB was not needed for an erythroid-specific activation of the L' promoter, while it was required to stimulate the L' promoter activity to a proper level. Finally, HSSB cannot be replaced by strong ubiquitous viral or cellular enhancers, suggesting a preferential interaction of the HSSB region with the L' promoter.
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Affiliation(s)
- V Lacronique
- Institut Cochin de Génétique Moléculaire, Unité 129 INSERM, Université René Descartes, Paris, France
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Transcriptional up-regulation of the mouse cytosolic glutathione peroxidase gene in erythroid cells is due to a tissue-specific 3' enhancer containing functionally important CACC/GT motifs and binding sites for GATA and Ets transcription factors. Mol Cell Biol 1993. [PMID: 8413228 DOI: 10.1128/mcb.13.10.6290] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nuclear run-on experiments have shown that the high level of expression of the mouse cytosolic glutathione peroxidase mRNA in erythroid cells is due to up-regulation of the gene at the transcriptional level. Studies of the chromatin structure around the cytosolic glutathione peroxidase gene have revealed a series of DNase I hypersensitive sites (DHSS) in the 3' flanking region of the gene in erythroid and other high-expression tissues that are lacking in low-expression cells, in addition to a DHSS over the promoter region in both high- and low-expression tissues. Functional transfection experiments have demonstrated that one of the 3' DHSS regions functions as an enhancer in erythroid cells but not in a low-expression epithelial cell line; and site-directed mutagenesis and footprinting experiments reveal that the activity of the erythroid cell-specific enhancer requires a cluster of binding sites for the CACC/GT box factors and the GATA and Ets families of transcription factors.
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O'Prey J, Ramsay S, Chambers I, Harrison PR. Transcriptional up-regulation of the mouse cytosolic glutathione peroxidase gene in erythroid cells is due to a tissue-specific 3' enhancer containing functionally important CACC/GT motifs and binding sites for GATA and Ets transcription factors. Mol Cell Biol 1993; 13:6290-303. [PMID: 8413228 PMCID: PMC364688 DOI: 10.1128/mcb.13.10.6290-6303.1993] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Nuclear run-on experiments have shown that the high level of expression of the mouse cytosolic glutathione peroxidase mRNA in erythroid cells is due to up-regulation of the gene at the transcriptional level. Studies of the chromatin structure around the cytosolic glutathione peroxidase gene have revealed a series of DNase I hypersensitive sites (DHSS) in the 3' flanking region of the gene in erythroid and other high-expression tissues that are lacking in low-expression cells, in addition to a DHSS over the promoter region in both high- and low-expression tissues. Functional transfection experiments have demonstrated that one of the 3' DHSS regions functions as an enhancer in erythroid cells but not in a low-expression epithelial cell line; and site-directed mutagenesis and footprinting experiments reveal that the activity of the erythroid cell-specific enhancer requires a cluster of binding sites for the CACC/GT box factors and the GATA and Ets families of transcription factors.
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Affiliation(s)
- J O'Prey
- Beatson Institute for Cancer Research, Cancer Research Campaign Beatson Laboratories, Bearsden, Glasgow, Scotland
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