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Duan L, Perez RE, Chen L, Blatter LA, Maki CG. p53 promotes AKT and SP1-dependent metabolism through the pentose phosphate pathway that inhibits apoptosis in response to Nutlin-3a. J Mol Cell Biol 2018; 10:331-340. [PMID: 29190376 PMCID: PMC6161407 DOI: 10.1093/jmcb/mjx051] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 10/16/2017] [Accepted: 11/25/2017] [Indexed: 12/13/2022] Open
Abstract
Nutlin-3a is a MDM2 antagonist and preclinical drug that activates p53. Cells with MDM2 gene amplification are especially prone to Nutlin-3a-induced apoptosis, though the basis for this is unclear. Glucose metabolism can inhibit apoptosis in response to Nutlin-3a through mechanisms that are incompletely understood. Glucose metabolism through the pentose phosphate pathway (PPP) produces NADPH that can protect cells from potentially lethal reactive oxygen species (ROS). We compared apoptosis and glucose metabolism in cancer cells with and without MDM2 gene amplification treated with Nutlin-3a. Apoptosis in MDM2-amplified cells was associated with a reduction in glycolysis and the PPP, reduced NADPH, increased ROS, and depletion of the transcription factor SP1, which normally promotes PPP gene expression. In contrast, glycolysis and the PPP were maintained or increased in MDM2 non-amplified cells treated with Nutlin-3a. This was dependent on p53-mediated AKT activation and was associated with maintenance of SP1 and continued expression of PPP genes. Knockdown or inhibition of AKT, SP1, or the PPP sensitized MDM2-non-amplified cells to apoptosis. The data indicate that p53 promotes AKT and SP1-dependent activation of the PPP that protects cells from Nutlin-3a-induced apoptosis. These findings provide insight into how glucose metabolism reduces Nutlin-3a-induced apoptosis, and also provide a mechanism for the heightened sensitivity of MDM2-amplified cells to apoptosis in response to Nutlin-3a.
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Affiliation(s)
- Lei Duan
- Department of Cell & Molecular Medicine, Rush University Medical Center, Chicago, IL, USA
| | - Ricardo E Perez
- Department of Cell & Molecular Medicine, Rush University Medical Center, Chicago, IL, USA
| | - Ling Chen
- Department of Laboratory Medicine, Shiyan Taihe Hospital, College of Biomedical Engineering, Hubei University of Medicine, Shiyan, China
| | - Lothar A Blatter
- Department of Physiology & Biophysics, Rush University Medical Center, Chicago, IL, USA
| | - Carl G Maki
- Department of Cell & Molecular Medicine, Rush University Medical Center, Chicago, IL, USA
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2
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Pettie KP, Dresch JM, Drewell RA. Spatial distribution of predicted transcription factor binding sites in Drosophila ChIP peaks. Mech Dev 2016; 141:51-61. [PMID: 27264535 DOI: 10.1016/j.mod.2016.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 04/24/2016] [Accepted: 06/01/2016] [Indexed: 11/19/2022]
Abstract
In the development of the Drosophila embryo, gene expression is directed by the sequence-specific interactions of a large network of protein transcription factors (TFs) and DNA cis-regulatory binding sites. Once the identity of the typically 8-10bp binding sites for any given TF has been determined by one of several experimental procedures, the sequences can be represented in a position weight matrix (PWM) and used to predict the location of additional TF binding sites elsewhere in the genome. Often, alignments of large (>200bp) genomic fragments that have been experimentally determined to bind the TF of interest in Chromatin Immunoprecipitation (ChIP) studies are trimmed under the assumption that the majority of the binding sites are located near the center of all the aligned fragments. In this study, ChIP/chip datasets are analyzed using the corresponding PWMs for the well-studied TFs; CAUDAL, HUNCHBACK, KNIRPS and KRUPPEL, to determine the distribution of predicted binding sites. All four TFs are critical regulators of gene expression along the anterio-posterior axis in early Drosophila development. For all four TFs, the ChIP peaks contain multiple binding sites that are broadly distributed across the genomic region represented by the peak, regardless of the prediction stringency criteria used. This result suggests that ChIP peak trimming may exclude functional binding sites from subsequent analyses.
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Affiliation(s)
- Kade P Pettie
- Department of Biology, Amherst College, Amherst, MA 01002, United States
| | - Jacqueline M Dresch
- Department of Mathematics and Computer Science, Clark University, 950 Main Street, Worcester, MA 01610, United States
| | - Robert A Drewell
- Biology Department, Clark University, 950 Main Street, Worcester, MA 01610, United States
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3
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Lim K, Yoon BH, Ha CH. O-Linked N-acetylglucosaminylation of Sp1 interferes with Sp1 activation of glycolytic genes. Biochem Biophys Res Commun 2015; 468:349-53. [PMID: 26499076 DOI: 10.1016/j.bbrc.2015.10.096] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 10/19/2015] [Indexed: 11/19/2022]
Abstract
Glycolysis, the primary pathway metabolizing glucose for energy production, is connected to the hexosamine biosynthetic pathway (HBP) which produces UDP-N-acetylglucosamine (UDP-GlcNAc), a GlcNAc donor for O-linked GlcNAc modification (O-GlcNAc), as well as for traditional elongated glycosylation. Thus, glycolysis and O-GlcNAc are intimately associated. The present study reports the transcriptional activation of glycolytic genes by the transcription factor Sp1 and the O-GlcNAc-mediated suppression of Sp1-dependent activation of glycolytic genes. O-GlcNAc-deficient mutant Sp1 stimulated the transcription of nine glycolytic genes and cellular production of pyruvate, the final product of glycolysis, to a greater extent than wild-type Sp1. Consistently, this mutant Sp1 increased the protein levels of the two key glycolytic enzymes, phosphofructokinase (PFK) and glyceraldehyde 3-phosphate dehydrogenase (GAPDH), to a greater extent than wild-type Sp1. Finally, the mutant Sp1 occupied GC-rich elements on PFK and GAPDH promoters more efficiently than wild-type Sp1. These results suggest that O-GlcNAcylation of Sp1 suppresses Sp1-mediated activation of glycolytic gene transcription.
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Affiliation(s)
- Kihong Lim
- David H. Smith Center for Vaccine Biology and Immunology, University of Rochester Medical Center, 601 Elmwood Avenue, Box 609, Rochester, NY 14642, United States
| | - Bo Hyun Yoon
- Asan Institute for Life Sciences, Asan Medical Center, College of Medicine, University of Ulsan, 86 Asanbyeoungwon-gil, Songpa-gu, Seoul 138-736, Republic of Korea
| | - Chang Hoon Ha
- Asan Institute for Life Sciences, Asan Medical Center, College of Medicine, University of Ulsan, 86 Asanbyeoungwon-gil, Songpa-gu, Seoul 138-736, Republic of Korea.
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4
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Moyes CD, LeMoine CMR. Control of muscle bioenergetic gene expression: implications for allometric scaling relationships of glycolytic and oxidative enzymes. J Exp Biol 2005; 208:1601-10. [PMID: 15855391 DOI: 10.1242/jeb.01502] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
SUMMARY
Muscle metabolic properties vary with body size, with larger animals relying relatively less on oxidative metabolism as a result of lower specific activities of mitochondrial enzymes and greater specific activities of glycolytic enzymes. While many have argued reasons why such relationships might be grounded in physical relationships, an explanation for the regulatory basis of the differences in enzyme levels remains unexplored. Focusing on skeletal muscle, we review potential cellular and genetic explanations for the relationship between bioenergetic enzymes and body mass. Differences in myonuclear domain (the ratio of fiber volume to nuclei number) in conjunction with constitutive expression may explain part of the variation in mitochondrial content among fiber types and species. Superimposed on such constitutive determinants are (1) extrinsic signalling pathways that control the muscle contractile and metabolic phenotype and (2) intrinsic signalling pathways that translate changes in cellular milieu (ions, metabolites, oxygen,redox) arising through the contractile phenotype into changes in enzyme synthesis. These signalling pathways work through transcriptional regulation,as well as post-transcriptional, translational and post-translational regulation, acting via synthesis and degradation.
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Hannemann A, Jandrig B, Gaunitz F, Eschrich K, Bigl M. Characterization of the human P-type 6-phosphofructo-1-kinase gene promoter in neural cell lines. Gene 2005; 345:237-47. [PMID: 15716112 DOI: 10.1016/j.gene.2004.11.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2004] [Revised: 10/12/2004] [Accepted: 11/17/2004] [Indexed: 11/27/2022]
Abstract
In humans three isoforms of 6-phosphofructo-1-kinase (PFK) exist. Among them platelet-type PFK (PFKP) is highly abundant in the brain. With its distinct allosteric properties PFKP is regarded to be the key enzyme for the regulation of glycolysis in this organ. We cloned 1.7 kb of the 5' upstream promoter of the human PFKP gene and analyzed the promoter activity by deletion and mutation analysis using a luciferase reporter. The transcription start point was determined at 48 bp upstream of the start codon. In deletion studies the region -65 to +48 turned out to be sufficient for promoter activity while fragment -153 to +48 showed the highest promoter activity. Sequence analysis of the region from -153 to +48 revealed a stretch of eight adjacent putative transcription factor binding sites, seven of which are Sp-family specific sites. Sp1 and Sp3 were shown to bind to most if not all of them. Additionally, an NF-Y binding site was identified. Results of deletion and mutation analysis suggest that all of these transcription factors contribute positively to promoter activity. The methylation status of the promoter region was analyzed in different neural tumor cell lines and compared with that in human leukocytes and muscle.
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Affiliation(s)
- Anke Hannemann
- Institute of Biochemistry, University of Leipzig (Medical Faculty), Liebigstrasse 16, D-04103 Leipzig, Germany
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6
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Catz SD, Babior BM, Johnson JL. JFC1 is transcriptionally activated by nuclear factor-kappaB and up-regulated by tumour necrosis factor alpha in prostate carcinoma cells. Biochem J 2002; 367:791-9. [PMID: 12137562 PMCID: PMC1222920 DOI: 10.1042/bj20020345] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2002] [Revised: 07/09/2002] [Accepted: 07/23/2002] [Indexed: 11/17/2022]
Abstract
The human promoter region of JFC1, a phosphatidylinositol 3,4,5-trisphosphate binding ATPase, was isolated by amplification of a 549 bp region upstream of the jfc1 gene by the use of a double-PCR system. By primer extension analysis we mapped the transcription initiation site at nucleotide -321 relative to the translation start site. Putative regulatory elements were identified in the jfc1 TATA-less promoter, including three consensus sites for nuclear factor-kappaB (NF-kappaB). We analysed the three putative NF-kappaB binding sites by gel retardation and supershift assays. Each of the putative NF-kappaB sites interacted specifically with recombinant NF-kappaB p50, and the complexes co-migrated with those formed by the NF-kappaB consensus sequence and p50. An antibody to p50 generated a supershifted complex for these NF-kappaB sites. These sites formed specific complexes with nuclear proteins from tumour necrosis factor alpha (TNFalpha)-treated WEHI 231 cells, which were supershifted with antibodies against p50 and p65. The jfc1 promoter was transcriptionally active in various cell lines, as determined by luciferase reporter assays following transfection with a jfc1 promoter luciferase vector. Co-transfection with NF-kappaB expression vectors or stimulation with TNFalpha resulted in significant transactivation of the jfc1 promoter construct, although transactivation of a mutated jfc1 promoter was negligible. The expression of a dominant negative IkappaB (inhibitor kappaB) decreased basal jfc1 promoter activity. The cell lines PC-3, LNCaP and DU-145, but not Epstein-Barr virus-transformed lymphocytes, showed a dramatic increase in the expression of JFC1 after treatment with TNFalpha, suggesting that transcriptional activation of JFC1 by the TNFalpha/NF-kappaB pathway is significant in prostate carcinoma cell lines.
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Affiliation(s)
- Sergio D Catz
- Biochemistry Division, Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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7
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Catz SD, Johnson JL. Transcriptional regulation of bcl-2 by nuclear factor kappa B and its significance in prostate cancer. Oncogene 2001; 20:7342-51. [PMID: 11704864 DOI: 10.1038/sj.onc.1204926] [Citation(s) in RCA: 412] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2001] [Revised: 08/09/2001] [Accepted: 08/15/2001] [Indexed: 01/17/2023]
Abstract
This work presents direct evidence that the bcl-2 gene is transcriptionally regulated by nuclear factor-kappa B (NF-kappa B) and directly links the TNF-alpha/NF-kappa B signaling pathway with Bcl-2 expression and its pro-survival response in human prostate carcinoma cells. DNase I footprinting, gel retardation and supershift analysis identified a NF-kappa B site in the bcl-2 p2 promoter. In the context of a minimal promoter, this bcl-2 p2 site 1 increased transcription 10-fold in the presence of the p50/p65 expression vectors, comparable to the increment observed with the consensus NF-kappa B site, while for the full p2 promoter region transcriptional activity was increased sixfold by over-expression of NF-kappa B, an effect eliminated by mutating the bcl-2 p2 site 1. The expression of Bcl-2 has been linked to the hormone-resistant phenotype of advanced prostate cancer. Here we show that an increase in the level of expression of Bcl-2 in the human prostate carcinoma cell line LNCaP observed in response to hormone withdrawal is further augmented by TNF-alpha treatment, and this effect is abated by inhibitors of NF-kappa B. Concomitantly, bcl-2 p2 promoter studies in LNCaP cells show a 40-fold increase in promoter activity after stimulation with TNF-alpha in the absence of hormone.
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Affiliation(s)
- S D Catz
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California, CA 92037, USA
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8
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Minet E, Ernest I, Michel G, Roland I, Remacle J, Raes M, Michiels C. HIF1A gene transcription is dependent on a core promoter sequence encompassing activating and inhibiting sequences located upstream from the transcription initiation site and cis elements located within the 5'UTR. Biochem Biophys Res Commun 1999; 261:534-40. [PMID: 10425220 DOI: 10.1006/bbrc.1999.0995] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hypoxia inducible factor-1 (HIF-1) is a transcription factor composed of two subunits, HIF-1alpha and ARNT, which is activated under hypoxia. HIF-1alpha mRNA is expressed constitutively in a wide variety of cell types, whereas in some others HIF1A gene expression is upregulated by hypoxia. In this report, we show that in endothelial cells (HMEC-1) the HIF-1alpha mRNA expression level is the same in both normoxia and hypoxia. Deletion analysis experiments of the HIF1A promoter showed that in hypoxia HIF1A gene expression is upregulated through a short sequence located next to the transcription initiation site. We also show that in hypoxia another sequence located upstream from the +1 initiation site plays an inhibitory role on HIF1A transcription in HMEC-1 but not in hepatoma cells and brings back this expression level to that observed in normoxia. Finally, we demonstrate that HIF1A gene transcription is dependent on Sp1 binding sites and that the 5'UTR sequence also contains other important cis-acting elements.
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Affiliation(s)
- E Minet
- Laboratoire de Biochimie et Biologie Cellulaire, Facultés Universitaires de la Paix, 61 rue de Bruxelles, Namur, 5000, Belgium.
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9
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Biesiada E, Hamamori Y, Kedes L, Sartorelli V. Myogenic basic helix-loop-helix proteins and Sp1 interact as components of a multiprotein transcriptional complex required for activity of the human cardiac alpha-actin promoter. Mol Cell Biol 1999; 19:2577-84. [PMID: 10082523 PMCID: PMC84050 DOI: 10.1128/mcb.19.4.2577] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Activation of the human cardiac alpha-actin (HCA) promoter in skeletal muscle cells requires the integrity of DNA binding sites for the serum response factor (SRF), Sp1, and the myogenic basic helix-loop-helix (bHLH) family. In this study we report that activation of the HCA correlates with formation of a muscle-specific multiprotein complex on the promoter. We provide evidence that proteins eluted from the multiprotein complex specifically react with antibodies directed against myogenin, Sp1, and SRF and that the complex can be assembled in vitro by using the HCA promoter and purified MyoD, E12, SRF, and Sp1. In vitro and in vivo assays revealed a direct association of Sp1 and myogenin-MyoD mediated by the DNA-binding domain of Sp1 and the HLH motif of myogenin. The results obtained in this study indicate that protein-protein interactions and the cooperative DNA binding of transcriptional activators are critical steps in the formation of a transcriptionally productive multiprotein complex on the HCA promoter and suggest that the same mechanisms might be utilized to regulate the transcription of muscle-specific and other genes.
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Affiliation(s)
- E Biesiada
- Institute for Genetic Medicine and Department of Biochemistry and Molecular Biology, University of Southern California School of Medicine, Los Angeles, California, USA
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10
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Yang J, Riley M, Thomas K. Cell-type-specific transcription factor interactions with cis-elements present in the mouse LDH/C proximal promoter region. ACTA ACUST UNITED AC 1998. [DOI: 10.1002/(sici)1097-010x(199809/10)282:1/2<179::aid-jez20>3.0.co;2-o] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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11
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Binding of Phosphorylated Sp1 Protein to Tandem Sp1 Binding Sites Regulates α2 Integrin Gene Core Promoter Activity. Blood 1997. [DOI: 10.1182/blood.v90.2.678.678_678_689] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The α2β1 integrin, a collagen/laminin receptor, is expressed by a variety of cell types, including epithelial cells, mesenchymal cells, and hematopoietic cells. To understand the molecular mechanisms that regulate expression of the α2β1 integrin in cells with megakaryocytic differentiation, we characterized the 5′ flanking region of the α2 integrin gene and identified three distinct regulatory regions, including a core promoter, a silencer, and megakaryocyte enhancers in the distal 5′ flank (Zutter et al, Blood 96:3006, 1995 and Zutter et al, J Biol Chem 269:463, 1994). We now focus on the core promoter of the α2 integrin gene located between bp −30 and −92 that is required for transcriptional activity of the α2 integrin gene. Sequence analysis identified two Sp1 consensus sites and a potential AP2 site. Gel retardation assays showed that nuclear proteins from uninduced K562 cells and K562 cells induced to become megakaryocytic bound specifically to the core promoter region (bp −30 to bp −92) producing two DNA-protein complexes. In addition, nuclear extracts from cells induced along the megakaryocyte lineage produced a selective increase in the slower migrating complex. Site-directed mutagenesis of the 5′, the 3′, or both Sp1 binding sites suggested that both Sp1 binding sites are required for full promoter activity and for DNA-protein complex formation. DNA footprinting also showed specific protection of the 5′ Sp1 site by nuclear extracts from uninduced K562 cells and protection of both the 5′ and the 3′ Sp1 sites by nuclear extracts from induced K562 cells. Sp1 protein-DNA complex formation was dependent on Sp1 phosphorylation. The faster migrating DNA-protein complex was enhanced by dephosphorylation; the slower migrating DNA-protein complex was diminished or lost.
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12
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Binding of Phosphorylated Sp1 Protein to Tandem Sp1 Binding Sites Regulates α2 Integrin Gene Core Promoter Activity. Blood 1997. [DOI: 10.1182/blood.v90.2.678] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractThe α2β1 integrin, a collagen/laminin receptor, is expressed by a variety of cell types, including epithelial cells, mesenchymal cells, and hematopoietic cells. To understand the molecular mechanisms that regulate expression of the α2β1 integrin in cells with megakaryocytic differentiation, we characterized the 5′ flanking region of the α2 integrin gene and identified three distinct regulatory regions, including a core promoter, a silencer, and megakaryocyte enhancers in the distal 5′ flank (Zutter et al, Blood 96:3006, 1995 and Zutter et al, J Biol Chem 269:463, 1994). We now focus on the core promoter of the α2 integrin gene located between bp −30 and −92 that is required for transcriptional activity of the α2 integrin gene. Sequence analysis identified two Sp1 consensus sites and a potential AP2 site. Gel retardation assays showed that nuclear proteins from uninduced K562 cells and K562 cells induced to become megakaryocytic bound specifically to the core promoter region (bp −30 to bp −92) producing two DNA-protein complexes. In addition, nuclear extracts from cells induced along the megakaryocyte lineage produced a selective increase in the slower migrating complex. Site-directed mutagenesis of the 5′, the 3′, or both Sp1 binding sites suggested that both Sp1 binding sites are required for full promoter activity and for DNA-protein complex formation. DNA footprinting also showed specific protection of the 5′ Sp1 site by nuclear extracts from uninduced K562 cells and protection of both the 5′ and the 3′ Sp1 sites by nuclear extracts from induced K562 cells. Sp1 protein-DNA complex formation was dependent on Sp1 phosphorylation. The faster migrating DNA-protein complex was enhanced by dephosphorylation; the slower migrating DNA-protein complex was diminished or lost.
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13
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Kang JS, Kohlhuber F, Hug H, Marmé D, Eick D, Ueffing M. Cloning and functional analysis of the hematopoietic cell-specific phospholipase C(gamma)2 promoter. FEBS Lett 1996; 399:14-20. [PMID: 8980110 DOI: 10.1016/s0014-5793(96)01276-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Phospholipase C(gamma)2 (PLCgamma2) is a phospholipid-converting enzyme which, upon receptor stimulation, is activated within membrane-bound signalling complexes. In contrast to the highly ubiquitous PLCgamma1, PLCgamma2 is expressed predominantly in B-lymphocytes. Associated with antigen-coupling receptors it is activated by tyrosine phosphorylation after the triggering of B-cell surface immunoglobulin. We have cloned and sequenced the human PLCgamma2 promoter. Primer extension analysis reveals the existence of a major transcriptional start site. The TATA-less promoter contains G+C-rich stretches with a cluster of contiguous SP1 consensus sites, an NF1, and an AP2 site between bp -220 to -70. A construct containing the region from -189 to +78 confers full promoter activity, as shown by fusion to a luciferase reporter gene construct. The distal part of the promoter between bp -662 to -293 containing an SRE, EBF and CACCC box contributed negatively to promoter activity in the B-cell line Raji but not in three adherent cell lines. In Raji cells, PLCgamma2 mRNA is expressed at low levels with a half life greater than 4 h. After treatment with serum, TPA, retinoic acid, or with 5-azacytidine increased levels of PLCgamma2 mRNA were induced in B-cells.
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Affiliation(s)
- J S Kang
- Mount Sinai Medical School, Department of Biochemistry, New York, NY 10029, USA
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14
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Thomas M, Skala H, Kahn A, Tuy FP. Functional dissection of the brain-specific rat aldolase C gene promoter in transgenic mice. Essential role of two GC-rich boxes and an HNF3 binding site. J Biol Chem 1995; 270:20316-21. [PMID: 7657603 DOI: 10.1074/jbc.270.35.20316] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The aldolase C gene product is a glycolytic isoenzyme specifically detected in brain. We have previously defined a short 115-base pair promoter fragment able to confer on a reporter chloramphenicol acetyltransferase (CAT) gene a specific expression in brain of transgenic mice. In this promoter fragment, two GC-rich regions (A/A' and B boxes) were detected by in vitro DNase1 footprinting experiments with brain, fibroblast, or liver nuclear extracts. Both A/A' and B boxes, sharing structural homology, are able to interact with Sp1, Krox20/Krox24 factors and with other proteins (Thomas, M., Makeh, I., Briand, P., Kahn, A., and Skala, H. (1993) Eur. J. Biochem. 218, 143-151). In this paper, we describe a new ubiquitous factor termed Ub able to bind the A/A' box. We also delimit a third element (box C) binding a hepatocyte-enriched protein displaced by a hepatocyte nuclear factor 3-specific oligonucleotide. The functional involvement of each binding site in brain-specific transcription of the aldolase C gene has been tested in transgenic mice carrying different mutant promoters cloned in front of the CAT gene. A promoter containing only box C was totally inactive, suggesting an essential role of the region containing A/A' and B boxes. However, mutations or deletions of either the A/A' or the B box have no significant effect on the CAT gene expression. We therefore hypothesize that the A/A' and B sites may be functionally redundant. Indeed, constructs harboring only one of these two boxes (A/A' or B) linked to the C box displayed a brain-specific CAT activity similar to that obtained with the wild-type promoter. Furthermore, a transgene with disruption of the C box, keeping intact the A/A' and B boxes, was totally inactive, suggesting a crucial role of the hepatocyte nuclear factor 3 binding site in activation of the aldolase C gene.
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Affiliation(s)
- M Thomas
- Institut Cochin de Génétique Moléculaire, Génétique et Pathologie Moléculaires, INSERM U129, Université René Descartes, Paris, France
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