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Pooley JR, Rivers CA, Kilcooley MT, Paul SN, Cavga AD, Kershaw YM, Muratcioglu S, Gursoy A, Keskin O, Lightman SL. Beyond the heterodimer model for mineralocorticoid and glucocorticoid receptor interactions in nuclei and at DNA. PLoS One 2020; 15:e0227520. [PMID: 31923266 PMCID: PMC6953809 DOI: 10.1371/journal.pone.0227520] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 12/19/2019] [Indexed: 12/20/2022] Open
Abstract
Glucocorticoid (GR) and mineralocorticoid receptors (MR) are believed to classically bind DNA as homodimers or MR-GR heterodimers to influence gene regulation in response to pulsatile basal or stress-evoked glucocorticoid secretion. Pulsed corticosterone presentation reveals MR and GR co-occupy DNA only at the peaks of glucocorticoid oscillations, allowing interaction. GR DNA occupancy was pulsatile, while MR DNA occupancy was prolonged through the inter-pulse interval. In mouse mammary 3617 cells MR-GR interacted in the nucleus and at a chromatin-associated DNA binding site. Interactions occurred irrespective of ligand type and receptors formed complexes of higher order than heterodimers. We also detected MR-GR interactions ex-vivo in rat hippocampus. An expanded range of MR-GR interactions predicts structural allostery allowing a variety of transcriptional outcomes and is applicable to the multiple tissue types that co-express both receptors in the same cells whether activated by the same or different hormones.
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Affiliation(s)
- John R. Pooley
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, United Kingdom
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Caroline A. Rivers
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, United Kingdom
| | - Michael T. Kilcooley
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, United Kingdom
| | - Susana N. Paul
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, United Kingdom
| | - Ayse Derya Cavga
- Department of Chemical and Biological Engineering, Koc University, Istanbul, Turkey
| | - Yvonne M. Kershaw
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, United Kingdom
| | - Serena Muratcioglu
- Department of Molecular and Cell Biology, University of California, Berkeley, California, United States of America
- Howard Hughes Medical Institute, University of California, Berkeley, California, United States of America
| | - Attila Gursoy
- Department of Chemical and Biological Engineering, Koc University, Istanbul, Turkey
| | - Ozlem Keskin
- Department of Chemical and Biological Engineering, Koc University, Istanbul, Turkey
| | - Stafford L. Lightman
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, United Kingdom
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2
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Oasa S, Mikuni S, Yamamoto J, Kurosaki T, Yamashita D, Kinjo M. Relationship Between Homodimeric Glucocorticoid Receptor and Transcriptional Regulation Assessed via an In Vitro Fluorescence Correlation Spectroscopy-Microwell System. Sci Rep 2018; 8:7488. [PMID: 29748590 PMCID: PMC5945783 DOI: 10.1038/s41598-018-25393-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 04/19/2018] [Indexed: 12/17/2022] Open
Abstract
Glucocorticoid receptor (GR) is a hormone-activated transcription regulatory protein involved in metabolism as well as adrenocortical responses to psychosocial stress. Ligand-activated GR localizes to the nucleus, where GR homodimers regulate gene transcription via direct binding to glucocorticoid response elements (GREs). The role of GR homodimers in transcriptional activation has not yet been elucidated. In this study, we determined the concentration of GR homodimer, and its dissociation constant (Kd), at the single-cell level, by using fluorescence correlation spectroscopy (FCS) combined with a microwell system. Results from dissociation constant analysis and diffusion analysis suggested that GR forms complexes with other proteins as well as homodimers. We determined the relationship between the concentration of GR homodimer and transcriptional activity using a triple-color FCS-microwell system-based fluorescent reporter assay. The binding affinity of GR to GREs was analyzed via fluorescence cross-correlation spectroscopy (FCCS). Our findings indicate that the GR homodimer is essential for activating target gene transcription.
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Affiliation(s)
- Sho Oasa
- Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science, Hokkaido University, Sapporo, 001-0021, Japan
| | - Shintaro Mikuni
- Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science, Hokkaido University, Sapporo, 001-0021, Japan
| | - Johtaro Yamamoto
- Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science, Hokkaido University, Sapporo, 001-0021, Japan
| | - Tsumugi Kurosaki
- Laboratory of Molecular Cell Dynamics, Graduate School of Life Science, Hokkaido University, Sapporo, 001-0021, Japan
| | - Daisuke Yamashita
- Laboratory of Molecular Cell Dynamics, Graduate School of Life Science, Hokkaido University, Sapporo, 001-0021, Japan
| | - Masataka Kinjo
- Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science, Hokkaido University, Sapporo, 001-0021, Japan.
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3
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Presman DM, Hager GL. More than meets the dimer: What is the quaternary structure of the glucocorticoid receptor? Transcription 2016; 8:32-39. [PMID: 27764575 PMCID: PMC5279712 DOI: 10.1080/21541264.2016.1249045] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
It is widely accepted that the glucocorticoid receptor (GR), a ligand-regulated transcription factor that triggers anti-inflammatory responses, binds specific response elements as a homodimer. Here, we will discuss the original primary data that established this model and contrast it with a recent report characterizing the GR-DNA complex as a tetramer.
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Affiliation(s)
- Diego M Presman
- a Laboratory of Receptor Biology and Gene Expression , National Cancer Institute, National Institutes of Health , Bethesda , MD , USA
| | - Gordon L Hager
- a Laboratory of Receptor Biology and Gene Expression , National Cancer Institute, National Institutes of Health , Bethesda , MD , USA
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4
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Belikov S, Berg OG, Wrange Ö. Quantification of transcription factor-DNA binding affinity in a living cell. Nucleic Acids Res 2015; 44:3045-58. [PMID: 26657626 PMCID: PMC4838337 DOI: 10.1093/nar/gkv1350] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 11/19/2015] [Indexed: 12/17/2022] Open
Abstract
The apparent dissociation constant (Kd) for specific binding of glucocorticoid receptor (GR) and androgen receptor (AR) to DNA was determined in vivo in Xenopus oocytes. The total nuclear receptor concentration was quantified as specifically retained [3H]-hormone in manually isolated oocyte nuclei. DNA was introduced by nuclear microinjection of single stranded phagemid DNA, chromatin is then formed during second strand synthesis. The fraction of DNA sites occupied by the expressed receptor was determined by dimethylsulphate in vivo footprinting and used for calculation of the receptor-DNA binding affinity. The forkhead transcription factor FoxA1 enhanced the DNA binding by GR with an apparent Kd of ∼1 μM and dramatically stimulated DNA binding by AR with an apparent Kd of ∼0.13 μM at a composite androgen responsive DNA element containing one FoxA1 binding site and one palindromic hormone receptor binding site known to bind one receptor homodimer. FoxA1 exerted a weak constitutive- and strongly cooperative DNA binding together with AR but had a less prominent effect with GR, the difference reflecting the licensing function of FoxA1 at this androgen responsive DNA element.
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Affiliation(s)
- Sergey Belikov
- Department of Cell and Molecular Biology, Karolinska Institutet, SE-17177 Stockholm, Sweden
| | - Otto G Berg
- Department of Cell and Molecular Biology, Uppsala University, BMC Box 596, SE-75124 Uppsala, Sweden
| | - Örjan Wrange
- Department of Cell and Molecular Biology, Karolinska Institutet, SE-17177 Stockholm, Sweden
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5
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Grøntved L, John S, Baek S, Liu Y, Buckley JR, Vinson C, Aguilera G, Hager GL. C/EBP maintains chromatin accessibility in liver and facilitates glucocorticoid receptor recruitment to steroid response elements. EMBO J 2013; 32:1568-83. [PMID: 23665916 DOI: 10.1038/emboj.2013.106] [Citation(s) in RCA: 169] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 04/10/2013] [Indexed: 01/22/2023] Open
Abstract
Mechanisms regulating transcription factor interaction with chromatin in intact mammalian tissues are poorly understood. Exploiting an adrenalectomized mouse model with depleted endogenous glucocorticoids, we monitor changes of the chromatin landscape in intact liver tissue following glucocorticoid injection. Upon activation of the glucocorticoid receptor (GR), proximal regions of activated and repressed genes are remodelled, and these remodelling events correlate with RNA polymerase II occupancy of regulated genes. GR is exclusively associated with accessible chromatin and 62% percent of GR-binding sites are occupied by C/EBPβ. At the majority of these sites, chromatin is preaccessible suggesting a priming function of C/EBPβ for GR recruitment. Disruption of C/EBPβ binding to chromatin results in attenuation of pre-programmed chromatin accessibility, GR recruitment and GR-induced chromatin remodelling specifically at sites co-occupied by GR and C/EBPβ. Collectively, we demonstrate a highly cooperative mechanism by which C/EBPβ regulates selective GR binding to the genome in liver tissue. We suggest that selective targeting of GR in other tissues is likely mediated by the combined action of cell-specific priming proteins and chromatin remodellers.
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Affiliation(s)
- Lars Grøntved
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, Bethesda, MD 20892, USA
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6
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Rodela TM, Esbaugh AJ, McDonald MD, Gilmour KM, Walsh PJ. Evidence for transcriptional regulation of the urea transporter in the gill of the Gulf toadfish, Opsanus beta. Comp Biochem Physiol B Biochem Mol Biol 2011; 160:72-80. [PMID: 21740977 DOI: 10.1016/j.cbpb.2011.06.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Revised: 06/24/2011] [Accepted: 06/24/2011] [Indexed: 02/01/2023]
Abstract
Ureotelic Gulf toadfish (Opsanus beta) do not excrete urea continuously; instead, urea is accumulated internally until a branchial urea transport mechanism is activated to facilitate the excretion of urea in distinct pulses. This unusual pulsatile urea excretion pattern is regulated, in part, by permissive declines in circulating cortisol concentrations. The current study examined toadfish urea transporter (tUT) and glucocorticoid receptor (GR) transcript levels in toadfish gill following chronic (days) and acute (hours) changes in corticosteroid activity. Experimentally lowering circulating cortisol did not significantly alter tUT mRNA abundance but increased GR mRNA. On an acute timescale, a 6.2-fold upregulation of tUT mRNA occurred 12 to 18 h following a urea pulse event with no change in GR mRNA. In silico analysis of an isolated 1.2 kb fragment, upstream promoter region of the tUT gene, revealed 6 putative glucocorticoid response element (GRE) half sites. In vivo reporter assays of the tUT promoter fragment demonstrated relative luciferase activity was enhanced 3.4- and 9.8-fold following exposure to moderate (via a 48 h crowding stress) and high (via infusion for 48 h) cortisol. We conclude that a GRE-mediated upregulation of mRNA may be required to maintain tUT activity by offsetting post-transcriptional and/or post-translational changes that may be associated with chronically elevated plasma cortisol.
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Affiliation(s)
- Tamara M Rodela
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada.
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7
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Presman DM, Alvarez LD, Levi V, Eduardo S, Digman MA, Martí MA, Veleiro AS, Burton G, Pecci A. Insights on glucocorticoid receptor activity modulation through the binding of rigid steroids. PLoS One 2010; 5:e13279. [PMID: 20949009 PMCID: PMC2952596 DOI: 10.1371/journal.pone.0013279] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Accepted: 09/16/2010] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND The glucocorticoid receptor (GR) is a transcription factor that regulates gene expression in a ligand-dependent fashion. This modular protein is one of the major pharmacological targets due to its involvement in both cause and treatment of many human diseases. Intense efforts have been made to get information about the molecular basis of GR activity. METHODOLOGY/PRINCIPAL FINDINGS Here, the behavior of four GR-ligand complexes with different glucocorticoid and antiglucocorticoid properties were evaluated. The ability of GR-ligand complexes to oligomerize in vivo was analyzed by performing the novel Number and Brightness assay. Results showed that most of GR molecules form homodimers inside the nucleus upon ligand binding. Additionally, in vitro GR-DNA binding analyses suggest that ligand structure modulates GR-DNA interaction dynamics rather than the receptor's ability to bind DNA. On the other hand, by coimmunoprecipitation studies we evaluated the in vivo interaction between the transcriptional intermediary factor 2 (TIF2) coactivator and different GR-ligand complexes. No correlation was found between GR intranuclear distribution, cofactor recruitment and the homodimerization process. Finally, Molecular determinants that support the observed experimental GR LBD-ligand/TIF2 interaction were found by Molecular Dynamics simulation. CONCLUSIONS/SIGNIFICANCE The data presented here sustain the idea that in vivo GR homodimerization inside the nucleus can be achieved in a DNA-independent fashion, without ruling out a dependent pathway as well. Moreover, since at least one GR-ligand complex is able to induce homodimer formation while preventing TIF2 coactivator interaction, results suggest that these two events might be independent from each other. Finally, 21-hydroxy-6,19-epoxyprogesterone arises as a selective glucocorticoid with potential pharmacological interest. Taking into account that GR homodimerization and cofactor recruitment are considered essential steps in the receptor activation pathway, results presented here contribute to understand how specific ligands influence GR behavior.
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Affiliation(s)
- Diego M. Presman
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- IFIBYNE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Lautaro D. Alvarez
- Departamento de Química Orgánica/UMYMFOR-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Valeria Levi
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Silvina Eduardo
- Departamento de Química Orgánica/UMYMFOR-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Michelle A. Digman
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering and Developmental Biology Center Optical Biology Core Facility, University of California Irvine, Irvine, California, United States of America
| | - Marcelo A. Martí
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- INQUIMAE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Adriana S. Veleiro
- Departamento de Química Orgánica/UMYMFOR-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Gerardo Burton
- Departamento de Química Orgánica/UMYMFOR-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Adali Pecci
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- IFIBYNE-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
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8
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Connaghan-Jones KD, Heneghan AF, Miura MT, Bain DL. Thermodynamic dissection of progesterone receptor interactions at the mouse mammary tumor virus promoter: monomer binding and strong cooperativity dominate the assembly reaction. J Mol Biol 2008; 377:1144-60. [PMID: 18313072 DOI: 10.1016/j.jmb.2008.01.052] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2007] [Revised: 01/17/2008] [Accepted: 01/18/2008] [Indexed: 10/22/2022]
Abstract
Progesterone receptors (PRs) play critical roles in eukaryotic gene regulation, yet the mechanisms by which they assemble at their promoters are poorly understood. One of the few promoters amenable to analysis is the mouse mammary tumor virus gene regulatory sequence. Embedded within this sequence are four progesterone response elements (PREs) corresponding to a palindromic PRE and three half-site PREs. Early mutational studies indicated that the presence of all four sites generated a synergistic and strong transcriptional response. However, DNA binding analyses suggested that receptor assembly at the promoter occurred in the absence of significant cooperativity. Taken together, the results indicated that cooperative interactions among PREs could not account for the observed functional synergy. More broadly, the studies raised the question of whether cooperativity was a common feature of PR-mediated gene regulation. As a step toward obtaining a quantitative and, thus, predictive understanding of receptor function, we have carried out a thermodynamic dissection of PR A-isoform interactions at the mouse mammary tumor virus promoter. Utilizing analytical ultracentrifugation and quantitative footprinting, we have resolved the microscopic energetics of PR A-isoform binding, including cooperativity terms. Our results reveal a model contrary to that inferred from previous biochemical investigations. Specifically, the binding unit at a half-site is not a receptor dimer but is instead a monomer; monomers bound at half-sites are capable of significant pairwise cooperative interactions; occupancy of all three half-sites is required to cooperatively engage the palindromic-bound dimer; and finally, large unfavorable forces accompany assembly. Overall, monomer binding accounts for the majority of the intrinsic binding energetics and cooperativity contributes an approximately 1000-fold increase in receptor-promoter stability. Finally, the partitioning of cooperativity suggests a framework for interpreting in vivo transcriptional synergy. These results highlight the insight available from rigorous analysis and demonstrate that receptor-promoter interactions are considerably more complex than typically envisioned.
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Affiliation(s)
- Keith D Connaghan-Jones
- Department of Pharmaceutical Sciences, C-238, University of Colorado Denver, 4200 East 9th Avenue, Denver, CO 80262, USA
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9
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Heneghan AF, Connaghan-Jones KD, Miura MT, Bain DL. Coactivator assembly at the promoter: efficient recruitment of SRC2 is coupled to cooperative DNA binding by the progesterone receptor. Biochemistry 2007; 46:11023-32. [PMID: 17845055 DOI: 10.1021/bi700850v] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A largely unsolved problem in eukaryotic gene regulation focuses on the mechanisms by which DNA-bound transcription factors recruit coactivators to a promoter. Recent work has suggested that promoter DNA acts as an allosteric ligand, serving not only to bind and localize transcription factors but also to trigger structural changes within the proteins in order to elicit coactivator recruitment. Unfortunately, a quantitative and molecular understanding of this phenomenon remains unclear. We have previously resolved the microstate interaction energetics of progesterone receptor A-isoform (PR-A) assembly at multiple promoters; here we extend this work to the role of PR-A in mediating promoter-dependent recruitment of the coactivator, SRC2. Quantitative footprinting and statistical thermodynamic modeling of PR-A:promoter interactions in the presence and absence of coactivator demonstrate that receptor binding to a single response element is maximally coupled to a 2-fold enhancement in SRC2 binding. By contrast, PR-A assembly at multiple response elements is linked to an additional 6- to 10-fold increase in SRC2 affinity. This effect arises due to a coupled reaction between SRC2 uptake and enhanced cooperative interactions between adjacently bound PR-A dimers. Put another way, increased coactivator levels stabilize a higher-order receptor-promoter complex. These results may thus not only offer a mechanism for explaining the weak transcriptional activity seen for promoters containing a single binding site and the synergistically strong activity seen for multisite promoters but also suggest that in vivo fluctuations of coactivator levels might serve as a physiological regulator of assembly for PR-A (and for other nuclear receptors) at the promoter.
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Affiliation(s)
- Aaron F Heneghan
- Department of Pharmaceutical Sciences, University of Colorado Health Sciences Center, 4200 East 9th Avenue, Denver, Colorado 80262, USA
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10
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Heneghan AF, Connaghan-Jones KD, Miura MT, Bain DL. Cooperative DNA binding by the B-isoform of human progesterone receptor: thermodynamic analysis reveals strongly favorable and unfavorable contributions to assembly. Biochemistry 2006; 45:3285-96. [PMID: 16519523 PMCID: PMC2505112 DOI: 10.1021/bi052046g] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Progesterone receptors (PR) play critical roles in eukaryotic gene regulation, yet the mechanisms by which they assemble at multisite promoters are poorly understood. Here we present a thermodynamic analysis of the interactions of the PR B-isoform (PR-B) with promoters containing either one or two progesterone response elements (PREs). Utilizing quantitative footprinting, we have resolved the microscopic energetics of PR-B binding, including cooperativity terms. The results of this analysis challenge a number of assumptions found in traditional models of receptor function. First, PR-B interactions at a single PRE can be equally well described by mechanisms invoking either the receptor monomer or the dimer as the active DNA binding species. If, as is commonly accepted, PR-B interacts with response elements only as a preformed dimer, then its intrinsic binding affinity is not the typically observed nanomolar but is rather picomolar. This high affinity binding is opposed, however, by a large energetic penalty. The penalty presumably pays for costly structural rearrangements of the receptor dimer and/or response element that are needed to form the protein-DNA complex. If PR-B assembles at a single response element via successive monomer binding reactions, then this penalty minimizes cooperative interactions between adjacent monomers. When binding to two response elements, the receptor exhibits strong intersite cooperativity. Although this phenomenon has been observed before, the present work demonstrates that the energetics reach levels seen in highly cooperative systems such as lambda cI repressor. This first quantitative dissection of cooperative receptor-promoter interactions suggests that PR-B function is more complex than traditionally envisioned.
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Affiliation(s)
- Aaron F Heneghan
- Department of Pharmaceutical Sciences, University of Colorado Health Sciences Center, 4200 East 9th Avenue, Denver, Colorado 80262, USA
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11
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Haarman EG, Kaspers GJL, Pieters R, Rottier MMA, Veerman AJP. Glucocorticoid receptor alpha, beta and gamma expression vs in vitro glucocorticod resistance in childhood leukemia. Leukemia 2004; 18:530-7. [PMID: 14724649 DOI: 10.1038/sj.leu.2403225] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Alternative splicing of the primary glucocorticoid receptor (GR) transcript, resulting in glucocorticoid receptor alpha GRalpha, glucocorticoid receptor beta GRbeta and glucocorticoid receptor gamma GRgamma, may influence glucocorticoid (GC) resistance in childhood leukemia. To test this hypothesis, we determined GRalpha/beta protein and GRalpha/beta/gamma mRNA expression levels in 43 initial acute lymphoblastic leukemia (iALL), 10 initial myeloid leukemia (iAML), 11 relapsed ALL (rALL) samples and one rAML sample. The results were correlated with in vitro GC resistance. GRalpha mRNA correlated with protein expression (rho=0.39-0.56, P<0.05), but the protein to mRNA ratio was median 2.2-fold lower in rALL than in iALL (P<0.05). GRbeta mRNA was median 137-fold lower than GRalpha mRNA and correlated with GRalpha mRNA expression (rho=0.71, P<0.0001). GRbeta could not be detected at the protein level. GRgamma accounted for a median of 2.8% (range 0.95-7.4%) of all GR transcripts. GRalpha (protein and mRNA) and GRbeta (mRNA) expressions or GRalpha/GRbeta ratios did not correlate with in vitro GC resistance in iALL, but GRgamma (mRNA) did (rho=0.52, P=0.007). These results suggest that GRbeta is not involved in GC resistance in childhood leukemia. The association between GRgamma expression and in vitro GC resistance in iALL and the decreased protein/mRNA ratio in rALL, a subgroup resistant to GCs, warrants further exploration.
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MESH Headings
- Acute Disease
- Alternative Splicing
- Bone Marrow/pathology
- Drug Resistance, Neoplasm
- Gene Expression Regulation, Neoplastic/drug effects
- Glucocorticoids/pharmacology
- Humans
- Leukemia, Myeloid/genetics
- Leukemia, Myeloid/metabolism
- Neoplasm Recurrence, Local/genetics
- Neoplasm Recurrence, Local/metabolism
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/metabolism
- Protein Isoforms
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Neoplasm/genetics
- RNA, Neoplasm/metabolism
- Receptors, Glucocorticoid/genetics
- Receptors, Glucocorticoid/metabolism
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Affiliation(s)
- E G Haarman
- Department of Pediatric Hematology/Oncology, VU University Medical Center, De Boelelaan, Amsterdam, The Netherlands.
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12
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Jho SH, Radoja N, Im MJ, Tomic-Canic M. Negative response elements in keratin genes mediate transcriptional repression and the cross-talk among nuclear receptors. J Biol Chem 2001; 276:45914-20. [PMID: 11591699 DOI: 10.1074/jbc.m103144200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Very little is known about the mechanisms responsible for the findings that binding of nuclear receptors (NR) to some promoter elements leads to transcriptional activation, whereas binding to others leads to repression. Case in point is the group of epidermal keratin genes and their DNA sequences responsible for repression by NR. Keratin response elements (KREs) interact with receptors for retinoic acid, thyroid hormone, and glucocorticoids. KREs, by their structure and sequence, direct the binding of retinoic acid and thyroid hormone as homodimers and glucocorticoids as monomers. Such specific DNA-receptor interactions are crucial for the repression signal of transcription. In this paper we have analyzed the interactions between the KREs and NR that lead to such repression. We have found that KREs are promoter-independent. They not only provide a docking platform for the receptors, but also play a key role in directing the receptors to bind into particular configurations and coordinating the interactions among different receptors. Both an intact KRE and an intact receptor DNA-binding domain are necessary for the regulation to occur, which emphasizes the importance of interaction between the DNA and NR for proper signaling. Furthermore, KREs allow simultaneous binding of multiple receptors, thus providing fine-tuning of transcriptional regulation. The DNA/DNA-binding domain interactions in keratin promoters exemplify tissue and gene specificity of hormone action.
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Affiliation(s)
- S H Jho
- Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York 10016, USA
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13
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Bristeau A, Catherin AM, Weiss MC, Faust DM. Hormone response of rodent phenylalanine hydroxylase requires HNF1 and the glucocorticoid receptor. Biochem Biophys Res Commun 2001; 287:852-8. [PMID: 11573942 DOI: 10.1006/bbrc.2001.5673] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Expression of the rodent phenylalanine hydroxylase (PAH) gene is dependent upon hormones. Induction by glucocorticoids and cAMP occurs slowly and maximal stimulation is obtained by a synergistic effect of the two compounds. Hormone responsiveness is conferred by the tissue-specific HSIII enhancer and involves (i) protein kinase A mediating the cAMP response, even though a consensus sequence for binding of the cAMP response element binding protein is not present; (ii) other serine/threonine kinases as deduced from inhibitor studies; (iii) glucocorticoid receptor protein bound to glucocorticoid response element half sites; and (iv) binding of the liver-enriched transcription factor hepatocyte nuclear factor 1 (HNF1) to sites in the enhancer. Glucocorticoid receptor and HNF1, bound to their cognate sites, cooperatively increase the glucocorticoid response of the PAH gene, this response being synergistically enhanced by cAMP after long-term treatment.
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Affiliation(s)
- A Bristeau
- Unité de Génétique de la Différenciation, FRE 2364, Centre National de la Recherche Scientifique, 25 rue du Docteur Roux, 75724 Paris Cedex 15, France
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14
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Banfi C, Eriksson P, Giandomenico G, Mussoni L, Sironi L, Hamsten A, Tremoli E. Transcriptional regulation of plasminogen activator inhibitor type 1 gene by insulin: insights into the signaling pathway. Diabetes 2001; 50:1522-30. [PMID: 11423472 DOI: 10.2337/diabetes.50.7.1522] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Impairment of the fibrinolytic system, caused primarily by increases in the plasma levels of plasminogen activator inhibitor (PAI) type 1, are frequently found in diabetes and the insulin-resistance syndrome. Among the factors responsible for the increases of PAI-1, insulin has recently attracted attention. In this study, we analyzed the effects of insulin on PAI-1 biosynthesis in HepG2 cells, paying particular attention to the signaling network evoked by this hormone. Experiments performed in CHO cells overexpressing the insulin receptor indicate that insulin increases PAI-1 gene transcription through interaction with its receptor. By using inhibitors of the different signaling pathways evoked by insulin-receptor binding, it has been shown that the biosynthesis of PAI-1 is due to phosphatidylinositol (PI) 3-kinase activation, followed by protein kinase C and ultimately by mitogen-activated protein (MAP) kinase activation and extracellular signal-regulated kinase 2 phosphorylation. We also showed that this pathway is Ras-independent. Transfection of HepG2 cells with several truncations of the PAI-1 promoter coupled to a CAT gene allowed us to recognize two major response elements located in the regions between -804 and -708 and between -211 and -54. Electrophoretic mobility shift assay identified three binding sites for insulin-induced factors, all colocalized with putative Sp1 binding sites. Using supershifting antibodies, the binding of Sp1 could only be confirmed at the binding site located just upstream from the transcription start site of the PAI-1 promoter. A construct comprising four tandem repeat copies of the -93/-62 region of the PAI-1 promoter linked to CAT was transcriptionally activated in HepG2 cells by insulin. These results outline the central role of MAP kinase activation in the regulation of PAI-1 induced by insulin.
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Affiliation(s)
- C Banfi
- Department of Pharmacological Sciences, University of Milan, Via Balzaretti 9, 20133 Milan, Italy
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15
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Bain DL, Franden MA, McManaman JL, Takimoto GS, Horwitz KB. The N-terminal region of the human progesterone A-receptor. Structural analysis and the influence of the DNA binding domain. J Biol Chem 2000; 275:7313-20. [PMID: 10702302 DOI: 10.1074/jbc.275.10.7313] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The role of the N-terminal region in nuclear receptor function was addressed by a biochemical and biophysical analysis of the progesterone receptor A-isoform lacking only the hormone binding domain (NT-A). Sedimentation studies demonstrate that NT-A is quantitatively monomeric, with a highly asymmetric shape. Contrary to dogma, the N-terminal region is structured as demonstrated by limited proteolysis. However, N-terminal structure is strongly stabilized by the DNA binding domain, possibly explaining the lack of structure seen in isolated activation domains. Upon DNA binding, NT-A undergoes N-terminal mediated assembly, suggestive of DNA-induced allostery, and consistent with changes in protease accessibility of sites outside the DNA binding domain. Microsequencing reveals that protease-accessible regions are limited to previously identified phosphorylation motifs and to functional domain boundaries.
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Affiliation(s)
- D L Bain
- Department of Medicine and Molecular Biology Program, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA.
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16
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Dwivedi Y, Pandey GN. Repeated administration of dexamethasone increases phosphoinositide-specific phospholipase C activity and mRNA and protein expression of the phospholipase C beta 1 isozyme in rat brain. J Neurochem 1999; 73:780-90. [PMID: 10428076 DOI: 10.1046/j.1471-4159.1999.0730780.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Altered hypothalamic-pituitary-adrenal (HPA) function has been shown to be associated with changes in mood and behavior. The enzyme phosphoinositide-specific phospholipase C (PI-PLC), an important component of the PI signal transduction system, plays a major role in mediating various physiological functions. In the present study, we investigated the effects of a single dose and of repeated administration (0.5 or 1.0 mg/kg for 10 days) of dexamethasone (DEX), a synthetic glucocorticoid, on PI-PLC activity and on expression of PLC isozymes (beta1, delta1, and gamma1) in rat brain. Repeated administration of DEX (1.0 mg/kg) caused a significant increase in PI-PLC activity and in protein expression of the PLC beta1 isozyme in both membrane and cytosol fractions of cortex and hippocampus; however, the repeated administration of a smaller dose of DEX (0.5 mg/kg) caused these changes only in hippocampus but not in cortex. The increase in PLC beta1 protein was associated with an increase in its mRNA level, as measured by competitive RT-PCR. A single administration of DEX (0.5 or 1.0 mg/kg) to rats had no significant effects on PI-PLC activity or on the protein expression of PLC isozymes. These results suggest that DEX up-regulates PI-PLC in rat brain, which presumably is due to a selective increase in expression of the PLC beta1 isozyme, and that these changes in PI-PLC may be related to HPA axis-mediated changes in mood and behavior.
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Affiliation(s)
- Y Dwivedi
- Psychiatric Institute, Department of Psychiatry, College of Medicine, University of Illinois at Chicago, 60612, USA
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17
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Liao M, Zhou ZX, Wilson EM. Redox-dependent DNA binding of the purified androgen receptor: evidence for disulfide-linked androgen receptor dimers. Biochemistry 1999; 38:9718-27. [PMID: 10423251 DOI: 10.1021/bi990589i] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Full-length histidine-tagged, dihydrotestosterone-bound human androgen receptor (AR) was purified to homogeneity by affinity and gel-filtration chromatography for antibody production and analysis of AR dimerization and DNA binding properties. A monoclonal antibody was raised that recognized human and rat AR epitope (360)ArgAspTyrTyrAsnPheProLeuAla(368) in the NH(2)-terminal domain and slowed migration of AR-DNA complexes in mobility shift assays. AR binding to androgen response element DNA had a K(d) of 2.0 nM and a Hill coefficient of 2.1, indicating high-affinity, cooperative binding. AR solution dimerization was detected only at >/=0.2 microM AR, and DNA binding increased dimerization up to 30-fold. Slow- and fast-migrating AR-DNA complexes were detected under different reducing conditions that differed 5-fold in their dissociation rates from DNA. Treatment with the sulfhydryl oxidizing reagent diamide formed the faster migrating, slower dissociating complex, indicating it represents disulfide-linked AR dimers bound to DNA. The results indicate that high concentrations of purified AR are required for solution dimerization and that cooperative DNA binding stabilizes two dimer forms that differ in redox state.
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Affiliation(s)
- M Liao
- Laboratories for Reproductive Biology, Department of Pediatrics, University of North Carolina, Chapel Hill 27599, USA
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18
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Dichtl W, Nilsson L, Goncalves I, Ares MP, Banfi C, Calara F, Hamsten A, Eriksson P, Nilsson J. Very low-density lipoprotein activates nuclear factor-kappaB in endothelial cells. Circ Res 1999; 84:1085-94. [PMID: 10325246 DOI: 10.1161/01.res.84.9.1085] [Citation(s) in RCA: 132] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
High plasma levels of VLDL are associated with increased risk for atherosclerosis. Here we show that VLDL (75 to 150 microg/mL) activates nuclear factor-kappaB (NF-kappaB), a transcription factor known to play a key role in regulation of inflammation. Oxidation of VLDL reduced its capacity to activate NF-kappaB in vitro, whereas free fatty acids such as linoleic and oleic acid activated NF-kappaB to the same extent as did VLDL. Intravenous injection of human VLDL (6 mg protein per kg) into rats resulted in arterial activation of NF-kappaB as assessed by electrophoretic mobility shift assay. Aortic endothelial cells showed positive nuclear staining for the activated RelA (p65) subunit of NF-kappaB at 6 to 24 hours after injection. There was also a parallel expression of the adhesion molecules intercellular adhesion molecule-1 and vascular cell adhesion molecule-1, as well as the cytokine tumor necrosis factor-alpha. Pretreatment of the rats with diet containing 1% of the antioxidant probucol for 8 weeks did not inhibit arterial activation of NF-kappaB in response to injection of VLDL. Moreover, injection of triglycerides (10% Intralipid, 5 mL/kg) activated arterial expression of NF-kappaB to the same extent as VLDL. Our results suggest that VLDL may promote the development of atherosclerotic lesions by activation of the proinflammatory transcription factor NF-kappaB. The effect appears to be mediated by a release of VLDL fatty acids but not to involve VLDL oxidation.
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Affiliation(s)
- W Dichtl
- Wallenberg Laboratory, Department of Medicine, University of Lund, Malmö University Hospital, Malmö, Sweden.
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19
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Allison BA, Nilsson L, Karpe F, Hamsten A, Eriksson P. Effects of native, triglyceride-enriched, and oxidatively modified LDL on plasminogen activator inhibitor-1 expression in human endothelial cells. Arterioscler Thromb Vasc Biol 1999; 19:1354-60. [PMID: 10323790 DOI: 10.1161/01.atv.19.5.1354] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Whereas VLDL has consistently been shown to induce a concentration-dependent increase in the expression of plasminogen activator inhibitor-1 (PAI-1) in human umbilical vein endothelial cells (HUVECs) and liver cells, variable effects have been reported for native and oxidatively modified LDL. In the present study, activation of PAI-1 protein and mRNA expression by native LDL (nLDL), UV-oxidized LDL (uvLDL), and triglyceride (TG)-enriched LDL was studied in HUVECs by using different incubation times and a wide range of lipoprotein concentrations. No significant increase of PAI-1 protein expression was observed after 4 hours of incubation with nLDL or uvLDL. However, PAI-1 protein secretion from HUVECs was markedly enhanced after 18 hours of incubation with uvLDL (200% increase at 10 microg/mL). Stimulation of PAI-1 protein expression in HUVECs by nLDL was seen, however, after increasing the TG content of the LDL particle. LDL enriched in phospholipid had no effect on PAI-1 secretion. PAI-1 mRNA levels on northern blot increased in parallel with the activation of PAI-1 protein expression by native and modified forms of LDL. Low concentrations of TG-enriched LDL (10 microg/mL) and higher concentrations of nLDL and uvLDL (100 microg/mL) were found to increase the binding of a VLDL-inducible transcription factor to the PAI-1 promoter. These results indicate that the TG content of the LDL particle influences PAI-1 expression in endothelial cells. Low concentrations of uvLDL enhanced PAI-1 protein and mRNA expression in the HUVECs after an 18-hour incubation but did not influence the VLDL-inducible transcription factor. This suggests that low levels of oxidized LDL increase PAI-1 expression by a different mechanism than VLDL and TG-enriched LDL.
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Affiliation(s)
- B A Allison
- Atherosclerosis Research Unit, King Gustaf V Research Institute, Department of Medicine, Karolinska Institute, Karolinska Hospital, Stockholm, Sweden
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20
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Zhang B, Ye S, Herrmann SM, Eriksson P, de Maat M, Evans A, Arveiler D, Luc G, Cambien F, Hamsten A, Watkins H, Henney AM. Functional polymorphism in the regulatory region of gelatinase B gene in relation to severity of coronary atherosclerosis. Circulation 1999; 99:1788-94. [PMID: 10199873 DOI: 10.1161/01.cir.99.14.1788] [Citation(s) in RCA: 443] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Gelatinase B, a matrix metalloproteinase that has proteolytic activity against connective tissue proteins, has been suggested to be important in the connective tissue remodeling processes associated with atherogenesis and plaque rupture. This study tested the hypothesis that sequence variation in the promoter region of the gelatinase B gene influences its expression, predisposing individuals carrying certain genetic variants to more severe atherosclerosis. METHODS AND RESULTS Single-strand conformation polymorphism analysis was carried out to search the promoter region of the gene encoding gelatinase B for naturally occurring genetic variation. As a result, an unreported common polymorphism was detected, which arose from a cytosine (C) to thymidine (T) transition at position -1562 relative to the start of transcription. Transient transfection experiments and DNA-protein interaction assays indicated that the T allele had a higher promoter activity than the C allele, which appeared to be due to preferential binding of a putative transcription repressor protein to the C allelic promoter. A sample of 584 male patients with myocardial infarction and 645 age-matched male healthy control subjects were genotyped. The allele frequencies were not significantly different between the cases and control subjects. However, in 374 patients with available angiographic data, 26% of those carrying 1 or 2 copies of the T allele had >50% stenosis in 3 coronary arteries, whereas only 15% of C/C homozygotes had triple-vessel disease. CONCLUSIONS These data suggest that this functional genetic variation influences gelatinase B gene promoter activity in an allele-specific manner and has an effect on atherosclerotic phenotype.
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Affiliation(s)
- B Zhang
- Department of Cardiovascular Medicine, University of Oxford, UK
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21
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Gast A, Schneikert J, Cato AC. N-terminal sequences of the human androgen receptor in DNA binding and transrepressing functions. J Steroid Biochem Mol Biol 1998; 65:117-23. [PMID: 9699864 DOI: 10.1016/s0960-0760(97)00176-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Androgen receptor is a ligand binding transcription factor that controls several physiological processes ranging from the development of the male sexual organs to the acquisition of secondary sex characteristics. It is composed of a carboxy-terminal ligand binding domain, a centrally located DNA binding domain and an amino terminal modulator region. Detailed study on the DNA and carboxy-terminal regions have been carried out, but only limited information is available on the activity of the N-terminus. With the use of truncated and chimeric receptor constructs we have demonstrated in transient transfection experiments that the N-terminus of the androgen receptor contributes to DNA binding, transactivation and transrepression functions of the receptor. We have shown that specific sequences at the N-terminus are needed for transactivation but we were unable to identify discrete sequences in this region for the DNA binding and transrepression functions. Sequences from the transcription factor NFI/X3 that bear no homology to the N-terminus of the androgen receptor nevertheless functionally replaced it in enhancing DNA binding, transrepression but not transactivation functions of the receptor. Thus, it appears that the structure rather than sequence specific elements determines the contribution of the N-terminus of the androgen receptor to DNA binding and transrepression functions.
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Affiliation(s)
- A Gast
- Forschungszentrum Karlsruhe, Institute of Genetics, Germany
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22
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Langley E, Kemppainen JA, Wilson EM. Intermolecular NH2-/carboxyl-terminal interactions in androgen receptor dimerization revealed by mutations that cause androgen insensitivity. J Biol Chem 1998; 273:92-101. [PMID: 9417052 DOI: 10.1074/jbc.273.1.92] [Citation(s) in RCA: 182] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Structural alignment of the human androgen receptor dimer was investigated by introducing steroid binding domain mutations that cause partial or complete androgen insensitivity into fusion proteins containing the full-length androgen receptor or the steroid binding domain. Most of the mutants had unchanged apparent equilibrium androgen binding affinity and increased dissociation rates of [3H]methyltrienolone and required increased dihydrotestosterone concentrations for transcriptional activation. In a 2-hybrid protein interaction assay in mammalian cells, the steroid binding domain interacts with an NH2-terminal-DNA binding domain fragment and with the full-length androgen receptor at physiological androgen concentrations in a dose-dependent manner. However, mutations at Val-889 and Arg-752 disrupt the NH2-/carboxyl-terminal interaction when introduced into the steroid binding domain fragment but not when present in the full-length androgen receptor. The N-C bimolecular interaction reduces the dissociation rate of bound androgen and slows the degradation rate of the carboxyl-terminal steroid binding domain fragment. The results suggest that steroid binding domain residues Val-889 and Arg-752 are critical to the NH2-/carboxyl-terminal interaction and that an intermolecular N-C interaction occurs during receptor dimerization that results in an antiparallel arrangement of androgen receptor monomers.
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Affiliation(s)
- E Langley
- Laboratories for Reproductive Biology, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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23
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Eriksson P, Nilsson L, Karpe F, Hamsten A. Very-low-density lipoprotein response element in the promoter region of the human plasminogen activator inhibitor-1 gene implicated in the impaired fibrinolysis of hypertriglyceridemia. Arterioscler Thromb Vasc Biol 1998; 18:20-6. [PMID: 9445251 DOI: 10.1161/01.atv.18.1.20] [Citation(s) in RCA: 127] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Hypertriglyceridemia and impaired fibrinolytic function are linked to coronary heart disease and other atherothrombotic disorders. Triglyceride-rich lipoproteins may attenuate fibrinolysis by increasing the plasma levels of plasminogen activator inhibitor-1 (PAI-1). Furthermore, a common 4/5 guanosine (4G/5G) polymorphism in the promoter region of the PAI-1 gene has been indicated to influence plasma PAI-1 activity and to be involved in an allele-specific response to triglycerides. Herein we show by transfection assays that VLDLs induce transcription of the human PAI-1 promoter in endothelial cells. A VLDL response element (VLDLRE) is located to residues -672 to -657 in the promoter region by electromobility shift assay, methylation interference, and DNase I footprinting, and its activity is shown to be influenced by the common 4G/5G polymorphism located adjacent to and upstream of the binding site of a VLDL-inducible transcription factor. These findings may provide a molecular explanation to the link between VLDL and PAI-1 activity elevation in plasma and to the interaction between the 4G/5G polymorphism and plasma triglycerides.
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Affiliation(s)
- P Eriksson
- King Gustaf V Research Institute, Department of Medicine, Karolinska Hospital, Stockholm, Sweden.
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24
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Herz JM, Thomsen WJ, Yarbrough GG. Molecular approaches to receptors as targets for drug discovery. J Recept Signal Transduct Res 1997; 17:671-776. [PMID: 9292776 DOI: 10.3109/10799899709044284] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The cloning of a great number of receptors and channels has revealed that many of these targets for drug discovery can be grouped into superfamilies based on sequence and structural similarities. This review presents an overview of how molecular biological approaches have revealed a plethora of receptor subtypes, led to new definitions of subtypes and isoforms, and played a role in the development of high selective drugs. Moreover, the diversity of subtypes has molded current views of the structure and function of receptor families. Practical difficulties and limitations inherent in the characterization of the ligand binding and signaling properties of expressed recombinant receptors are discussed. The importance of evaluating drug-receptor interactions that differ with temporally transient and distinct receptor conformational states is emphasized. Structural motifs and signal transduction features are presented for the following major receptor superfamilies: ligand-gated ion channel, voltage-dependent ion channel, G-protein coupled, receptor tyrosine-kinase, receptor protein tyrosine-phosphatase, cytokine and nuclear hormone. In addition, a prototypic receptor is analyzed to illustrate functional properties of a given family. The review concludes with a discussion of future directions in receptor research that will impact drug discovery, with a specific focus on orphan receptors as targets for drug discovery. Methods for classifying orphan receptors based upon homologies with members of existing superfamilies are presented together with molecular approaches to the greater challenge of defining their physiological roles. Besides revealing new orphan receptors, the human genome sequencing project will result in the identification of an abundance of novel receptors that will be molecular targets for the development of highly selective drugs. These findings will spur the discovery and development of an exciting new generation of receptor-subtype specific drugs with enhanced therapeutic specificity.
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Affiliation(s)
- J M Herz
- Applied Receptor Sciences, Mill Creek, WA 98012, USA
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25
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Rowan BG, Ip MM. Differential binding of mutant glucocorticoid receptors to the glucocorticoid response element of the tyrosine aminotransferase gene. J Steroid Biochem Mol Biol 1996; 58:147-62. [PMID: 8809196 DOI: 10.1016/0960-0760(96)00026-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Glucocorticoid receptors (GCRs) in sublines of the mouse P1798 lymphosarcoma that are sensitive (S) or resistant (R) to glucocorticoid-induced cell lysis were examined for their ability to bind to a single glucocorticoid responsive element (GRE). Mobility shift assays detected two specific complexes that were identical in both S and R cellular extracts. Antibodies against the GCR N-terminus supershifted complexes, suggesting that the 97 kDa wild-type GCR (WT-GCR) in S cells, and the variant, 97 kDa non-steroid-binding GCR (NSB-GCR) in R cells were components of both complexes. Sephacryl S300 gel filtration column fractions containing the WT-GCR and NSB-GCR formed complexes with the GRE, while fractions containing a second GCR variant in R cells, the 45 kDa steroid-binding truncated GCR (TR-GCR), did not. Southwestern blotting detected a GRE-binding, 97 kDa protein band in both S and R extracts. A 45 kDa band was not detected. UV crosslinking of protein to DNA revealed protein in the range of 92-120 kDa crosslinked to the GRE in both S and R extracts. No crosslinking was detected at 45 kDa. Strong interaction of the NSB-GCR with GREs and lack of binding of the TR-GCR to single GREs illustrate a complex receptor system in the P1798 lymphosarcoma.
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Affiliation(s)
- B G Rowan
- Department of Experimental Therapeutics, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
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26
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Segard-Maurel I, Rajkowski K, Jibard N, Schweizer-Groyer G, Baulieu EE, Cadepond F. Glucocorticosteroid receptor dimerization investigated by analysis of receptor binding to glucocorticosteroid responsive elements using a monomer-dimer equilibrium model. Biochemistry 1996; 35:1634-42. [PMID: 8634295 DOI: 10.1021/bi951369h] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The aim of this study was to analyze the role of regions of the glucocorticosteroid receptor (GR) outside the DNA binding domain (DBD) in GR binding and homodimerization efficiencies by using a model according to which GR monomers and dimers are in equilibrium and able to bind to each half-palindromic motif of a GRE. We studied wild-type human GR (hGR), an N-terminal domain deleted mutant (lacking amino acids 1-417), a C-terminal deleted mutant (lacking amino acids 550-777, the main part of the ligand binding domain), and two rat GR derivatives limited to the DNA binding domain and proximal sequences. Specific GR monomer and dimer complexes with 33P-labeled palindromic or half-palindromic GREs were identified by gel-shift and methylation interference experiments. The different complexes were quantified, and the multiple equilibrium constants for their formation were determined. The affinity of the monomer for the GRE was not affected by the deletions of regions outside the DBD. However, the affinity of the dimer for the GRE was clearly increased by the presence of the N-terminal domain and, to a lesser extent, by that of the main part of the C-terminal domain. By using this model, we also obtained a GR dimerization constant in the absence of specific binding to GRE. Dimerization of the DBD was not increased by the presence of only one of the GR terminal domains, but an increase in dimerization efficiency was observed when both domains were present, suggesting a structural synergy between the N- and C-terminal domains in GR homodimerization.
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Affiliation(s)
- I Segard-Maurel
- Institut National de la Santé et de la Recherche Médicale U33, Le Kremlin-Bicêtre, France
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27
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Blomquist P, Li Q, Wrange O. The affinity of nuclear factor 1 for its DNA site is drastically reduced by nucleosome organization irrespective of its rotational or translational position. J Biol Chem 1996; 271:153-9. [PMID: 8550551 DOI: 10.1074/jbc.271.1.153] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
A DNA-bending sequence has been used for in vitro reconstitution of nucleosomes in order to direct a nuclear factor 1 (NF-1) binding site into different nucleosome positions. By this strategy nucleosomes were obtained that had one of two rotational positions of the NF-1 binding site, one oriented toward the periphery and the other toward the histone octamer, translationally positioned 50 and 45 base pairs, respectively, from the nucleosome dyad. The affinity of partially purified NF-1 for these nucleosomal targets was compared with its affinity for free DNA by dimethylsulfate methylation protection and DNase I footprinting assays. The binding affinity of NF-1 to all nucleosomal targets was reduced 100-300-fold compared with its affinity for free DNA. The two rotational settings of the NF-1 site showed the same binding affinity for NF-1 as did other nucleosome constructs in which the NF-1 binding site was translationally positioned from 10 to 40 base pairs from the nucleosome dyad. We conclude that the nucleosomal inhibition of NF-1 binding is an inherent characteristic of NF-1 since another transcription factor, the glucocorticoid receptor, is able to bind to its DNA site in a nucleosome.
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Affiliation(s)
- P Blomquist
- Department of Cell and Molecular Biology, Medical Nobel Institute, Karolinska Institute, Stockholm, Sweden
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28
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Abstract
Molecular dynamics simulations have been conducted to investigate the binding of the glucocorticoid receptor (GR) dimer to DNA. For this purpose simulations of the complex formed by a DNA segment and a dimer of GR-DNA binding domains (GR-DBD) have been carried out, employing an available X-ray structure. A second set of simulations was based on this structure as well, except that the DNA segment was altered to the consensus glucocorticoid response element (GRE). Simulations of a single GR-DBD and of the uncomplexed GRE served as controls. For the simulations, each system was encapsulated in an ellipsoid of water. Protein-DNA interactions, dimer interactions, and DNA structural parameters were analyzed for each system and compared. The consensus GRE is found to yield more favorable and symmetric interactions between the GR-DBDs and the GRE, explaining the ability of the GR dimer to recognize this DNA segment. Further analysis focused on deformations of the DNA that are induced by the binding of GR. The deformations observed involve a 35 degree bend of the DNA, an unwinding, and a displacement of the helical axis. These deformations are consistent with a mechanism for transcriptional regulation that involves a change of nucleosome packing upon GR binding. Significant protein-protein and protein-DNA interactions, both direct and water mediated, develop due to the deformations of the GRE and are indicative of an increased recognition achieved through DNA deformation. The interactions include direct interactions between the GRE and glycine-458 and serine-459, side groups which differentiate GR from other members of the nuclear hormone receptor family.
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Affiliation(s)
- T C Bishop
- Beckman Institute, Department of Chemistry, University of Illinois at Urbana-Champaign 61801, USA
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29
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Langley E, Zhou ZX, Wilson EM. Evidence for an anti-parallel orientation of the ligand-activated human androgen receptor dimer. J Biol Chem 1995; 270:29983-90. [PMID: 8530400 DOI: 10.1074/jbc.270.50.29983] [Citation(s) in RCA: 181] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Domain interactions of the human androgen receptor (AR) dimer were investigated using a protein-protein interaction assay in which the NH2- and carboxyl-terminal regions of human AR were fused to the Saccharomyces cerevisiae GAL4 DNA-binding domain and herpes simplex virus VP16 transactivation domain to produce chimeric proteins. Transcriptional activation of a GAL4 luciferase reporter vector up to 100-fold was greater than Fos/Jun leucine zipper binding, indicating stable AR interaction between AR NH2-terminal residues 1-503 and steroid-binding domain residues 624-919 that was specific for and dependent on androgen binding to the steroid-binding domain and was inhibited by anti-androgen binding. Deletion mutagenesis within the NH2-terminal region indicated transactivation domain residues 142-337 were not required for dimerization, whereas deletions near the NH2 terminus (delta 14-150) or NH2-terminal to the DNA-binding domain (delta 339-499) reduced or eliminated the AR interaction, respectively. An NH2-/NH2-terminal interaction was also observed, but no interaction was detected between ligand-free or bound steroid-binding domains. The results indicate that high affinity androgen binding promotes interactions between the NH2-terminal and steroid-binding domains of human AR, raising the possibility of an androgen-induced anti-parallel AR dimer.
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Affiliation(s)
- E Langley
- Laboratory for Reproductive Biology, University of North Carolina, Chapel Hill 27599, USA
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30
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Herman JP, Watson SJ. Stress regulation of mineralocorticoid receptor heteronuclear RNA in rat hippocampus. Brain Res 1995; 677:243-9. [PMID: 7552249 DOI: 10.1016/0006-8993(95)00152-g] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Localization and regulation of mineralocorticoid receptor (MR) heteronuclear RNA (hnRNA) was assessed in rat hippocampus using an intron-directed in situ hybridization approach. The presence of hnRNA in the cell nucleus reflects recent gene transcriptional events and can be used as an index of neuronal transcriptional activation or inhibition. In the present study, sections incubated with an MR intron probe labeled cells in all regions known to contain MR mRNA. Signal generated by the intron probe was localized specifically to the nuclear compartment, consistent with recognition of hnRNA. Analysis of distribution across hippocampus indicated that MR hnRNA was particularly abundant in dentate gyrus (DG). In contrast, MR mRNA shows similar levels of expression across all hippocampal subfields. Exposure of animals to acute restraint markedly reduced MR hnRNA levels in CA1 and DG 60 min and 120 min following stress exposure, consistent with reduced gene transcription. These data support the hypothesis that stress-induced glucocorticoid secretion can rapidly affect transcription of steroid receptor genes. MR mRNA levels did not decrease over comparable time periods, suggesting either a significant lag-time between transcriptional changes and changes in cytoplasmic mRNA pools or stimulus-driven alterations in post-transcriptional RNA processing.
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Affiliation(s)
- J P Herman
- Department of Anatomy and Neurobiology, University of Kentucky Medical Center, Lexington 40536-0084, USA
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31
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Affiliation(s)
- I Wong
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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32
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Warriar N, Yu C, Govindan MV. Hormone binding domain of human glucocorticoid receptor. Enhancement of transactivation function by substitution mutants M565R and A573Q. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(19)62006-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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33
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11 Structure and Regulation of Genes for Estrogen Receptors. ACTA ACUST UNITED AC 1994. [DOI: 10.1016/s1546-5098(08)60072-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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34
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Simons SS. Function/activity of specific amino acids in glucocorticoid receptors. VITAMINS AND HORMONES 1994; 49:49-130. [PMID: 7810076 DOI: 10.1016/s0083-6729(08)61146-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- S S Simons
- Steroid Hormones Section/LMCB, NIDDK, National Institutes of Health, Bethesda, Maryland 20892
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35
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Wright AP, Zilliacus J, McEwan IJ, Dahlman-Wright K, Almlöf T, Carlstedt-Duke J, Gustafsson JA. Structure and function of the glucocorticoid receptor. J Steroid Biochem Mol Biol 1993; 47:11-9. [PMID: 8274424 DOI: 10.1016/0960-0760(93)90052-x] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Glucocorticoids cause changes in the expression of target genes via interaction with an intracellular receptor protein, the glucocorticoid receptor. This signal transduction process can be divided into a number of steps, each of which represents a functional facet of the receptor protein. These steps include (i) receptor transformation to an active form resulting from specific interaction with glucocorticoid steroid hormones, (ii) homo-dimerization, (iii) DNA-binding to specific hormone response elements in the genome and (iv) modulation of the expression levels of linked genes. These aspects of glucocorticoid receptor function have been studied using a combination of tertiary structure determination, biochemical assays and a genetic approach using a yeast system to screen for mutant receptors that are altered in function. The results show that contacts involving both the DNA and steroid binding domains are involved in dimerization and high affinity DNA binding. Genetic experiments have illuminated the role of amino acids within the recognition helix of the DNA-binding domain in discriminating between cognate DNA response elements for the glucocorticoid receptor and closely related binding sites for other nuclear receptors. Squelching experiments suggest that the N-terminal transactivation domain of the receptor contacts components of the general transcriptional machinery that appear to be distinct from the TATA binding protein, TFIID, during transactivation of gene expression by the DNA-bound receptor.
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Affiliation(s)
- A P Wright
- Center for Biotechnology, Karolinska Institute, Huddinge, Sweden
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36
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Herman JP. Regulation of adrenocorticosteroid receptor mRNA expression in the central nervous system. Cell Mol Neurobiol 1993; 13:349-72. [PMID: 8252607 DOI: 10.1007/bf00711577] [Citation(s) in RCA: 146] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
1. The adrenocorticosteroid receptors are hormone-activated transcription factors that have the potential to influence gene expression in a wide variety of CNS neurons. This review summarizes the present state of knowledge regarding the localization and regulation of glucocorticoid (or type II corticosteroid) receptor and mineralocorticoid (or type I corticosteroid) receptor mRNAs in brain, from the perspective of their potential influence on a wide variety of hormone-responsive genes. 2. Corticosteroid receptors are widely but not uniformly localized in the CNS and exhibit very complex regulation by glucocorticoids, gonadal steroids, neurotransmitter systems, and endogenous circadian drive. Both receptor species are present during development, implying an ability for these transcription factors to interact with neuronal differentiation, growth, and viability, and both receptors appear to regulate with age, suggesting relationships between adrenocorticosteroid receptor populations and brain aging. Regulation of adrenocorticosteroid receptor mRNA expression at the level of polyadenylation and splicing indicates that GR and MR biosynthesis is a dynamic process susceptible to numerous classes of information. 3. Further study of GR and MR biosynthesis at the gene, mRNA, and protein level is required to determine the true meaning of the regulatory complexities seen in defined neuronal circuits.
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Affiliation(s)
- J P Herman
- Department of Anatomy and Neurobiology, University of Kentucky Medical Center, Lexington 40536-0084
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37
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Eriksson P, Wrange O. The glucocorticoid receptor acts as an antirepressor in receptor-dependent in vitro transcription. EUROPEAN JOURNAL OF BIOCHEMISTRY 1993; 215:505-11. [PMID: 8393792 DOI: 10.1111/j.1432-1033.1993.tb18060.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Glucocorticoid-receptor-dependent and glucocorticoid-response-element-dependent in vitro transcription was established using a crude nuclear extract and purified glucocorticoid receptor from rat liver. The capacity of glucocorticoid receptor to stimulate in vitro transcription was only detectable when basal transcription, i.e. transcription in the absence of glucocorticoid receptor, had been repressed. Transcriptional repression was achieved either by adding purified histone H1, or by lowering the amount of DNA template relative to the amount of crude nuclear extract. Glucocorticoid receptor caused a 1.1 +/- 0.7-fold stimulation of transcription from the mouse-mammary-tumor-virus promoter when basal transcription was not repressed, and a 7.0 +/- 1.5-fold stimulation when basal transcription had been repressed by addition of histone H1. Similar results were obtained when using a minimal promoter consisting of two glucocorticoid-response elements and a TATA box. Our data suggest that glucocorticoid receptor stimulates in vitro transcription by an antirepression mechanism.
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Affiliation(s)
- P Eriksson
- Department of Cell and Molecular Biology, Medical Nobel Institute, Karolinska Institutet, Stockholm, Sweden
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38
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Affiliation(s)
- M M Ip
- Grace Cancer Drug Center, Roswell Park Cancer Institute, Buffalo, New York 14263
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39
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Cohen-Solal K, Bailly A, Rauch C, Quesne M, Milgrom E. Specific binding of progesterone receptor to progesterone-responsive elements does not require prior dimerization. EUROPEAN JOURNAL OF BIOCHEMISTRY 1993; 214:189-95. [PMID: 7685278 DOI: 10.1111/j.1432-1033.1993.tb17912.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Steroid-hormone receptors undergo, prior to binding to DNA, a hormone-dependent dimerization. It is generally accepted that this dimerization is indispensable for the high-affinity binding of hormone receptor to hormone-responsive elements. Using a progesterone-receptor mutant with the complete steroid-binding domain deleted (positions 663-930), with or without the epitope required for binding the monoclonal antibody Let 126, we have shown that this receptor species was unable to undergo dimerization in solution. However, this mutant retained a high affinity (60-70% of the affinity of the wild-type receptor) for the progesterone-responsive elements of the mouse-mammary-tumor-virus long-terminal-repeat promoter and for a consensus palindromic progesterone-responsive element, as measured by both DNase-I protection experiments and gel-shift experiments. This mutant also increased gene transcription. Thus, at least in the case of the progesterone receptor, prior dimerization is dispensable for receptor binding to regulatory DNA elements and for subsequent transcription activation.
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MESH Headings
- Animals
- Antibodies, Monoclonal
- Base Sequence
- Binding Sites
- Cell Line
- DNA, Viral/metabolism
- Deoxyribonuclease I/metabolism
- Electrophoresis, Polyacrylamide Gel
- Epitopes
- Mammary Tumor Virus, Mouse/chemistry
- Mammary Tumor Virus, Mouse/genetics
- Mice
- Molecular Sequence Data
- Mutation
- Oligodeoxyribonucleotides/genetics
- Oligodeoxyribonucleotides/metabolism
- Polymers
- Receptors, Progesterone/immunology
- Receptors, Progesterone/isolation & purification
- Receptors, Progesterone/metabolism
- Regulatory Sequences, Nucleic Acid
- Transcription, Genetic/genetics
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Affiliation(s)
- K Cohen-Solal
- Unité de Recherche Hormones et Reproduction, Faculté de Médecine, Paris-Sud, Le Kremlin-Bicêtre, France
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40
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Bocquel MT, Ji J, Ylikomi T, Benhamou B, Vergezac A, Chambon P, Gronemeyer H. Type II antagonists impair the DNA binding of steroid hormone receptors without affecting dimerization. J Steroid Biochem Mol Biol 1993; 45:205-15. [PMID: 8499329 DOI: 10.1016/0960-0760(93)90334-s] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Two types of steroid antagonists exert their activity by different mechanisms when bound to the cognate receptor. Type I anti-progestins, such as RU486, induce DNA binding of the human progesterone receptor (hPR), while no hPR/DNA complexes were seen in gel shift assays in the presence of the type II anti-progestin ZK98,299 or RU50,331. ZK98,299-liganded hPR exerted significantly less tight nuclear binding than receptor complexes formed with RU486. Also a type II anti-glucocorticoid (RU43,044) was detected which completely abrogated DNA binding of its cognate receptor in vivo. In keeping with the existence of two different classes of anti-progestins, agonist- or RU486-induced hyperphosphorylation of the two hPR isoforms present in the T47D breast cancer cells was not induced by ZK98,299. This lack of hyperphosphorylation was, however, not the cause but most likely the consequence, of the reduced ability of the hPR/ZK98,299 complex to interact with DNA. No "mixed-ligand" heterodimers were formed in vitro between hPR isoform A bound to ZK98,299 and R5020-liganded isoform B, but nuclear co-translocation studies indicated that ZK98,299 efficiently induced hPR dimerization in vivo.
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Affiliation(s)
- M T Bocquel
- Laboratoire de Génétique Moléculaire des Eucaryotes du CNRS, Unité 184 de Biologie Moléculaire et de Génie Génétique de l'INSERM, Faculté de Médecine, Strasbourg, France
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41
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Ashraf J, Thompson EB. Glucocorticoid receptors in leukemias, lymphomas and myelomas of young and old. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1993; 330:241-69. [PMID: 8368136 DOI: 10.1007/978-1-4615-2926-2_18] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In this paper we have briefly reviewed the nature of leukemias and lymphomas in the old and the young. We surveyed in general the ways in which lymphoid cells and other hematologic elements respond to glucocorticoids, mentioning that there may be direct or indirect effects on their growth by these ligands. We have reviewed the current general model for the action of glucocorticoids in all cells, namely the fact that the actions of these steroids are mediated to a large extent through binding with ligand-activated transcription factors, their receptors. The growing wealth of detail about the nature of the interaction of these receptors with regulatory sites in the genome is discussed. Finally, we have described our results with lines of tissue culture cells representing clones from a typical leukemia of the young, and of myeloma, a typical hematologic malignancy of the elderly. Several features of the effects of glucocorticoids on these cells point up areas that would be pertinent to explore in aging and in the relationship of hematologic diseases to survival and response to therapy in the older versus the younger patient.
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Affiliation(s)
- J Ashraf
- Department of Human Biological Genetics and Chemistry, University of Texas Medical Branch, Galveston 77550
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42
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Konecki DS, Wang Y, Trefz FK, Lichter-Konecki U, Woo SL. Structural characterization of the 5' regions of the human phenylalanine hydroxylase gene. Biochemistry 1992; 31:8363-8. [PMID: 1326329 DOI: 10.1021/bi00150a033] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Human phenylalanine hydroxylase (PAH) is expressed in a liver-specific manner and catalyzes the enzymatic conversion of phenylalanine to tyrosine. Genetic deficiency of PAH results in the autosomal-recessive disorder phenylketonuria (PKU). Through the application of genomic and cDNA cloning, primer extension studies, SI mapping experiments, and PCR methodologies, the transcription initiation (CAP) site has been identified and the 5'-flanking region determined. The most upstream CAP site for the human hepatic PAH gene transcript is located 154 nucleotides upstream of the first translation codon. The genomic and cDNA sequences analyzed demonstrated that the previously reported cDNA sequence, phPAH247 [Kwok et al. (1985) Biochemistry 24, 556-561], contained a 164-nucleotide cloning artifact at its 5'-end. The 319 base pair region immediately upstream of the CAP site is characterized by the lack of a proximal TATA box and the presence of sequences similar to GC boxes, CACCC boxes, CCAAT boxes, activator protein 2 (Ap-2) sites, partial glucocorticoid response elements (GREs), and partial cyclic AMP response elements (CREs). This suggests that the human PAH gene has a TATA-less promoter regulated by multiple transcription factors.
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43
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Dahlman-Wright K, Wright A, Carlstedt-Duke J, Gustafsson JA. DNA-binding by the glucocorticoid receptor: a structural and functional analysis. J Steroid Biochem Mol Biol 1992; 41:249-72. [PMID: 1562506 DOI: 10.1016/0960-0760(92)90351-i] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The glucocorticoid receptor belongs to a family of ligand activated nuclear receptors. This family includes, in addition to the receptors for steroid hormones, receptors for thyroid hormone, retinoic acid and 1,25-dihydroxy vitamin D3 as well as some receptors with as yet unknown ligands. The glucocorticoid receptor DNA-binding domain has been expressed in E. coli. The purified protein binds to the same DNA sequences as the native receptor and is therefore suitable for biochemical and structural studies of the DNA-binding function of the receptor protein. This protein has been shown to bind as a dimer to its DNA-binding site. Protein-protein interactions facilitate DNA-binding and a segment responsible for these interactions has been identified close to the C-terminal zinc-binding site. The family of nuclear receptors, with their related DNA-binding sites, provides an opportunity to study determinants for DNA sequence recognition. A segment close to the N-terminal zinc ion has been shown to be responsible for the target specificity of glucocorticoid and estrogen receptors. DNA-binding domains of nuclear receptors include nine conserved cysteine residues which have been shown to coordinate two zinc ions and zinc has been shown to be required for the structural integrity and DNA-binding ability of the glucocorticoid receptor DNA-binding domain. A motif for DNA recognition, based around zinc ions, was first described for transcription factor IIIA and nuclear receptors were believed to recognize DNA via a similar motif. However, the three-dimensional structure determination of the glucocorticoid receptor DNA-binding domain shows that its structure is clearly different from that of the TFIIIA type zinc-binding domains.
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Affiliation(s)
- K Dahlman-Wright
- Department of Medical Nutrition, Huddinge Hospital, Karolinska Institute, Sweden
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44
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Fritsch M, Welch RD, Murdoch FE, Anderson I, Gorski J. DNA allosterically modulates the steroid binding domain of the estrogen receptor. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)46020-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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45
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Argentin S, Sun Y, Lihrmann I, Schmidt T, Drouin J, Nemer M. Distal cis-acting promoter sequences mediate glucocorticoid stimulation of cardiac atrial natriuretic factor gene transcription. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)54498-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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46
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Alksnis M, Barkhem T, Strömstedt P, Ahola H, Kutoh E, Gustafsson J, Poellinger L, Nilsson S. High level expression of functional full length and truncated glucocorticoid receptor in Chinese hamster ovary cells. Demonstration of ligand-induced down-regulation of expressed receptor mRNA and protein. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)99192-1] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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47
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Cairns W, Cairns C, Pongratz I, Poellinger L, Okret S. Assembly of a glucocorticoid receptor complex prior to DNA binding enhances its specific interaction with a glucocorticoid response element. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)99151-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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48
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Structure of the 5'-flanking regulatory region and gene for the human growth factor-activatable Na/H exchanger NHE-1. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)99091-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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49
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Gasiewicz TA, Elferink CJ, Henry EC. Characterization of multiple forms of the Ah receptor: recognition of a dioxin-responsive enhancer involves heteromer formation. Biochemistry 1991; 30:2909-16. [PMID: 1848780 DOI: 10.1021/bi00225a026] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We have employed a combination of gel retardation, protein-DNA cross-linking, and protein-protein cross-linking techniques to further examine the 2,3,7,8-tetrachlorodibenzo-p- dioxin-(TCDD-) dependent changes in the Ah receptor that result in a DNA-binding conformation. Gel retardation analysis of DNA-Sepharose chromatographic fractions of rat hepatic cytosol indicated that TCDD-dependent and sequence-specific DNA binding coeluted with a 200-kDa form of the Ah receptor (peak 2) previously characterized as being multimeric and having high affinity for calf thymus DNA. The TCDD-bound, 100-kDa form of the receptor (peak 1) bound weakly to the DNA recognition motif. These results indicated that the DNA-binding form of the Ah receptor is a multimer. SDS-polyacrylamide gel electrophoresis of peak 2 cross-linked to a bromodeoxyuridine-substituted DNA recognition motif indicated that this form of the receptor present in rat hepatic cytosol is composed of at least two DNA-binding proteins of approximately 100 and 110 kDa. Using the chemical cross-linking agent dimethyl pimelimidate, we further established that the 100-kDa form of the receptor (peak 1) associates with a different protein to generate the receptor form (peak 2) that binds to the dioxin-responsive enhancer. Photoaffinity-labeling studies indicated that only the 100-kDa protein (peak 1), and not the 110-kDa protein, binds ligand. Together, these observations imply that the DNA-binding form of the Ah receptor exists as a heteromer.
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Affiliation(s)
- T A Gasiewicz
- Department of Biophysics, University of Rochester School of Medicine, New York 14642
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50
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Interaction of androgen response elements with the DNA-binding domain of the rat androgen receptor expressed in Escherichia coli. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(19)67814-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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