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Cook DN, Kang HS, Jetten AM. Retinoic Acid-Related Orphan Receptors (RORs): Regulatory Functions in Immunity, Development, Circadian Rhythm, and Metabolism. NUCLEAR RECEPTOR RESEARCH 2015; 2. [PMID: 26878025 PMCID: PMC4750502 DOI: 10.11131/2015/101185] [Citation(s) in RCA: 120] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
In this overview, we provide an update on recent progress made in understanding the mechanisms of action, physiological functions, and roles in disease of retinoic acid related orphan receptors (RORs). We are particularly focusing on their roles in the regulation of adaptive and innate immunity, brain function, retinal development, cancer, glucose and lipid metabolism, circadian rhythm, metabolic and inflammatory diseases and neuropsychiatric disorders. We also summarize the current status of ROR agonists and inverse agonists, including their regulation of ROR activity and their therapeutic potential for management of various diseases in which RORs have been implicated.
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Affiliation(s)
- Donald N Cook
- Immunogenetics Section, Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Hong Soon Kang
- Cell Biology Section, Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Anton M Jetten
- Cell Biology Section, Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
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Cook DN, Kang HS, Jetten AM. Retinoic Acid-Related Orphan Receptors (RORs): Regulatory Functions in Immunity, Development, Circadian Rhythm, and Metabolism. NUCLEAR RECEPTOR RESEARCH 2015. [PMID: 26878025 DOI: 10.1038/nbt.3121.chip-nexus] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023] Open
Abstract
In this overview, we provide an update on recent progress made in understanding the mechanisms of action, physiological functions, and roles in disease of retinoic acid related orphan receptors (RORs). We are particularly focusing on their roles in the regulation of adaptive and innate immunity, brain function, retinal development, cancer, glucose and lipid metabolism, circadian rhythm, metabolic and inflammatory diseases and neuropsychiatric disorders. We also summarize the current status of ROR agonists and inverse agonists, including their regulation of ROR activity and their therapeutic potential for management of various diseases in which RORs have been implicated.
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Affiliation(s)
- Donald N Cook
- Immunogenetics Section, Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Hong Soon Kang
- Cell Biology Section, Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Anton M Jetten
- Cell Biology Section, Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
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Jetten AM. Retinoid-related orphan receptors (RORs): critical roles in development, immunity, circadian rhythm, and cellular metabolism. NUCLEAR RECEPTOR SIGNALING 2009; 7:e003. [PMID: 19381306 PMCID: PMC2670432 DOI: 10.1621/nrs.07003] [Citation(s) in RCA: 496] [Impact Index Per Article: 33.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Accepted: 03/18/2009] [Indexed: 12/11/2022]
Abstract
The last few years have witnessed a rapid increase in our knowledge of the retinoid-related orphan receptors RORα, -β, and -γ (NR1F1-3), their mechanism of action, physiological functions, and their potential role in several pathologies. The characterization of ROR-deficient mice and gene expression profiling in particular have provided great insights into the critical functions of RORs in the regulation of a variety of physiological processes. These studies revealed that RORα plays a critical role in the development of the cerebellum, that both RORα and RORβ are required for the maturation of photoreceptors in the retina, and that RORγ is essential for the development of several secondary lymphoid tissues, including lymph nodes. RORs have been further implicated in the regulation of various metabolic pathways, energy homeostasis, and thymopoiesis. Recent studies identified a critical role for RORγ in lineage specification of uncommitted CD4+ T helper cells into Th17 cells. In addition, RORs regulate the expression of several components of the circadian clock and may play a role in integrating the circadian clock and the rhythmic pattern of expression of downstream (metabolic) genes. Study of ROR target genes has provided insights into the mechanisms by which RORs control these processes. Moreover, several reports have presented evidence for a potential role of RORs in several pathologies, including osteoporosis, several autoimmune diseases, asthma, cancer, and obesity, and raised the possibility that RORs may serve as potential targets for chemotherapeutic intervention. This prospect was strengthened by recent evidence showing that RORs can function as ligand-dependent transcription factors.
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Affiliation(s)
- Anton M Jetten
- Cell Biology Section, Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA.
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Pardee KI, Xu X, Reinking J, Schuetz A, Dong A, Liu S, Zhang R, Tiefenbach J, Lajoie G, Plotnikov AN, Botchkarev A, Krause HM, Edwards A. The structural basis of gas-responsive transcription by the human nuclear hormone receptor REV-ERBbeta. PLoS Biol 2009; 7:e43. [PMID: 19243223 PMCID: PMC2652392 DOI: 10.1371/journal.pbio.1000043] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2008] [Accepted: 01/12/2009] [Indexed: 01/07/2023] Open
Abstract
Heme is a ligand for the human nuclear receptors (NR) REV-ERBalpha and REV-ERBbeta, which are transcriptional repressors that play important roles in circadian rhythm, lipid and glucose metabolism, and diseases such as diabetes, atherosclerosis, inflammation, and cancer. Here we show that transcription repression mediated by heme-bound REV-ERBs is reversed by the addition of nitric oxide (NO), and that the heme and NO effects are mediated by the C-terminal ligand-binding domain (LBD). A 1.9 A crystal structure of the REV-ERBbeta LBD, in complex with the oxidized Fe(III) form of heme, shows that heme binds in a prototypical NR ligand-binding pocket, where the heme iron is coordinately bound by histidine 568 and cysteine 384. Under reducing conditions, spectroscopic studies of the heme-REV-ERBbeta complex reveal that the Fe(II) form of the LBD transitions between penta-coordinated and hexa-coordinated structural states, neither of which possess the Cys384 bond observed in the oxidized state. In addition, the Fe(II) LBD is also able to bind either NO or CO, revealing a total of at least six structural states of the protein. The binding of known co-repressors is shown to be highly dependent upon these various liganded states. REV-ERBs are thus highly dynamic receptors that are responsive not only to heme, but also to redox and gas. Taken together, these findings suggest new mechanisms for the systemic coordination of molecular clocks and metabolism. They also raise the possibility for gas-based therapies for the many disorders associated with REV-ERB biological functions.
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Affiliation(s)
- Keith I Pardee
- Banting and Best Department of Medical Research, The Department of Molecular Genetics, University of Toronto, Toronto, Canada
- Terrence Donnelly Centre for Cellular & Biomolecular Research, University of Toronto, Toronto, Canada
| | - Xiaohui Xu
- Banting and Best Department of Medical Research, The Department of Molecular Genetics, University of Toronto, Toronto, Canada
- Terrence Donnelly Centre for Cellular & Biomolecular Research, University of Toronto, Toronto, Canada
- Midwest Center for Structural Genomics, University of Toronto, Toronto, Canada
| | - Jeff Reinking
- Banting and Best Department of Medical Research, The Department of Molecular Genetics, University of Toronto, Toronto, Canada
- Terrence Donnelly Centre for Cellular & Biomolecular Research, University of Toronto, Toronto, Canada
- Department of Biology, State University of New York at New Paltz, New Paltz, New York, United States of America
| | - Anja Schuetz
- Structural Genomics Consortium, University of Toronto, Toronto, Canada
| | - Aiping Dong
- Structural Genomics Consortium, University of Toronto, Toronto, Canada
| | - Suya Liu
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada
| | - Rongguang Zhang
- Midwest Center for Structural Genomics, Argonne National Lab, Argonne, Illinois, United States of America
| | - Jens Tiefenbach
- Banting and Best Department of Medical Research, The Department of Molecular Genetics, University of Toronto, Toronto, Canada
- Terrence Donnelly Centre for Cellular & Biomolecular Research, University of Toronto, Toronto, Canada
| | - Gilles Lajoie
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada
| | | | - Alexey Botchkarev
- Structural Genomics Consortium, University of Toronto, Toronto, Canada
| | - Henry M Krause
- Banting and Best Department of Medical Research, The Department of Molecular Genetics, University of Toronto, Toronto, Canada
- Terrence Donnelly Centre for Cellular & Biomolecular Research, University of Toronto, Toronto, Canada
- * To whom correspondence should be addressed. E-mail: (AE); (HMK)
| | - Aled Edwards
- Banting and Best Department of Medical Research, The Department of Molecular Genetics, University of Toronto, Toronto, Canada
- Terrence Donnelly Centre for Cellular & Biomolecular Research, University of Toronto, Toronto, Canada
- Midwest Center for Structural Genomics, University of Toronto, Toronto, Canada
- Structural Genomics Consortium, University of Toronto, Toronto, Canada
- * To whom correspondence should be addressed. E-mail: (AE); (HMK)
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Ovchinnikov DA, van Zuylen WJM, DeBats CEE, Alexander KA, Kellie S, Hume DA. Expression of Gal4-dependent transgenes in cells of the mononuclear phagocyte system labeled with enhanced cyan fluorescent protein usingCsf1r-Gal4VP16/UAS-ECFP double-transgenic mice. J Leukoc Biol 2007; 83:430-3. [DOI: 10.1189/jlb.0807585] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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Jetten AM, Joo JH. Retinoid-related Orphan Receptors (RORs): Roles in Cellular Differentiation and Development. ADVANCES IN DEVELOPMENTAL BIOLOGY (AMSTERDAM, NETHERLANDS) 2006; 16:313-355. [PMID: 18418469 DOI: 10.1016/s1574-3349(06)16010-x] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Retinoid-related orphan receptors RORalpha, -beta, and -gamma are transcription factors belonging to the steroid hormone receptor superfamily. During embryonic development RORs are expressed in a spatial and temporal manner and are critical in the regulation of cellular differentiation and the development of several tissues. RORalpha plays a key role in the development of the cerebellum particularly in the regulation of the maturation and survival of Purkinje cells. In RORalpha-deficient mice, the reduced production of sonic hedgehog by these cells appears to be the major cause of the decreased proliferation of granule cell precursors and the observed cerebellar atrophy. RORalpha has been implicated in the regulation of a number of other physiological processes, including bone formation. RORbeta expression is largely restricted to several regions of the brain, the retina, and pineal gland. Mice deficient in RORbeta develop retinal degeneration that results in blindness. RORgamma is essential for lymph node organogenesis. In the intestine RORgamma is required for the formation of several other lymphoid tissues: Peyer's patches, cryptopatches, and isolated lymphoid follicles. RORgamma plays a key role in the generation of lymphoid tissue inducer (LTi) cells that are essential for the development of these lymphoid tissues. In addition, RORgamma is a critical regulator of thymopoiesis. It controls the differentiation of immature single-positive thymocytes into double-positive thymocytes and promotes the survival of double-positive thymocytes by inducing the expression of the anti-apoptotic gene Bcl-X(L). Interestingly, all three ROR receptors appear to play a role in the control of circadian rhythms. RORalpha positively regulates the expression of Bmal1, a transcription factor that is critical in the control of the circadian clock. This review intends to provide an overview of the current status of the functions RORs have in these biological processes.
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Affiliation(s)
- Anton M Jetten
- Cell Biology Section, Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709
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Crossgrove K, Laudet V, Maina CV. Dirofilaria immitis encodes Di-nhr-7, a putative orthologue of the Drosophila ecdysone-regulated E78 gene. Mol Biochem Parasitol 2002; 119:169-77. [PMID: 11814569 DOI: 10.1016/s0166-6851(01)00412-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Filarial parasites are responsible for several serious human diseases with symptoms such as lymphoedema, elephantiasis, and blindness. An understanding of how these parasites pass through developmental checkpoints may elucidate the general mechanisms of these illnesses and suggest potential targets for intervention. A useful model system for the study of human filariasis is the related nematode Dirofilaria immitis, the causative agent of dog heartworm disease. In D. immitis, molting from the third to the fourth larval stage can be induced in vitro by the insect hormone 20-OH ecdysone, suggesting that ecdysone, or some related hormone, may play a similar role in the development of D. immitis. Ecdysone has a well-characterized developmental role in insects, where it is involved in the control of molting and metamorphosis. We have identified a D. immitis orthologue of the Drosophila ecdysone response early gene E78, a member of the nuclear receptor (NR) superfamily. The D. immitis gene, Di-nhr-7 (NR1E1) encodes at least three isoforms, including two potential negative regulatory isoforms, and is expressed in a sex-specific manner. An MBP/Di-NHR-7 fusion protein is able to bind to DNA response elements that are recognized by the closely related mammalian NR Rev-erb(alpha).
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8
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Renaud JP, Harris JM, Downes M, Burke LJ, Muscat GE. Structure-function analysis of the Rev-erbA and RVR ligand-binding domains reveals a large hydrophobic surface that mediates corepressor binding and a ligand cavity occupied by side chains. Mol Endocrinol 2000; 14:700-17. [PMID: 10809233 DOI: 10.1210/mend.14.5.0444] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Rev-erbA/RVR are closely related orphan nuclear receptors (NRs) functioning as dominant transcriptional silencers through an association with the nuclear receptor corepressor N-CoR. In contrast with ligand-regulated NRs, Rev-erbA/RVR lack the ligand-binding domain (LBD) C-terminal activation helix, H12. In the case of retinoid acid receptor and thyroid hormone receptor, ligand binding is thought to reposition H12, causing corepressor dissociation and coactivator recruitment, thus leading to transcriptional activation. Here we present homology models of the Rev-erbA/RVR LBDs, which show that the putative ligand cavity is occupied by side chains, suggesting the absence of endogenous ligands. Modeling also revealed a very hydrophobic surface due to the absence of H12, exposing residues from H3, loop 3-4, H4, and H11. Mutation of specific residues from this surface severely impaired the in vitro and in vivo interaction of the Rev-erbA/RVR LBD with the receptor-interacting domain of the corepressors N-CoR or its splice variant RIP13delta1, reinforcing the view of the physical association of N-CoR with a LBD surface encompassing H3-H4 and H11. Furthermore, mutations in the LBD surface significantly reduced the ability of Rev-erbA and RVR to function as repressors of transcription. Interestingly, a hydrophobic surface comprised of H3-H4 and H12 in liganded NRs mediates the interaction with coactivators. Hence, it appears that corepressors and coactivators bind to overlapping surfaces of NR LBDs, the conformational change associated with H12 upon ligand binding resulting in a switch from a corepressor- to a coactivator-binding surface.
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MESH Headings
- Amino Acid Sequence
- Amino Acid Substitution
- Binding Sites
- Chemical Phenomena
- Chemistry, Physical
- DNA-Binding Proteins
- Humans
- Ligands
- Models, Molecular
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Nerve Tissue Proteins/chemistry
- Nerve Tissue Proteins/genetics
- Nerve Tissue Proteins/metabolism
- Nuclear Receptor Subfamily 1, Group D, Member 1
- Promoter Regions, Genetic
- Protein Conformation
- Protein Structure, Tertiary
- Proteins/chemistry
- Proteins/genetics
- Proteins/metabolism
- Receptors, Cytoplasmic and Nuclear/chemistry
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Receptors, Retinoic Acid/chemistry
- Receptors, Thyroid Hormone
- Recombinant Fusion Proteins/chemistry
- Recombinant Fusion Proteins/metabolism
- Repressor Proteins/chemistry
- Repressor Proteins/genetics
- Repressor Proteins/metabolism
- Retinoic Acid Receptor alpha
- Sequence Alignment
- Sequence Homology, Amino Acid
- Structure-Activity Relationship
- Transcription, Genetic
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Affiliation(s)
- J P Renaud
- Centre Nationale de la Recherche Scientifique, UPR9004 Laboratoire de Biologie et Genomic Structurales, Institut de Génétique et Biologie Moléculaire et Cellulaire, Illkirch, France
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Nagl SB, Das S, Smith TF. Prediction of interaction partners for orphan nuclear receptors by prior-based protein sequence profiles. J Mol Recognit 2000; 13:117-26. [PMID: 10867707 DOI: 10.1002/1099-1352(200005/06)13:3<117::aid-jmr494>3.0.co;2-d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We present a prior-based profile method for the prediction of protein-protein interaction partners that is here applied to the nuclear receptor superfamily. In this method, the diagnostic features are locally encoded in the physicochemical properties of residues in the interaction surface that are conserved in all proteins belonging to the defining set. The procedure models the positional variation based on that observed in the defining set and a prior-based substitution matrix derived from over 20,000 highly conserved positions in a set of 147 functional protein families. The method clusters sets of nuclear receptors known to interact with retinoid X receptor or corepressor proteins with predictive sets of receptors in C. elegans and higher metazoans. The method effectively reduces the search space of all possible interactions and yields experimentally testable predictions. Applications of this novel approach extend to interaction prediction problems in general, particularly to those that are not amenable to analysis by the rigid-body approximation.
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Affiliation(s)
- S B Nagl
- Department of Biochemistry and Molecular Biology, University College London, UK.
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10
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Abstract
Nur77 is a transcription factor that is induced to a high level during TCR-mediated apoptosis of thymocytes and T cell hybridomas. Expression of a dominant-negative mutant of Nur77 can inhibit TCR-mediated apoptosis, while constitutive expression of full-length Nur77 in thymocytes leads to massive apoptosis. Nur77 is similar to the steroid receptor family and consists of a transactivation, a DNA-binding and a C-terminal "ligand-binding" domain. In contrast to the other nuclear receptors, Nur77 activity does not appear to depend on any ligand. However, its C-terminal region can regulate its transactivation activity. A short C-terminal deletion results in a protein with only 15 - 20% activity while deletion of the entire C-terminal region increases its activity. To further study the role of Nur77 transcription in apoptosis, we have generated transgenic mice expressing Nur77 with a short C-terminal deletion or Nur77 without its entire C-terminal domain. Mice expressing the shorter deletion/transcriptionally less active mutant displayed a mild phenotype. However, mice with the larger deletion/more transcriptionally active mutant showed massive thymocyte apoptosis. These data suggest that Nur77 transcription correlates with its apoptotic function in vivo.
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Affiliation(s)
- A A Kuang
- Department of Molecular Biology, Division of Immunology and Cancer Research Laboratory, 469 LSA, University of California at Berkeley, Berkeley, USA
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UNC-55, an orphan nuclear hormone receptor, orchestrates synaptic specificity among two classes of motor neurons in Caenorhabditis elegans. J Neurosci 1999. [PMID: 9852581 DOI: 10.1523/jneurosci.18-24-10438.1998] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Loss of UNC-55 function in the nematode Caenorhabditis elegans causes one motor neuron class, the ventral D (VD) motor neurons, to adopt the synaptic pattern of another motor neuron class, the dorsal D (DD) motor neurons. Here we show that unc-55 encodes a member of the nuclear hormone receptor gene family that is similar to the vertebrate chicken ovalbumin upstream promoter transcription factors. Although the VD and DD motor neuron classes arise from different lineages at different developmental stages, they share a number of structural and functional features that appear to be the product of identical genetic programs. UNC-55 is expressed in the VD but not the DD motor neurons to modify this genetic program and to create the synaptic pattern that distinguishes the two motor neuron classes from one another.
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Zhou HM, Walthall WW. UNC-55, an orphan nuclear hormone receptor, orchestrates synaptic specificity among two classes of motor neurons in Caenorhabditis elegans. J Neurosci 1998; 18:10438-44. [PMID: 9852581 PMCID: PMC6793349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
Loss of UNC-55 function in the nematode Caenorhabditis elegans causes one motor neuron class, the ventral D (VD) motor neurons, to adopt the synaptic pattern of another motor neuron class, the dorsal D (DD) motor neurons. Here we show that unc-55 encodes a member of the nuclear hormone receptor gene family that is similar to the vertebrate chicken ovalbumin upstream promoter transcription factors. Although the VD and DD motor neuron classes arise from different lineages at different developmental stages, they share a number of structural and functional features that appear to be the product of identical genetic programs. UNC-55 is expressed in the VD but not the DD motor neurons to modify this genetic program and to create the synaptic pattern that distinguishes the two motor neuron classes from one another.
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MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Body Patterning
- Caenorhabditis elegans/genetics
- Caenorhabditis elegans Proteins
- Cloning, Molecular
- Drosophila/genetics
- Green Fluorescent Proteins
- Humans
- Luminescent Proteins/genetics
- Molecular Sequence Data
- Motor Neurons/chemistry
- Motor Neurons/physiology
- Multigene Family
- Polymerase Chain Reaction
- Receptors, Cell Surface/chemistry
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Receptors, Cell Surface/physiology
- Receptors, Cytoplasmic and Nuclear/chemistry
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Receptors, Cytoplasmic and Nuclear/physiology
- Recombinant Fusion Proteins/analysis
- Recombinant Fusion Proteins/genetics
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Synapses/genetics
- Zebrafish/genetics
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Affiliation(s)
- H M Zhou
- Department of Biology and Center for Neural Communication and Computation, Georgia State University, Atlanta, Georgia 30303, USA
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13
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Muscat GE, Burke LJ, Downes M. The corepressor N-CoR and its variants RIP13a and RIP13Delta1 directly interact with the basal transcription factors TFIIB, TAFII32 and TAFII70. Nucleic Acids Res 1998; 26:2899-907. [PMID: 9611234 PMCID: PMC147645 DOI: 10.1093/nar/26.12.2899] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Repression of transcription by the classical nuclear receptors (e.g. TR, RAR), the orphan nuclear receptors (e.g. Rev-erbAalpha/beta), Mxi-1 and Mad bHLH-zip proteins and the oncoproteins PLZF and LAZ3/BCL6 is mediated by the corepressors N-CoR and SMRT. The interaction of the corepressors with the components involved in chromatin remodelling, such as the recruiting proteins Sin3A/B and the histone deacteylases HDAc-1 and RPD3, has been analysed in detail. The N-CoR/Sin3/HDAc complexes have a key role in the regulation of cellular proliferation and differentiation. However, the interaction of these corepressors with the basal transcriptional machinery has remained obscure. In this study we demonstrated that the N-terminalrepression domains and the receptor interactiondomains (RID) of N-CoR and its splice variants, RIP13a and RIP13Delta1, directly interact with TAFII32 in vivo and in vitro . We show that interaction domain II within the N-CoR and RIP13a RID is required for the interaction with TAFII32. We also observed that N-CoR directly interacts with each of the basal factors, TFIIB and TAFII70, and can simultaneously interact with all three basal factors in a non-competitive manner. Furthermore, we provide evidence that suggests the RVR/Rev-erbbeta-corepressor complex also interacts with the general transcriptional machinery, and that the physicalassociation of TFIIB with N-CoR also occurs in the presence of Sin3B and HDAc-1. Interestingly, we observed that N-CoR expression ablated the functional interaction between TFIIB and TAFII32 that is critical to the initiation of transcription. In conclusion, this study demonstrates that the N-terminal repressor region and the C-terminal RIDs are part of the corepressor contact interface that mediates the interaction with the general transcription factors, and demonstrates that TAFs can also directly interact with corepressors to mediate signals from repressors to the basal machinery. We also suggest that N-CoR interacts with the central components of the transcriptional initiation process (TFIIB, TAFs) and locks them into a non-functional complex or conformation that is not conducive to transcription.
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Affiliation(s)
- G E Muscat
- University of Queensland, Centre for Molecular and Cellular Biology, Ritchie Research Laboratories, B402A, St Lucia 4072, Queensland, Australia.
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14
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Seol W, Chung M, Moore DD. Novel receptor interaction and repression domains in the orphan receptor SHP. Mol Cell Biol 1997; 17:7126-31. [PMID: 9372944 PMCID: PMC232569 DOI: 10.1128/mcb.17.12.7126] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
SHP (short heterodimer partner) is a novel orphan receptor that lacks a conventional DNA binding domain and interacts with other members of the nuclear hormone receptor superfamily. We have characterized the SHP sequences required for interaction with other superfamily members, and have defined an SHP repressor domain. In the mammalian two-hybrid system, a fusion of full-length SHP to the GAL4 DNA binding domain shows 9-cis-retinoic acid-dependent interaction with a VP16-retinoid X receptor alpha (RXR alpha) fusion. By deletion analysis, sequences required for this RXR interaction map to the central portion of SHP (amino acids 92 to 148). The same region is required for interaction with RXR in vitro and in the yeast two-hybrid system, and results from the yeast system suggest that the same SHP sequences are required for interaction with other members of the nuclear hormone receptor superfamily such as thyroid hormone receptor and retinoic acid receptor. In mammalian cells, a GAL4-SHP fusion protein shows about 10-fold-decreased transcriptional activation relative to GAL4 alone, and fusion of SHP to the C terminus of a GAL4-VP16 fusion to generate a triple chimera also results in a strong decrease in transactivation activity. Sequences required for this repressor function were mapped to the C terminus of SHP. This region is distinct from that required for corepressor interaction by other members of the nuclear hormone receptor superfamily, and SHP did not interact with N-CoR in either the yeast or mammalian two-hybrid system. Together, these results identify novel receptor interaction and repressor domains in SHP and suggest two distinct mechanisms for inhibition of receptor signaling pathways by SHP.
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Affiliation(s)
- W Seol
- Department of Molecular Biology, Massachusetts General Hospital, Boston 02114, USA
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15
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Bailey PJ, Dowhan DH, Franke K, Burke LJ, Downes M, Muscat GE. Transcriptional repression by COUP-TF II is dependent on the C-terminal domain and involves the N-CoR variant, RIP13delta1. J Steroid Biochem Mol Biol 1997; 63:165-74. [PMID: 9459182 DOI: 10.1016/s0960-0760(97)00079-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
COUP-TF II/ARP-1 is an 'orphan' steroid receptor that inhibits basal transcription, and represses trans-activation by the vitamin D, thyroid hormone and retinoid receptors. The molecular basis of repression by COUP-TF II remains obscure. In this study we utilized the GAL4 hybrid system to demonstrate that COUP-TF II contains sequences within the C-terminal region that encode a dominant transcriptional repressor that inhibits the ability of the potent chimeric transactivator GAL4VP16 to induce transcription. Mammalian two hybrid analysis demonstrated that COUP-TF II did not efficiently interact with either interaction domains I or II from N-CoR and RIP13. However, COUP-TF II efficiently interacts with a region comprised of interaction domains I + II from the corepressor, RIP13delta1. Efficient interaction of the orphan receptor with the corepressor was critically dependent on a large region comprised of the C, D and E domains of COUP-TF II, which correlated with the domain that maximally represses transcription. This investigation suggested that the N-CoR variant, RIP13delta1 interacts with a region of COUP-TF II that functions as a dominant transcriptional repressor.
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Affiliation(s)
- P J Bailey
- University of Queensland, Centre for Molecular and Cellular Biology, Ritchie Research Laboratories, Brisbane, Australia
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Smith CL, Nawaz Z, O'Malley BW. Coactivator and corepressor regulation of the agonist/antagonist activity of the mixed antiestrogen, 4-hydroxytamoxifen. Mol Endocrinol 1997; 11:657-66. [PMID: 9171229 DOI: 10.1210/mend.11.6.0009] [Citation(s) in RCA: 399] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Mixed antiestrogens, such as 4-hydroxytamoxifen (4HT), act as either partial agonists or antagonists of estrogen receptor (ER) function in a tissue-, cell-, and promoter-specific manner, suggesting that intracellular factors modulate their ability to regulate transcription. To determine whether coactivators and corepressors have the capacity to modulate the relative agonist/antagonist activity of 4HT, ER-dependent gene expression was measured in the absence or presence of expression vectors for SRC-1 (steroid receptor coactivator-1) or SMRT (silencing mediator of retinoic acid and thyroid hormone receptors). In Hep G2 cells in which 4HT is an agonist, exogenous SRC-1 enhanced estradiol (E2)- and 4HT-stimulated transcription in a dose-dependent manner, while SMRT overexpression strongly reduced basal and 4HT-stimulated gene expression with no effect on E2 activity. These observations were not cell- or promoter-specific inasmuch as similar results were obtained in HeLa cells under conditions in which 4HT is an antagonist. A protein-protein interaction assay indicated that the full-length ER binds to SMRT in vitro. To assess whether relative coactivator and corepressor expression within a given cell could modulate the balance of 4HT agonist/antagonist activity, SRC-1 and SMRT were coexpressed. SMRT overexpression blocked SRC-1 coactivation of 4HT-stimulated gene expression and preferentially inhibited 4HT agonist activity whether or not exogenous SRC-1 was present. The cumulative data in this model system indicate that the relative expression of coactivators and corepressors can modulate 4HT regulation of ER transcriptional activity and suggest they could contribute to the tissue-specific ability of mixed antiestrogens to activate or inhibit ER-mediated gene expression.
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Affiliation(s)
- C L Smith
- Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030-3498, USA
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Downes M, Burke LJ, Bailey PJ, Muscat GE. Two receptor interaction domains in the corepressor, N-CoR/RIP13, are required for an efficient interaction with Rev-erbA alpha and RVR: physical association is dependent on the E region of the orphan receptors. Nucleic Acids Res 1996; 24:4379-86. [PMID: 8948627 PMCID: PMC146280 DOI: 10.1093/nar/24.22.4379] [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: 02/03/2023] Open
Abstract
Rev-erbA alpha and RVR/Rev-erb beta/BD73 are orphan steroid receptors that have no known ligands in the 'classical sense'. These 'orphans' do not activate transcription, but function as dominant transcriptional silencers. The thyroid hormone receptor (TR) and the retinoic acid receptor (RAR) act as transcriptional silencers by binding corepressors (e.g. N-CoR/RIP13 and SMRT/TRAC-2) in the absence of ligands. The molecular basis of repression by orphan receptors, however, remains obscure, and it is unclear whether these corepressors mediate transcriptional silencing by Rev-erbA alpha and RVR. Recently, two new variants of N-CoR have been described, RIP13a and RIP13delta1. The characterisation of these splice variants has identified a second receptor interaction domain (ID-II), in addition to the previously characterised interaction domain (ID-I). This investigation utilised the mammalian two hybrid system and transfection analysis to demonstrate that Rev-erbA alpha and RVR will not efficiently interact with either ID-I or ID-II separately from RIP13a or RIP13delta1. However, they interact efficiently with a domain composed of ID-I and ID-II from RIP13a. Interestingly, the interaction of Rev-erbA alpha and RVR is strongest with ID-I and ID-II from RIP13delta1. Detailed deletion analysis of the orphan receptor interaction with RIP13/N-CoR rigorously demonstrated that the physical association was critically dependent on an intact E region of Rev-erbA alpha and RVR. Over-expression of the corepressor interaction domains (i.e. dominant negative forms of N-CoR/RIP13) could alleviate orphan receptor-mediated repression of transactivation by GALVP16. This demonstrated that these regions could function as anti-repressors. In conclusion, these data from two independent approaches demonstrate that repression by Rev-erbA alpha and RVR is mediated by an interaction of ID-I and ID-II of N-CoR, RIP13a and delta1 with the putative ligand binding domain of the orphan receptors.
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Affiliation(s)
- M Downes
- University of Queensland, Centre for Molecular and Cellular Biology, Ritchie Research Laboratories, St Lucia, Australia
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