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Li X, Liu M, Xing Y, Niu Y, Liu TH, Sun JL, Liu Y, Hemba-Waduge RUS, Ji JY. Distinct effects of CDK8 module subunits on cellular growth and proliferation in Drosophila. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.30.591924. [PMID: 38746212 PMCID: PMC11092604 DOI: 10.1101/2024.04.30.591924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
The Mediator complex, composed of about 30 conserved subunits, plays a pivotal role in facilitating RNA polymerase II-dependent transcription in eukaryotes. Within this complex, the CDK8 kinase module (CKM), comprising Med12, Med13, CDK8, and CycC (Cyclin C), serves as a dissociable subcomplex that modulates the activity of the small Mediator complex. Genetic studies in Drosophila have revealed distinct phenotypes of CDK8-CycC and Med12-Med13 mutations, yet the underlying mechanism has remained unknown. Here, using Drosophila as a model organism, we show that depleting CDK8-CycC enhances E2F1 target gene expression and promotes cell-cycle progression. Conversely, depletion of Med12-Med13 affects the expression of ribosomal protein genes and fibrillarin, indicating a more severe reduction in ribosome biogenesis and cellular growth compared to the loss of CDK8-CycC. Moreover, we found that the stability of CDK8 and CycC relies on Med12 and Med13, with a mutually interdependent relationship between Med12 and Med13. Furthermore, CycC stability depends on the other three CKM subunits. These findings reveal distinct roles for CKM subunits in vivo , with Med12-Med13 disruption exerting a more pronounced impact on ribosome biogenesis and cellular growth compared to the loss of CDK8-CycC. Significance The CDK8 kinase module (CKM), comprising CDK8, CycC, Med12, and Med13, is essential in the Mediator complex for RNA polymerase II-dependent transcription in eukaryotes. While expected to function jointly, CKM subunit mutations result in distinct phenotypes in Drosophila . This study investigates the mechanisms driving these differing effects. Our analysis reveals the role of Med12-Med13 pair in regulating ribosomal biogenesis and cellular growth, contrasting with the involvement of CDK8-CycC in E2F1-dependent cell-cycle progression. Additionally, an asymmetric interdependence in the stability of CDK8-CycC and Med12-Med13 was observed. CKM mutations or overexpression are associated with cancers and cardiovascular diseases. Our findings underscore the distinct impacts of CKM mutations on cellular growth and proliferation, advancing our understanding of their diverse consequences in vivo .
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Cho YW, Fu Y, Huang CCJ, Wu X, Ng L, Kelley KA, Vella KR, Berg AH, Hollenberg AN, Liu H, Forrest D. Thyroid hormone-regulated chromatin landscape and transcriptional sensitivity of the pituitary gland. Commun Biol 2023; 6:1253. [PMID: 38081939 PMCID: PMC10713718 DOI: 10.1038/s42003-023-05546-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Accepted: 11/03/2023] [Indexed: 12/18/2023] Open
Abstract
Thyroid hormone (3,5,3'-triiodothyronine, T3) is a key regulator of pituitary gland function. The response to T3 is thought to hinge crucially on interactions of nuclear T3 receptors with enhancers but these sites in pituitary chromatin remain surprisingly obscure. Here, we investigate genome-wide receptor binding in mice using tagged endogenous thyroid hormone receptor β (TRβ) and analyze T3-regulated open chromatin using an anterior pituitary-specific Cre driver (Thrbb2Cre). Strikingly, T3 regulates histone modifications and chromatin opening primarily at sites that maintain TRβ binding regardless of T3 levels rather than at sites where T3 abolishes or induces de novo binding. These sites associate more frequently with T3-activated than T3-suppressed genes. TRβ-deficiency blunts T3-regulated gene expression, indicating that TRβ confers transcriptional sensitivity. We propose a model of gene activation in which poised receptor-enhancer complexes facilitate adjustable responses to T3 fluctuations, suggesting a genomic basis for T3-dependent pituitary function or pituitary dysfunction in thyroid disorders.
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Affiliation(s)
- Young-Wook Cho
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Yulong Fu
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Chen-Che Jeff Huang
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Xuefeng Wu
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Lily Ng
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Kevin A Kelley
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York, 10029, USA
| | - Kristen R Vella
- Division of Endocrinology, Diabetes and Metabolism, Weill Department of Medicine Weill Cornell Medicine, New York, New York, 10065, USA
| | - Anders H Berg
- Department of Pathology, Cedars Sinai Medical Center, Los Angeles, California, 90048, USA
| | - Anthony N Hollenberg
- Division of Endocrinology, Diabetes and Metabolism, Weill Department of Medicine Weill Cornell Medicine, New York, New York, 10065, USA
| | - Hong Liu
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Douglas Forrest
- Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA.
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Hernandez A, Martinez ME, Chaves C, Anselmo J. Epigenetic developmental programming and intergenerational effects of thyroid hormones. VITAMINS AND HORMONES 2023; 122:23-49. [PMID: 36863795 PMCID: PMC10938172 DOI: 10.1016/bs.vh.2023.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Mounting evidence is showing that altered signaling through the nuclear hormone receptor superfamily can cause abnormal, long-term epigenetic changes which translate into pathological modifications and susceptibility to disease. These effects seem to be more prominent if the exposure occurs early in life, when transcriptomic profiles are rapidly changing. At this time, the coordination of the complex coordinated processes of cell proliferation and differentiation that characterize mammalian development. Such exposures may also alter the epigenetic information of the germ line, potentially leading to developmental changes and abnormal outcomes in subsequent generations. Thyroid hormone (TH) signaling is mediated by specific nuclear receptors, which have the ability to markedly change chromatin structure and gene transcription, and can also regulate other determinants of epigenetic marks. TH exhibits pleiotropic effects in mammals, and during development, its action is regulated in a highly dynamic manner to suit the rapidly evolving needs of multiple tissues. Their molecular mechanisms of action, timely developmental regulation and broad biological effects place THs in a central position to play a role in the developmental epigenetic programming of adult pathophysiology and, through effects on the germ line, in inter- and trans-generational epigenetic phenomena. These areas of epigenetic research are in their infancy, and studies regarding THs are limited. In the context of their characteristics as epigenetic modifiers and their finely tuned developmental action, here we review some of the observations underscoring the role that altered TH action may play in the developmental programming of adult traits and in the phenotypes of subsequent generations via germ line transmission of altered epigenetic information. Considering the relatively high prevalence of thyroid disease and the ability of some environmental chemicals to disrupt TH action, the epigenetic effects of abnormal levels of TH action may be important contributors to the non-genetic etiology of human disease.
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Affiliation(s)
- Arturo Hernandez
- Center for Molecular Medicine, MaineHealth Institute for Research, MaineHealth, Scarborough, ME, United States; Graduate School for Biomedical Sciences and Engineering, University of Maine, Orono, ME, United States; Department of Medicine, Tufts University School of Medicine, Boston, MA, United States.
| | - M Elena Martinez
- Center for Molecular Medicine, MaineHealth Institute for Research, MaineHealth, Scarborough, ME, United States
| | - Carolina Chaves
- Serviço de Endocrinologia e Nutrição, Hospital Divino Espírito Santo, Ponta Delgada, Açores, Portugal
| | - Joao Anselmo
- Serviço de Endocrinologia e Nutrição, Hospital Divino Espírito Santo, Ponta Delgada, Açores, Portugal
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Wang M, Roggero VR, Allison LA. Mediator subunit MED1 differentially modulates mutant thyroid hormone receptor intracellular dynamics in Resistance to Thyroid Hormone syndrome. Mol Cell Endocrinol 2023; 559:111781. [PMID: 36191835 PMCID: PMC9985138 DOI: 10.1016/j.mce.2022.111781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 09/16/2022] [Accepted: 09/27/2022] [Indexed: 02/03/2023]
Abstract
Thyroid hormone receptor (TR) controls the expression of thyroid hormone (T3)-responsive genes, while undergoing rapid nucleocytoplasmic shuttling. In Resistance to Thyroid Hormone syndrome (RTH), mutant TR fails to activate T3-dependent transcription. Previously, we showed that Mediator subunit 1 (MED1) plays a role in TR nuclear retention. Here, we investigated MED1's effect on RTH mutants using nucleocytoplasmic scoring and fluorescence recovery after photobleaching in transfected cells. MED1 overexpression and knockout did not change the nucleocytoplasmic distribution or intranuclear mobility of C392X and P398R TRα1 at physiological T3 levels. At elevated T3 levels, however, overexpression increased P398R's nuclear retention and MED1 knockout decreased P398R's and A263V's intranuclear mobility, while not impacting C392X. Although A263V TRα1-transfected cells had a high percentage of aggregates, MED1 rescued A263V's impaired intranuclear mobility, suggesting that MED1 ameliorates nonfunctional aggregates. Results correlate with clinical severity, suggesting that altered interaction between MED1 and TRα1 mutants contributes to RTH pathology.
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Affiliation(s)
- Moyao Wang
- Department of Biology, William & Mary, 540 Landrum Drive, Integrated Science Center 3030, Williamsburg, VA, 23185, USA
| | - Vincent R Roggero
- Department of Biology, William & Mary, 540 Landrum Drive, Integrated Science Center 3030, Williamsburg, VA, 23185, USA
| | - Lizabeth A Allison
- Department of Biology, William & Mary, 540 Landrum Drive, Integrated Science Center 3030, Williamsburg, VA, 23185, USA.
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Zhou J, Singh BK, Ho JP, Lim A, Bruinstroop E, Ohba K, Sinha RA, Yen PM. MED1 mediator subunit is a key regulator of hepatic autophagy and lipid metabolism. Autophagy 2021; 17:4043-4061. [PMID: 33734012 DOI: 10.1080/15548627.2021.1899691] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Hepatic macroautophagy/autophagy and fatty acid metabolism are transcriptionally regulated by nuclear receptors (NRs); however, it is not known whether their transcriptional co-activators are involved in autophagy. We thus examined MED1 (mediator complex subunit 1), a key component of the Mediator Complex that directly interacts with NRs, on these processes. We found that MED1 knockdown (KD) in cultured hepatic cells decreased autophagy and mitochondrial activity that was accompanied by decreased transcription of genes involved in these processes. Lipophagy and fatty acid β-oxidation also were impaired. These effects also occurred after thyroid hormone stimulation, nutrient-replete or -deplete conditions, and in liver-specific Med1 KD (Med1 LKD) mice under fed and fasting conditions. Together, these findings showed that Med1 played a key role in hepatic autophagy, mitochondria function, and lipid metabolism under these conditions. Additionally, we identified downregulated hepatic genes in Med1 LKD mice, and subjected them to ChIP Enrichment Analysis. Our findings showed that the transcriptional activity of several NRs and transcription factors (TFs), including PPARA and FOXO1, likely were affected by Med1 LKD. Finally, Med1 expression and autophagy also were decreased in two mouse models of nonalcoholic fatty liver disease (NAFLD) suggesting that decreased Med1 may contribute to hepatosteatosis. In summary, MED1 plays an essential role in regulating hepatic autophagy and lipid oxidation during different hormonal and nutrient conditions. Thus, MED1 may serve as an integrator of multiple transcriptional pathways involved in these metabolic processes.Abbreviations: BAF: bafilomycin A1; db/db mice; Leprdb/db mice; ECAR: extracellular acidification rate; KD: knockdown; MED1: mediator complex subunit 1; NAFLD: nonalcoholic fatty liver disease; OCR: oxygen consumption rate; PPARA/PPARα: peroxisomal proliferator activated receptor alpha; TF: transcription factor; TFEB: transcription factor EB; tf-LC3: tandem fluorescence RFP-GFP-LC3; TG: triglyceride; TH: Thyroid hormone; TR: thyroid hormone receptors; V-ATPase: vacuolar-type H+-ATPase; WDF: Western diet with 15% fructose in drinking water.
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Affiliation(s)
- Jin Zhou
- Program of Cardiovascular & Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore
| | - Brijesh K Singh
- Program of Cardiovascular & Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore
| | - Jia Pei Ho
- Program of Cardiovascular & Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore
| | - Andrea Lim
- Program of Cardiovascular & Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore
| | - Eveline Bruinstroop
- Department of Endocrinology and Metabolism, Amsterdam UMC, Amsterdam, The Netherlands
| | - Kenji Ohba
- Program of Cardiovascular & Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore
| | - Rohit A Sinha
- Program of Cardiovascular & Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore.,Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow India
| | - Paul M Yen
- Program of Cardiovascular & Metabolic Disorders, Duke-NUS Medical School Singapore, Singapore.,Duke Molecular Physiology Institute and Department of Medicine, Duke University Medical Center, Durham, NC USA
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Asangani I, Blair IA, Van Duyne G, Hilser VJ, Moiseenkova-Bell V, Plymate S, Sprenger C, Wand AJ, Penning TM. Using biochemistry and biophysics to extinguish androgen receptor signaling in prostate cancer. J Biol Chem 2021; 296:100240. [PMID: 33384381 PMCID: PMC7949100 DOI: 10.1074/jbc.rev120.012411] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 12/19/2020] [Accepted: 12/31/2020] [Indexed: 12/12/2022] Open
Abstract
Castration resistant prostate cancer (CRPC) continues to be androgen receptor (AR) driven. Inhibition of AR signaling in CRPC could be advanced using state-of-the-art biophysical and biochemical techniques. Structural characterization of AR and its complexes by cryo-electron microscopy would advance the development of N-terminal domain (NTD) and ligand-binding domain (LBD) antagonists. The structural basis of AR function is unlikely to be determined by any single structure due to the intrinsic disorder of its NTD, which not only interacts with coregulators but likely accounts for the constitutive activity of AR-splice variants (SV), which lack the LBD and emerge in CRPC. Using different AR constructs lacking the LBD, their effects on protein folding, DNA binding, and transcriptional activity could reveal how interdomain coupling explains the activity of AR-SVs. The AR also interacts with coregulators that promote chromatin looping. Elucidating the mechanisms involved can identify vulnerabilities to treat CRPC, which do not involve targeting the AR. Phosphorylation of the AR coactivator MED-1 by CDK7 is one mechanism that can be blocked by the use of CDK7 inhibitors. CRPC gains resistance to AR signaling inhibitors (ARSI). Drug resistance may involve AR-SVs, but their role requires their reliable quantification by SILAC-mass spectrometry during disease progression. ARSI drug resistance also occurs by intratumoral androgen biosynthesis catalyzed by AKR1C3 (type 5 17β-hydroxysteroid dehydrogenase), which is unique in that its acts as a coactivator of AR. Novel bifunctional inhibitors that competitively inhibit AKR1C3 and block its coactivator function could be developed using reverse-micelle NMR and fragment-based drug discovery.
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Affiliation(s)
- Irfan Asangani
- Department Cancer Biology, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Ian A Blair
- Department Systems Pharmacology & Translational Therapeutics, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Gregory Van Duyne
- Department of Biochemistry & Biophysics, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Vincent J Hilser
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Vera Moiseenkova-Bell
- Department Systems Pharmacology & Translational Therapeutics, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Stephen Plymate
- Division of Gerontology & Geriatric Medicine, Department of Medicine, University of Washington, and GRECC, Seattle, Washington, USA
| | - Cynthia Sprenger
- Division of Gerontology & Geriatric Medicine, Department of Medicine, University of Washington, and GRECC, Seattle, Washington, USA
| | - A Joshua Wand
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas, USA
| | - Trevor M Penning
- Department Systems Pharmacology & Translational Therapeutics, Perelman School of Medicine University of Pennsylvania, Philadelphia, Pennsylvania, USA.
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Liu J, Zhu J, Zhang X, Jia Y, Lee X, Gao Z. Hsa-miR-637 inhibits human hepatocyte proliferation by targeting Med1-interacting proteins. LIVER RESEARCH 2021. [DOI: 10.1016/j.livres.2021.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Xu W, Xie XJ, Faust AK, Liu M, Li X, Chen F, Naquin AA, Walton AC, Kishbaugh PW, Ji JY. All-Atomic Molecular Dynamic Studies of Human and Drosophila CDK8: Insights into Their Kinase Domains, the LXXLL Motifs, and Drug Binding Site. Int J Mol Sci 2020; 21:E7511. [PMID: 33053834 PMCID: PMC7590003 DOI: 10.3390/ijms21207511] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 09/29/2020] [Accepted: 10/01/2020] [Indexed: 12/14/2022] Open
Abstract
Cyclin-dependent kinase 8 (CDK8) and its regulatory partner Cyclin C (CycC) play conserved roles in modulating RNA polymerase II (Pol II)-dependent gene expression. To understand the structure and function relations of CDK8, we analyzed the structures of human and Drosophila CDK8 proteins using molecular dynamics simulations, combined with functional analyses in Drosophila. Specifically, we evaluated the structural differences between hCDK8 and dCDK8 to predict the effects of the LXXLL motif mutation (AQKAA), the P154L mutations, and drug binding on local structures of the CDK8 proteins. First, we have observed that both the LXXLL motif and the kinase activity of CDK8 are required for the normal larval-to-pupal transition in Drosophila. Second, our molecular dynamic analyses have revealed that hCDK8 has higher hydrogen bond occupation of His149-Asp151 and Asp151-Asn156 than dCDK8. Third, the substructure of Asp282, Phe283, Arg285, Thr287 and Cys291 can distinguish human and Drosophila CDK8 structures. In addition, there are two hydrogen bonds in the LXXLL motif: a lower occupation between L312 and L315, and a relatively higher occupation between L312 and L316. Human CDK8 has higher hydrogen bond occupation between L312 and L316 than dCDK8. Moreover, L312, L315 and L316 in the LXXLL motif of CDK8 have the specific pattern of hydrogen bonds and geometries, which could be crucial for the binding to nuclear receptors. Furthermore, the P154L mutation dramatically decreases the hydrogen bond between L312 and L315 in hCDK8, but not in dCDK8. The mutations of P154L and AQKAA modestly alter the local structures around residues 154. Finally, we identified the inhibitor-induced conformational changes of hCDK8, and our results suggest a structural difference in the drug-binding site between hCDK8 and dCDK8. Taken together, these results provide the structural insights into the roles of the LXXLL motif and the kinase activity of CDK8 in vivo.
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Affiliation(s)
- Wu Xu
- Department of Chemistry, University of Louisiana at Lafayette, P.O. Box 44370, Lafayette, LA 70504, USA; (A.K.F.); (A.A.N.); (A.C.W.); (P.W.K.)
| | - Xiao-Jun Xie
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, 8447 Riverside Parkway, Bryan, TX 77807, USA; (X.-J.X.); (M.L.); (X.L.)
| | - Ali K. Faust
- Department of Chemistry, University of Louisiana at Lafayette, P.O. Box 44370, Lafayette, LA 70504, USA; (A.K.F.); (A.A.N.); (A.C.W.); (P.W.K.)
| | - Mengmeng Liu
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, 8447 Riverside Parkway, Bryan, TX 77807, USA; (X.-J.X.); (M.L.); (X.L.)
| | - Xiao Li
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, 8447 Riverside Parkway, Bryan, TX 77807, USA; (X.-J.X.); (M.L.); (X.L.)
| | - Feng Chen
- High Performance Computing, 329 Frey Computing Services Center, Louisiana State University, Baton Rouge, LA 70803, USA;
| | - Ashlin A. Naquin
- Department of Chemistry, University of Louisiana at Lafayette, P.O. Box 44370, Lafayette, LA 70504, USA; (A.K.F.); (A.A.N.); (A.C.W.); (P.W.K.)
| | - Avery C. Walton
- Department of Chemistry, University of Louisiana at Lafayette, P.O. Box 44370, Lafayette, LA 70504, USA; (A.K.F.); (A.A.N.); (A.C.W.); (P.W.K.)
| | - Peter W. Kishbaugh
- Department of Chemistry, University of Louisiana at Lafayette, P.O. Box 44370, Lafayette, LA 70504, USA; (A.K.F.); (A.A.N.); (A.C.W.); (P.W.K.)
| | - Jun-Yuan Ji
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, 8447 Riverside Parkway, Bryan, TX 77807, USA; (X.-J.X.); (M.L.); (X.L.)
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Zhai Q, Deng L, Li C. Mediator subunit MED25: at the nexus of jasmonate signaling. CURRENT OPINION IN PLANT BIOLOGY 2020; 57:78-86. [PMID: 32777679 DOI: 10.1016/j.pbi.2020.06.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 06/16/2020] [Accepted: 06/24/2020] [Indexed: 05/26/2023]
Abstract
Upon perception by plant cells, the immunity hormone jasmonate (JA) triggers a genome-wide transcriptional program, which is largely regulated by the master transcription factor MYC2. The function of MYC2 depends on its physical and functional interaction with MED25, a subunit of the Mediator transcriptional co-activator complex. In addition to interacting with MYC2 and RNA polymerase II for preinitiation complex formation, MED25 also interacts with multiple genetic and epigenetic regulators and controls almost every step of MYC2-dependent transcription, including nuclear hormone receptor activation, epigenetic regulation, mRNA processing, transcriptional termination, and chromatin loop formation. These diversified functions have ascribed MED25 to a signal-processing and signal-integrating center during JA-regulated gene transcription. This review is focused on the interactions of MED25 with diverse transcriptional regulators and how these mechanistic interactions contribute to the initiation, amplification, and fine tuning of the transcriptional output of JA signaling.
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Affiliation(s)
- Qingzhe Zhai
- State Key Laboratory of Plant Genomics, National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Innovation Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China; CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lei Deng
- State Key Laboratory of Plant Genomics, National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Innovation Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China
| | - Chuanyou Li
- State Key Laboratory of Plant Genomics, National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Innovation Academy of Seed Design, Chinese Academy of Sciences, Beijing 100101, China; CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China.
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Immarigeon C, Bernat-Fabre S, Guillou E, Verger A, Prince E, Benmedjahed MA, Payet A, Couralet M, Monte D, Villeret V, Bourbon HM, Boube M. Mediator complex subunit Med19 binds directly GATA transcription factors and is required with Med1 for GATA-driven gene regulation in vivo. J Biol Chem 2020; 295:13617-13629. [PMID: 32737196 DOI: 10.1074/jbc.ra120.013728] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 07/21/2020] [Indexed: 02/02/2023] Open
Abstract
The evolutionarily conserved multiprotein Mediator complex (MED) serves as an interface between DNA-bound transcription factors (TFs) and the RNA Pol II machinery. It has been proposed that each TF interacts with a dedicated MED subunit to induce specific transcriptional responses. But are these binary partnerships sufficient to mediate TF functions? We have previously established that the Med1 Mediator subunit serves as a cofactor of GATA TFs in Drosophila, as shown in mammals. Here, we observe mutant phenotype similarities between another subunit, Med19, and the Drosophila GATA TF Pannier (Pnr), suggesting functional interaction. We further show that Med19 physically interacts with the Drosophila GATA TFs, Pnr and Serpent (Srp), in vivo and in vitro through their conserved C-zinc finger domains. Moreover, Med19 loss of function experiments in vivo or in cellulo indicate that it is required for Pnr- and Srp-dependent gene expression, suggesting general GATA cofactor functions. Interestingly, Med19 but not Med1 is critical for the regulation of all tested GATA target genes, implying shared or differential use of MED subunits by GATAs depending on the target gene. Lastly, we show a direct interaction between Med19 and Med1 by GST pulldown experiments indicating privileged contacts between these two subunits of the MED middle module. Together, these findings identify Med19/Med1 as a composite GATA TF interface and suggest that binary MED subunit-TF partnerships are probably oversimplified models. We propose several mechanisms to account for the transcriptional regulation of GATA-targeted genes.
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Affiliation(s)
- Clément Immarigeon
- Centre de Biologie Integrative CBD, UMR5547 CNRS/UPS, Université de Toulouse, Toulouse Cedex, France
| | - Sandra Bernat-Fabre
- Centre de Biologie Integrative CBD, UMR5547 CNRS/UPS, Université de Toulouse, Toulouse Cedex, France
| | - Emmanuelle Guillou
- Centre de Biologie Integrative CBD, UMR5547 CNRS/UPS, Université de Toulouse, Toulouse Cedex, France
| | - Alexis Verger
- Inserm, CHU Lille, Institut Pasteur de Lille, CNRS ERL 9002 Integrative Structural Biology, Université Lille, Lille, France
| | - Elodie Prince
- Centre de Biologie Integrative CBD, UMR5547 CNRS/UPS, Université de Toulouse, Toulouse Cedex, France
| | - Mohamed A Benmedjahed
- Centre de Biologie Integrative CBD, UMR5547 CNRS/UPS, Université de Toulouse, Toulouse Cedex, France
| | - Adeline Payet
- Centre de Biologie Integrative CBD, UMR5547 CNRS/UPS, Université de Toulouse, Toulouse Cedex, France
| | - Marie Couralet
- Centre de Biologie Integrative CBD, UMR5547 CNRS/UPS, Université de Toulouse, Toulouse Cedex, France
| | - Didier Monte
- Inserm, CHU Lille, Institut Pasteur de Lille, CNRS ERL 9002 Integrative Structural Biology, Université Lille, Lille, France
| | - Vincent Villeret
- Inserm, CHU Lille, Institut Pasteur de Lille, CNRS ERL 9002 Integrative Structural Biology, Université Lille, Lille, France
| | - Henri-Marc Bourbon
- Centre de Biologie Integrative CBD, UMR5547 CNRS/UPS, Université de Toulouse, Toulouse Cedex, France
| | - Muriel Boube
- Centre de Biologie Integrative CBD, UMR5547 CNRS/UPS, Université de Toulouse, Toulouse Cedex, France.
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Li X, Liu M, Ren X, Loncle N, Wang Q, Hemba-Waduge RUS, Yu SH, Boube M, Bourbon HMG, Ni JQ, Ji JY. The Mediator CDK8-Cyclin C complex modulates Dpp signaling in Drosophila by stimulating Mad-dependent transcription. PLoS Genet 2020; 16:e1008832. [PMID: 32463833 PMCID: PMC7282676 DOI: 10.1371/journal.pgen.1008832] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 06/09/2020] [Accepted: 05/05/2020] [Indexed: 11/19/2022] Open
Abstract
Dysregulation of CDK8 (Cyclin-Dependent Kinase 8) and its regulatory partner CycC (Cyclin C), two subunits of the conserved Mediator (MED) complex, have been linked to diverse human diseases such as cancer. Thus, it is essential to understand the regulatory network modulating the CDK8-CycC complex in both normal development and tumorigenesis. To identify upstream regulators or downstream effectors of CDK8, we performed a dominant modifier genetic screen in Drosophila based on the defects in vein patterning caused by specific depletion or overexpression of CDK8 or CycC in developing wing imaginal discs. We identified 26 genomic loci whose haploinsufficiency can modify these CDK8- or CycC-specific phenotypes. Further analysis of two overlapping deficiency lines and mutant alleles led us to identify genetic interactions between the CDK8-CycC pair and the components of the Decapentaplegic (Dpp, the Drosophila homolog of TGFβ, or Transforming Growth Factor-β) signaling pathway. We observed that CDK8-CycC positively regulates transcription activated by Mad (Mothers against dpp), the primary transcription factor downstream of the Dpp/TGFβ signaling pathway. CDK8 can directly interact with Mad in vitro through the linker region between the DNA-binding MH1 (Mad homology 1) domain and the carboxy terminal MH2 (Mad homology 2) transactivation domain. Besides CDK8 and CycC, further analyses of other subunits of the MED complex have revealed six additional subunits that are required for Mad-dependent transcription in the wing discs: Med12, Med13, Med15, Med23, Med24, and Med31. Furthermore, our analyses confirmed the positive roles of CDK9 and Yorkie in regulating Mad-dependent gene expression in vivo. These results suggest that CDK8 and CycC, together with a few other subunits of the MED complex, may coordinate with other transcription cofactors in regulating Mad-dependent transcription during wing development in Drosophila.
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Affiliation(s)
- Xiao Li
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, Bryan, Texas, United States of America
| | - Mengmeng Liu
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, Bryan, Texas, United States of America
| | - Xingjie Ren
- School of Medicine, Tsinghua University, Beijing, China
| | - Nicolas Loncle
- Centre de Biologie Intégrative, Centre de Biologie du Développement, UMR5544 du CNRS, Université de Toulouse, Toulouse, France
| | - Qun Wang
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, Bryan, Texas, United States of America
| | - Rajitha-Udakara-Sampath Hemba-Waduge
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, Bryan, Texas, United States of America
| | - Stephen H. Yu
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, Bryan, Texas, United States of America
| | - Muriel Boube
- Centre de Biologie Intégrative, Centre de Biologie du Développement, UMR5544 du CNRS, Université de Toulouse, Toulouse, France
| | - Henri-Marc G. Bourbon
- Centre de Biologie Intégrative, Centre de Biologie du Développement, UMR5544 du CNRS, Université de Toulouse, Toulouse, France
| | - Jian-Quan Ni
- School of Medicine, Tsinghua University, Beijing, China
| | - Jun-Yuan Ji
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, Bryan, Texas, United States of America
- Department of Nutrition, Texas A&M University, College Station, Texas, United States of America
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12
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Femia MR, Evans RM, Zhang J, Sun X, Lebegue CJ, Roggero VR, Allison LA. Mediator subunit MED1 modulates intranuclear dynamics of the thyroid hormone receptor. J Cell Biochem 2019; 121:2909-2926. [PMID: 31692077 DOI: 10.1002/jcb.29532] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 10/10/2019] [Indexed: 12/26/2022]
Abstract
The thyroid hormone receptors (TRs) mediate thyroid hormone (T3 )-dependent gene expression. The nuclear import and export signals that direct TR shuttling are well characterized, but little is known about factors modulating nuclear retention. We used fluorescence-based nucleocytoplasmic scoring and fluorescence recovery after photobleaching in transfected cells to investigate whether Mediator subunits MED1 and MED13 play a role in nuclear retention of TR. When MED1 was overexpressed, there was a striking shift towards a greater nuclear localization of TRβ1 and the oncoprotein v-ErbA, subtypes with cytosolic populations at steady-state, and TRβ1 intranuclear mobility was reduced. For TRα1, there was no observable change in its predominantly nuclear distribution pattern or mobility. Consistent with a role for MED1 in nuclear retention, the cytosolic TRα1 and TRβ1 population were significantly greater in MED1-/- cells, compared with MED1+/+ cells. Exposure to T3 and epidermal growth factor, which induces MED1 phosphorylation, also altered TR intranuclear dynamics. Overexpression of miR-208a, which downregulates MED13, led to a more cytosolic distribution of nuclear-localized TRα1; however, overexpression of MED13 had no effect on TRβ1 localization. The known binding site of MED1 overlaps with a transactivation domain and nuclear export signal in helix 12 of TR's ligand-binding domain (LBD). Coimmunoprecipitation assays demonstrated that TR's LBD interacts directly with exportins 5 and 7, suggesting that binding of exportins and MED1 to TR may be mutually exclusive. Collectively, our data provide evidence that MED1 promotes nuclear retention of TR, and highlight the dual functionality of helix 12 in TR transactivation and nuclear export.
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Affiliation(s)
- Matthew R Femia
- Department of Biology, William and Mary, Williamsburg, Viginia
| | | | - Jibo Zhang
- Department of Biology, William and Mary, Williamsburg, Viginia
| | - Xiaopeng Sun
- Department of Biology, William and Mary, Williamsburg, Viginia
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13
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Rasool RU, Natesan R, Deng Q, Aras S, Lal P, Sander Effron S, Mitchell-Velasquez E, Posimo JM, Carskadon S, Baca SC, Pomerantz MM, Siddiqui J, Schwartz LE, Lee DJ, Palanisamy N, Narla G, Den RB, Freedman ML, Brady DC, Asangani IA. CDK7 Inhibition Suppresses Castration-Resistant Prostate Cancer through MED1 Inactivation. Cancer Discov 2019; 9:1538-1555. [PMID: 31466944 PMCID: PMC7202356 DOI: 10.1158/2159-8290.cd-19-0189] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 07/09/2019] [Accepted: 08/21/2019] [Indexed: 02/06/2023]
Abstract
Metastatic castration-resistant prostate cancer (CRPC) is a fatal disease, primarily resulting from the transcriptional addiction driven by androgen receptor (AR). First-line CRPC treatments typically target AR signaling, but are rapidly bypassed, resulting in only a modest survival benefit with antiandrogens. Therapeutic approaches that more effectively block the AR-transcriptional axis are urgently needed. Here, we investigated the molecular mechanism underlying the association between the transcriptional coactivator MED1 and AR as a vulnerability in AR-driven CRPC. MED1 undergoes CDK7-dependent phosphorylation at T1457 and physically engages AR at superenhancer sites, and is essential for AR-mediated transcription. In addition, a CDK7-specific inhibitor, THZ1, blunts AR-dependent neoplastic growth by blocking AR/MED1 corecruitment genome-wide, as well as reverses the hyperphosphorylated MED1-associated enzalutamide-resistant phenotype. In vivo, THZ1 induces tumor regression of AR-amplified human CRPC in a xenograft mouse model. Together, we demonstrate that CDK7 inhibition selectively targets MED1-mediated, AR-dependent oncogenic transcriptional amplification, thus representing a potential new approach for the treatment of CRPC. SIGNIFICANCE: Potent inhibition of AR signaling is critical to treat CRPC. This study uncovers a driver role for CDK7 in regulating AR-mediated transcription through phosphorylation of MED1, thus revealing a therapeutically targetable potential vulnerability in AR-addicted CRPC.See related commentary by Russo et al., p. 1490.This article is highlighted in the In This Issue feature, p. 1469.
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Affiliation(s)
- Reyaz Ur Rasool
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ramakrishnan Natesan
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Qu Deng
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Shweta Aras
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Priti Lal
- Department of Pathology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Samuel Sander Effron
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Erick Mitchell-Velasquez
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jessica M Posimo
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Shannon Carskadon
- Department of Urology, Vattikuti Urology Institute, Henry Ford Health System, Detroit, Michigan
| | - Sylvan C Baca
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts
| | - Mark M Pomerantz
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts
| | - Javed Siddiqui
- Department of Pathology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Lauren E Schwartz
- Department of Pathology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Daniel J Lee
- Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Nallasivam Palanisamy
- Department of Urology, Vattikuti Urology Institute, Henry Ford Health System, Detroit, Michigan
| | - Goutham Narla
- Division of Genetic Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Robert B Den
- Department of Radiation Oncology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Matthew L Freedman
- Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts
| | - Donita C Brady
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Irfan A Asangani
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
- Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
- Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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14
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Bianco AC, Dumitrescu A, Gereben B, Ribeiro MO, Fonseca TL, Fernandes GW, Bocco BMLC. Paradigms of Dynamic Control of Thyroid Hormone Signaling. Endocr Rev 2019; 40:1000-1047. [PMID: 31033998 PMCID: PMC6596318 DOI: 10.1210/er.2018-00275] [Citation(s) in RCA: 140] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 03/15/2019] [Indexed: 12/17/2022]
Abstract
Thyroid hormone (TH) molecules enter cells via membrane transporters and, depending on the cell type, can be activated (i.e., T4 to T3 conversion) or inactivated (i.e., T3 to 3,3'-diiodo-l-thyronine or T4 to reverse T3 conversion). These reactions are catalyzed by the deiodinases. The biologically active hormone, T3, eventually binds to intracellular TH receptors (TRs), TRα and TRβ, and initiate TH signaling, that is, regulation of target genes and other metabolic pathways. At least three families of transmembrane transporters, MCT, OATP, and LAT, facilitate the entry of TH into cells, which follow the gradient of free hormone between the extracellular fluid and the cytoplasm. Inactivation or marked downregulation of TH transporters can dampen TH signaling. At the same time, dynamic modifications in the expression or activity of TRs and transcriptional coregulators can affect positively or negatively the intensity of TH signaling. However, the deiodinases are the element that provides greatest amplitude in dynamic control of TH signaling. Cells that express the activating deiodinase DIO2 can rapidly enhance TH signaling due to intracellular buildup of T3. In contrast, TH signaling is dampened in cells that express the inactivating deiodinase DIO3. This explains how THs can regulate pathways in development, metabolism, and growth, despite rather stable levels in the circulation. As a consequence, TH signaling is unique for each cell (tissue or organ), depending on circulating TH levels and on the exclusive blend of transporters, deiodinases, and TRs present in each cell. In this review we explore the key mechanisms underlying customization of TH signaling during development, in health and in disease states.
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Affiliation(s)
- Antonio C Bianco
- Section of Endocrinology, Diabetes, and Metabolism, University of Chicago Medical Center, Chicago, Illinois
| | - Alexandra Dumitrescu
- Section of Endocrinology, Diabetes, and Metabolism, University of Chicago Medical Center, Chicago, Illinois
| | - Balázs Gereben
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Miriam O Ribeiro
- Developmental Disorders Program, Center of Biologic Sciences and Health, Mackenzie Presbyterian University, São Paulo, São Paulo, Brazil
| | - Tatiana L Fonseca
- Section of Endocrinology, Diabetes, and Metabolism, University of Chicago Medical Center, Chicago, Illinois
| | - Gustavo W Fernandes
- Section of Endocrinology, Diabetes, and Metabolism, University of Chicago Medical Center, Chicago, Illinois
| | - Barbara M L C Bocco
- Section of Endocrinology, Diabetes, and Metabolism, University of Chicago Medical Center, Chicago, Illinois
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15
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Coordinated transcriptional regulation by thyroid hormone and glucocorticoid interaction in adult mouse hippocampus-derived neuronal cells. PLoS One 2019; 14:e0220378. [PMID: 31348800 PMCID: PMC6660079 DOI: 10.1371/journal.pone.0220378] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 07/15/2019] [Indexed: 12/04/2022] Open
Abstract
The hippocampus is a well-known target of thyroid hormone (TH; e.g., 3,5,3’-triiodothyronine—T3) and glucocorticoid (GC; e.g., corticosterone—CORT) action. Despite evidence that TH and GC play critical roles in neural development and function, few studies have identified genes and patterns of gene regulation influenced by the interaction of these hormones at a genome-wide scale. In this study we investigated gene regulation by T3, CORT, and T3 + CORT in the mouse hippocampus-derived cell line HT-22. We treated cells with T3, CORT, or T3 + CORT for 4 hr before cell harvest and RNA isolation for microarray analysis. We identified 9 genes regulated by T3, 432 genes by CORT, and 412 genes by T3 + CORT. Among the 432 CORT-regulated genes, there were 203 genes that exhibited an altered CORT response in the presence of T3, suggesting that T3 plays a significant role in modulating CORT-regulated genes. We also found 80 genes synergistically induced, and 73 genes synergistically repressed by T3 + CORT treatment. We performed in silico analysis using publicly available mouse neuronal chromatin immunoprecipitation-sequencing datasets and identified a considerable number of synergistically regulated genes with TH receptor and GC receptor peaks mapping within 1 kb of chromatin marks indicative of hormone-responsive enhancer regions. Functional annotation clustering of synergistically regulated genes reveal the relevance of proteasomal-dependent degradation, neuroprotective effect of growth hormones, and neuroinflammatory responses as key pathways to how TH and GC may coordinately influence learning and memory. Taken together, our transcriptome data represents a promising exploratory dataset for further study of common molecular mechanisms behind synergistic TH and GC gene regulation, and identify specific genes and their role in processes mediated by cross-talk between the thyroid and stress axes in a mammalian hippocampal model system.
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16
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Zhai Q, Li C. The plant Mediator complex and its role in jasmonate signaling. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:3415-3424. [PMID: 31089685 PMCID: PMC6609880 DOI: 10.1093/jxb/erz233] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Accepted: 05/07/2019] [Indexed: 05/20/2023]
Abstract
The Mediator complex is an essential, multisubunit transcriptional coactivator that is highly conserved in eukaryotes. Mediator interacts with gene-specific transcription factors, the RNA polymerase II transcriptional machinery, as well as several other factors involved in transcription, and acts as an integral hub to regulate various aspects of transcription. Recent studies of the plant Mediator complex have established that it functions in diverse aspects of plant development and fitness. Jasmonate (JA) is an oxylipin-derived plant hormone that regulates plant immunity and development. The basic helix-loop-helix transcription factor MYC2, which is a master regulator of JA signaling, orchestrates genome-wide transcriptional reprogramming of plant cells to coordinate defense- and growth-related processes. Here, we review the function of the plant Mediator complex in regulating JA signaling. We focus on the multifunctional Mediator subunit MED25, which emerges as an integrative hub for the transcriptional regulation of jasmonate signaling.
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Affiliation(s)
- Qingzhe Zhai
- State Key Laboratory of Plant Genomics, National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
| | - Chuanyou Li
- State Key Laboratory of Plant Genomics, National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
- Correspondence:
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17
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Napoli C, Schiano C, Soricelli A. Increasing evidence of pathogenic role of the Mediator (MED) complex in the development of cardiovascular diseases. Biochimie 2019; 165:1-8. [PMID: 31255603 DOI: 10.1016/j.biochi.2019.06.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 06/24/2019] [Indexed: 12/20/2022]
Abstract
Cardiovascular diseases (CVDs) are the first cause of death in the World. Mediator (MED) is an evolutionarily conserved protein complex, which mediates distinct protein-protein interactions. Pathogenic events in MED subunit have been associated with human diseases. Novel increasing evidence showed that missense mutations in MED13L gene are associated with transposition of great arteries while MED12, MED13, MED15, and MED30, have been correlated with heart development. Moreover, MED23 and MED25 have been associated with heart malformations in humans. Relevantly, MED1, MED13, MED14, MED15, MED23, MED25, and CDK8, were found modify glucose and/or lipid metabolism. Indeed, MED1, MED15, MED25, and CDK8 interact in the PPAR- and SREBP-mediated signaling pathways. MED1, MED14 and MED23 are involved in adipocyte differentiation, whereas MED23 mediates smooth muscle cell differentiation. MED12, MED19, MED23, and MED30 regulate endothelial differentiation by alternative splicing mechanism. Thus, MEDs have a central role in early pathogenic events involved in CVDs representing novel targets for clinical prevention and therapeutic approaches.
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Affiliation(s)
- C Napoli
- University Department of Advanced Medical and Surgical Sciences, Clinical Department of Internal Medicine and Specialistic Units, University of Campania "L. Vanvitelli", 80138, Naples, Italy
| | | | - A Soricelli
- IRCCS SDN, 80143, Naples, Italy; Department of Motor Sciences and Healthiness, University of Naples Parthenope, 80134, Naples, Italy
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18
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Drosophila Mediator Subunit Med1 Is Required for GATA-Dependent Developmental Processes: Divergent Binding Interfaces for Conserved Coactivator Functions. Mol Cell Biol 2019; 39:MCB.00477-18. [PMID: 30670567 DOI: 10.1128/mcb.00477-18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 01/13/2019] [Indexed: 01/26/2023] Open
Abstract
DNA-bound transcription factors (TFs) governing developmental gene regulation have been proposed to recruit polymerase II machinery at gene promoters through specific interactions with dedicated subunits of the evolutionarily conserved Mediator (MED) complex. However, whether such MED subunit-specific functions and partnerships have been conserved during evolution has been poorly investigated. To address this issue, we generated the first Drosophila melanogaster loss-of-function mutants for Med1, known as a specific cofactor for GATA TFs and hormone nuclear receptors in mammals. We show that Med1 is required for cell proliferation and hematopoietic differentiation depending on the GATA TF Serpent (Srp). Med1 physically binds Srp in cultured cells and in vitro through its conserved GATA zinc finger DNA-binding domain and the divergent Med1 C terminus. Interestingly, GATA-Srp interaction occurs through the longest Med1 isoform, suggesting a functional diversity of MED complex populations. Furthermore, we show that Med1 acts as a coactivator for the GATA factor Pannier during thoracic development. In conclusion, the Med1 requirement for GATA-dependent regulatory processes is a common feature in insects and mammals, although binding interfaces have diverged. Further work in Drosophila should bring valuable insights to fully understand GATA-MED functional partnerships, which probably involve other MED subunits depending on the cellular context.
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19
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Zhai Q, Li L, An C, Li C. Conserved function of mediator in regulating nuclear hormone receptor activation between plants and animals. PLANT SIGNALING & BEHAVIOR 2018; 13:e1403709. [PMID: 29125388 PMCID: PMC6103278 DOI: 10.1080/15592324.2017.1403709] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 10/31/2017] [Indexed: 05/26/2023]
Abstract
Perception of the plant hormone jasmonoyl-isoleucine (JA-Ile) involves the formation of a co-receptor complex between COI1, the F-box subunit of a SCF-type E3 ubiquitin ligase, and its substrates, a group of jasmonate ZIM-domain (JAZ) transcriptional repressors. In recent studies, we show that MED25, a subunit of the Arabidopsis Mediator, physically and functionally interacts with COI1 and the master transcription factor MYC2 on MYC2 target promoters. Here we provide evidence that MED25 also physically interacts with a subset of JAZ proteins. Therefore, in term of their interaction with Mediator, the JA-Ile co-receptor complex SCFCOI1-JAZs together with the master transcription factor MYC2 resembles the nuclear hormone receptor system of metazoans. In addition, we show that the plant MED25 and its animal counterpart also cooperates with similar epigenetic regulators in distinct signaling pathways. Our study reveals a scenario that plants and animals have evolved distinct, yet largely similar, mechanism for nuclear hormone receptor activation at the level of transcriptional regulation.
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Affiliation(s)
- Qingzhe Zhai
- State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Taian, Shandong, China
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Lin Li
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Chunpeng An
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Chuanyou Li
- State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Taian, Shandong, China
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
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20
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Amoasii L, Olson EN, Bassel-Duby R. Control of Muscle Metabolism by the Mediator Complex. Cold Spring Harb Perspect Med 2018; 8:cshperspect.a029843. [PMID: 28432117 DOI: 10.1101/cshperspect.a029843] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Exercise represents an energetic challenge to whole-body homeostasis. In skeletal muscle, exercise activates a variety of signaling pathways that culminate in the nucleus to regulate genes involved in metabolism and contractility; however, much remains to be learned about the transcriptional effectors of exercise. Mediator is a multiprotein complex that links signal-dependent transcription factors and other transcriptional regulators with the basal transcriptional machinery, thereby serving as a transcriptional "hub." In this article, we discuss recent studies highlighting the role of Mediator subunits in metabolic regulation and glucose metabolism, as well as exercise responsiveness. Elucidation of the roles of Mediator subunits in metabolic control has revealed new mechanisms and molecular targets for the modulation of metabolism and metabolic disorders.
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Affiliation(s)
- Leonela Amoasii
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, and Sen. Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 7539-9148
| | - Eric N Olson
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, and Sen. Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 7539-9148
| | - Rhonda Bassel-Duby
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, and Sen. Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 7539-9148
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21
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An C, Li L, Zhai Q, You Y, Deng L, Wu F, Chen R, Jiang H, Wang H, Chen Q, Li C. Mediator subunit MED25 links the jasmonate receptor to transcriptionally active chromatin. Proc Natl Acad Sci U S A 2017; 114:E8930-E8939. [PMID: 28973940 PMCID: PMC5651773 DOI: 10.1073/pnas.1710885114] [Citation(s) in RCA: 121] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Jasmonoyl-isoleucine (JA-Ile), the active form of the plant hormone jasmonate (JA), is sensed by the F-box protein CORONATINE INSENSITIVE 1 (COI1), a component of a functional Skp-Cullin-F-box E3 ubiquitin ligase complex. Sensing of JA-Ile by COI1 rapidly triggers genome-wide transcriptional changes that are largely regulated by the basic helix-loop-helix transcription factor MYC2. However, it remains unclear how the JA-Ile receptor protein COI1 relays hormone-specific regulatory signals to the RNA polymerase II general transcriptional machinery. Here, we report that the plant transcriptional coactivator complex Mediator directly links COI1 to the promoters of MYC2 target genes. MED25, a subunit of the Mediator complex, brings COI1 to MYC2 target promoters and facilitates COI1-dependent degradation of jasmonate-ZIM domain (JAZ) transcriptional repressors. MED25 and COI1 influence each other's enrichment on MYC2 target promoters. Furthermore, MED25 physically and functionally interacts with HISTONE ACETYLTRANSFERASE1 (HAC1), which plays an important role in JA signaling by selectively regulating histone (H) 3 lysine (K) 9 (H3K9) acetylation of MYC2 target promoters. Moreover, the enrichment and function of HAC1 on MYC2 target promoters depend on COI1 and MED25. Therefore, the MED25 interface of Mediator links COI1 with HAC1-dependent H3K9 acetylation to activate MYC2-regulated transcription of JA-responsive genes. This study exemplifies how a single Mediator subunit integrates the actions of both genetic and epigenetic regulators into a concerted transcriptional program.
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Affiliation(s)
- Chunpeng An
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Lin Li
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Qingzhe Zhai
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China;
- State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Taian, Shandong 271018, China
| | - Yanrong You
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Lei Deng
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Fangming Wu
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Rong Chen
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Hongling Jiang
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Hang Wang
- State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Taian, Shandong 271018, China
| | - Qian Chen
- State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Taian, Shandong 271018, China
| | - Chuanyou Li
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China;
- State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Taian, Shandong 271018, China
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Sasaki S, Matsushita A, Kuroda G, Nakamura HM, Oki Y, Suda T. The Mechanism of Negative Transcriptional Regulation by Thyroid Hormone: Lessons From the Thyrotropin β Subunit Gene. VITAMINS AND HORMONES 2017; 106:97-127. [PMID: 29407449 DOI: 10.1016/bs.vh.2017.06.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Thyroid hormone (T3) activates (positive regulation) or represses (negative regulation) target genes at the transcriptional level. The molecular mechanism of the former has been elucidated in detail; however, the mechanism for negative regulation has not been established. The best example of the gene that is negatively regulated by T3 is the thyrotropin (thyroid-stimulating hormone) β subunit (TSHβ) gene. Analogous to the T3-responsive element (TRE) in positive regulation, a negative TRE (nTRE) has been postulated in the TSHβ gene. However, TSHβ promoter analysis, performed in the presence of transcription factors Pit1 and GATA2, which are determinants of thyrotroph differentiation in the pituitary, revealed that the nTRE is dispensable for inhibition by T3. We propose a tethering model in which the T3 receptor is tethered to GATA2 via protein-protein interaction and inhibits GATA2-dependent transactivation of the TSHβ gene in a T3-dependent manner.
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Affiliation(s)
| | | | - Go Kuroda
- Hamamatsu University School of Medicine, Shizuoka, Japan
| | | | - Yutaka Oki
- Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Takafumi Suda
- Hamamatsu University School of Medicine, Shizuoka, Japan
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Silvagno F, Pescarmona G. Spotlight on vitamin D receptor, lipid metabolism and mitochondria: Some preliminary emerging issues. Mol Cell Endocrinol 2017; 450:24-31. [PMID: 28414049 DOI: 10.1016/j.mce.2017.04.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 04/07/2017] [Accepted: 04/09/2017] [Indexed: 12/19/2022]
Abstract
Transcriptional control and modulation of calcium fluxes underpin the differentiating properties of vitamin D (1,25(OH)2D3). In the latest years however few studies have pointed out the relevance of the mitochondrial effects of the hormone. It is now time to focus on the metabolic results of vitamin D receptor (VDR) action in mitochondria, which can explain the pleiotropic effects of 1,25(OH)2D3 and may elucidate few contrasting aspects of its activity. The perturbation of lipid metabolism described in VDR knockout mice and vitamin D deficient animals can be revisited based on the newly identified mechanism of action of 1,25(OH)2D3 in mitochondria. From the same point of view, the controversial role of 1,25(OH)2D3 in adipogenesis can be better interpreted.
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Affiliation(s)
- Francesca Silvagno
- Department of Oncology, University of Torino, Via Santena 5 bis, 10126 Torino, Italy.
| | - Gianpiero Pescarmona
- Department of Oncology, University of Torino, Via Santena 5 bis, 10126 Torino, Italy.
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24
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Abstract
Thyroid hormones (TH) are endocrine messengers essential for normal development and function of virtually every vertebrate. The hypothalamic-pituitary-thyroid axis is exquisitely modulated to maintain nearly constant TH (T4 and T3) levels in circulation. However peripheral tissues and the CNS control the intracellular availability of TH, suggesting that circulating concentrations of TH are not fully representative of what each cell type sees. Indeed, recent work in the field has identified that TH transporters, deiodinases and thyroid hormone receptor coregulators can strongly control tissue-specific sensitivity to a set amount of TH. Furthermore, the mechanism by which the thyroid hormone receptors regulate target gene expression can vary by gene, tissue and cellular context. This review will highlight novel insights into the machinery that controls the cellular response to TH, which include unique signaling cascades. These findings shed new light into the pathophysiology of human diseases caused by abnormal TH signaling.
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Affiliation(s)
- Arturo Mendoza
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Anthony N Hollenberg
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
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25
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Jia Y, Chang HC, Schipma MJ, Liu J, Shete V, Liu N, Sato T, Thorp EB, Barger PM, Zhu YJ, Viswakarma N, Kanwar YS, Ardehali H, Thimmapaya B, Reddy JK. Cardiomyocyte-Specific Ablation of Med1 Subunit of the Mediator Complex Causes Lethal Dilated Cardiomyopathy in Mice. PLoS One 2016; 11:e0160755. [PMID: 27548259 PMCID: PMC4993490 DOI: 10.1371/journal.pone.0160755] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 07/25/2016] [Indexed: 11/19/2022] Open
Abstract
Mediator, an evolutionarily conserved multi-protein complex consisting of about 30 subunits, is a key component of the polymerase II mediated gene transcription. Germline deletion of the Mediator subunit 1 (Med1) of the Mediator in mice results in mid-gestational embryonic lethality with developmental impairment of multiple organs including heart. Here we show that cardiomyocyte-specific deletion of Med1 in mice (csMed1-/-) during late gestational and early postnatal development by intercrossing Med1fl/fl mice to α-MyHC-Cre transgenic mice results in lethality within 10 days after weaning due to dilated cardiomyopathy-related ventricular dilation and heart failure. The csMed1-/- mouse heart manifests mitochondrial damage, increased apoptosis and interstitial fibrosis. Global gene expression analysis revealed that loss of Med1 in heart down-regulates more than 200 genes including Acadm, Cacna1s, Atp2a2, Ryr2, Pde1c, Pln, PGC1α, and PGC1β that are critical for calcium signaling, cardiac muscle contraction, arrhythmogenic right ventricular cardiomyopathy, dilated cardiomyopathy and peroxisome proliferator-activated receptor regulated energy metabolism. Many genes essential for oxidative phosphorylation and proper mitochondrial function such as genes coding for the succinate dehydrogenase subunits of the mitochondrial complex II are also down-regulated in csMed1-/- heart contributing to myocardial injury. Data also showed up-regulation of about 180 genes including Tgfb2, Ace, Atf3, Ctgf, Angpt14, Col9a2, Wisp2, Nppa, Nppb, and Actn1 that are linked to cardiac muscle contraction, cardiac hypertrophy, cardiac fibrosis and myocardial injury. Furthermore, we demonstrate that cardiac specific deletion of Med1 in adult mice using tamoxifen-inducible Cre approach (TmcsMed1-/-), results in rapid development of cardiomyopathy and death within 4 weeks. We found that the key findings of the csMed1-/- studies described above are highly reproducible in TmcsMed1-/- mouse heart. Collectively, these observations suggest that Med1 plays a critical role in the maintenance of heart function impacting on multiple metabolic, compensatory and reparative pathways with a likely therapeutic potential in the management of heart failure.
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MESH Headings
- Animals
- Apoptosis
- Cadherins/genetics
- Cadherins/metabolism
- Calcium Channels, L-Type/genetics
- Calcium Channels, L-Type/metabolism
- Calcium Signaling
- Cardiomyopathy, Dilated/genetics
- Cardiomyopathy, Dilated/metabolism
- Cardiomyopathy, Dilated/pathology
- Cyclic Nucleotide Phosphodiesterases, Type 1/genetics
- Cyclic Nucleotide Phosphodiesterases, Type 1/metabolism
- Embryo, Mammalian
- Energy Metabolism
- Female
- Gene Deletion
- Gene Expression Profiling
- Gene Expression Regulation
- Genes, Lethal
- Gestational Age
- Heart Failure/genetics
- Heart Failure/metabolism
- Heart Failure/pathology
- Mediator Complex Subunit 1/deficiency
- Mediator Complex Subunit 1/genetics
- Mice
- Mice, Knockout
- Mitochondria/metabolism
- Mitochondria/pathology
- Myocardial Contraction
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- Peroxisome Proliferator-Activated Receptors/genetics
- Peroxisome Proliferator-Activated Receptors/metabolism
- Pregnancy
- Ryanodine Receptor Calcium Release Channel/genetics
- Ryanodine Receptor Calcium Release Channel/metabolism
- Sarcoplasmic Reticulum Calcium-Transporting ATPases/genetics
- Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism
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Affiliation(s)
- Yuzhi Jia
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Hsiang-Chun Chang
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Matthew J. Schipma
- Next Generation Sequencing Core Facility, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Jing Liu
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Varsha Shete
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Ning Liu
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Tatsuya Sato
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Edward B. Thorp
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Philip M. Barger
- Center for Cardiovascular Research, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Yi-Jun Zhu
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Navin Viswakarma
- Department of Surgery, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Yashpal S. Kanwar
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Hossein Ardehali
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Bayar Thimmapaya
- Department of Microbiology and Immunology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
- * E-mail: (JKR); (BT)
| | - Janardan K. Reddy
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
- * E-mail: (JKR); (BT)
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27
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Hernández-Puga G, Navarrete-Ramírez P, Mendoza A, Olvera A, Villalobos P, Orozco A. 3,5-Diiodothyronine-mediated transrepression of the thyroid hormone receptor beta gene in tilapia. Insights on cross-talk between the thyroid hormone and cortisol signaling pathways. Mol Cell Endocrinol 2016; 425:103-10. [PMID: 26820127 DOI: 10.1016/j.mce.2016.01.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 01/22/2016] [Accepted: 01/22/2016] [Indexed: 11/30/2022]
Abstract
T3 and cortisol activate or repress gene expression in virtually every vertebrate cell mainly by interacting with their nuclear hormone receptors. In contrast to the mechanisms for hormone gene activation, the mechanisms involved in gene repression remain elusive. In teleosts, the thyroid hormone receptor beta gene or thrb produces two isoforms of TRβ1 that differ by nine amino acids in the ligand-binding domain of the long-TRβ1, whereas the short-TRβ1 lacks the insert. Previous reports have shown that the genomic effects exerted by 3,5-T2, a product of T3 outer-ring deiodination, are mediated by the long-TRβ1. Furthermore, 3,5-T2 and T3 down-regulate the expression of long-TRβ1 and short-TRβ1, respectively. In contrast, cortisol has been shown to up-regulate the expression of thrb. To understand the molecular mechanisms for thrb modulation by thyroid hormones and cortisol, we used an in silico approach to identify thyroid- and cortisol-response elements within the proximal promoter of thrb from tilapia. We then characterized the identified response elements by EMSA and correlated our observations with the effects of THs and cortisol upon expression of thrb in tilapia. Our data show that 3,5-T2 represses thrb expression and impairs its up-regulation by cortisol possibly through a transrepression mechanism. We propose that for thrb down-regulation, ligands other than T3 are required to orchestrate the pleiotropic effects of thyroid hormones in vertebrates.
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Affiliation(s)
- Gabriela Hernández-Puga
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Boulevard Juriquilla 3001, Querétaro, Qro. 76230, Mexico
| | - Pamela Navarrete-Ramírez
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Boulevard Juriquilla 3001, Querétaro, Qro. 76230, Mexico
| | - Arturo Mendoza
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Boulevard Juriquilla 3001, Querétaro, Qro. 76230, Mexico
| | - Aurora Olvera
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Boulevard Juriquilla 3001, Querétaro, Qro. 76230, Mexico
| | - Patricia Villalobos
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Boulevard Juriquilla 3001, Querétaro, Qro. 76230, Mexico
| | - Aurea Orozco
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Boulevard Juriquilla 3001, Querétaro, Qro. 76230, Mexico.
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28
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Motojima K. [Lessons Learned after 25 Years of Studies on the Physiological Roles of the Peroxisome Proliferator-activated Receptor]. YAKUGAKU ZASSHI 2015; 135:1083-9. [PMID: 26423862 DOI: 10.1248/yakushi.15-00150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The peroxisome proliferator-activated receptor (PPAR) was discovered a quarter of a century ago. PPAR was soon recognized as a general transcriptional regulator of lipid homeostasis, and several hypolipidemic and antidiabetic agents were shown to be effective ligands for it. Since then, many attempts to develop more potent drugs have been made worldwide, but most were unsuccessful due to serious side effects. It appears that the PPAR boom has ended. This review summarizes the short history of PPAR studies, including our own results, and discusses the lessons learned from the rise and fall of studies in this field for next-generation basic studies and drug development research.
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29
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Xie XJ, Hsu FN, Gao X, Xu W, Ni JQ, Xing Y, Huang L, Hsiao HC, Zheng H, Wang C, Zheng Y, Xiaoli AM, Yang F, Bondos SE, Ji JY. CDK8-Cyclin C Mediates Nutritional Regulation of Developmental Transitions through the Ecdysone Receptor in Drosophila. PLoS Biol 2015. [PMID: 26222308 PMCID: PMC4519132 DOI: 10.1371/journal.pbio.1002207] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The steroid hormone ecdysone and its receptor (EcR) play critical roles in orchestrating developmental transitions in arthropods. However, the mechanism by which EcR integrates nutritional and developmental cues to correctly activate transcription remains poorly understood. Here, we show that EcR-dependent transcription, and thus, developmental timing in Drosophila, is regulated by CDK8 and its regulatory partner Cyclin C (CycC), and the level of CDK8 is affected by nutrient availability. We observed that cdk8 and cycC mutants resemble EcR mutants and EcR-target genes are systematically down-regulated in both mutants. Indeed, the ability of the EcR-Ultraspiracle (USP) heterodimer to bind to polytene chromosomes and the promoters of EcR target genes is also diminished. Mass spectrometry analysis of proteins that co-immunoprecipitate with EcR and USP identified multiple Mediator subunits, including CDK8 and CycC. Consistently, CDK8-CycC interacts with EcR-USP in vivo; in particular, CDK8 and Med14 can directly interact with the AF1 domain of EcR. These results suggest that CDK8-CycC may serve as transcriptional cofactors for EcR-dependent transcription. During the larval–pupal transition, the levels of CDK8 protein positively correlate with EcR and USP levels, but inversely correlate with the activity of sterol regulatory element binding protein (SREBP), the master regulator of intracellular lipid homeostasis. Likewise, starvation of early third instar larvae precociously increases the levels of CDK8, EcR and USP, yet down-regulates SREBP activity. Conversely, refeeding the starved larvae strongly reduces CDK8 levels but increases SREBP activity. Importantly, these changes correlate with the timing for the larval–pupal transition. Taken together, these results suggest that CDK8-CycC links nutrient intake to developmental transitions (EcR activity) and fat metabolism (SREBP activity) during the larval–pupal transition. During the larval-pupal transition in Drosophila, CDK8-CycC helps to link nutrient intake to development by activating ecdysone receptor-dependent transcription and to fat metabolism by inhibiting SREBP-activated gene expression. Arthropods are estimated to account for over 80% of animal species on earth. Characterized by their rigid exoskeletons, juvenile arthropods must periodically shed their thick outer cuticles by molting in order to grow. The steroid hormone ecdysone plays an essential role in regulating the timing of developmental transitions, but exactly how ecdysone and its receptor EcR activates transcription correctly after integrating nutritional and developmental cues remains unknown. Our developmental genetic analyses of two Drosophila mutants, cdk8 and cycC, show that they are lethal during the prepupal stage, with aberrant accumulation of fat and a severely delayed larval–pupal transition. As we have reported previously, CDK8-CycC inhibits fat accumulation by directly inactivating SREBP, a master transcription factor that controls the expression of lipogenic genes, which explains the abnormal fat accumulation in the cdk8 and cycC mutants. We find that CDK8 and CycC are required for EcR to bind to its target genes, serving as transcriptional cofactors for EcR-dependent gene expression. The expression of EcR target genes is compromised in cdk8 and cycC mutants and underpins the retarded pupariation phenotype. Starvation of feeding larvae precociously up-regulates CDK8 and EcR, prematurely down-regulates SREBP activity, and leads to early pupariation, whereas re-feeding starved larvae has opposite effects. Taken together, these results suggest that CDK8 and CycC play important roles in coordinating nutrition intake with fat metabolism by directly inhibiting SREBP-dependent gene expression and regulating developmental timing by activating EcR-dependent transcription in Drosophila.
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Affiliation(s)
- Xiao-Jun Xie
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, Texas, United States of America
| | - Fu-Ning Hsu
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, Texas, United States of America
| | - Xinsheng Gao
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, Texas, United States of America
| | - Wu Xu
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, Los Angeles, United States of America
| | - Jian-Quan Ni
- Gene Regulatory Laboratory, School of Medicine, Tsinghua University, Beijing, China
| | - Yue Xing
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, Texas, United States of America
| | - Liying Huang
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, Los Angeles, United States of America
| | - Hao-Ching Hsiao
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, Texas, United States of America
| | - Haiyan Zheng
- Biological Mass Spectrometry Facility, Robert Wood Johnson Medical School and Rutgers, the State University of New Jersey, Frelinghuysen Road, Piscataway, New Jersey, United States of America
| | - Chenguang Wang
- Key Laboratory of Tianjin Radiation and Molecular Nuclear Medicine; Institute of Radiation Medicine, Peking Union Medical College & Chinese Academy of Medical Sciences, Tianjin, China
| | - Yani Zheng
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, Texas, United States of America
| | - Alus M. Xiaoli
- Department of Medicine, Division of Endocrinology, Diabetes Research and Training Center, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Fajun Yang
- Department of Medicine, Division of Endocrinology, Diabetes Research and Training Center, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Sarah E. Bondos
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, Texas, United States of America
- Department of Biosciences, Rice University, Houston, Texas, United States of America
| | - Jun-Yuan Ji
- Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M University Health Science Center, College Station, Texas, United States of America
- * E-mail:
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30
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Iida S, Chen W, Nakadai T, Ohkuma Y, Roeder RG. PRDM16 enhances nuclear receptor-dependent transcription of the brown fat-specific Ucp1 gene through interactions with Mediator subunit MED1. Genes Dev 2015; 29:308-21. [PMID: 25644605 PMCID: PMC4318147 DOI: 10.1101/gad.252809.114] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
PRDM16 induces expression of brown fat-specific genes in brown and beige adipocytes. Here, Iida et al. show that PRDM16, through its zinc finger domains, directly interacts with the MED1 subunit of the Mediator complex and is recruited to the enhancer of the brown fat-specific Ucp1 gene through this interaction. This enhances thyroid hormone receptor-driven transcription in a biochemically defined system in a Mediator-dependent manner, thus providing a direct link to the general transcription machinery. PR domain-containing 16 (PRDM16) induces expression of brown fat-specific genes in brown and beige adipocytes, although the underlying transcription-related mechanisms remain largely unknown. Here, in vitro studies show that PRDM16, through its zinc finger domains, directly interacts with the MED1 subunit of the Mediator complex, is recruited to the enhancer of the brown fat-specific uncoupling protein 1 (Ucp1) gene through this interaction, and enhances thyroid hormone receptor (TR)-driven transcription in a biochemically defined system in a Mediator-dependent manner, thus providing a direct link to the general transcription machinery. Complementary cell-based studies show that upon forskolin treatment, PRDM16 induces Ucp1 expression in undifferentiated murine embryonic fibroblasts, that this induction depends on MED1 and TR, and, consistent with a direct effect, that PRDM16 is recruited to the Ucp1 enhancer. Related studies have defined MED1 and PRDM16 interaction domains important for Ucp1 versus Ppargc1a induction by PRDM16. These results reveal novel mechanisms for PRDM16 function through the Mediator complex.
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Affiliation(s)
- Satoshi Iida
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, New York 10065, USA
| | - Wei Chen
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, New York 10065, USA
| | - Tomoyoshi Nakadai
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, New York 10065, USA
| | - Yoshiaki Ohkuma
- Laboratory of Gene Regulation, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, Toyama 930-0194, Japan
| | - Robert G Roeder
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, New York 10065, USA;
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31
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Abstract
Skeletal and cardiac muscles play key roles in the regulation of systemic energy homeostasis and display remarkable plasticity in their metabolic responses to caloric availability and physical activity. In this Perspective we discuss recent studies highlighting transcriptional mechanisms that govern systemic metabolism by striated muscles. We focus on the participation of the Mediator complex in this process, and suggest that tissue-specific regulation of Mediator subunits impacts metabolic homeostasis.
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Affiliation(s)
- Kedryn K Baskin
- Department of Molecular Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9148, USA
| | - Benjamin R Winders
- Department of Molecular Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9148, USA; Cardiology Division, Department of Internal Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9148, USA
| | - Eric N Olson
- Department of Molecular Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9148, USA; Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9148, USA.
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32
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Zhang D, Wang X, Li Y, Zhao L, Lu M, Yao X, Xia H, Wang YC, Liu MF, Jiang J, Li X, Ying H. Thyroid hormone regulates muscle fiber type conversion via miR-133a1. ACTA ACUST UNITED AC 2014; 207:753-66. [PMID: 25512392 PMCID: PMC4274265 DOI: 10.1083/jcb.201406068] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Thyroid hormone promotes slow-to-fast muscle fiber type conversion by inducing miR-133a1 and thereby repressing the expression of the slow muscle determinant TEAD1. It is known that thyroid hormone (TH) is a major determinant of muscle fiber composition, but the molecular mechanism by which it does so remains unclear. Here, we demonstrated that miR-133a1 is a direct target gene of TH in muscle. Intriguingly, miR-133a, which is enriched in fast-twitch muscle, regulates slow-to-fast muscle fiber type conversion by targeting TEA domain family member 1 (TEAD1), a key regulator of slow muscle gene expression. Inhibition of miR-133a in vivo abrogated TH action on muscle fiber type conversion. Moreover, TEAD1 overexpression antagonized the effect of miR-133a as well as TH on muscle fiber type switch. Additionally, we demonstrate that TH negatively regulates the transcription of myosin heavy chain I indirectly via miR-133a/TEAD1. Collectively, we propose that TH inhibits the slow muscle phenotype through a novel epigenetic mechanism involving repression of TEAD1 expression via targeting by miR-133a1. This identification of a TH-regulated microRNA therefore sheds new light on how TH achieves its diverse biological activities.
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Affiliation(s)
- Duo Zhang
- Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences; and Center for RNA Research, State Key Laboratory of Molecular Biology; University of Chinese Academy of Sciences, Shanghai 200031, China Key Laboratory of Food Safety Risk Assessment, Ministry of Health, Beijing 100021, China
| | - Xiaoyun Wang
- Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences; and Center for RNA Research, State Key Laboratory of Molecular Biology; University of Chinese Academy of Sciences, Shanghai 200031, China Key Laboratory of Food Safety Risk Assessment, Ministry of Health, Beijing 100021, China
| | - Yuying Li
- Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences; and Center for RNA Research, State Key Laboratory of Molecular Biology; University of Chinese Academy of Sciences, Shanghai 200031, China Key Laboratory of Food Safety Risk Assessment, Ministry of Health, Beijing 100021, China
| | - Lei Zhao
- Department of Neuromuscular Disease, Children's Hospital of Fudan University, Shanghai 201102, China
| | - Minghua Lu
- Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences; and Center for RNA Research, State Key Laboratory of Molecular Biology; University of Chinese Academy of Sciences, Shanghai 200031, China Shanghai Key Laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, and Clinical Research Center of Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Xuan Yao
- Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences; and Center for RNA Research, State Key Laboratory of Molecular Biology; University of Chinese Academy of Sciences, Shanghai 200031, China Key Laboratory of Food Safety Risk Assessment, Ministry of Health, Beijing 100021, China
| | - Hongfeng Xia
- Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences; and Center for RNA Research, State Key Laboratory of Molecular Biology; University of Chinese Academy of Sciences, Shanghai 200031, China Key Laboratory of Food Safety Risk Assessment, Ministry of Health, Beijing 100021, China
| | - Yu-Cheng Wang
- Department of Nutrition, Shanghai Xuhui Central Hospital, Shanghai 200031, China
| | - Mo-Fang Liu
- Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences; and Center for RNA Research, State Key Laboratory of Molecular Biology; University of Chinese Academy of Sciences, Shanghai 200031, China Shanghai Key Laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, and Clinical Research Center of Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Jingjing Jiang
- Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Xihua Li
- Department of Neuromuscular Disease, Children's Hospital of Fudan University, Shanghai 201102, China
| | - Hao Ying
- Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences; and Center for RNA Research, State Key Laboratory of Molecular Biology; University of Chinese Academy of Sciences, Shanghai 200031, China Key Laboratory of Food Safety Risk Assessment, Ministry of Health, Beijing 100021, China Shanghai Key Laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, and Clinical Research Center of Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
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Soukup T. Effects of long-term thyroid hormone level alterations, n-3 polyunsaturated fatty acid supplementation and statin administration in rats. Physiol Res 2014; 63:S119-31. [PMID: 24564652 DOI: 10.33549/physiolres.932623] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Thyroid hormones (THs) play multiple roles in the organism and alterations of their levels can result in many pathological changes. Currently, we use hyperthyroid and hypothyroid rats as "models of a diseased organism" and analyze whether n-3 polyunsaturated fatty acids (n-3 PUFA) administration can ameliorate TH-induced pathophysiological changes. We investigate myosin heavy chain composition, calsequestrin levels, changes in cardiac tissue remodeling and cell-to-cell communication, expression of protein kinases, mitochondrial functions, oxidative stress markers and cell death, changes in serum lipid levels, activities of key enzymes of thyroid hormone metabolism, activity of acetylcholine esterase and membrane anisotropy, as well as mobile behavior and thermal sensitivity. Additionally we also mention our pilot experiments dealing with the effect of statin administration on skeletal muscles and sensory functions. As THs and n-3 PUFA possess multiple sites of potential action, we hope that our complex research will contribute to a better understanding of their actions, which can be useful in the treatment of different pathophysiological events including cardiac insufficiency in humans.
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Affiliation(s)
- T Soukup
- Department of Functional Morphology, Institute of Physiology Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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Shi Z, Yang W, Goldstein JA, Zhang SY. Med25 is required for estrogen receptor alpha (ERα)-mediated regulation of human CYP2C9 expression. Biochem Pharmacol 2014; 90:425-31. [PMID: 24960263 DOI: 10.1016/j.bcp.2014.06.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 06/16/2014] [Accepted: 06/16/2014] [Indexed: 11/16/2022]
Abstract
The CYP2C subfamily of cytochrome P450 enzymes is an important class of drug metabolizing enzymes in human liver. CYP2C9 is the most abundant member of the human CYP2C subfamily in liver and metabolizes ~15% of the therapeutic drugs as well as other xenobiotics and endogenous compounds. A number of nuclear receptors including xenobiotic-sensing receptors such as the constitutive androstane receptor (CAR), pregnane X receptor (PXR), and glucocorticoid receptor (GR) as well as liver enriched receptors hepatic nuclear factor 4α (HNF4α) and the estrogen receptor α (ERα) regulate CYP2C9 expression. Here, we show that Med25, a variable component of Mediator complex, enhanced ligand dependent ERα-mediated transcriptional activation of CYP2C9 promoter and interacts with activated ERα by 17β-estradiol through its C-terminal LXXLL motif. In conclusion, Med25 is identified as a new coactivator of ERα that is required for ERα-mediated regulation of CYP2C9 expression.
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Affiliation(s)
- Zhe Shi
- Department of Preventive Medicine, School of Environmental Science and Public Health, Wenzhou Medical University, Wenzhou, Zhejiang 325035, PR China
| | - Wenjun Yang
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325035, PR China
| | - Joyce A Goldstein
- Human Metabolism Section, Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Shu-Yun Zhang
- Department of Preventive Medicine, School of Environmental Science and Public Health, Wenzhou Medical University, Wenzhou, Zhejiang 325035, PR China.
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Otsuka S, Ishihara A, Yamauchi K. Ioxynil and Tetrabromobisphenol A Suppress Thyroid-Hormone-Induced Activation of Transcriptional Elongation Mediated by Histone Modifications and RNA Polymerase II Phosphorylation. Toxicol Sci 2014; 138:290-9. [DOI: 10.1093/toxsci/kfu012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Jia Y, Viswakarma N, Reddy JK. Med1 subunit of the mediator complex in nuclear receptor-regulated energy metabolism, liver regeneration, and hepatocarcinogenesis. Gene Expr 2014; 16:63-75. [PMID: 24801167 PMCID: PMC4093800 DOI: 10.3727/105221614x13919976902219] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Several nuclear receptors regulate diverse metabolic functions that impact on critical biological processes, such as development, differentiation, cellular regeneration, and neoplastic conversion. In the liver, some members of the nuclear receptor family, such as peroxisome proliferator-activated receptors (PPARs), constitutive androstane receptor (CAR), farnesoid X receptor (FXR), liver X receptor (LXR), pregnane X receptor (PXR), glucocorticoid receptor (GR), and others, regulate energy homeostasis, the formation and excretion of bile acids, and detoxification of xenobiotics. Excess energy burning resulting from increases in fatty acid oxidation systems in liver generates reactive oxygen species, and the resulting oxidative damage influences liver regeneration and liver tumor development. These nuclear receptors are important sensors of exogenous activators as well as receptor-specific endogenous ligands. In this regard, gene knockout mouse models revealed that some lipid-metabolizing enzymes generate PPARα-activating ligands, while others such as ACOX1 (fatty acyl-CoA oxidase1) inactivate these endogenous PPARα activators. In the absence of ACOX1, the unmetabolized ACOX1 substrates cause sustained activation of PPARα, and the resulting increase in energy burning leads to hepatocarcinogenesis. Ligand-activated nuclear receptors recruit the multisubunit Mediator complex for RNA polymerase II-dependent gene transcription. Evidence indicates that the Med1 subunit of the Mediator is essential for PPARα, PPARγ, CAR, and GR signaling in liver. Med1 null hepatocytes fail to respond to PPARα activators in that these cells do not show induction of peroxisome proliferation and increases in fatty acid oxidation enzymes. Med1-deficient hepatocytes show no increase in cell proliferation and do not give rise to liver tumors. Identification of nuclear receptor-specific coactivators and Mediator subunits should further our understanding of the complexities of metabolic diseases associated with increased energy combustion in liver.
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Affiliation(s)
- Yuzhi Jia
- *Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA
| | - Navin Viswakarma
- †Department of Molecular Pharmacology and Therapeutics, Loyola University Chicago, Maywood, IL, USA
| | - Janardan K. Reddy
- *Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA
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Abstract
Steroid hormones trigger a wide variety of biological responses through stage- and tissue-specific activation of target gene expression. The mechanisms that provide specificity to systemically released pulses of steroids, however, remain poorly understood. We previously completed a forward genetic screen for mutations that disrupt the destruction of larval salivary glands during metamorphosis in Drosophila melanogaster, a process triggered by the steroid hormone 20-hydroxyecdysone (ecdysone). Here, we characterize 10 complementation groups mapped to genes from this screen. Most of these mutations disrupt the ecdysone-induced expression of death activators, thereby failing to initiate tissue destruction. However, other responses to ecdysone, even within salivary glands, occur normally in mutant animals. Many of these newly identified regulators of ecdysone signaling, including brwd3, med12, med24, pak, and psg2, represent novel components of the ecdysone-triggered transcriptional hierarchy. These genes function combinatorially to provide specificity to ecdysone pulses, amplifying the hormonal cue in a stage-, tissue-, and target gene-specific manner. Most of the ecdysone response genes identified in this screen encode homologs of mammalian nuclear receptor coregulators, demonstrating an unexpected degree of functional conservation in the mechanisms that regulate steroid signaling between insects and mammals.
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Affiliation(s)
- Jiannan Guo
- Biochemistry Department, University of Iowa , Iowa City, Iowa 52242, United States
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Abstract
The Mediator complex is a multi-subunit assembly that appears to be required for regulating expression of most RNA polymerase II (pol II) transcripts, which include protein-coding and most non-coding RNA genes. Mediator and pol II function within the pre-initiation complex (PIC), which consists of Mediator, pol II, TFIIA, TFIIB, TFIID, TFIIE, TFIIF and TFIIH and is approximately 4.0 MDa in size. Mediator serves as a central scaffold within the PIC and helps regulate pol II activity in ways that remain poorly understood. Mediator is also generally targeted by sequence-specific, DNA-binding transcription factors (TFs) that work to control gene expression programs in response to developmental or environmental cues. At a basic level, Mediator functions by relaying signals from TFs directly to the pol II enzyme, thereby facilitating TF-dependent regulation of gene expression. Thus, Mediator is essential for converting biological inputs (communicated by TFs) to physiological responses (via changes in gene expression). In this review, we summarize an expansive body of research on the Mediator complex, with an emphasis on yeast and mammalian complexes. We focus on the basics that underlie Mediator function, such as its structure and subunit composition, and describe its broad regulatory influence on gene expression, ranging from chromatin architecture to transcription initiation and elongation, to mRNA processing. We also describe factors that influence Mediator structure and activity, including TFs, non-coding RNAs and the CDK8 module.
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Affiliation(s)
- Zachary C Poss
- Department of Chemistry and Biochemistry, University of Colorado , Boulder, CO , USA
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Suh JH, Sieglaff DH, Zhang A, Xia X, Cvoro A, Winnier GE, Webb P. SIRT1 is a direct coactivator of thyroid hormone receptor β1 with gene-specific actions. PLoS One 2013; 8:e70097. [PMID: 23922917 PMCID: PMC3724829 DOI: 10.1371/journal.pone.0070097] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 06/15/2013] [Indexed: 02/07/2023] Open
Abstract
Sirtuin 1 (SIRT1) NAD+-dependent deacetylase regulates energy metabolism by modulating expression of genes involved in gluconeogenesis and other liver fasting responses. While many effects of SIRT1 on gene expression are mediated by deacetylation and activation of peroxisome proliferator activated receptor coactivator α (PGC-1α), SIRT1 also binds directly to DNA bound transcription factors, including nuclear receptors (NRs), to modulate their activity. Since thyroid hormone receptor β1 (TRβ1) regulates several SIRT1 target genes in liver and interacts with PGC-1α, we hypothesized that SIRT1 may influence TRβ1. Here, we confirm that SIRT1 cooperates with PGC-1α to enhance response to triiodothyronine, T3. We also find, however, that SIRT1 stimulates TRβ1 activity in a manner that is independent of PGC-1α but requires SIRT1 deacetylase activity. SIRT1 interacts with TRβ1 in vitro, promotes TRβ1 deacetylation in the presence of T3 and enhances ubiquitin-dependent TRβ1 turnover; a common response of NRs to activating ligands. More surprisingly, SIRT1 knockdown only strongly inhibits T3 response of a subset of TRβ1 target genes, including glucose 6 phosphatase (G-6-Pc), and this is associated with blockade of TRβ1 binding to the G-6-Pc promoter. Drugs that target the SIRT1 pathway, resveratrol and nicotinamide, modulate T3 response at dual TRβ1/SIRT1 target genes. We propose that SIRT1 is a gene-specific TRβ1 co-regulator and TRβ1/SIRT1 interactions could play important roles in regulation of liver metabolic response. Our results open possibilities for modulation of subsets of TR target genes with drugs that influence the SIRT1 pathway.
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Affiliation(s)
- Ji Ho Suh
- Genomic Medicine Program, Methodist Hospital Research Institute, Houston, Texas, United States of America
| | - Douglas H. Sieglaff
- Genomic Medicine Program, Methodist Hospital Research Institute, Houston, Texas, United States of America
| | - Aijun Zhang
- Genomic Medicine Program, Methodist Hospital Research Institute, Houston, Texas, United States of America
| | - Xuefeng Xia
- Genomic Medicine Program, Methodist Hospital Research Institute, Houston, Texas, United States of America
| | - Aleksandra Cvoro
- Genomic Medicine Program, Methodist Hospital Research Institute, Houston, Texas, United States of America
| | - Glenn E. Winnier
- Genomic Medicine Program, Methodist Hospital Research Institute, Houston, Texas, United States of America
| | - Paul Webb
- Genomic Medicine Program, Methodist Hospital Research Institute, Houston, Texas, United States of America
- * E-mail:
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Lin JZ, Sieglaff DH, Yuan C, Su J, Arumanayagam AS, Firouzbakht S, Cantu Pompa JJ, Reynolds FD, Zhou X, Cvoro A, Webb P. Gene specific actions of thyroid hormone receptor subtypes. PLoS One 2013; 8:e52407. [PMID: 23300972 PMCID: PMC3536777 DOI: 10.1371/journal.pone.0052407] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Accepted: 11/14/2012] [Indexed: 11/22/2022] Open
Abstract
There are two homologous thyroid hormone (TH) receptors (TRs α and β), which are members of the nuclear hormone receptor (NR) family. While TRs regulate different processes in vivo and other highly related NRs regulate distinct gene sets, initial studies of TR action revealed near complete overlaps in their actions at the level of individual genes. Here, we assessed the extent that TRα and TRβ differ in target gene regulation by comparing effects of equal levels of stably expressed exogenous TRs +/− T3 in two cell backgrounds (HepG2 and HeLa). We find that hundreds of genes respond to T3 or to unliganded TRs in both cell types, but were not able to detect verifiable examples of completely TR subtype-specific gene regulation. TR actions are, however, far from identical and we detect TR subtype-specific effects on global T3 response kinetics in HepG2 cells and many examples of TR subtype specificity at the level of individual genes, including effects on magnitude of response to TR +/− T3, TR regulation patterns and T3 dose response. Cycloheximide (CHX) treatment confirms that at least some differential effects involve verifiable direct TR target genes. TR subtype/gene-specific effects emerge in the context of widespread variation in target gene response and we suggest that gene-selective effects on mechanism of TR action highlight differences in TR subtype function that emerge in the environment of specific genes. We propose that differential TR actions could influence physiologic and pharmacologic responses to THs and selective TR modulators (STRMs).
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Affiliation(s)
- Jean Z. Lin
- Genomic Medicine, The Methodist Hospital Research Institute, Houston, Texas, United States of America
- Department of Biology and Biochemistry, Center for Nuclear Receptors and Cell Signaling, University of Houston, Houston, Texas, United States of America
| | - Douglas H. Sieglaff
- Genomic Medicine, The Methodist Hospital Research Institute, Houston, Texas, United States of America
| | - Chaoshen Yuan
- Diabetes Center, University of California Medical Center, San Francisco, California, United States of America
| | - Jing Su
- Radiology Department, The Methodist Hospital Research Institute, Houston, Texas, United States of America
| | | | - Sharareh Firouzbakht
- Genomic Medicine, The Methodist Hospital Research Institute, Houston, Texas, United States of America
| | - Jaime J. Cantu Pompa
- Genomic Medicine, The Methodist Hospital Research Institute, Houston, Texas, United States of America
- Department of Research and Innovation, Tec de Monterrey School of Medicine and Health Science, Monterrey, Mexico
| | - Frances Denoto Reynolds
- Diabetes Center, University of California Medical Center, San Francisco, California, United States of America
| | - Xiabo Zhou
- Radiology Department, The Methodist Hospital Research Institute, Houston, Texas, United States of America
| | - Aleksandra Cvoro
- Genomic Medicine, The Methodist Hospital Research Institute, Houston, Texas, United States of America
| | - Paul Webb
- Genomic Medicine, The Methodist Hospital Research Institute, Houston, Texas, United States of America
- * E-mail:
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Marsman J, Horsfield JA. Long distance relationships: enhancer-promoter communication and dynamic gene transcription. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2012; 1819:1217-27. [PMID: 23124110 DOI: 10.1016/j.bbagrm.2012.10.008] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Revised: 10/18/2012] [Accepted: 10/22/2012] [Indexed: 11/27/2022]
Abstract
The three-dimensional regulation of gene transcription involves loop formation between enhancer and promoter elements, controlling spatiotemporal gene expression in multicellular organisms. Enhancers are usually located in non-coding DNA and can activate gene transcription by recruiting transcription factors, chromatin remodeling factors and RNA Polymerase II. Research over the last few years has revealed that enhancers have tell-tale characteristics that facilitate their detection by several approaches, although the hallmarks of enhancers are not always uniform. Enhancers likely play an important role in the activation of genes by functioning as a primary point of contact for transcriptional activators, and by making physical contact with gene promoters often by means of a chromatin loop. Although numerous transcriptional regulators participate in the formation of chromatin loops that bring enhancers into proximity with promoters, the mechanism(s) of enhancer-promoter connectivity remain enigmatic. Here we discuss enhancer function, review some of the many proteins shown to be involved in establishing enhancer-promoter loops, and describe the dynamics of enhancer-promoter contacts during development, differentiation and in specific cell types.
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Affiliation(s)
- Judith Marsman
- Department of Pathology, The University of Otago, Dunedin, New Zealand
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