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Ko JS, Lemahieu J, Billings SD, Tirode F, Payton D, Boone B, Pissaloux D, de la Fouchardiere A. MED15::ATF1-Rearranged Tumor: A Novel Cutaneous Tumor With Melanocytic Differentiation. Mod Pathol 2024; 37:100438. [PMID: 38278485 DOI: 10.1016/j.modpat.2024.100438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 11/29/2023] [Accepted: 01/09/2024] [Indexed: 01/28/2024]
Abstract
We recently described novel dermal tumors with melanocytic differentiation and morphologic and biological similarities to cutaneous clear cell sarcoma, including CRTC1::TRIM11 cutaneous tumor, and clear cell tumors with melanocytic differentiation and either ACTIN::MITF or MITF::CREM. Here, we describe a series of 3 patients presenting with tumors reminiscent of CRTC1::TRIM11 cutaneous tumor, found to demonstrate a novel MED15::ATF1 fusion. All 3 patients were children (5-16 years old). Primary excision of case 1 showed a circumscribed wedge-shaped silhouette with peripheral intercalation into collagen fibers and scattered lymphoid aggregates. All 3 tumors abutted the epidermis; one showed a junctional component. Tumors were highly cellular and comprised of monomorphic, oval-to-round epithelioid cells arranged in vague nests and short fascicles in variably fibrotic stroma. Mitotic rate was high (hotspot 6-12/mm2), without atypical mitoses. Necrosis was focally present in case 3. All cases showed strong, diffuse nuclear staining for SOX10 and MITF (2/2) but showed variable expression for S100 protein (1/3) and other melanocytic markers-Melan-A (focal in 2/3), HMB45 (focal in 1/3), and Pan-Melanoma (patchy in 1/1). Whole-exome RNA sequencing demonstrated a MED15::ATF1 fusion without any other notable alterations. Cases 1 and 2 were completely excised without recurrence (12 months). Case 3 developed a grossly apparent regional lymph node spread shortly after primary biopsy. The patient was treated with wide excision, radiation, cervical lymph node dissection (4/46 with >75% lymph node replacement), and neoadjuvant and adjuvant nivolumab (alive without disease at cycle 11). This series is presented to aid in future diagnosis of this novel dermal tumor with melanocytic differentiation and emphasize the potential for aggressive biologic behavior, which should be considered in patient management planning.
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Affiliation(s)
- Jennifer S Ko
- Department of Pathology, Cleveland Clinic, Cleveland, Ohio.
| | | | | | - Franck Tirode
- Department of Pathobiology, Centre Léon Bérard, Lyon, France; INSERM 1052, CNRS 5286, Research Cancer Center of Lyon, Centre Léon Bérard, Université Claude Bernard Lyon 1, Lyon, France
| | - Diane Payton
- Anatomic Pathology, Royal Brisbane and Women's Hospital and Queensland Children's Hospital, Brisbane, Australia
| | - Barbara Boone
- Dermatology Department, Ghent University Hospital, Ghent, Belgium
| | - Daniel Pissaloux
- Department of Pathobiology, Centre Léon Bérard, Lyon, France; INSERM 1052, CNRS 5286, Research Cancer Center of Lyon, Centre Léon Bérard, Université Claude Bernard Lyon 1, Lyon, France
| | - Arnaud de la Fouchardiere
- Department of Pathobiology, Centre Léon Bérard, Lyon, France; INSERM 1052, CNRS 5286, Research Cancer Center of Lyon, Centre Léon Bérard, Université Claude Bernard Lyon 1, Lyon, France
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2
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Furtado LV, Cardenas M, Santiago T, Ruiz RE, Shi Z, Pappo A, Kacar M. Novel MED15::ATF1 fusion in a pediatric melanoma with spitzoid features and aggressive presentation. Genes Chromosomes Cancer 2024; 63:e23230. [PMID: 38459940 DOI: 10.1002/gcc.23230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 02/13/2024] [Accepted: 02/17/2024] [Indexed: 03/11/2024] Open
Abstract
Childhood melanoma is a rare and biologically heterogeneous pediatric malignancy. The differential diagnosis of pediatric melanoma is usually broad, including a wide variety of spindle cell or epithelioid neoplasms. Different molecular alterations affecting the MAPK and PI3K/AKT/mTOR pathways, tumor suppressor genes, and telomerase reactivation have been implicated in melanoma tumorigenesis and progression. Here, we report a novel MED15::ATF1 fusion in a pediatric melanoma with spitzoid features and an aggressive clinical course.
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Affiliation(s)
- Larissa V Furtado
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Maria Cardenas
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Teresa Santiago
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Robert E Ruiz
- Department of Pathology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Zonggao Shi
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Alberto Pappo
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Marija Kacar
- Department of Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
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3
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Suzuki H, Furugori K, Abe R, Ogawa S, Ito S, Akiyama T, Horiuchi K, Takahashi H. MED26-containing Mediator may orchestrate multiple transcription processes through organization of nuclear bodies. Bioessays 2023; 45:e2200178. [PMID: 36852638 DOI: 10.1002/bies.202200178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 02/04/2023] [Accepted: 02/06/2023] [Indexed: 03/01/2023]
Abstract
Mediator is a coregulatory complex that plays essential roles in multiple processes of transcription regulation. One of the human Mediator subunits, MED26, has a role in recruitment of the super elongation complex (SEC) to polyadenylated genes and little elongation complex (LEC) to non-polyadenylated genes, including small nuclear RNAs (snRNAs) and replication-dependent histone (RDH) genes. MED26-containing Mediator plays a role in 3' Pol II pausing at the proximal region of transcript end sites in RDH genes through recruitment of Cajal bodies (CBs) to histone locus bodies (HLBs). This finding suggests that Mediator is involved in the association of CBs with HLBs to facilitate 3' Pol II pausing and subsequent 3'-end processing by supplying 3'-end processing factors from CBs. Thus, we argue the possibility that Mediator is involved in the organization of nuclear bodies to orchestrate multiple processes of gene transcription.
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Affiliation(s)
- Hidefumi Suzuki
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Kazuki Furugori
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Ryota Abe
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Shintaro Ogawa
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Sayaka Ito
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Tomohiko Akiyama
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Keiko Horiuchi
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
| | - Hidehisa Takahashi
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Kanagawa, Japan
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Friedl MS, Djakovic L, Kluge M, Hennig T, Whisnant AW, Backes S, Dölken L, Friedel CC. HSV-1 and influenza infection induce linear and circular splicing of the long NEAT1 isoform. PLoS One 2022; 17:e0276467. [PMID: 36279270 PMCID: PMC9591066 DOI: 10.1371/journal.pone.0276467] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 10/07/2022] [Indexed: 11/18/2022] Open
Abstract
The herpes simplex virus 1 (HSV-1) virion host shut-off (vhs) protein cleaves both cellular and viral mRNAs by a translation-initiation-dependent mechanism, which should spare circular RNAs (circRNAs). Here, we show that vhs-mediated degradation of linear mRNAs leads to an enrichment of circRNAs relative to linear mRNAs during HSV-1 infection. This was also observed in influenza A virus (IAV) infection, likely due to degradation of linear host mRNAs mediated by the IAV PA-X protein and cap-snatching RNA-dependent RNA polymerase. For most circRNAs, enrichment was not due to increased circRNA synthesis but due to a general loss of linear RNAs. In contrast, biogenesis of a circRNA originating from the long isoform (NEAT1_2) of the nuclear paraspeckle assembly transcript 1 (NEAT1) was induced both in HSV-1 infection-in a vhs-independent manner-and in IAV infection. This was associated with induction of novel linear splicing of NEAT1_2 both within and downstream of the circRNA. NEAT1_2 forms a scaffold for paraspeckles, nuclear bodies located in the interchromatin space, must likely remain unspliced for paraspeckle assembly and is up-regulated in HSV-1 and IAV infection. We show that NEAT1_2 splicing and up-regulation can be induced by ectopic co-expression of the HSV-1 immediate-early proteins ICP22 and ICP27, potentially linking increased expression and splicing of NEAT1_2. To identify other conditions with NEAT1_2 splicing, we performed a large-scale screen of published RNA-seq data. This uncovered both induction of NEAT1_2 splicing and poly(A) read-through similar to HSV-1 and IAV infection in cancer cells upon inhibition or knockdown of CDK7 or the MED1 subunit of the Mediator complex phosphorylated by CDK7. In summary, our study reveals induction of novel circular and linear NEAT1_2 splicing isoforms as a common characteristic of HSV-1 and IAV infection and highlights a potential role of CDK7 in HSV-1 or IAV infection.
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Affiliation(s)
- Marie-Sophie Friedl
- Institute of Informatics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Lara Djakovic
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Michael Kluge
- Institute of Informatics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Thomas Hennig
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Adam W. Whisnant
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Simone Backes
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Lars Dölken
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Caroline C. Friedel
- Institute of Informatics, Ludwig-Maximilians-Universität München, Munich, Germany
- * E-mail:
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Lozano M, Yousefi P, Broberg K, Soler-Blasco R, Miyashita C, Pesce G, Kim WJ, Rahman M, Bakulski KM, Haug LS, Ikeda-Araki A, Huel G, Park J, Relton C, Vrijheid M, Rifas-Shiman S, Oken E, Dou JF, Kishi R, Gutzkow KB, Annesi-Maesano I, Won S, Hivert MF, Fallin MD, Vafeiadi M, Ballester F, Bustamante M, Llop S. DNA methylation changes associated with prenatal mercury exposure: A meta-analysis of prospective cohort studies from PACE consortium. Environ Res 2022; 204:112093. [PMID: 34562483 PMCID: PMC10879652 DOI: 10.1016/j.envres.2021.112093] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 09/17/2021] [Accepted: 09/18/2021] [Indexed: 06/13/2023]
Abstract
Mercury (Hg) is a ubiquitous heavy metal that originates from both natural and anthropogenic sources and is transformed in the environment to its most toxicant form, methylmercury (MeHg). Recent studies suggest that MeHg exposure can alter epigenetic modifications during embryogenesis. In this study, we examined associations between prenatal MeHg exposure and levels of cord blood DNA methylation (DNAm) by meta-analysis in up to seven independent studies (n = 1462) as well as persistence of those relationships in blood from 7 to 8 year-old children (n = 794). In cord blood, we found limited evidence of differential DNAm at cg24184221 in MED31 (β = 2.28 × 10-4, p-value = 5.87 × 10-5) in relation to prenatal MeHg exposure. In child blood, we identified differential DNAm at cg15288800 (β = 0.004, p-value = 4.97 × 10-5), also located in MED31. This repeated link to MED31, a gene involved in lipid metabolism and RNA Polymerase II transcription function, may suggest a DNAm perturbation related to MeHg exposure that persists into early childhood. Further, we found evidence for association between prenatal MeHg exposure and child blood DNAm levels at two additional CpGs: cg12204245 (β = 0.002, p-value = 4.81 × 10-7) in GRK1 and cg02212000 (β = -0.001, p-value = 8.13 × 10-7) in GGH. Prenatal MeHg exposure was associated with DNAm modifications that may influence health outcomes, such as cognitive or anthropometric development, in different populations.
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Affiliation(s)
- Manuel Lozano
- Preventive Medicine and Public Health, Food Sciences, Toxicology and Forensic Medicine Department, Universitat de València, Valencia, Spain; Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain.
| | - Paul Yousefi
- MRC Integrative Epidemiology Unit, University of Bristol, Bristol, United Kingdom; Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Karin Broberg
- Unit of Metals and Health, Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden; Division of Occupational and Environmental Medicine, Lund University, Lund, Sweden
| | - Raquel Soler-Blasco
- Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain
| | - Chihiro Miyashita
- Center for Environmental and Health Sciences, Hokkaido University, Hokkaido, Japan
| | - Giancarlo Pesce
- INSERM UMR1018, Université Paris-Saclay, UVSQ, Centre for Epidemiology and Public Health (CESP), Villejuif, France
| | - Woo Jin Kim
- Department of Internal Medicine and Environmental Health Center, Kangwon National University, Chuncheon, South Korea
| | - Mohammad Rahman
- Division of Chronic Disease Research Across the Lifecourse, Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA, United States
| | - Kelly M Bakulski
- School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Line S Haug
- Norwegian Institute of Public Health, Division of Climate and Environment, Oslo, Norway
| | - Atsuko Ikeda-Araki
- Center for Environmental and Health Sciences, Hokkaido University, Hokkaido, Japan; Faculty of Health Sciences, Hokkaido University, Hokkaido, Japan
| | - Guy Huel
- INSERM UMR1018, Université Paris-Saclay, UVSQ, Centre for Epidemiology and Public Health (CESP), Villejuif, France
| | - Jaehyun Park
- Interdisciplinary Program of Bioinformatics, College of Natural Sciences, Seoul National University, Seoul, South Korea
| | - Caroline Relton
- MRC Integrative Epidemiology Unit, University of Bristol, Bristol, United Kingdom; Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Martine Vrijheid
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain; ISGlobal, Barcelona, Spain; Universitat Pompeu Fabra, Barcelona, Spain
| | - Sheryl Rifas-Shiman
- Division of Chronic Disease Research Across the Lifecourse, Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA, United States
| | - Emily Oken
- Division of Chronic Disease Research Across the Lifecourse, Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA, United States
| | - John F Dou
- School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Reiko Kishi
- Center for Environmental and Health Sciences, Hokkaido University, Hokkaido, Japan
| | - Kristine B Gutzkow
- Norwegian Institute of Public Health, Division of Climate and Environment, Oslo, Norway
| | - Isabella Annesi-Maesano
- INSERM UMR1302, Montpellier University, Insitut Desbrest d'Épidémiologie et de Santé Publique (IDESP), Montpellier, France
| | - Sungho Won
- Interdisciplinary Program of Bioinformatics, College of Natural Sciences, Seoul National University, Seoul, South Korea; Department of Public Health Sciences, Seoul National University, Seoul, South Korea
| | - Marie-France Hivert
- Division of Chronic Disease Research Across the Lifecourse, Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA, United States; Diabetes Unit, Massachusetts General Hospital, Boston, MA, United States
| | - M Daniele Fallin
- Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Marina Vafeiadi
- Department of Social Medicine, School of Medicine, University of Crete, Heraklion, Greece
| | - Ferran Ballester
- Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain; School of Nursing, Universitat de València, Valencia, Spain
| | - Mariona Bustamante
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain; ISGlobal, Barcelona, Spain; Universitat Pompeu Fabra, Barcelona, Spain
| | - Sabrina Llop
- Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain; Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain
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Affiliation(s)
- Valentin Hammoudi
- Institute of Biology-Applied Genetics, Freie Universität Berlin, Albrecht Thaer Weg 6, 14195 Berlin, Germany
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Käser L. [Studying Human Medicine at the University of Zurich]. Praxis (Bern 1994) 2020; 109:843-846. [PMID: 32873170 DOI: 10.1024/1661-8157/a003555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Studying Human Medicine at the University of Zurich Abstract. We compile the most important published information on studying human medicine at the Medical Faculty of the University of Zurich (as of 8.6.2020), with a brief overview of the 'Education Network' (www.medunet.ch) of the six participating locations with the Universities of Zurich, Basel, St. Gallen, Lucerne, the Università della Svizzera italiana and the ETH Zurich. Within the educational network, the Universities of Lucerne and St. Gallen offer the so-called 'Lucerne Track' and 'St. Gallen Track' for 40 medical students each as a joint Master's program with the University of Zurich. The two partners present their curriculum in separate articles. Finally, information on the current curriculum revision is provided under the label ZH Med4, which stands for the main focus areas of digitization, research, networking and primary care.
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Abstract
Mediator is a large, multi-module complex that plays a key role in transcription regulation in eukaryotes. A divergent Mediator from a unicellular eukaryote has been identified and characterized, revealing novel adaptations to mRNA and ncRNA transcription.
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Affiliation(s)
- Xiaolu Zhao
- Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Yifan Liu
- Department of Pathology, University of Michigan, Ann Arbor, MI 48109, USA.
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9
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Garson K, Duhig T, Fried M. Tissue-specific processing of the Surf-5 and Surf-4 mRNAs. Gene Expr 2018; 6:209-18. [PMID: 9196076 PMCID: PMC6148271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The mouse surfeit locus is an unusually tight cluster of at least six "housekeeping" genes that do not share any sequence homology and whose gene organization may play a role in gene expression. The transcription of each of the five well-characterized genes (Surf-1 to -5) alternates with respect to its neighbor(s) and no more than 159 bp separates any two adjacent genes with the Surf-4 and Surf-2 genes overlapping at their 3' ends by 133 bp. In this work, the expression of the Surf-5 and Surf-4 genes has been examined in various mouse tissues. In addition to the ubiquitously expressed 3.5-kb Surf-5 mRNA, a second alternatively spliced Surf-5 mRNA, Surf-5b, was discovered that was highly expressed in the brain, heart, testis, and skeletal muscle. The alternative splice donor site of the Surf-5b mRNA is similar to splice donor sites found in neuron-specific mRNAs. Surf-5b encodes a unique protein, which, like the ubiquitous Surf-5 protein, has been found to be primarily located in the soluble fraction of the cytoplasm. The expression of the Surf-5b protein was also found to increase in embryonal carcinoma cells differentiated into neuronal cultures. Although the Surf-5 gene is highly conserved through evolution, the presence of the Surf-5b alternative splice may be restricted to higher vertebrates. The Surf-4 gene was ubiquitously expressed in eight different mouse tissues; however, the ratios of the three previously reported Surf-4 mRNAs (two of which are known to derive from different sites of polyadenylation) altered dramatically between tissues. The use of different forms of mRNA processing for regulation of tissue-specific expression of ubiquitously expressed genes is discussed.
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Affiliation(s)
- Ken Garson
- Eukaryotic Gene Organization and Expression Laboratory, Imperial Cancer Research Fund, P.O. Box 123, Lincoln’s Inn Fields, London WC2A 3PX UK
- Address correspondence to Mike Fried. Tel: 44-171-269-3297; Fax: 44-171-269-3581; E-mail:
| | - Trevor Duhig
- Eukaryotic Gene Organization and Expression Laboratory, Imperial Cancer Research Fund, P.O. Box 123, Lincoln’s Inn Fields, London WC2A 3PX UK
| | - Mike Fried
- Eukaryotic Gene Organization and Expression Laboratory, Imperial Cancer Research Fund, P.O. Box 123, Lincoln’s Inn Fields, London WC2A 3PX UK
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Neltner JH, Abner EL, Jicha GA, Schmitt FA, Patel E, Poon LW, Marla G, Green RC, Davey A, Johnson MA, Jazwinski SM, Kim S, Davis D, Woodard JL, Kryscio RJ, Van Eldik LJ, Nelson PT. Brain pathologies in extreme old age. Neurobiol Aging 2015; 37:1-11. [PMID: 26597697 DOI: 10.1016/j.neurobiolaging.2015.10.009] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 09/28/2015] [Accepted: 10/08/2015] [Indexed: 12/31/2022]
Abstract
With an emphasis on evolving concepts in the field, we evaluated neuropathologic data from very old research volunteers whose brain autopsies were performed at the University of Kentucky Alzheimer's Disease Center, incorporating data from the Georgia Centenarian Study (n = 49 cases included), Nun Study (n = 17), and University of Kentucky Alzheimer's Disease Center (n = 11) cohorts. Average age of death was 102.0 (range: 98-107) years overall. Alzheimer's disease pathology was not universal (62% with "moderate" or "frequent" neuritic amyloid plaque densities), whereas frontotemporal lobar degeneration was absent. By contrast, some hippocampal neurofibrillary tangles (including primary age-related tauopathy) were observed in every case. Lewy body pathology was seen in 16.9% of subjects and hippocampal sclerosis of aging in 20.8%. We describe anatomic distributions of pigment-laden macrophages, expanded Virchow-Robin spaces, and arteriolosclerosis among Georgia Centenarians. Moderate or severe arteriolosclerosis pathology, throughout the brain, was associated with both hippocampal sclerosis of aging pathology and an ABCC9 gene variant. These results provide fresh insights into the complex cerebral multimorbidity, and a novel genetic risk factor, at the far end of the human aging spectrum.
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Affiliation(s)
- Janna H Neltner
- Department of Pathology, Division of Neuropathology, University of Kentucky, Lexington, KY, USA
| | - Erin L Abner
- Department of Epidemiology, University of Kentucky, Lexington, KY, USA; Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Gregory A Jicha
- Department of Epidemiology, University of Kentucky, Lexington, KY, USA; Department of Neurology, University of Kentucky, Lexington, KY, USA
| | - Frederick A Schmitt
- Department of Epidemiology, University of Kentucky, Lexington, KY, USA; Department of Neurology, University of Kentucky, Lexington, KY, USA
| | - Ela Patel
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA
| | - Leonard W Poon
- Institute of Gerontology, The University of Georgia, Athens, GA, USA
| | - Gearing Marla
- Department of Pathology, Emory University, Atlanta, GA, USA
| | - Robert C Green
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Adam Davey
- Department of Epidemiology and Biostatistics, Temple University, Philadelphia, PA, USA
| | - Mary Ann Johnson
- Institute of Gerontology, The University of Georgia, Athens, GA, USA
| | - S Michal Jazwinski
- Department of Medicine, Tulane Center for Aging, Tulane University, New Orleans, LA, USA
| | - Sangkyu Kim
- Department of Medicine, Tulane Center for Aging, Tulane University, New Orleans, LA, USA
| | - Daron Davis
- Department of Pathology, Baptist Health Care, Lexington, KY, USA
| | - John L Woodard
- Department of Psychology, Wayne State University, Detroit MI, USA
| | - Richard J Kryscio
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA; Department of Statistics, University of Kentucky, Lexington, KY, USA
| | - Linda J Van Eldik
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA; Department of Anatomy and Neurobiology, University of Kentucky, Lexington, KY, USA
| | - Peter T Nelson
- Department of Pathology, Division of Neuropathology, University of Kentucky, Lexington, KY, USA; Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA.
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11
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Antón LC, Yewdell JW. Translating DRiPs: MHC class I immunosurveillance of pathogens and tumors. J Leukoc Biol 2014; 95:551-62. [PMID: 24532645 PMCID: PMC3958739 DOI: 10.1189/jlb.1113599] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 01/15/2014] [Accepted: 01/19/2014] [Indexed: 11/24/2022] Open
Abstract
MHC class I molecules display oligopeptides on the cell surface to enable T cell immunosurveillance of intracellular pathogens and tumors. Speed is of the essence in detecting viruses, which can complete a full replication cycle in just hours, whereas tumor detection is typically a finding-the-needle-in-the-haystack exercise. We review current evidence supporting a nonrandom, compartmentalized selection of peptidogenic substrates that focuses on rapidly degraded translation products as a main source of peptide precursors to optimize immunosurveillance of pathogens and tumors.
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Affiliation(s)
- Luis C Antón
- 1.NIAID, NIH, Bldg. 33, Bethesda, MD 20892, USA.
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Abstract
The NF-κB family of transcription factors is crucial for the expression of multiple genes involved in cell survival, proliferation, differentiation, and inflammation. The molecular basis by which NF-κB activates endogenous promoters is largely unknown, but it seems likely that it should include the means to tailor transcriptional output to match the wide functional range of its target genes. To dissect NF-κB–driven transcription at native promoters, we disrupted the interaction between NF-κB p65 and the Mediator complex. We found that expression of many endogenous NF-κB target genes depends on direct contact between p65 and Mediator, and that this occurs through the Trap-80 subunit and the TA1 and TA2 regions of p65. Unexpectedly, however, a subset of p65-dependent genes are transcribed normally even when the interaction of p65 with Mediator is abolished. Moreover, a mutant form of p65 lacking all transcription activation domains previously identified in vitro can still activate such promoters in vivo. We found that without p65, native NF-κB target promoters cannot be bound by secondary transcription factors. Artificial recruitment of a secondary transcription factor was able to restore transcription of an otherwise NF-κB–dependent target gene in the absence of p65, showing that the control of promoter occupancy constitutes a second, independent mode of transcriptional activation by p65. This mode enables a subset of promoters to utilize a wide choice of transcription factors, with the potential to regulate their expression accordingly, whilst remaining dependent for their activation on NF-κB. Transcriptional activation by the NF-κB family of transcription factors is crucial for the expression of multiple genes involved in cell survival, proliferation, differentiation, and inflammation. The activation domain of the p65 subunit of NF-κB has been extensively studied in vitro and on artificial reporter plasmids, but the molecular basis by which it drives expression of natural target genes in vivo is still not well understood. Moreover, it is unclear how any single activation mechanism could allow different target genes to fine tune their timing and expression according to their biological requirements. To address this, we experimentally blocked the interaction of p65 with the Mediator complex—a key factor for transcription by most, if not all, activators. While this prevented expression of many NF-κB–dependent genes, others were unaffected, revealing that p65 is able to drive their expression by an independent mode, which does not depend on direct contact with Mediator. Further experiments indicated that p65 accomplishes this by controlling the recruitment of other, secondary transcription factors to its target promoters. This may enable NF-κB to retain overall control over activation of its target genes, but at the same time allow secondary transcription factors to specify appropriate expression levels according to the cell-type and stimulus. The p65 subunit of NF-κB drives expression of target genes not only as a classical activator, via direct interactions with the basic transcriptional machinery, but also independently by controlling the recruitment of secondary transcription factors to target promoters.
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Affiliation(s)
| | - Bettina Engist
- Max Planck Institute for Immunobiology, Freiburg, Germany
| | - Gioacchino Natoli
- Department of Experimental Oncology, European Institute of Oncology (IEO), IFOM-IEO Campus, Milan, Italy
| | - Simona Saccani
- Max Planck Institute for Immunobiology, Freiburg, Germany
- * To whom correspondence should be addressed. E-mail:
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Piluso G, D'Amico F, Saccone V, Bismuto E, Rotundo IL, Di Domenico M, Aurino S, Schwartz CE, Neri G, Nigro V. A missense mutation in CASK causes FG syndrome in an Italian family. Am J Hum Genet 2009; 84:162-77. [PMID: 19200522 DOI: 10.1016/j.ajhg.2008.12.018] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Revised: 12/19/2008] [Accepted: 12/27/2008] [Indexed: 11/19/2022] Open
Abstract
First described in 1974, FG syndrome (FGS) is an X-linked multiple congenital anomaly/mental retardation (MCA/MR) disorder, characterized by high clinical variability and genetic heterogeneity. Five loci (FGS1-5) have so far been linked to this phenotype on the X chromosome, but only one gene, MED12, has been identified to date. Mutations in this gene account for a restricted number of FGS patients with a more distinctive phenotype, referred to as the Opitz-Kaveggia phenotype. We report here that a p.R28L (c.83G-->T) missense mutation in CASK causes FGS phenotype in an Italian family previously mapped to Xp11.4-p11.3 (FGS4). The identified missense mutation cosegregates with the phenotype in this family and is absent in 1000 control X chromosomes of the same ethnic origin. An extensive analysis of CASK protein functions as well as structural and dynamic studies performed by molecular dynamics (MD) simulation did not reveal significant alterations induced by the p.R28L substitution. However, we observed a partial skipping of the exon 2 of CASK, presumably a consequence of improper recognition of exonic splicing enhancers (ESEs) induced by the c.83G-->T transversion. CASK is a multidomain scaffold protein highly expressed in the central nervous system (CNS) with specific localization to the synapses, where it forms large signaling complexes regulating neurotransmission. We suggest that the observed phenotype is most likely a consequence of an altered CASK expression profile during embryogenesis, brain development, and differentiation.
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Affiliation(s)
- Giulio Piluso
- Dipartimento di Patologia Generale, Seconda Università degli Studi di Napoli, Napoli 80138, Italy.
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14
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Esnault C, Ghavi-Helm Y, Brun S, Soutourina J, Van Berkum N, Boschiero C, Holstege F, Werner M. Mediator-dependent recruitment of TFIIH modules in preinitiation complex. Mol Cell 2008; 31:337-46. [PMID: 18691966 DOI: 10.1016/j.molcel.2008.06.021] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2007] [Revised: 02/10/2008] [Accepted: 06/01/2008] [Indexed: 11/18/2022]
Abstract
In vitro, without Mediator, the association of general transcription factors (GTF) and RNA polymerase II (Pol II) in preinitiation complexes (PIC) occurs in an orderly fashion. In this work, we explore the in vivo function of Mediator in GTF recruitment to PIC. A direct interaction between Med11 Mediator head subunit and Rad3 TFIIH subunit was identified. We explored the significance of this interaction and those of Med11 with head module subunits Med17 and Med22 and found that impairing these interactions could differentially affect the recruitment of TFIIH, TFIIE, and Pol II in the PIC. A med11 mutation that altered promoter occupancy by the TFIIK kinase module of TFIIH genome-wide also reduced Pol II CTD serine 5 phosphorylation. We conclude that the Mediator head module plays a critical role in TFIIH and TFIIE recruitment to the PIC. We identify steps in PIC formation that suggest a branched assembly pathway.
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15
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Ding N, Zhou H, Esteve PO, Chin HG, Kim S, Xu X, Joseph SM, Friez MJ, Schwartz CE, Pradhan S, Boyer TG. Mediator links epigenetic silencing of neuronal gene expression with x-linked mental retardation. Mol Cell 2008; 31:347-59. [PMID: 18691967 DOI: 10.1016/j.molcel.2008.05.023] [Citation(s) in RCA: 183] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2007] [Revised: 04/20/2008] [Accepted: 05/29/2008] [Indexed: 11/18/2022]
Abstract
Mediator occupies a central role in RNA polymerase II transcription as a sensor, integrator, and processor of regulatory signals that converge on protein-coding gene promoters. Compared to its role in gene activation, little is known regarding the molecular mechanisms and biological implications of Mediator as a transducer of repressive signals. Here we describe a protein interaction network required for extraneuronal gene silencing comprising Mediator, G9a histone methyltransferase, and the RE1 silencing transcription factor (REST; also known as neuron restrictive silencer factor, NRSF). We show that the MED12 interface in Mediator links REST with G9a-dependent histone H3K9 dimethylation to suppress neuronal genes in nonneuronal cells. Notably, missense mutations in MED12 causing the X-linked mental retardation (XLMR) disorders FG syndrome and Lujan syndrome disrupt its REST corepressor function. These findings implicate Mediator in epigenetic restriction of neuronal gene expression to the nervous system and suggest a pathologic basis for MED12-associated XLMR involving impaired REST-dependent neuronal gene regulation.
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Affiliation(s)
- Ning Ding
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78245, USA
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16
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Willis IM, Chua G, Tong AH, Brost RL, Hughes TR, Boone C, Moir RD. Genetic interactions of MAF1 identify a role for Med20 in transcriptional repression of ribosomal protein genes. PLoS Genet 2008; 4:e1000112. [PMID: 18604275 PMCID: PMC2435279 DOI: 10.1371/journal.pgen.1000112] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Accepted: 05/28/2008] [Indexed: 11/19/2022] Open
Abstract
Transcriptional repression of ribosomal components and tRNAs is coordinately regulated in response to a wide variety of environmental stresses. Part of this response involves the convergence of different nutritional and stress signaling pathways on Maf1, a protein that is essential for repressing transcription by RNA polymerase (pol) III in Saccharomyces cerevisiae. Here we identify the functions buffering yeast cells that are unable to down-regulate transcription by RNA pol III. MAF1 genetic interactions identified in screens of non-essential gene-deletions and conditionally expressed essential genes reveal a highly interconnected network of 64 genes involved in ribosome biogenesis, RNA pol II transcription, tRNA modification, ubiquitin-dependent proteolysis and other processes. A survey of non-essential MAF1 synthetic sick/lethal (SSL) genes identified six gene-deletions that are defective in transcriptional repression of ribosomal protein (RP) genes following rapamycin treatment. This subset of MAF1 SSL genes included MED20 which encodes a head module subunit of the RNA pol II Mediator complex. Genetic interactions between MAF1 and subunits in each structural module of Mediator were investigated to examine the functional relationship between these transcriptional regulators. Gene expression profiling identified a prominent and highly selective role for Med20 in the repression of RP gene transcription under multiple conditions. In addition, attenuated repression of RP genes by rapamycin was observed in a strain deleted for the Mediator tail module subunit Med16. The data suggest that Mediator and Maf1 function in parallel pathways to negatively regulate RP mRNA and tRNA synthesis. The Maf1 protein is an essential negative regulator of transcription by RNA polymerase III in S. cerevisiae and functions to integrate responses from diverse nutritional and stress signaling pathways that coordinately regulate ribosome and tRNA synthesis. These signaling pathways are not well-defined, and efforts to understand the role of Maf1 in this process have been complicated by a lack of known functional motifs in the protein and by a paucity of direct physical interactions with Maf1. To understand the biological importance of down-regulating RNA polymerase III transcription and to identify functional relationships with Maf1, we employed synthetic genetic array (SGA) analysis. We show that the genetic neighborhood around Maf1 is highly interconnected and enriched for a small number of functional categories, most of which are logically linked to the function of Maf1 as the regulator of RNA polymerase III transcription. We found that deletions in a subset of MAF1 SSL genes, including subunits of the RNA polymerase II Mediator complex, lead to defects in transcriptional repression of ribosomal protein (RP) genes. Since Mediator subunits are not efficiently cross-linked to RP genes in chromatin, our results suggest that Mediator interactions with these highly expressed genes are fundamentally different from many other genes.
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Affiliation(s)
- Ian M Willis
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, United States of America.
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17
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Abstract
The Mediator complex is a fluid assemblage of approximately 25 proteins that is essential for eukaryotic transcriptional regulation. Mediator of RNA polymerase II transcription (MED)12 (HOPA) is a 25-kb Xq13 member of the Mediator complex that plays a key role in the complex and directly moderates receptor tyrosine kinase, nuclear receptor and Wnt pathway signaling. Sequence variation in two MED12 protein domains has been linked to neuropsychiatric illness. First, variants in the Leu-Ser domain have been linked to Opitz-Kaveggia and Lujan syndromes, which are forms of X-linked mental retardation. Second, a balanced polymorphism in the C terminus opposite-paired domain, a key motif in the MED12-mediated transcriptional repression of Wnt signaling, has been associated with increased risk for psychosis. We conclude that variation of MED12 is associated with a wide variety of clinical presentations whose severity is dependent on the location and nature of the variation, and that a thorough understanding of MED12's role in transcriptional regulation could have significant benefits for human healthcare.
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Affiliation(s)
- Robert A Philibert
- The University of Iowa, Department of Psychiatry, Neuroscience Program, Room 2-126 MEB, Iowa City, IA 52242-1000, USA.
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18
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Guglielmi B, Soutourina J, Esnault C, Werner M. TFIIS elongation factor and Mediator act in conjunction during transcription initiation in vivo. Proc Natl Acad Sci U S A 2007; 104:16062-7. [PMID: 17901206 PMCID: PMC2042162 DOI: 10.1073/pnas.0704534104] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The transcription initiation and elongation steps of protein-coding genes usually rely on unrelated protein complexes. However, the TFIIS elongation factor is implicated in both processes. We found that, in the absence of the Med31 Mediator subunit, yeast cells required the TFIIS polymerase II (Pol II)-binding domain but not its RNA cleavage stimulatory activity that is associated with its elongation function. We also found that the TFIIS Pol II-interacting domain was needed for the full recruitment of Pol II to several promoters in the absence of Med31. This work demonstrated that, in addition to its thoroughly characterized role in transcription elongation, TFIIS is implicated through its Pol II-binding domain in the formation or stabilization of the transcription initiation complex in vivo.
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Affiliation(s)
- Benjamin Guglielmi
- Commissariat à l'Energie Atomique, Institut de Biologie et Technologies de Saclay, Bâtiment 144, Commissariat à l'Energie Atomique/Saclay, Gif-sur-Yvette Cedex F-91191, France
| | - Julie Soutourina
- Commissariat à l'Energie Atomique, Institut de Biologie et Technologies de Saclay, Bâtiment 144, Commissariat à l'Energie Atomique/Saclay, Gif-sur-Yvette Cedex F-91191, France
| | - Cyril Esnault
- Commissariat à l'Energie Atomique, Institut de Biologie et Technologies de Saclay, Bâtiment 144, Commissariat à l'Energie Atomique/Saclay, Gif-sur-Yvette Cedex F-91191, France
| | - Michel Werner
- Commissariat à l'Energie Atomique, Institut de Biologie et Technologies de Saclay, Bâtiment 144, Commissariat à l'Energie Atomique/Saclay, Gif-sur-Yvette Cedex F-91191, France
- To whom correspondence should be addressed. E-mail:
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19
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Beyer KS, Beauchamp RL, Lee MF, Gusella JF, Näär AM, Ramesh V. Mediator subunit MED28 (Magicin) is a repressor of smooth muscle cell differentiation. J Biol Chem 2007; 282:32152-7. [PMID: 17848560 DOI: 10.1074/jbc.m706592200] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Magicin, a protein that we isolated earlier as an interactor of the neurofibromatosis 2 protein merlin, was independently identified as MED28, a subunit of the mammalian Mediator complex. Mediator complex is an evolutionarily conserved transcriptional cofactor, which plays an essential role in positive and negative gene regulation. Distinct Mediator subunit composition is thought to contribute to gene regulation specificity based on the interaction of specific subunits with subsets of transcription factors. Here we report that down-regulation of Med28 expression in NIH3T3 cells results in a significant induction of several genes associated with smooth muscle cell (SMC) differentiation. Conversely, overexpression of MED28 represses expression of SMC genes, in concordance with our knockdown data. More importantly, multipotent mesenchymal-derived murine precursors can transdifferentiate into SMCs when Med28 is down-regulated. Our data also show that Med28 functions as a negative regulator of SMC differentiation in concert with other Mediator subunits including Med6, Med8, and Med18 within the Mediator head module. Our results provide strong evidence that MED28 may function as a scaffolding protein by maintaining the stability of a submodule within the head module and that components of this submodule act together in a gene regulatory program to suppress SMC differentiation. The results presented here demonstrate for the first time that the mammalian Mediator subunit MED28 functions as a repressor of SMC differentiation, which could have implications for disorders associated with abnormalities in SMC growth and differentiation, including atherosclerosis, asthma, hypertension, and smooth muscle tumors.
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Affiliation(s)
- Kim S Beyer
- Molecular Neurogenetics Unit, Center for Human Genetic Research, Massachusetts General Hospital, Boston 02114, and Department of Cell Biology, Harvard Medical School, Charlestown, Massachusetts 02129, USA
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20
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Philibert RA, Bohle P, Secrest D, Deaderick J, Sandhu H, Crowe R, Black DW. The association of the HOPA(12bp) polymorphism with schizophrenia in the NIMH Genetics Initiative for Schizophrenia sample. Am J Med Genet B Neuropsychiatr Genet 2007; 144B:743-7. [PMID: 17299734 DOI: 10.1002/ajmg.b.30489] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
HOPA (MED12) is an X-chromosome gene that codes for a critical member of the Mediator Complex, a group of proteins that regulates transcription via the nuclear receptor, Wnt and Receptor Tyrosine Kinase pathways. In prior association and meta-analyses, we have shown that the presence of an evolutionarily conserved, 12 bp (4 amino acid) insertional polymorphism in exon 43 of this gene is associated with increased risk for an endophenotype of schizophrenia. In this communication, we describe the results of our work with subjects and data from the National Institutes of Mental Health (NIMH) Genetics Initiative for Schizophrenia. We report that the presence of the HOPA(12bp) polymorphism is associated with increased risk for schizophrenia in subjects of European ancestry. In the light of this new study and the prior wealth of clinical and basic science data, we conclude that the HOPA(12bp) allele is a risk factor for schizophrenia in subjects of European ancestry and suggest that further studies to define the endophenotype and mechanisms of illness associated with this polymorphism are indicated.
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Affiliation(s)
- Robert A Philibert
- Department of Psychiatry, The University of Iowa, Iowa City, Iowa 52242-1000, USA.
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21
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Lee HK, Park UH, Kim EJ, Um SJ. MED25 is distinct from TRAP220/MED1 in cooperating with CBP for retinoid receptor activation. EMBO J 2007; 26:3545-57. [PMID: 17641689 PMCID: PMC1949011 DOI: 10.1038/sj.emboj.7601797] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2006] [Accepted: 06/04/2007] [Indexed: 11/08/2022] Open
Abstract
We isolated MED25, which associates with retinoic acid (RA)-bound retinoic acid receptor (RAR) through the C-terminal nuclear hormone receptor (NR) box/LxxLL motif, and increases RAR/RXR-mediated transcription. When tethered to a promoter, MED25 showed intrinsic transcriptional activity in its PTOV domain, which is likely accomplished by direct association with CBP. Reporter assays using dominant negatives of MED25 demonstrated the importance of the N-terminal Mediator-binding and C-terminal domains in CBP and RAR/RXR binding, which affect MED25 activity. Downregulation of MED25 specifically reduced RAR but not thyroid hormone receptor (TR) activity. Stimulation of RAR by MED25 was correlated with enhanced RA cytotoxicity in vivo. Chromatin immunoprecipitation (ChIP) assays revealed the RA-dependent recruitment of MED25 to the RARbeta2 promoter. Recruitment of CBP and TRAP220 was diminished by the overexpression of a MED25 NR box deletion mutant, and by treatment with MED25 siRNA. Time-course ChIP assays indicated that CBP, together with RAR and MED25, is recruited early, whereas TRAP220 is recruited later to the promoter. Our data suggest that MED25, in cooperation with CBP and Mediators through its distinct domains, imposes a selective advantage on RAR/RXR activation.
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Affiliation(s)
- Hye-Kyung Lee
- Department of Bioscience and Biotechnology, Institute of Bioscience, Sejong University, Seoul, Korea
| | - Ui-Hyun Park
- Department of Bioscience and Biotechnology, Institute of Bioscience, Sejong University, Seoul, Korea
| | - Eun-Joo Kim
- Department of Bioscience and Biotechnology, Institute of Bioscience, Sejong University, Seoul, Korea
| | - Soo-Jong Um
- Department of Bioscience and Biotechnology, Institute of Bioscience, Sejong University, Seoul, Korea
- Chebigen Inc., 305-B, Chungmugwan, Sejong University, Seoul, Korea
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22
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Abstract
PURPOSE The FG syndrome, also known as Opitz-Kaveggia syndrome, is an X-linked disorder characterized by developmental delay, congenital hypotonia, characteristic facial appearance, relative macrocephaly and anomalies affecting the genitourinary, gastrointestinal and musculoskeletal systems. Genitourinary abnormalities in the FG syndrome include cryptorchidism, hypospadias, inguinal hernia, hydrocele and occasional anomalies of renal or ureteral development. To our knowledge no previous study has systematically evaluated the genitourinary aspects of the disorder. We describe the genitourinary anomalies seen in children with the FG syndrome. This report may help elucidate the pathogenic mechanisms responsible for the disorder. Also, we provide a simple checklist for urologists that will help guide referrals for genetics and other specialty consultations. MATERIALS AND METHODS We retrospectively reviewed 228 patients with the FG syndrome to identify the frequency of characteristic historical and physical findings. These patients were diagnosed on the basis of a firsthand history and physical examination, or by a careful outside evaluation including detailed records and photographs. RESULTS Of the patients 90% were male. The overall incidence of any genitourinary anomaly was 48.5% in boys, 13.6% in girls and 44.7% overall. In boys the most common abnormalities were cryptorchidism (24%), hypospadias (14%) and hernia or hydrocele (13%). CONCLUSIONS The FG syndrome is a disorder with a greater prevalence than previously thought, yet is rarely suspected by urologists. The manifestations may be complex. Identification of patients with syndromal genitourinary anomalies by urologists will enhance the quality of care based on referral of patients for additional evaluation.
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MESH Headings
- Abnormalities, Multiple/diagnosis
- Abnormalities, Multiple/genetics
- Abnormalities, Multiple/surgery
- Child
- Child, Preschool
- Chromosomes, Human, X/genetics
- Craniofacial Abnormalities/diagnosis
- Craniofacial Abnormalities/genetics
- Cryptorchidism/diagnosis
- Cryptorchidism/genetics
- Cryptorchidism/surgery
- Developmental Disabilities/diagnosis
- Developmental Disabilities/genetics
- Diagnosis, Differential
- Facies
- Female
- Follow-Up Studies
- Hernia, Inguinal/diagnosis
- Hernia, Inguinal/genetics
- Hernia, Inguinal/surgery
- Humans
- Hypospadias/diagnosis
- Hypospadias/genetics
- Hypospadias/surgery
- Infant
- Male
- Mediator Complex
- Muscle Hypotonia/diagnosis
- Muscle Hypotonia/genetics
- Mutation
- Phenotype
- Receptors, Thyroid Hormone/genetics
- Referral and Consultation
- Sex Chromosome Aberrations
- Syndrome
- Testicular Hydrocele/diagnosis
- Testicular Hydrocele/genetics
- Testicular Hydrocele/surgery
- Urogenital Abnormalities/diagnosis
- Urogenital Abnormalities/genetics
- Urogenital Abnormalities/surgery
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Affiliation(s)
- James F Smith
- Division of Urology, University of Utah, Salt Lake City, Utah, USA
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24
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Affiliation(s)
- Douglas L Mann
- Winters Center for Heart Failure Research, Baylor College of Medicine, Houston, USA
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25
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Kob R, Baniahmad A, Escher N, von Eggeling F, Melle C. Detection and identification of transcription factors as interaction partners of alien in vivo. Cell Cycle 2007; 6:993-6. [PMID: 17438371 DOI: 10.4161/cc.6.8.4108] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Interacting proteins are often involved in the same cellular processes, and thus the identification of interacting partners of a given protein with unknown function may give insight into the physiological role of this protein. For the detection of protein-protein interactions of the corepressor Alien we used a proteomic approach comprising mass spectrometry and immunological techniques. We assessed solely endogenously expressed proteins. In this study we present for the first time that Alien is interacting within a network of proteins involved in transcriptional regulation, DNA repair, and cell cycle in vivo. In this way we detected protein interactions of Alien involving nucleophosmin, ERCC3, TRIP11, as well as CRSP3.
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26
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Furumoto T, Tanaka A, Ito M, Malik S, Hirose Y, Hanaoka F, Ohkuma Y. A kinase subunit of the human mediator complex, CDK8, positively regulates transcriptional activation. Genes Cells 2007; 12:119-32. [PMID: 17212659 DOI: 10.1111/j.1365-2443.2007.01036.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The human thyroid hormone receptor-associated proteins (TRAP)/Mediator and related complexes mediate transcription through regulatory factors. To further understand the structural and functional diversity of these complexes we established three HeLa cell lines each expressing one of three epitope-tagged human TRAP/Mediator subunits, MED6, MED7, and CDK8 and isolated the complexes in which these subunits were contained by affinity and HPLC-gel filtration chromatography. The largest complexes from each cell line had a molecular mass of 1.5 MDa and possessed almost identical subunit compositions; we designated these complexes TRAP/Mediator-like complex 1 (TMLC1). Two potential subcomplexes were additionally observed: a 1-MDa complex from the CDK8-cell line (TMLC2) and a 600-kDa complex from the MED6-cell line (TMLC3). All three complexes regulated transcription in vitro; TMLC1 and TMLC3 augmented transcriptional activation, whereas TMLC2 repressed it. TMLC1 and TMLC2 phosphorylated RNA polymerase II (Pol II), but TMLC3 did not. Furthermore, TMLC1 predominantly interacted with the general transcription factors TFIIE, TFIIF, and TFIIH, which function during transcription initiation and the transition to elongation. In a final experiment, knockdown of CDK8 using RNA interference prevented transcriptional activation by Gal4-VP16 in a luciferase-assay. This, together with the effect of TMLC1 on transcription in vitro, suggests that CDK8 play positive roles in transcriptional activation.
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Affiliation(s)
- Tadashi Furumoto
- Graduate School of Frontier Biosciences, Osaka Universuty, Suita, Osaka 565-0871, Japan
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27
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Abstract
EG-1 is a gene product that is significantly elevated in human breast cancer tissues. Previously, we have shown that EG-1 overexpression stimulates cellular proliferation both in vitro and in vivo. Here, we ask whether this molecule can be targeted for experimental therapeutic purpose. siRNA lentivirus and polyclonal antibodies were designed to suppress EG-1 expression. These agents were then used in cell culture proliferation assays and breast tumor xenograft models. Serum and urine from breast cancer patients were also analyzed for the presence of EG-1 peptide. We report here for the first time that endogenous EG-1 can be targeted to inhibit breast tumor growth. This inhibition, whether delivered via siRNA lentivirus or polyclonal antibody, resulted in decreased cellular proliferation in culture and smaller xenografts in mice. The effects were shown in both ER (estrogen receptor)-positive human breast cancer MCF-7 cells, as well as in ER-negative MDA-MB-231 cells. Furthermore, we detected soluble EG-1 in serum and urine of breast cancer patients. These observations demonstrate that EG-1 is relevant to human breast cancer, and is a molecular target worthy of translational efforts into effective breast cancer therapy.
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Affiliation(s)
- Ming Lu
- University of California, Los Angeles School of Medicine, Department of Surgery, Division of Oncology, Los Angeles, California, USA
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28
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Abstract
The heart responds to diverse forms of stress by hypertrophic growth accompanied by fibrosis and eventual diminution of contractility, which results from down-regulation of alpha-myosin heavy chain (alphaMHC) and up-regulation of betaMHC, the primary contractile proteins of the heart. We found that a cardiac-specific microRNA (miR-208) encoded by an intron of the alphaMHC gene is required for cardiomyocyte hypertrophy, fibrosis, and expression of betaMHC in response to stress and hypothyroidism. Thus, the alphaMHC gene, in addition to encoding a major cardiac contractile protein, regulates cardiac growth and gene expression in response to stress and hormonal signaling through miR-208.
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Affiliation(s)
- Eva van Rooij
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148, USA
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Schwartz CE, Tarpey PS, Lubs HA, Verloes A, May MM, Risheg H, Friez MJ, Futreal PA, Edkins S, Teague J, Briault S, Skinner C, Bauer-Carlin A, Simensen RJ, Joseph SM, Jones JR, Gecz J, Stratton MR, Raymond FL, Stevenson RE. The original Lujan syndrome family has a novel missense mutation (p.N1007S) in the MED12 gene. J Med Genet 2007; 44:472-7. [PMID: 17369503 PMCID: PMC2597996 DOI: 10.1136/jmg.2006.048637] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
A novel missense mutation in the mediator of RNA polymerase II transcription subunit 12 (MED12) gene has been found in the original family with Lujan syndrome and in a second family (K9359) that was initially considered to have Opitz-Kaveggia (FG) syndrome. A different missense mutation in the MED12 gene has been reported previously in the original family with FG syndrome and in five other families with compatible clinical findings. Neither sequence alteration has been found in over 1400 control X chromosomes. Lujan (Lujan-Fryns) syndrome is characterised by tall stature with asthenic habitus, macrocephaly, a tall narrow face, maxillary hypoplasia, a high narrow palate with dental crowding, a small or receding chin, long hands with hyperextensible digits, hypernasal speech, hypotonia, mild-to-moderate mental retardation, behavioural aberrations and dysgenesis of the corpus callosum. Although Lujan syndrome has not been previously considered to be in the differential diagnosis of FG syndrome, there are some overlapping clinical manifestations. Specifically, these are dysgenesis of the corpus callosum, macrocephaly/relative macrocephaly, a tall forehead, hypotonia, mental retardation and behavioural disturbances. Thus, it seems that these two X-linked mental retardation syndromes are allelic, with mutations in the MED12 gene.
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Risheg H, Graham JM, Clark RD, Rogers RC, Opitz JM, Moeschler JB, Peiffer AP, May M, Joseph SM, Jones JR, Stevenson RE, Schwartz CE, Friez MJ. A recurrent mutation in MED12 leading to R961W causes Opitz-Kaveggia syndrome. Nat Genet 2007; 39:451-3. [PMID: 17334363 DOI: 10.1038/ng1992] [Citation(s) in RCA: 155] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2006] [Accepted: 02/01/2007] [Indexed: 11/10/2022]
Abstract
Opitz-Kaveggia syndrome (also known as FG syndrome) is an X-linked disorder characterized by mental retardation, relative macrocephaly, hypotonia and constipation. We report here that the original family for whom the condition is named and five other families have a recurrent mutation (2881C>T, leading to R961W) in MED12 (also called TRAP230 or HOPA), a gene located at Xq13 that functions as a thyroid receptor-associated protein in the Mediator complex.
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Affiliation(s)
- Hiba Risheg
- Greenwood Genetic Center, Greenwood, South Carolina 29646, USA
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Kuuselo R, Savinainen K, Azorsa DO, Basu GD, Karhu R, Tuzmen S, Mousses S, Kallioniemi A. Intersex-like (IXL) is a cell survival regulator in pancreatic cancer with 19q13 amplification. Cancer Res 2007; 67:1943-9. [PMID: 17332321 DOI: 10.1158/0008-5472.can-06-3387] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Pancreatic cancer is a highly aggressive disease characterized by poor prognosis and vast genetic instability. Recent microarray-based, genome-wide surveys have identified multiple recurrent copy number aberrations in pancreatic cancer; however, the target genes are, for the most part, unknown. Here, we characterized the 19q13 amplicon in pancreatic cancer to identify putative new drug targets. Copy number increases at 19q13 were quantitated in 16 pancreatic cancer cell lines and 31 primary tumors by fluorescence in situ hybridization. Cell line copy number data delineated a 1.1 Mb amplicon, the presence of which was also validated in 10% of primary pancreatic tumors. Comprehensive expression analysis by quantitative real-time reverse transcription-PCR indicated that seven transcripts within this region had consistently elevated expression levels in the amplified versus nonamplified cell lines. High-throughput loss-of-function screen by RNA interference was applied across the amplicon to identify genes whose down-regulation affected cell viability. This screen revealed five genes whose down-regulation led to significantly decreased cell viability in the amplified PANC-1 cells but not in the nonamplified MiaPaca-2 cells, suggesting the presence of multiple biologically interesting genes in this region. Of these, the transcriptional regulator intersex-like (IXL) was consistently overexpressed in amplified cells and had the most dramatic effect on cell viability. IXL silencing also resulted in G(0)-G(1) cell cycle arrest and increased apoptosis in PANC-1 cells. These findings implicate IXL as a novel amplification target gene in pancreatic cancer and suggest that IXL is required for cancer cell survival in 19q13-amplified tumors.
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Affiliation(s)
- Riina Kuuselo
- Laboratory of Cancer Genetics, Institute of Medical Technology, University of Tampere and Tampere University Hospital, Tampere, Finland
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32
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Abstract
The Saccharomyces cerevisiae Mediator is a 25-subunit complex that facilitates both transcriptional activation and repression. Structural and functional studies have divided Mediator subunits into four distinct modules. The Head, Middle, and Tail modules form the core functional Mediator complex, whereas a fourth, the Cyc-C module, is variably associated with the core. By purifying Mediator from a strain lacking the Med19(Rox3) subunit, we have found that a complex missing only the Med19(Rox3) subunit can be isolated under mild conditions. Additionally, we have established that the entire Middle module is released when the Deltamed19(rox3) Mediator is purified under more stringent conditions. In contrast to most models of the modular structure of Mediator, we show that release of the Middle module in the Deltamed19(rox3) Mediator leaves a stable complex made up solely of Head and Tail subunits. Both the intact and Head-Tail Deltamed19(rox3) Mediator complexes have defects in enhanced basal transcription, enhanced TFIIH phosphorylation of the CTD, as well as binding of RNA Pol II and the CTD. The largely intact Deltamed19(rox3) complex facilitates activated transcription at levels similar to the wild type Mediator. In the absence of the Middle module, however, the Deltamed19(rox3) Mediator is unable to facilitate activated transcription. Although the Middle module is unnecessary for holding the Head and Tail modules together, it is required for the complex to function as a conduit between activators and the core transcription machinery.
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Affiliation(s)
- Shamara M Baidoobonso
- Department of Biochemistry, Dartmouth Medical School, Hanover, New Hampshire 03755, USA
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Lee J, Safe S. Coactivation of estrogen receptor alpha (ER alpha)/Sp1 by vitamin D receptor interacting protein 150 (DRIP150). Arch Biochem Biophys 2007; 461:200-10. [PMID: 17306756 PMCID: PMC1978170 DOI: 10.1016/j.abb.2006.12.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Accepted: 12/24/2006] [Indexed: 11/30/2022]
Abstract
Vitamin D receptor interacting protein (DRIP150) coactivates estrogen receptor alpha (ERalpha)-mediated transactivation in breast cancer cell lines transfected with a construct (pERE(3)) containing three estrogen responsive elements (EREs). In this study, we show that DRIP150 also coactivates ERalpha/Sp1-mediated transactivation in ZR-75, MCF-7, and MDA-MB-231 breast cancer cells transfected with a construct (pSp1(3)) containing three consensus GC-rich motifs. Studies on coactivation of wild-type and variant ERalpha/Sp1 by DRIP150 indicates that the DNA-binding domain and helix 12 in the ligand binding domain of ERalpha are required and the coactivation response is squelched by overexpressing an NR-box peptide that contains two LXXLL motifs from GRIP2. In contrast, coactivation of ERalpha/Sp1 by wild-type and mutant DRIP150 expression plasmids show that coactivation of ERalpha/Sp1 by DRIP150 is independent of the NR-boxes. Deletion analysis of DRIP150 demonstrates that coactivation requires an alpha-helical NIFSEVRVYN (amino acids 795-804) motif within 23 amino acid sequence (789-811) in the central region of DRIP150 and similar results were obtained for coactivation of ERalpha by DRIP150. Thus, although different domains of ERalpha are required for hormone-dependent activation of ERalpha and ERalpha/Sp1, coactivation of these transcription factors by DRIP150 requires the alpha-helical amino acids 795-804. This is the first report of a coactivator that enhances ERalpha/Sp1-mediated transactivation in breast cancer cells.
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Affiliation(s)
- Jeongeun Lee
- Department of Veterinary Physiology and Pharmacology, Texas A&M University College Station, TX 77843-4466
| | - Stephen Safe
- Department of Veterinary Physiology and Pharmacology, Texas A&M University College Station, TX 77843-4466
- Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX 77030-3303
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Lallet S, Garreau H, Garmendia-Torres C, Szestakowska D, Boy-Marcotte E, Quevillon-Chéruel S, Jacquet M. Role of Gal11, a component of the RNA polymerase II mediator in stress-induced hyperphosphorylation of Msn2 in Saccharomyces cerevisiae. Mol Microbiol 2007; 62:438-52. [PMID: 17020582 DOI: 10.1111/j.1365-2958.2006.05363.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
In the yeast Saccharomyces cerevisiae, the Msn2 transcription factor is a key element in mediating the environmental stress response (ESR), leading to the induction of 100-200 genes through the cis-acting Stress Response Element (STRE) in response to various physico-chemical stresses and nutritional variations. This activation is accompanied by a stress-induced hyperphosphorylation of Msn2. By a systematic screening we identified two proteins essential in this process: (i) the cyclin-dependent Ssn3/Srb10 protein kinase, part of a module of the RNA polymerase II mediator, which has already been shown to be involved in hyperphosphorylation and degradation of Msn2 upon stress, and (ii) Gal11, a component of the mediator. In a gal11 mutant, stress-induced hyperphosphorylation of Msn2 is abolished, stress-induced transcription of Msn2-dependent genes is decreased and Msn2 degradation is impaired. Rgr1, another component of the mediator, is also critical for this hyperphosphorylation, indicating that the integrity of the mediator is required for this process. Moreover the transactivating region of Msn2 interacts in vitro with the N-terminal domain of Gal11. These results point out the role of the mediator, especially its Gal11 subunit, in the hyperphosphorylation and degradation of Msn2 during stress response.
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Affiliation(s)
- Sylvie Lallet
- Laboratoire Polarité cellulaire, Traffic membranaire & Signalisation, UMR 6061 CNRS, Université Rennes 1, Faculté de Médecine, 2 Avenue du Pr Léon Bernard, CS 34317, 35043 Rennes Cedex, France
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35
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Ren J, Kee Y, Huibregtse JM, Piper RC. Hse1, a component of the yeast Hrs-STAM ubiquitin-sorting complex, associates with ubiquitin peptidases and a ligase to control sorting efficiency into multivesicular bodies. Mol Biol Cell 2007; 18:324-35. [PMID: 17079730 PMCID: PMC1751313 DOI: 10.1091/mbc.e06-06-0557] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2006] [Revised: 10/16/2006] [Accepted: 10/19/2006] [Indexed: 11/11/2022] Open
Abstract
Ubiquitinated integral membrane proteins are delivered to the interior of the lysosome/vacuole for degradation. This process relies on specific ubiquitination of potential cargo and recognition of that Ub-cargo by sorting receptors at multiple compartments. We show that the endosomal Hse1-Vps27 sorting receptor binds to ubiquitin peptidases and the ubiquitin ligase Rsp5. Hse1 is linked to Rsp5 directly via a PY element within its C-terminus and through a novel protein Hua1, which recruits a complex of Rsp5, Rup1, and Ubp2. The SH3 domain of Hse1 also binds to the deubiquitinating protein Ubp7. Functional analysis shows that when both modes of Rsp5 association with Hse1 are altered, sorting of cargo that requires efficient ubiquitination for entry into the MVB is blocked, whereas sorting of cargo containing an in-frame addition of ubiquitin is normal. Further deletion of Ubp7 restores sorting of cargo when the Rsp5:Hse1 interaction is compromised suggesting that both ubiquitin ligases and peptidases associate with the Hse1-Vps27 sorting complex to control the ubiquitination status and sorting efficiency of cargo proteins. Additionally, we find that disruption of UBP2 and RUP1 inhibits MVB sorting of some cargos suggesting that Rsp5 requires association with Ubp2 to properly ubiquitinate cargo for efficient MVB sorting.
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Affiliation(s)
- Jihui Ren
- *Department of Physiology and Biophysics, University of Iowa, Iowa City, IA 52242; and
| | - Younghoon Kee
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712
| | - Jon M. Huibregtse
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712
| | - Robert C. Piper
- *Department of Physiology and Biophysics, University of Iowa, Iowa City, IA 52242; and
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Abstract
VP16 has been widely used to unravel the mechanisms underlying gene transcription. Much of the previous work has been conducted in reconstituted in vitro systems. Here we study the formation of transcription complexes at stable reporters under the control of an inducible Tet-VP16 activator in living cells. In this simplified model for gene activation VP16 recruits the general factors and the cofactors Mediator, GCN5, CBP, and PC4, within minutes to the promoter region. Activation is accompanied by only minor changes in histone acetylation and H3K4 methylation but induces a marked promoter-specific increase in H3K79 methylation. Mediated through contacts with VP16 several subunits of the cleavage and polyadenylation factor (CPSF/CstF) are concentrated at the promoter region. We provide in vitro and in vivo evidence that VP16 activates transcription through a specific MED25-associated Mediator, which is deficient in CDK8.
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Affiliation(s)
- Thomas Uhlmann
- Gene Expression, National Research Center for Environment and Health, Marchionini-Strasse 25, D-81377 Munich, Germany
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37
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Abstract
The unique profiles of gene expression dictate distinct cellular identity. How these profiles are established during development is not clear. Here we report that the mutant motionless (mot), identified in a genetic screen for mutations that affect neuronal development in zebrafish, displays deficits of monoaminergic neurons and cranial sensory ganglia, whereas expression of the pan-neuronal marker Hu is largely unperturbed; GABAergic and subsets of cranial motor neurons do not appear to be deficient. Positional cloning reveals that mot encodes Med12, a component of the evolutionarily conserved Mediator complex, whose in vivo function is not well understood in vertebrates. mot/med12 transcripts are enriched in the embryonic brain and appear distinct from two other Mediator components Med17 and Med21. Delivery of human med12 RNA into zebrafish restores normality to the mot mutant and, strikingly, leads to premature neuronal differentiation and an increased production of monoaminergic neuronal subtypes in WT. Further investigation reveals that mot/med12 is necessary to regulate, and when overexpressed is capable of increasing, the expression of distinct neuronal determination genes, including zash1a and lim1, and serves as an in vivo cofactor for Sox9 in this process. Together, our analyses reveal a regulatory role of Mot/Med12 in vertebrate neuronal development.
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Affiliation(s)
- Xiaoqun Wang
- *Programs in Genetics, Neuroscience, and Developmental Biology, Department of Biopharmaceutical Sciences, and Center for Human Genetics, University of California, San Francisco, CA 94143; and
| | - Nan Yang
- *Programs in Genetics, Neuroscience, and Developmental Biology, Department of Biopharmaceutical Sciences, and Center for Human Genetics, University of California, San Francisco, CA 94143; and
| | - Etsuko Uno
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10021
| | - Robert G. Roeder
- Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10021
| | - Su Guo
- *Programs in Genetics, Neuroscience, and Developmental Biology, Department of Biopharmaceutical Sciences, and Center for Human Genetics, University of California, San Francisco, CA 94143; and
- To whom correspondence should be addressed. E-mail:
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Léonard VHJ, Kohl A, Hart TJ, Elliott RM. Interaction of Bunyamwera Orthobunyavirus NSs protein with mediator protein MED8: a mechanism for inhibiting the interferon response. J Virol 2006; 80:9667-75. [PMID: 16973571 PMCID: PMC1617248 DOI: 10.1128/jvi.00822-06] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The NSs protein of Bunyamwera virus (Bunyaviridae) is an antiapoptotic interferon antagonist involved in silencing host protein expression by interfering with mRNA synthesis. Here, we show that the ability to inhibit both host transcription and the interferon response is linked to interaction of NSs with the MED8 component of Mediator, a protein complex necessary for mRNA production. The interacting domain on NSs was mapped to the C-terminal region, which contains amino acids conserved among orthobunyavirus NSs proteins. A recombinant virus in which the interacting domain in NSs was deleted had strongly reduced ability to inhibit host protein expression and was unable to inhibit the interferon response. This study provides further information on the mechanisms by which bunyavirus nonstructural proteins are involved in pathogenesis.
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Affiliation(s)
- Vincent H J Léonard
- Division of Virology, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G11 5JR, Scotland, United Kingdom
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39
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Abstract
BACKGROUND It is generally acknowledged that the vast majority of serious mental disorders have significant genetic contributions that manifest complex inheritance patterns. Despite this, few gene polymorphisms have been unambiguously identified as risk factors for behavioral illness and the mechanisms through which these select polymorphisms affect human behavior is completely unclear. One of the major reasons for this lack of progress is the phenomenon of gene-environment (GxE) interactions. METHODS We review prior evidence of GxE interactions for major depressive disorder (MDD) in the Iowa Adoption Studies. RESULTS The results demonstrate the usefulness of these cohorts to direct G effects for MDD. CONCLUSIONS We conclude that further use of the adoption paradigm will generate critical insight into the effects of candidate genes for a variety of complex human behavioral illnesses.
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40
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Lu M, Zhang L, Sartippour MR, Norris AJ, Brooks MN. EG-1 interacts with c-Src and activates its signaling pathway. Int J Oncol 2006; 29:1013-8. [PMID: 16964398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023] Open
Abstract
EG-1 is significantly elevated in breast, colorectal, and prostate cancers. Overexpression of EG-1 stimulates cellular proliferation, and targeted inhibition blocks mouse xenograft tumor growth. To further clarify the function of EG-1, we investigated its role in c-Src activation. We observed that EG-1 overexpression results in activation of c-Src, but found no evidence that EG-1 is a direct Src substrate. EG-1 also binds to other members of the Src family. Furthermore, EG-1 shows interaction with multiple other SH3- and WW-containing molecules involved in various signaling pathways. These observations suggest that EG-1 may be involved in signaling pathways including c-Src activation.
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Affiliation(s)
- Ming Lu
- Department of Surgery, Division of Oncology, UCLA School of Medicine, Los Angeles, CA, USA
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41
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Köffel R, Schneiter R. Yeh1 constitutes the major steryl ester hydrolase under heme-deficient conditions in Saccharomyces cerevisiae. Eukaryot Cell 2006; 5:1018-25. [PMID: 16835446 PMCID: PMC1489292 DOI: 10.1128/ec.00002-06] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Steryl esters are stored in intracellular lipid droplets from which they are mobilized upon demand and hydrolyzed to yield free sterols and fatty acids. The mechanisms that control steryl ester mobilization are not well understood. We have previously identified a family of three lipases of Saccharomyces cerevisiae that are required for efficient steryl ester hydrolysis, Yeh1, Yeh2, and Tgl1 (R. Köffel, R. Tiwari, L. Falquet, and R. Schneiter, Mol. Cell. Biol. 25:1655-1668, 2005). Both Yeh1 and Tgl1 localize to lipid droplets, whereas Yeh2 is localized to the plasma membrane. To characterize the precise function of these three partially redundant lipases, we examined steryl ester mobilization under heme-deficient conditions. S. cerevisiae is a facultative anaerobic organism that becomes auxotrophic for sterols and unsaturated fatty acids in the absence of molecular oxygen. Anaerobic conditions can be mimicked in cells that are deficient for heme synthesis. We here report that Yeh1 is the sole active steryl ester hydrolase under such heme-deficient conditions, indicating that Yeh1 is activated whereas Yeh2 and Tgl1 are inactivated by the lack of heme. The heme-dependent activation of Yeh1 is mediated at least in part by an increase in steady-state levels of Yeh1 at the expense of Yeh2 and Tgl1 in exponentially growing cells. This increase in steady-state levels of Yeh1 requires Rox3, a component of the mediator complex that regulates transcription by RNA polymerase II. These data thus provide the first link between fat degradation and the transcriptional control of lipase activity in yeast.
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Affiliation(s)
- René Köffel
- Department of Medicine, Division of Biochemistry, University of Fribourg, Chemin du Musée 5, CH-1700 Fribourg, Switzerland
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Abstract
The physiological and pathological manifestations of Sonic hedgehog (Shh) signaling arise from the specification of unique transcriptional programs dependent upon key nuclear effectors of the Ci/Gli family of transcription factors. However, the underlying mechanism by which Gli proteins regulate target gene transcription in the nucleus remains poorly understood. Here, we identify and characterize a physical and functional interaction between Gli3 and the MED12 subunit within the RNA polymerase II transcriptional Mediator. We show that Gli3 binds to MED12 and intact Mediator both in vitro and in vivo through a Gli3 transactivation domain (MBD; MED12/Mediator-binding domain) whose activity derives from concerted functional interactions with both Mediator and the histone acetyltransferase CBP. Analysis of MBD truncation mutants revealed an excellent correlation between the in vivo activation strength of an MBD derivative and its ability to bind MED12 and intact Mediator in vitro, indicative of a critical functional interaction between the Gli3 MBD and the MED12 interface in Mediator. Disruption of the Gli3-MED12 interaction through dominant-negative interference inhibited, while RNA interference-mediated MED12 depletion enhanced, both MBD transactivation function and Gli3 target gene induction in response to Shh signaling. We propose that activated Gli3 physically targets the MED12 interface within Mediator in order to functionally reverse Mediator-dependent suppression of Shh target gene transcription. These findings thus link MED12 to the modulation of Gli3-dependent Shh signaling and further implicate Mediator in a broad range of developmental and pathological processes driven by Shh signal transduction.
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Affiliation(s)
- Haiying Zhou
- Department of Molecular Medicine, Institute of Biotechnology, The University of Texas Health Science Center at San Antonio, 15355 Lambda Drive, San Antonio, TX 78245-3207, USA
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Takagi Y, Calero G, Komori H, Brown JA, Ehrensberger AH, Hudmon A, Asturias F, Kornberg RD. Head module control of mediator interactions. Mol Cell 2006; 23:355-64. [PMID: 16885025 DOI: 10.1016/j.molcel.2006.06.007] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2006] [Revised: 05/22/2006] [Accepted: 06/07/2006] [Indexed: 10/24/2022]
Abstract
Yeast Mediator proteins interacting with Med17(Srb4) have been expressed at a high level with the use of recombinant baculoviruses and recovered in homogeneous form as a seven subunit, 223 kDa complex. Electron microscopy and single-particle analysis identify this complex as the Mediator head module. The recombinant head module complements "headless" Mediator for the initiation of transcription in vitro. The module interacts with an RNA polymerase II-TFIIF complex, but not with the polymerase or TFIIF alone. This interaction is lost in the presence of a DNA template and associated RNA transcript, recapitulating the release of Mediator that occurs upon the initiation of transcription. Disruption of the head module in a temperature-sensitive mutant in vivo leads to the release of middle and tail modules from a transcriptionally active promoter. The head module evidently controls Mediator-RNA polymerase II and Mediator-promoter interactions.
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Affiliation(s)
- Yuichiro Takagi
- Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305, USA
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44
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Mitchell DC, Stafford LJ, Li D, Bar-Eli M, Liu M. Transcriptional regulation of KiSS-1 gene expression in metastatic melanoma by specificity protein-1 and its coactivator DRIP-130. Oncogene 2006; 26:1739-47. [PMID: 16964286 DOI: 10.1038/sj.onc.1209963] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Loss of the metastasis suppressor gene, KiSS-1 has been strongly correlated to the progression of metastases in numerous types of cancers. The mechanism through which KiSS-1 is lost during metastasis, however, is still not completely known. Previous studies have shown that genetic material on human chromosome 6q16.3-q23 is essential for KiSS-1 expression in normal tissues. Additionally, microcell-mediated transfer of this chromosome in cancerous tissue results in rescued expression of KiSS-1 and reduced metastatic phenotype. Here, we show that loss of Sp1-coactivator protein DRIP-130, which is encoded by human chromosome 6q16.3-q23, results in reduced KiSS-1 promoter activation in highly malignant melanoma cells. Co-expression of Sp1 and DRIP-130 not only rescues KiSS-1 expression, but also induces an inhibition of the invasive and migratory behavior in highly metastatic melanoma cells, similar to the overexpression of KiSS-1 metastasis suppressor gene in those cells. Furthermore, we demonstrate that KiSS-1 expression is regulated by Sp1 elements within the first 100-bp region of the KiSS-1 promoter and that targeted deletion of a single GC-rich region spanning -93 to -58 interrupts Sp1- and DRIP-130-modulated transcriptional control of KiSS-1 expression. Our results thus suggest that DRIP-130 is a key regulator in KiSS-1 transactivation in normal tissue, and that the loss of DRIP-130 expression, as a result of the gross loss of human chromosome 6q16.3-q23, provokes increased tumor metastasis.
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Affiliation(s)
- D C Mitchell
- Institute of Biosciences and Technology, and Department of Molecular and Cellular Medicine, Texas A&M University System Health Science Center, Houston, TX 77030, USA
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45
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Larivière L, Geiger S, Hoeppner S, Röther S, Strässer K, Cramer P. Structure and TBP binding of the Mediator head subcomplex Med8-Med18-Med20. Nat Struct Mol Biol 2006; 13:895-901. [PMID: 16964259 DOI: 10.1038/nsmb1143] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2006] [Accepted: 08/15/2006] [Indexed: 11/09/2022]
Abstract
The Mediator head module stimulates basal RNA polymerase II (Pol II) transcription and enables transcriptional regulation. Here we show that the head subunits Med8, Med18 and Med20 form a subcomplex (Med8/18/20) with two submodules. The highly conserved N-terminal domain of Med8 forms one submodule that binds the TATA box-binding protein (TBP) in vitro and is essential in vivo. The second submodule consists of the C-terminal region of Med8 (Med8C), Med18 and Med20. X-ray analysis of this submodule reveals that Med18 and Med20 form related beta-barrel folds. A conserved putative protein-interaction face on the Med8C/18/20 submodule includes sites altered by srb mutations, which counteract defects resulting from Pol II truncation. Our results and published data support a positive role of the Med8/18/20 subcomplex in initiation-complex formation and suggest that the Mediator head contains a multipartite TBP-binding site that can be modulated by transcriptional activators.
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Affiliation(s)
- Laurent Larivière
- Gene Center Munich, Department of Chemistry and Biochemistry, Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, 81377 Munich, Germany
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46
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Abstract
The SREBP pathway plays a central role in the regulation of lipid metabolism. In a recent letter, Yang et al. present a comprehensive series of experiments, spanning a wide range of disciplines, that identify ARC105 as a component of the ARC complex that interacts directly with SREBP and is necessary for SREBP function (Yang et al., 2006).
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Affiliation(s)
- Robert B Rawson
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390, USA
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Lee MF, Beauchamp RL, Beyer KS, Gusella JF, Ramesh V. Magicin associates with the Src-family kinases and is phosphorylated upon CD3 stimulation. Biochem Biophys Res Commun 2006; 348:826-31. [PMID: 16899217 DOI: 10.1016/j.bbrc.2006.07.126] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2006] [Accepted: 07/13/2006] [Indexed: 11/18/2022]
Abstract
We recently identified a novel actin cytoskeleton-associated protein magicin, for merlin and Grb2 interacting cytoskeletal protein. To unravel the cellular functions of magicin, we used a yeast two-hybrid system and identified Fyn tyrosine kinase as a specific binding partner for magicin. Fyn phosphorylates magicin in vitro. In addition to Fyn, Src and Lck also interact with magicin. Upon stimulation with anti-CD3 antibody, magicin is phosphorylated in the T lymphocyte leukemia Jurkat cell line. Magicin phosphorylation is not observed in an Lck-deficient line, J.CaM1.6, indicating that Lck is the major Src family kinase for phosphorylating magicin in Jurkat cells. Employing site-directed mutagenesis along with in vitro kinase assays, we found that Y64 of magicin is phosphorylated by Lck creating a SH2-Grb2 binding motif. Magicin has also been identified as a Mediator subunit (MED28) in the nucleus involved in transcriptional regulation, therefore we propose that magicin may serve as a multi-faceted adaptor/scaffold to relay cellular signaling to the cytoskeleton and from the cytoskeleton to the nucleus.
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Affiliation(s)
- Ming-Fen Lee
- Molecular Neurogenetics Unit, Center for Human Genetic Research, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114, USA
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48
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Ishikawa H, Tachikawa H, Miura Y, Takahashi N. TRIM11 binds to and destabilizes a key component of the activator-mediated cofactor complex (ARC105) through the ubiquitin-proteasome system. FEBS Lett 2006; 580:4784-92. [PMID: 16904669 DOI: 10.1016/j.febslet.2006.07.066] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2006] [Revised: 07/03/2006] [Accepted: 07/19/2006] [Indexed: 10/24/2022]
Abstract
TRIM11 is a member of the tripartite-motif-containing protein family and is known to destabilize humanin, an inhibitor of Alzheimer-like neuronal insults. In this study, we demonstrate that TRIM11 interacts with activator-recruited cofactor 105-kDa component (ARC105) that mediates chromatin-directed transcription activation and is a key regulatory factor for transforming growth factor beta (TGFbeta) signaling. Co-expression of TRIM11 increased ARC105 degradation but a proteasome inhibitor suppressed this. Co-expression of TRIM11 and ARC105 also increased ubiquitination of ARC105. In addition, TRIM11 suppressed ARC105-mediated transcriptional activation induced with TGFbeta in a reporter assay. These results suggest that TRIM11, with the ubiquitin-proteasome pathway, regulates ARC105 function in TGFbeta signaling.
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Affiliation(s)
- Hideaki Ishikawa
- Department of Bioengineering, Applied Life Science, United Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan
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49
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Rau MJ, Fischer S, Neumann CJ. Zebrafish Trap230/Med12 is required as a coactivator for Sox9-dependent neural crest, cartilage and ear development. Dev Biol 2006; 296:83-93. [PMID: 16712834 DOI: 10.1016/j.ydbio.2006.04.437] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2005] [Revised: 04/05/2006] [Accepted: 04/05/2006] [Indexed: 11/26/2022]
Abstract
The vertebrate Sox9 transcription factor directs the development of neural crest, otic placodes, cartilage and bone. In zebrafish, there are two Sox9 orthologs, Sox9a and Sox9b, which together perform the functions of the single-copy tetrapod Sox9. In a large-scale genetic screen, we have identified a novel zebrafish mutant that strongly resembles the Sox9a/Sox9b double mutant phenotype. We show that this mutation disrupts the zebrafish Trap230/Med12 ortholog, a member of the Mediator complex. Mediator is a coactivator complex transducing the interaction of DNA-binding transcription factors with RNA polymerase II, and our results reveal a critical function of the Trap230 subunit as a coactivator for Sox9.
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Affiliation(s)
- Marlene J Rau
- European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany
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Takai N, Kawamata N, Walsh CS, Gery S, Desmond JC, Whittaker S, Said JW, Popoviciu LM, Jones PA, Miyakawa I, Koeffler HP. Discovery of epigenetically masked tumor suppressor genes in endometrial cancer. Mol Cancer Res 2006; 3:261-9. [PMID: 15886297 DOI: 10.1158/1541-7786.mcr-04-0110] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Realization that many tumor suppressor genes are silenced by epigenetic mechanisms has stimulated the discovery of novel tumor suppressor genes. We used a variety of research tools to search for genes that are epigenetically silenced in human endometrial cancers. Changes in global gene expression of the endometrial cancer cell line Ishikawa was analyzed after treatment with the demethylating agent 5-aza-2'-deoxycytidine combined with the histone deacetylase inhibitor suberoylanilide bishydroxamide. By screening over 22,000 genes, candidate tumor suppressor genes were identified. Additional microarray analysis and real-time reverse transcription-PCR of normal and cancerous endometrial samples and search for CpG islands further refined the list. Tazarotene-induced gene-1 (Tig1) and CCAAT/enhancer binding protein-alpha (C/ebpalpha) were chosen for further study. Expression of both genes was low in endometrial cancer cell lines and clinical samples but high in normal endometrial tissues. Bisulfite sequencing, restriction analysis, and/or methylation-specific PCR revealed aberrant methylation of the CpG island in the Tig1 gene of all 6 endometrial cancer cell lines examined and 4 of 18 clinical endometrial cancers, whereas the C/ebpalpha promoter remained unmethylated in endometrial cancers. Chromatin immunoprecipitation showed increased acetylated histone H3 bound to both Tig1 and C/ebpalpha genes after treatment with 5-aza-2'-deoxycytidine and/or suberoylanilide bishydroxamide. Forced expression of either TIG1 or C/EBPalpha led to significant growth reduction of Ishikawa cells. Our data suggest that C/ebpalpha and Tig1 function as tumor suppressor proteins in endometrial cancers and that their reexpression may be a therapeutic target.
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Affiliation(s)
- Noriyuki Takai
- Division of Hematology/Oncology, Cedars-Sinai Medical Center/University of California at Los Angeles School of Medicine, 8700 Beverly Boulevard, Los Angeles, CA 90048, USA
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