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Körholz J, Gabrielyan A, Sowerby JM, Boschann F, Chen LS, Paul D, Brandt D, Kleymann J, Kolditz M, Toepfner N, Knöfler R, Jacobsen EM, Wolf C, Conrad K, Röber N, Lee-Kirsch MA, Smith KGC, Mundlos S, Berner R, Dalpke AH, Schuetz C, Rae W. One Gene, Many Facets: Multiple Immune Pathway Dysregulation in SOCS1 Haploinsufficiency. Front Immunol 2021; 12:680334. [PMID: 34421895 PMCID: PMC8375263 DOI: 10.3389/fimmu.2021.680334] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 07/13/2021] [Indexed: 01/25/2023] Open
Abstract
Background Inborn errors of immunity (IEI) present with a large phenotypic spectrum of disease, which can pose diagnostic and therapeutic challenges. Suppressor of cytokine signaling 1 (SOCS1) is a key negative regulator of cytokine signaling, and has recently been associated with a novel IEI. Of patients described to date, it is apparent that SOCS1 haploinsufficiency has a pleiotropic effect in humans. Objective We sought to investigate whether dysregulation of immune pathways, in addition to STAT1, play a role in the broad clinical manifestations of SOCS1 haploinsufficiency. Methods We assessed impacts of reduced SOCS1 expression across multiple immune cell pathways utilizing patient cells and CRISPR/Cas9 edited primary human T cells. Results SOCS1 haploinsufficiency phenotypes straddled across the International Union of Immunological Societies classifications of IEI. We found that reduced SOCS1 expression led to dysregulation of multiple intracellular pathways in immune cells. STAT1 phosphorylation is enhanced, comparably with STAT1 gain-of-function mutations, and STAT3 phosphorylation is similarly reduced with concurrent reduction of Th17 cells. Furthermore, reduced SOCS1 E3 ligase function was associated with increased FAK1 in immune cells, and increased AKT and p70 ribosomal protein S6 kinase phosphorylation. We also found Toll-like receptor responses are increased in SOCS1 haploinsufficiency patients. Conclusions SOCS1 haploinsufficiency is a pleiotropic monogenic IEI. Dysregulation of multiple immune cell pathways may explain the variable clinical phenotype associated with this new condition. Knowledge of these additional dysregulated immune pathways is important when considering the optimum management for SOCS1 haploinsufficient patients.
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Affiliation(s)
- Julia Körholz
- Department of Pediatrics, University Hospital and Medical Faculty Carl-Gustav-Carus, Technische Universität Dresden, Dresden, Germany.,UniversitätsCentrum für seltene Erkrankungen, Medizinische Fakultät Carl-Gustav-Carus, Technische Universität Dresden, Dresden, Germany
| | - Anastasia Gabrielyan
- Department of Pediatrics, University Hospital and Medical Faculty Carl-Gustav-Carus, Technische Universität Dresden, Dresden, Germany
| | - John M Sowerby
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, Jeffrey Cheah Biomedical Centre, University of Cambridge, Cambridge, United Kingdom.,Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Felix Boschann
- Institute of Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Lan-Sun Chen
- Institute of Medical Microbiology and Virology, Medical Faculty Carl-Gustav-Carus, Technische Universität Dresden, Dresden, Germany
| | - Diana Paul
- Department of Pediatrics, University Hospital and Medical Faculty Carl-Gustav-Carus, Technische Universität Dresden, Dresden, Germany
| | - David Brandt
- Department of Pediatrics, University Hospital and Medical Faculty Carl-Gustav-Carus, Technische Universität Dresden, Dresden, Germany
| | - Janina Kleymann
- Department of Internal Medicine, Pneumology, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Martin Kolditz
- Department of Internal Medicine, Pneumology, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Nicole Toepfner
- Department of Pediatrics, University Hospital and Medical Faculty Carl-Gustav-Carus, Technische Universität Dresden, Dresden, Germany
| | - Ralf Knöfler
- Department of Pediatrics, University Hospital and Medical Faculty Carl-Gustav-Carus, Technische Universität Dresden, Dresden, Germany
| | | | - Christine Wolf
- Department of Pediatrics, University Hospital and Medical Faculty Carl-Gustav-Carus, Technische Universität Dresden, Dresden, Germany
| | - Karsten Conrad
- Institute of Immunology, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Nadja Röber
- Institute of Immunology, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Min Ae Lee-Kirsch
- Department of Pediatrics, University Hospital and Medical Faculty Carl-Gustav-Carus, Technische Universität Dresden, Dresden, Germany.,UniversitätsCentrum für seltene Erkrankungen, Medizinische Fakultät Carl-Gustav-Carus, Technische Universität Dresden, Dresden, Germany
| | - Kenneth G C Smith
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, Jeffrey Cheah Biomedical Centre, University of Cambridge, Cambridge, United Kingdom.,Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Stefan Mundlos
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom.,Institute of Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Max Planck Institute for Molecular Genetics, Research Group (RG) Development and Disease, Berlin, Germany.,Berlin-Brandenburg Center for Regenerative Therapies, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Reinhard Berner
- Department of Pediatrics, University Hospital and Medical Faculty Carl-Gustav-Carus, Technische Universität Dresden, Dresden, Germany.,UniversitätsCentrum für seltene Erkrankungen, Medizinische Fakultät Carl-Gustav-Carus, Technische Universität Dresden, Dresden, Germany
| | - Alexander H Dalpke
- Institute of Medical Microbiology and Virology, Medical Faculty Carl-Gustav-Carus, Technische Universität Dresden, Dresden, Germany
| | - Catharina Schuetz
- Department of Pediatrics, University Hospital and Medical Faculty Carl-Gustav-Carus, Technische Universität Dresden, Dresden, Germany.,UniversitätsCentrum für seltene Erkrankungen, Medizinische Fakultät Carl-Gustav-Carus, Technische Universität Dresden, Dresden, Germany
| | - William Rae
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, Jeffrey Cheah Biomedical Centre, University of Cambridge, Cambridge, United Kingdom.,Department of Medicine, University of Cambridge, Cambridge, United Kingdom
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The role of upstream open reading frames in translation regulation in the apicomplexan parasites Plasmodium falciparum and Toxoplasma gondii. Parasitology 2021; 148:1277-1287. [PMID: 34099078 PMCID: PMC8383288 DOI: 10.1017/s0031182021000937] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
During their complex life cycles, the Apicomplexan parasites Plasmodium falciparum and Toxoplasma gondii employ several layers of regulation of their gene expression. One such layer is mediated at the level of translation through upstream open reading frames (uORFs). As uORFs are found in the upstream regions of a majority of transcripts in both the parasites, it is essential that their roles in translational regulation be appreciated to a greater extent. This review provides a comprehensive summary of studies that show uORF-mediated gene regulation in these parasites and highlights examples of clinically and physiologically relevant genes, including var2csa in P. falciparum, and ApiAT1 in T. gondii, that exhibit uORF-mediated regulation. In addition to these examples, several studies that use bioinformatics, transcriptomics, proteomics and ribosome profiling also indicate the possibility of widespread translational regulation by uORFs. Further analysis of these genome-wide datasets, taking into account uORFs associated with each gene, will reveal novel genes involved in key biological pathways such as cell-cycle progression, stress-response and pathogenicity. The cumulative evidence from studies presented in this review suggests that uORFs will play crucial roles in regulating gene expression during clinical disease caused by these important human pathogens.
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Toniato E, Flati V, Laglia E, Mincione G, Martinotti S. Genomic Organization and Cytokine-Mediated Inducibility of the Human Trim-8/Gerp Gene. Int J Immunopathol Pharmacol 2016; 17:71-6. [PMID: 15345195 DOI: 10.1177/03946320040170s212] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Cytokine signaling is negatively regulated by a set of SH2 domain-containing proteins, the Suppressors of Cytokine Signaling (SOCS) acting as intracellular modulators. Experimental evidence indicates that SOCS gene expression is induced by cytokines and pro-inflammatory stimuli and is highly controlled both at transcription and translation level. Furthermore, SOCS proteins appear rapidly degraded inside the cells, mostly controlling their stability by interacting with specific molecules such as elongin B and C. It has been shown that SOCS-1/JAB, a member of the SOCS family, interacts with TRIM-8/Gerp, a new ring protein specifically binding SOCS-1 recombinant polypeptide in-vitro and in-vivo. Trim-8/Gerp, transcribes a 3.0-kb mRNA, spans 551 AA and is highly conserved during evolution. In addition, it can be induced by IFN-γ in epithelial and lymphoid cells and is expressed mostly ubiquitously in murine and human tissues. Here in this report we present the genomic organization of this new SOCS-1 interactor, and we add new tools for extending investigation of the complex mechanism that undergoes negatively regulation of cytokine signaling.
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Affiliation(s)
- E Toniato
- Department of Oncology and Neuroscience, University of Chieti - UDA, Chieti, Italy.
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Fields AP, Rodriguez EH, Jovanovic M, Stern-Ginossar N, Haas BJ, Mertins P, Raychowdhury R, Hacohen N, Carr SA, Ingolia NT, Regev A, Weissman JS. A Regression-Based Analysis of Ribosome-Profiling Data Reveals a Conserved Complexity to Mammalian Translation. Mol Cell 2016; 60:816-827. [PMID: 26638175 PMCID: PMC4720255 DOI: 10.1016/j.molcel.2015.11.013] [Citation(s) in RCA: 166] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 09/08/2015] [Accepted: 11/16/2015] [Indexed: 10/22/2022]
Abstract
A fundamental goal of genomics is to identify the complete set of expressed proteins. Automated annotation strategies rely on assumptions about protein-coding sequences (CDSs), e.g., they are conserved, do not overlap, and exceed a minimum length. However, an increasing number of newly discovered proteins violate these rules. Here we present an experimental and analytical framework, based on ribosome profiling and linear regression, for systematic identification and quantification of translation. Application of this approach to lipopolysaccharide-stimulated mouse dendritic cells and HCMV-infected human fibroblasts identifies thousands of novel CDSs, including micropeptides and variants of known proteins, that bear the hallmarks of canonical translation and exhibit translation levels and dynamics comparable to that of annotated CDSs. Remarkably, many translation events are identified in both mouse and human cells even when the peptide sequence is not conserved. Our work thus reveals an unexpected complexity to mammalian translation suited to provide both conserved regulatory or protein-based functions.
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Affiliation(s)
- Alexander P Fields
- Howard Hughes Medical Institute, Department of Cellular and Molecular Pharmacology, University of California, San Francisco and California Institute for Quantitative Biomedical Research, San Francisco, CA 94158, USA
| | - Edwin H Rodriguez
- Howard Hughes Medical Institute, Department of Cellular and Molecular Pharmacology, University of California, San Francisco and California Institute for Quantitative Biomedical Research, San Francisco, CA 94158, USA
| | - Marko Jovanovic
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Noam Stern-Ginossar
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Brian J Haas
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Philipp Mertins
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | | | - Nir Hacohen
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Steven A Carr
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Nicholas T Ingolia
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Aviv Regev
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02140, USA
| | - Jonathan S Weissman
- Howard Hughes Medical Institute, Department of Cellular and Molecular Pharmacology, University of California, San Francisco and California Institute for Quantitative Biomedical Research, San Francisco, CA 94158, USA.
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Contribution of a TANK-binding kinase 1-interferon (IFN) regulatory factor 7 pathway to IFN-γ-induced gene expression. Mol Cell Biol 2012; 32:1032-43. [PMID: 22252317 DOI: 10.1128/mcb.06021-11] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Signal transducers and activators of transcription (STATs) and interferon regulatory factors (IRFs) share common target genes. Here we show that the Irf7 gene is regulated by transcription factors STAT1 and IRF9 in response to the type II interferon (IFN) IFN-γ. IRF7 cooperated with STAT1 and IRF1 to stimulate the expression of a subset of IFN-γ-induced STAT1 target genes. IRF7-mediated control of the Gbp2 gene required the presence and basal activity of the S/T kinase TANK-binding kinase 1 (TBK1), whereas the binding of IRF7 to the Gbp2 promoter did not. Analysis of RNA polymerase II (Pol II) recruitment to the Gbp2 promoter revealed a role for IRF7 at later stages of the IFN-γ response. In support of the role of IRF7 in establishing an effective antibacterial response, IFN-γ-pretreated Irf7(-/-) macrophages showed an increased bacterial burden after infection with Listeria monocytogenes. Our data thus describe a biologically relevant basal activity of TBK1 and identify IRF7 as a novel player in the IFN-γ response.
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Lohse I, Reilly P, Zaugg K. The CPT1C 5'UTR contains a repressing upstream open reading frame that is regulated by cellular energy availability and AMPK. PLoS One 2011; 6:e21486. [PMID: 21961029 PMCID: PMC3178533 DOI: 10.1371/journal.pone.0021486] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Accepted: 05/30/2011] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Translational control is utilized as a means of regulating gene expression in many species. In most cases, posttranscriptional regulatory mechanisms play an important role in stress response pathways and can lead to dysfunctional physiology if blocked by mutations. Carnitine Palmitoyltransferase 1 C (CPT1C), the brain-specific member of the CPT 1 family, has previously been shown to be involved in regulating metabolism in situations of energy surplus. PRINCIPAL FINDINGS Sequence analysis of the CPT1C mRNA revealed that it contains an upstream open reading frame (uORF) in the 5' UTR of its mRNA. Using CPT1C 5' UTR/luciferase constructs, we investigated the role of the uORF in translational regulation. The results presented here show that translation from the CPT1C main open reading frame (mORF) is repressed by the presence of the uORF, that this repression is relieved in response to specific stress stimuli, namely glucose deprivation and palmitate-BSA treatment, and that AMPK inhibition can relieve this uORF-dependent repression. SIGNIFICANCE The fact that the mORF regulation is relieved in response to a specific set of stress stimuli rather than general stress response, hints at an involvement of CPT1C in cellular energy-sensing pathways and provides further evidence for a role of CPT1C in hypothalamic regulation of energy homeostasis.
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Affiliation(s)
- Ines Lohse
- Department of Radiation Oncology, University Hospital Zurich, Zurich, Switzerland
| | - Patrick Reilly
- Department of Radiation Oncology, University Hospital Zurich, Zurich, Switzerland
- Department of Cellular and Molecular Research, National Cancer Centre Singapore, Singapore, Singapore
| | - Kathrin Zaugg
- Department of Radiation Oncology, University Hospital Zurich, Zurich, Switzerland
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Rizzi F, Coletta M, Bettuzzi S. Chapter 2: Clusterin (CLU): From one gene and two transcripts to many proteins. Adv Cancer Res 2010; 104:9-23. [PMID: 19878770 DOI: 10.1016/s0065-230x(09)04002-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Clusterin (CLU) has kept many researchers engaged for a long time since its first discovery and characterization in the attempt to unravel its biological role in mammals. Although there is a general consensus on the fact that CLU is supposed to play important roles in nearly all fundamental biological phenomena and in many human diseases including cancer, after about 10 years of work CLU has been defined as an "enigmatic" protein. This sense of frustration among the researchers is originated by the fact that, despite considerable scientific production concerning CLU, there is still a lack of basic information about the complex regulation of its expression. The CLU gene is a single 9-exon gene expressed at very different levels in almost all major tissues in mammals. The gene produces at least three protein forms with different subcellular localization and diverse biological functions. The molecular mechanism of production of these protein forms remains unclear. The best known is the glycosylated mature form of CLU (sCLU), secreted with very big quantitative differences at different body sites. Hormones and growth factors are the most important regulators of CLU gene expression. Before 2006, it was believed that a unique transcript of about 1.9 kb was originated by transcription of the CLU gene. Now we know that alternative transcriptional initiation, possibly driven by two distinct promoters, may produce at least two distinct CLU mRNA isoforms differing in their unique first exon, named Isoform 1 and Isoform 2. A third transcript, named Isoform 11036, has been recently found as one of the most probable mRNA variants. Approaches like cloning, expression, and functional characterization of the different CLU protein products have generated a critical mass of information teaching us an important lesson about CLU gene expression regulation. Nevertheless, further studies are necessary to better understand the tissue-specific regulation of CLU expression and to identify the specific signals triggering the expression of different/alternative transcript isoforms and protein forms in different cell types at appropriate time.
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Affiliation(s)
- Federica Rizzi
- Dipartimento di Medicina Sperimentale, Sezione di Biochimica, Biochimica Clinica e Biochimica dell'Esercizio Fisico, Parma, Italy
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Letourneur M, Valentino L, Travagli-Gross J, Bertoglio J, Pierre J. Sp2 regulates interferon-gamma-mediated socs1 gene expression. Mol Immunol 2009; 46:2151-60. [PMID: 19482358 DOI: 10.1016/j.molimm.2009.05.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Accepted: 05/04/2009] [Indexed: 11/26/2022]
Abstract
Suppressor of cytokine signalling (SOCS) proteins are inducible feedback inhibitors of Janus kinase (JAK) and signal transducers and activators of transcription signalling (STAT) pathways. Interferon (IFN)-gamma induces the expression of the socs1 gene in several cell types through several cis elements present in its promoter and their binding proteins. Socs1 expression is induced in the human keratinocytes HaCaT cell line through sequential activation of STAT1 and IRF-1. Comparison of the 5'-upstream sequences of the mouse and human socs1 genes identified conserved binding sites for IRF-1 regulatory elements. Although this response element is able to bind IRF-1 in human cells, no IFN-gamma responsiveness was observed with human socs1 promoter reporter constructs containing this element. In contrast the mouse socs1 promoter was fully responsive. The mouse promoter contains two cis-acting elements which modulate its expression and are recognized by IRF-1 and Sp2. Despite the absence of Sp2 in the 5'-upstream sequence of the human promoter, silencing of Sp2 by RNA interference clearly demonstrated that Sp2 is required for IFN-gamma-induced regulation of socs1 mRNA both in human and mouse.
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Affiliation(s)
- Martine Letourneur
- INSERM U749, Faculté de Pharmacie, 5 rue Jean-Baptiste Clément, 92296 Châtenay-Malabry, France
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Fukuyama S, Nakano T, Matsumoto T, Oliver BGG, Burgess JK, Moriwaki A, Tanaka K, Kubo M, Hoshino T, Tanaka H, McKenzie ANJ, Matsumoto K, Aizawa H, Nakanishi Y, Yoshimura A, Black JL, Inoue H. Pulmonary suppressor of cytokine signaling-1 induced by IL-13 regulates allergic asthma phenotype. Am J Respir Crit Care Med 2009; 179:992-8. [PMID: 19299500 DOI: 10.1164/rccm.200806-992oc] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Th2 cytokines play an important role in allergic diseases. These cytokines activate signal transduction pathways, including Janus kinase/signal transducer and activator of transcription (STAT) signaling. Although the suppressor of cytokine signaling (SOCS) family protein, a negative regulator of the Janus kinase/STAT signaling pathway, contributes to helper T cell differentiation during immune responses, the role of SOCS proteins within the structural cells of a target organ has not been clarified in allergy. OBJECTIVES To study the local function of SOCS in the development of asthma. METHODS We used mouse models of IL-13- and ovalbumin (OVA)-induced allergic airway disease. Airway smooth muscle cells were cultured from patients with asthma. MEASUREMENTS AND MAIN RESULTS The administration of IL-13 induced not only airway responses but also SOCS1 expression at the local inflammatory site. The up-regulated SOCS1 markedly suppressed IL-13-dependent STAT6 activation and eotaxin expression and subsequently down-regulated IL-13-induced airway inflammatory responses. The inactivation of SOCS1 induced airway hyperresponsiveness after IL-13 treatment even in hyporesponsive C57BL/6 background mice. In an OVA-induced model of allergic airway disease, allergen exposure up-regulated local SOCS1 expression, and the induction of SOCS1 in the airways attenuated allergen-induced airway responses. Inactivation of IL-13 inhibited SOCS1 induction in a model of allergic airway disease. Interestingly, airway smooth muscle cells from individuals with asthma had impaired up-regulation of SOCS1 after IL-13 stimulation. CONCLUSIONS SOCS1 induction by IL-13 in airway structural cells is critical to negatively control allergic airway disease.
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Affiliation(s)
- Satoru Fukuyama
- Research Institute for Diseases of the Chest, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
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Wang T, Secombes CJ. Rainbow trout suppressor of cytokine signalling (SOCS)-1, 2 and 3: Molecular identification, expression and modulation. Mol Immunol 2008; 45:1449-57. [DOI: 10.1016/j.molimm.2007.08.016] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2007] [Revised: 08/24/2007] [Accepted: 08/29/2007] [Indexed: 11/30/2022]
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Putnik J, Zhang CD, Archangelo LF, Tizazu B, Bartels S, Kickstein M, Greif PA, Bohlander SK. The interaction of ETV6 (TEL) and TIP60 requires a functional histone acetyltransferase domain in TIP60. BIOCHIMICA ET BIOPHYSICA ACTA 2007; 1772:1211-24. [PMID: 17980166 DOI: 10.1016/j.bbadis.2007.09.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2007] [Revised: 09/25/2007] [Accepted: 09/27/2007] [Indexed: 12/19/2022]
Abstract
The ets-family transcription factor ETV6 (TEL) has been shown to be the target of a large number of balanced chromosomal translocations in various hematological malignancies and in some soft tissue tumors. Furthermore, ETV6 is essential for hematopoietic stem cell function. We identified ETV6 interacting proteins using the yeast two hybrid system. One of these proteins is the HIV Tat interacting protein (TIP60), a histone acetyltransferase (HAT) containing the highly conserved MYST domain. TIP60 functions as a corepressor of ETV6 in reporter gene assays. Fluorescently tagged ETV6 and TIP60 colocalize in the nucleus and an increase in nuclear localization of ETV6 was seen when TIP60 was cotransfected. ETV6 interacts with TIP60 through a 63 amino acids region located in the central domain of ETV6 between the pointed and the ets domain. The ETV6 interacting region of TIP60 mapped to the C2HC zinc finger of the TIP60 MYST domain. The interaction of TIP60 with full length ETV6 required an intact acetyltransferase domain of TIP60. Interestingly, the MYST domains of MOZ and MORF were also able to interact with portions of ETV6. These observations suggest that MYST domain HATs regulate ETV6 transcriptional activity and may therefore play critical roles in leukemogenesis and possibly in normal hematopoietic development.
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Affiliation(s)
- Jasmina Putnik
- Institute of Human Genetics, Heinrich-Düker-Weg 12, 37037 Göttingen, Germany
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12
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Chinen T, Kobayashi T, Ogata H, Takaesu G, Takaki H, Hashimoto M, Yagita H, Nawata H, Yoshimura A. Suppressor of cytokine signaling-1 regulates inflammatory bowel disease in which both IFNgamma and IL-4 are involved. Gastroenterology 2006; 130:373-88. [PMID: 16472593 DOI: 10.1053/j.gastro.2005.10.051] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2005] [Accepted: 10/19/2005] [Indexed: 12/16/2022]
Abstract
BACKGROUND & AIMS The suppressor of cytokine signaling-1 (SOCS1) is a potent negative regulator of various cytokines and it has been implicated in the regulation of immune responses. However, the role of SOCS1 in inflammatory bowel diseases (IBDs) has not been clarified. To determine the role of SOCS1 in colitis, we generated SOCS1/T-cell receptor alpha (TCRalpha) double knockout (DKO) mice. METHODS The depletion of interferon gamma (IFNgamma) and IL-4 was achieved by crossing the DKO mice with IFNgamma knockout (KO) mice and by the administration of anti-IL-4 antibody, respectively. The activation of cytokine-induced transcription factors was determined by Western blotting with phosphorylation-specific antibodies, and the induction of inflammatory factors was measured by reverse-transcription polymerase chain reaction. RESULTS Much more severe colitis developed in 100% of the DKO mice within 9 weeks of age than in TCRalpha-KO mice. Although the proportion and the activation status of CD4(+) TCRalpha(-)beta(+) T cells in DKO mice were similar to those in TCRalpha-KO mice, signal transducer and activator of transcription 1, nuclear factor kappaB, and their target genes were hyperactivated in infiltrated mononuclear cells and colonic epithelial cells in DKO mice. Cytokine-depletion experiments showed that exacerbated colitis in the DKO mice was dependent on both IFNgamma and IL-4. SOCS1-deficient cells were hypersensitive to IFNgamma, IL-4, and lipopolysaccharides, depending on the target genes. CONCLUSIONS SOCS1 plays an important role in preventing murine colitis by restricting the cytokine signals. SOCS1/TCRalpha DKO mice could be a useful model for investigating human IBD.
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Affiliation(s)
- Takatoshi Chinen
- Division of Molecular and Cellular Immunology, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
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Netzer C, Bohlander SK, Hinzke M, Chen Y, Kohlhase J. Defining the heterochromatin localization and repression domains of SALL1. Biochim Biophys Acta Mol Basis Dis 2006; 1762:386-91. [PMID: 16443351 DOI: 10.1016/j.bbadis.2005.12.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2005] [Revised: 11/24/2005] [Accepted: 12/05/2005] [Indexed: 12/31/2022]
Abstract
SALL1 has been identified as one of four human homologues of the Drosophila region-specific homeotic gene spalt (sal), encoding zinc finger proteins of characteristic structure. Mutations of SALL1 on chromosome 16q12.1 cause Townes-Brocks syndrome (TBS, OMIM 107480). We have shown previously that SALL1 acts as a strong transcriptional repressor in mammalian cells when fused to a heterologous DNA-binding domain. Here, we report that SALL1 contains two repression domains, one located at the extreme N-terminus of the protein and the other in the central region. SALL1 fragments with the central repression domain exhibited a punctate nuclear distribution pattern at pericentromeric heterochromatin foci in murine NIH-3T3 cells, suggesting an association between repression and heterochromatin localization. The implications of these findings for the pathogenesis of Townes-Brocks syndrome are discussed.
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Affiliation(s)
- Christian Netzer
- Institute of Human Genetics, University of Bonn, Wilhelmstr. 31, 53111 Bonn, Germany
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14
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Rakesh K, Agrawal DK. Controlling cytokine signaling by constitutive inhibitors. Biochem Pharmacol 2005; 70:649-57. [PMID: 15936728 DOI: 10.1016/j.bcp.2005.04.042] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2005] [Accepted: 04/14/2005] [Indexed: 11/21/2022]
Abstract
Cytokines are secreted proteins that regulate diverse biological functions by binding to receptors at the cell surface to activate complex signal transduction pathways including the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway. Stringent mechanisms of signal attenuation are essential for ensuring an appropriate, controlled cellular response. Three families of proteins, the SH2-containing phosphatases (SHP), the protein inhibitors of activated STATs (PIAS), and the suppressors of cytokine signaling (SOCS), inhibit specific and distinct aspects of cytokine signal transduction. The analysis of mice lacking genes for members of the SHP has shed much light on the roles of these proteins in vivo. In recent in vitro studies, the protein modifiers ubiquitin and small ubiquitin-like modifier (SUMO) have emerged as key players in the strategies employed by SOCS and PIAS to repress signaling. This review throws light on the mechanisms of action of these regulators as being evolved by the latest researches.
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Affiliation(s)
- Kriti Rakesh
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE 68178, USA.
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15
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Iacono M, Mignone F, Pesole G. uAUG and uORFs in human and rodent 5′untranslated mRNAs. Gene 2005; 349:97-105. [PMID: 15777708 DOI: 10.1016/j.gene.2004.11.041] [Citation(s) in RCA: 185] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2004] [Revised: 10/28/2004] [Accepted: 11/24/2004] [Indexed: 11/21/2022]
Abstract
The control of translation is a fundamental mechanism in the regulation of gene expression. Among the cis-acting elements that play a role in translation regulation are upstream open reading frames (uORFs) and upstream AUG (uAUGs) located in the 5'UTR of mRNAs. We present here a genome-wide analysis of uAUGs and uORFs in a curated set of human and rodent mRNAs. Our study shows that the occurrence of uAUGs is suppressed more strongly than that of uORFs and that in-frame uAUGs are more strongly suppressed than out-of-frame uAUGs. A very similar pattern of uAUG/uORF frequency was also observed in mouse mRNAs. The analysis of orthologous 5'UTR sequences revealed a remarkable degree of evolutionary conservation only of those uORFs which acquired some functional activity. Our data suggest that besides leaky scanning and reinitiation, which likely occur with variable and gene-specific efficiency, the ribosome-shunt mechanism, eventually coupled to reinitiation after uORF translation, may be a widespread mode of translation regulation in eukaryotes.
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Affiliation(s)
- Michele Iacono
- Dipartimento di Scienze Biomolecolari e Biotecnologie, Università di Milano, Via Celoria, 26, 20133 Milano, Italy
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16
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17
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Naka T, Fujimoto M, Tsutsui H, Yoshimura A. Negative regulation of cytokine and TLR signalings by SOCS and others. Adv Immunol 2005; 87:61-122. [PMID: 16102572 DOI: 10.1016/s0065-2776(05)87003-8] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Tetsuji Naka
- Department of Molecular Medicine, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
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18
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Abstract
Signal transduction via cytokine receptors is regulated by several mechanisms that control initiation, magnitude and duration of the signaling pathways. Cytokine-induced SOCS family adaptors function as feedback inhibitors of cytokine receptor signaling by inhibiting the JAK-STAT signal transduction pathway. Specific gene-targeted mice have unveiled critical, non-overlapping functions for SOCS1 and SOCS3 in lymphocyte development and homeostasis, and in the regulation of macrophage and dendritic cell functions. In this review, we will discuss the structure of SOCS proteins, mechanisms by which they control the JAK-STAT pathway and their role in immune regulation.
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Affiliation(s)
- Subburaj Ilangumaran
- Faculty of Medicine, Immunology Division, University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, Que., Canada J1H 5N4.
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19
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Alexander WS, Hilton DJ. The role of suppressors of cytokine signaling (SOCS) proteins in regulation of the immune response. Annu Rev Immunol 2004; 22:503-29. [PMID: 15032587 DOI: 10.1146/annurev.immunol.22.091003.090312] [Citation(s) in RCA: 530] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Cytokines are an integral component of the adaptive and innate immune responses. The signaling pathways triggered by the engagement of cytokines with their specific cell surface receptors have been extensively studied and have provided a profound understanding of the intracellular machinery that translates exposure of cells to cytokine to a coordinated biological response. It has also become clear that cells have evolved sophisticated mechanisms to prevent excessive responses to cytokines. In this review we focus on the suppressors of cytokine signaling (SOCS) family of cytoplasmic proteins that completes a negative feedback loop to attenuate signal transduction from cytokines that act through the janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway. SOCS proteins inhibit components of the cytokine signaling cascade via direct binding or by preventing access to the signaling complex. The SOCS proteins also appear to target signal transducers for proteasomal destruction. Analyses of genetically modified mice in which SOCS proteins are overexpressed or deleted have established that this family of negative regulators has indispensable roles in regulating cytokine responses in cells of the immune system as well as other tissues. Emerging evidence also suggests that disruption of SOCS expression or activity is associated with several immune and inflammatory diseases, raising the prospect that manipulation of SOCS activity may provide a novel future therapeutic strategy in the management of immunological disorders.
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Affiliation(s)
- Warren S Alexander
- The Walter and Eliza Hall Institute of Medical Research and The Cooperative Research Center for Cellular Growth Factors, Parkville, 3052 Victoria, Australia.
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20
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Travagli J, Letourneur M, Bertoglio J, Pierre J. STAT6 and Ets-1 Form a Stable Complex That Modulates Socs-1 Expression by Interleukin-4 in Keratinocytes. J Biol Chem 2004; 279:35183-92. [PMID: 15199062 DOI: 10.1074/jbc.m403223200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Supressor of cytokine signaling (SOCS)-1 is selectively and rapidly induced by appropriate agonists and modulates cytokine responses by interfering with the Janus kinase/signal transducer and activator of transcription (Jak/STAT) pathway. On the basis of the observation that interleukin (IL)-4 up-regulates Socs-1 in the keratinocyte HaCaT cell line, we investigated which sequences of the 5'-Socs-1 gene are responsive to IL-4. We therefore have cloned the 5'-flanking region of this gene, and by promoter analysis we identified a functional IL-4-responsive element located at nucleotide (-684/-570) upstream from the transcription initiation site, whose presence and integrity are necessary to ensure IL-4 responsiveness. This element contains three STAT6 and one Ets consensus binding sequences of which specific mutations abolished IL-4 responsiveness either partially or totally. We also report that Ets-1 physically interacted with STAT6. Exogenous expression of Ets-1 in conjunction with STAT6 activation strongly inhibited expression of a Socs-1 promoter-luciferase reporter. Collectively, our data demonstrated the involvement of STAT6 and Ets, via a composite DNA element, in the IL-4 regulation of Socs-1 gene expression in keratinocytes.
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Affiliation(s)
- Julia Travagli
- INSERM U461, Faculté de pharmacie, 5 Rue J. B. Clément, 92296-Chatenay-Malabry, France
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21
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De Pietri Tonelli D, Mihailovich M, Di Cesare A, Codazzi F, Grohovaz F, Zacchetti D. Translational regulation of BACE-1 expression in neuronal and non-neuronal cells. Nucleic Acids Res 2004; 32:1808-17. [PMID: 15034149 PMCID: PMC390341 DOI: 10.1093/nar/gkh348] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
As the main beta-secretase of the central nervous system, BACE-1 is a key protein in the pathogenesis of Alzheimer's disease. Excessive expression of the protein might cause an overproduction of the neurotoxic beta-amyloid peptide. Therefore, a tight regulation of BACE-1 expression is expected in vivo. In addition to a possible transcriptional control, the BACE-1 transcript leader contains features that might constitute mechanisms of translational regulation of protein expression. Moreover, recent work has revealed an increase of BACE-1 protein and beta-secretase activity in some Alzheimer's disease patients, although a corresponding increase of transcript has not been reported. Here we show that BACE-1 translation could be modulated at multiple stages. The presence of several upstream ATGs strongly reduces the translation of the main open reading frame. This inhibition could be overcome with conditions that favour skipping of upstream ATGs. We also report an alternative splicing of the BACE-1 transcript leader that reduces the number of upstream ATGs. Finally, we show that translation driven by the BACE-1 transcript leader is increased in activated astrocytes independently of the splicing event, indicating yet another mechanism of translational control. Our findings might explain why increases in BACE-1 protein or activity are reported in the brain of Alzheimer's disease patients even in the absence of changes in transcript levels.
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Affiliation(s)
- Davide De Pietri Tonelli
- Cellular Neurophysiology Unit, Department of Neuroscience, San Raffaele Scientific InstituteMilano, Italy
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22
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Hebenstreit D, Luft P, Schmiedlechner A, Regl G, Frischauf AM, Aberger F, Duschl A, Horejs-Hoeck J. IL-4 and IL-13 induce SOCS-1 gene expression in A549 cells by three functional STAT6-binding motifs located upstream of the transcription initiation site. THE JOURNAL OF IMMUNOLOGY 2004; 171:5901-7. [PMID: 14634100 DOI: 10.4049/jimmunol.171.11.5901] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Proteins of the suppressors of cytokine signaling (SOCS) family have important functions as negative regulators of cytokine signaling. We show here that SOCS-1 expression can be induced in the human epithelial lung cell line A549 by IL-4 and IL-13. Analysis of reporter gene constructs under control of the SOCS-1 promoter provides evidence that IL-4- and IL-13-induced up-regulation is dependent on three IFN-gamma-activated sequence motifs of the sequence TTC(N)(4)GAA, which is known for binding STAT6. The three motifs are situated close to each other approximately 600 bp upstream of the transcriptional initiation site. When mutations were inserted into all three IFN-gamma-activated sequence motifs at the same time, IL-4-IL-13-induced luciferase activity was abrogated. With single and double mutants, promoter activity was diminished in comparison with the wild-type promoter. STAT6 is therefore required for IL-4-IL-13-dependent SOCS-1 expression in A549 cells, and the three identified binding motifs cooperate to induce maximal transcription. EMSAs conducted with nuclear extracts of IL-4- and IL-13-stimulated A549 cells showed that STAT6 was able to bind to each of the three binding motifs. Finally, cotransfection of a SOCS-1 expression vector inhibited activation of SOCS-1 promoter luciferase constructs. Thus, SOCS-1 is able to autoregulate its expression via a negative feedback loop.
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Affiliation(s)
- Daniel Hebenstreit
- Institute of Chemistry and Biochemistry, University of Salzburg, Salzburg, Austria
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23
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Heeg K, Dalpke A. TLR-induced negative regulatory circuits: role of suppressor of cytokine signaling (SOCS) proteins in innate immunity. Vaccine 2003; 21 Suppl 2:S61-7. [PMID: 12763685 DOI: 10.1016/s0264-410x(03)00202-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Recognition of pathogen-associated molecular pattern (PAMP) by PAMP receptors of innate immune cells leads to activation and initiation of innate and adaptive immune responses. While the initial steps have been elucidated recently, the mechanisms how innate immune responses are controlled and regulated are only poorly understood. Suppressor of cytokine signaling (SOCS) proteins seem to play an important role in this process. It has been recognized that SOCS proteins not only regulate JAK/STAT-dependent cytokine signaling pathways but are also induced by TLR stimuli and in addition might also regulate TLR signaling.
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Affiliation(s)
- Klaus Heeg
- Institute of Medical Microbiology and Hygiene, Philipps University, Marburg, Germany.
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24
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Mazzarella G, MacDonald TT, Salvati VM, Mulligan P, Pasquale L, Stefanile R, Lionetti P, Auricchio S, Pallone F, Troncone R, Monteleone G. Constitutive activation of the signal transducer and activator of transcription pathway in celiac disease lesions. THE AMERICAN JOURNAL OF PATHOLOGY 2003; 162:1845-55. [PMID: 12759242 PMCID: PMC1868135 DOI: 10.1016/s0002-9440(10)64319-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The biological effects of interferon (IFN)-gamma rely mainly on the activity of the transcription factor signal transducer and activator of transcription (STAT) 1 and the intracellular levels of suppressor of cytokine signaling (SOCS)-1, a negative regulator that controls the amplitude and duration of STAT-1 activation. IFN-gamma is a key mediator of the immunopathology in celiac disease (CD, gluten-sensitive enteropathy). Thus we have investigated STAT-1 signaling and SOCS-1 expression in this condition. As expected, high local concentrations of IFN-gamma were invariably seen in duodenal biopsies from CD patients in comparison to controls. On the basis of immunohistochemistry, STAT-1 phosphorylation, nuclear localization, and DNA-binding activity, STAT-1 activation was consistently more pronounced in CD compared with controls. Despite samples from CD patients containing abundant SOCS-1 mRNA, SOCS-1 protein was expressed at the same level in CD patients and controls. In explant cultures of CD biopsies, gliadin induced the activation of STAT-1 but not SOCS-1. Furthermore, inhibition of STAT-1 prevented the gliadin-mediated induction of ICAM-1 and B7-2. These data suggest that persistent STAT-1 activation can contribute to maintaining and expanding the local inflammatory response in CD.
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Affiliation(s)
- Giuseppe Mazzarella
- Istituto di Scienze dell'Alimentazione, Consiglio Nazionale delle Ricerche, Avellino, Italy
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25
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Sarna MK, Ingley E, Busfield SJ, Cull VS, Lepere W, McCarthy DJ, Wright MJ, Palmer GA, Chappell D, Sayer MS, Alexander WS, Hilton DJ, Starr R, Watowich SS, Bittorf T, Klinken SP, Tilbrook PA. Differential regulation of SOCS genes in normal and transformed erythroid cells. Oncogene 2003; 22:3221-30. [PMID: 12761492 PMCID: PMC2396148 DOI: 10.1038/sj.onc.1206381] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The SOCS family of genes are negative regulators of cytokine signalling with SOCS-1 displaying tumor suppressor activity. SOCS-1, CIS and SOCS-3 have been implicated in the regulation of red blood cell production. In this study, a detailed examination was conducted on the expression patterns of these three SOCS family members in normal erythroid progenitors and a panel of erythroleukemic cell lines. Unexpectedly, differences in SOCS gene expression were observed during maturation of normal red cell progenitors, viz changes to CIS were inversely related to the alterations of SOCS-1 and SOCS-3. Similarly, these SOCS genes were differentially expressed in transformed erythoid cells - erythroleukemic cells immortalized at an immature stage of differentiation expressed SOCS-1 and SOCS-3 mRNA constitutively, whereas in more mature cell lines SOCS-1 and CIS were induced only after exposure to erythropoietin (Epo). Significantly, when ectopic expression of the tyrosine kinase Lyn was used to promote differentiation of immature cell lines, constitutive expression of SOCS-1 and SOCS-3 was completely suppressed. Modulation of intracellular signalling via mutated Epo receptors in mature erythroleukemic lines also highlighted different responses by the three SOCS family members. Close scrutiny of SOCS-1 revealed that, despite large increases in mRNA levels, the activity of the promoter did not alter after erythropoietin stimulation; in addition, erythroid cells from SOCS-1-/- mice displayed increased sensitivity to Epo. These observations indicate complex, stage-specific regulation of SOCS genes during normal erythroid maturation and in erythroleukemic cells.
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Affiliation(s)
- Mohinder K Sarna
- Laboratory for Cancer Medicine, Western Australian Institute for Medical Research, Royal Perth Hospital and Centre for Medical Research, The University of Western Australia, Perth, Australia
| | - Evan Ingley
- Laboratory for Cancer Medicine, Western Australian Institute for Medical Research, Royal Perth Hospital and Centre for Medical Research, The University of Western Australia, Perth, Australia
| | - Samantha J Busfield
- Neurotrauma Laboratory, Western Australian Institute for Medical Research, Royal Perth Hospital, Australia
| | - Vanessa S Cull
- Laboratory for Cancer Medicine, Western Australian Institute for Medical Research, Royal Perth Hospital and Centre for Medical Research, The University of Western Australia, Perth, Australia
| | - Winald Lepere
- Laboratory for Cancer Medicine, Western Australian Institute for Medical Research, Royal Perth Hospital and Centre for Medical Research, The University of Western Australia, Perth, Australia
- Institute of Medical Biochemistry, University of Rostock, Rostock, Germany
| | - David J McCarthy
- Laboratory for Cancer Medicine, Western Australian Institute for Medical Research, Royal Perth Hospital and Centre for Medical Research, The University of Western Australia, Perth, Australia
| | - Michael J Wright
- Laboratory for Cancer Medicine, Western Australian Institute for Medical Research, Royal Perth Hospital and Centre for Medical Research, The University of Western Australia, Perth, Australia
| | - Gene A Palmer
- Laboratory for Cancer Medicine, Western Australian Institute for Medical Research, Royal Perth Hospital and Centre for Medical Research, The University of Western Australia, Perth, Australia
| | - David Chappell
- Laboratory for Cancer Medicine, Western Australian Institute for Medical Research, Royal Perth Hospital and Centre for Medical Research, The University of Western Australia, Perth, Australia
| | - Melissa S Sayer
- Laboratory for Cancer Medicine, Western Australian Institute for Medical Research, Royal Perth Hospital and Centre for Medical Research, The University of Western Australia, Perth, Australia
| | - Warren S Alexander
- Walter and Eliza Hall Institute of Medical Research and The Cooperative Research Center for Cellular Growth Factors, PO Box Royal Melbourne Hospital, Melbourne, Australia
| | - Douglas J Hilton
- Walter and Eliza Hall Institute of Medical Research and The Cooperative Research Center for Cellular Growth Factors, PO Box Royal Melbourne Hospital, Melbourne, Australia
| | - Robyn Starr
- Walter and Eliza Hall Institute of Medical Research and The Cooperative Research Center for Cellular Growth Factors, PO Box Royal Melbourne Hospital, Melbourne, Australia
| | | | - Thomas Bittorf
- Institute of Medical Biochemistry, University of Rostock, Rostock, Germany
| | - S Peter Klinken
- Laboratory for Cancer Medicine, Western Australian Institute for Medical Research, Royal Perth Hospital and Centre for Medical Research, The University of Western Australia, Perth, Australia
- *Correspondence: SP Klinken, Laboratory for Cancer Medicine, Western Australian Institute for Medical Research, 6th Floor MRF Building, Rear, 50 Murray St, Perth, WA 6000, Australia; E-mail:
| | - Peta A Tilbrook
- Laboratory for Cancer Medicine, Western Australian Institute for Medical Research, Royal Perth Hospital and Centre for Medical Research, The University of Western Australia, Perth, Australia
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26
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Son GH, Jung H, Seong JY, Choe Y, Geum D, Kim K. Excision of the first intron from the gonadotropin-releasing hormone (GnRH) transcript serves as a key regulatory step for GnRH biosynthesis. J Biol Chem 2003; 278:18037-44. [PMID: 12639969 DOI: 10.1074/jbc.m209850200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mammalian gonadotropin-releasing hormone (GnRH) gene consists of four short exons (denoted as 1, 2, 3, and 4) and three intervening introns (A, B, and C). Recently, we demonstrated that excision of the first intron (intron A) from the GnRH transcript is regulated in a tissue- and developmental stage-specific fashion and is severely attenuated in hypogonadal (hpg) mouse because of its lack of exonic splicing enhancers (ESE) 3 and 4. In the present study, we examined the influence of intron A on translational efficiency, thereby establishing a post-transcriptional control over GnRH biosynthesis. First, we verified that an intron A-retained GnRH transcript is a splicing variant but not a splicing intermediate. Intron A-retained transcripts can be transported to the cytoplasm in contrast to intron B-containing transcripts, which are restricted to the nucleus. This result implicates the intron A-retained GnRH transcript as a splicing variant; it has a long 5'-untranslated region, as the GnRH prohormone open reading frame (ORF) begins on exon 2. We investigated whether an intron A-retained GnRH transcript can properly initiate translation at the appropriate start codon and found that intron A completely blocks the translation initiation of its downstream reporter ORF both in vivo and in vitro. The inhibition of translation initiation appears to be due to the presence of a tandem repeat of ATG sequences within intron A. Constructs bearing mutations of ATGs to AAGs restored translation initiation at the downstream start codon; the extent of this restoration correlated with the number of mutated ATGs. Besides the failure in the translation initiation of GnRH-coding region in the intron A-containing variant, the present study also suggests that the interference between mature GnRH mRNA and intron A-retained splicing variant could occur to lower the efficiency of GnRH biosynthesis in the GT1-1-immortalized GnRH-producing cell line. Therefore, our results indicate that the precise and efficient excision of intron A and the joining of adjacent exons may be a critical regulatory step for the post-transcriptional regulation of GnRH biosynthesis.
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Affiliation(s)
- Gi Hoon Son
- School of Biological Sciences, Seoul National University, Seoul 151-742, Korea
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27
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Greenhalgh CJ, Miller ME, Hilton DJ, Lund PK. Suppressors of cytokine signaling: Relevance to gastrointestinal function and disease. Gastroenterology 2002; 123:2064-81. [PMID: 12454862 DOI: 10.1053/gast.2002.37068] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND & AIMS The suppressor of cytokine signaling (SOCS) proteins are a family of Src homology 2 domain-containing proteins. Currently, there are 8 members of the SOCS family, of which a number have been implicated strongly in the negative regulation of cytokine signal transduction pathways. METHODS This review focuses on recent discoveries about 4 SOCS family members, SOCS-1, -2, and -3, and cytokine-inducible SH2-domain containing (CIS), and provides more limited information about other SOCS family members. RESULTS A large number of cytokines and growth factors are now known to induce SOCS proteins. In turn, SOCS inhibit the actions of a growing number of cytokines and growth factors in vitro or in vivo. SOCS proteins exert their inhibitory effects at the level of activation of janus kinases (JAKs) or by competing with transcription factors for binding sites on activated cytokine receptors. SOCS proteins also may mediate the ubiquitination and subsequent degradation of the SOCS protein and its bound signaling complex. Genetic modification of SOCS genes in mice has revealed crucial roles in the negative regulation of a number of important physiologic parameters including interferon gamma activity, growth, blood cell production, and placental development. CONCLUSIONS Information about SOCS action in gastrointestinal function and disease is only just emerging, but available data indicate a role in growth of gastrointestinal tissues, inflammatory bowel disease, and cancer.
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Affiliation(s)
- Christopher J Greenhalgh
- Cancer and Haematology Division, The Walter and Eliza Hall Institute of Medical Research and the Cooperative Research Centre for Cellular Growth Factors, Royal Melbourne Hospital, Australia
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28
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Toniato E, Chen XP, Losman J, Flati V, Donahue L, Rothman P. TRIM8/GERP RING finger protein interacts with SOCS-1. J Biol Chem 2002; 277:37315-22. [PMID: 12163497 DOI: 10.1074/jbc.m205900200] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Members of the suppressor of cytokine signaling (SOCS) family of signaling molecules regulate the activation of cytokine signaling. Experimental evidence indicates that SOCS expression is induced by cytokines and pro-inflammatory stimuli and is controlled at both the transcriptional and post-transcriptional levels. SOCS proteins are unstable and seem to be rapidly degraded by proteasomal pathways. However, the mechanisms by which SOCS protein levels are regulated remain unclear. Here, we show that TRIM8/GERP, a RING finger protein, interacts with SOCS-1 in vitro and in vivo. TRIM8/GERP, previously identified as a new member of the family of proteins containing a tripartite motif (TRIM), is a 551-amino acid RING finger protein conserved across species. TRIM8/GERP expression can be induced by interferon-gamma in epithelial and lymphoid cells. Coexpression of TRIM8/GERP with SOCS-1 decreases SOCS-1 protein stability and levels. Functionally, expression of TRIM8/GERP decreases the repression of interferon-gamma signaling mediated by SOCS-1. These data suggest that TRIM8/GERP may be a regulator of SOCS-1 function.
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Affiliation(s)
- Elena Toniato
- Department of Medicine and Microbiology, Columbia University, College of Physicians and Surgeons, New York, New York 10032, USA
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29
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Münch C, Ebstein M, Seefried U, Zhu B, Stamm S, Landwehrmeyer GB, Ludolph AC, Schwalenstöcker B, Meyer T. Alternative splicing of the 5'-sequences of the mouse EAAT2 glutamate transporter and expression in a transgenic model for amyotrophic lateral sclerosis. J Neurochem 2002; 82:594-603. [PMID: 12153483 DOI: 10.1046/j.1471-4159.2002.01012.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Glutamate-mediated neurotoxicity and a reduced expression of the excitatory amino acid transporter 2 (EAAT2) have been described in the pathogenesis of several acute and chronic neurological conditions. EAAT2 is the major carrier of glutamate in the mammalian brain. However, the principles of EAAT2 expression regulation are not fully understood. For the human brain, extensive alternative splicing of the EAAT2 RNA has been shown. To delineate the complex RNA regulation of EAAT2 we investigated whether the murine species is a suitable model for the study of EAAT2 splicing events. We identified five splice variants (mEAAT2/5UT1-5) encoding different 5'-untranslated sequences and two distinct N-termini of the putative EAAT2 polypeptide. In the murine CNS we found a region-specific expression pattern of the novel 5'-variants of EAAT2 as shown by in situ hybridization, dot blotting and competitive reverse transcription polymerase chain reaction. Furthermore, we performed an expression analysis of the EAAT2 splice variants in the spinal cord of a transgenic model (SOD1G93A) of amyotrophic lateral sclerosis, a motor neurone disease for which altered splicing of EAAT2 has been discussed. We found an increased expression of mEAAT2/5UT4 and a reduction of mEAAT2/5UT5 in the early course of the disease. We conclude that alternative splicing of 5'-sequences may contribute to the regional expression of the EAAT2 RNA and was altered in the pre-symptomatic stage of the SOD1G93A-mouse model for amyotrophic lateral sclerosis.
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Affiliation(s)
- C Münch
- Department of Neurology, University of Ulm, Germany
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Jegalian AG, Wu H. Differential roles of SOCS family members in EpoR signal transduction. J Interferon Cytokine Res 2002; 22:853-60. [PMID: 12396724 DOI: 10.1089/107999002760274863] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
To elucidate the roles of suppressor of cytokine signaling (SOCS) family members in erythropoietin (EPO) signaling, we explored SOCS gene regulation, mRNA stability, and protein function in two EPO-responsive hematopoietic cell lines. Using two independent approaches, one involving inhibition of specific signaling molecules and the other employing cell lines that express particular EpoR mutants and thereby activate only subsets of signaling cascades, we demonstrate that induction of SOCS1, SOCS2, SOCS3, and cytokine-inducible SH2-containing protein (CIS) in response to EPO stimulation appears to depend on Stat5 but not on mitogen-activated protein kinase (MAPK) or phosphatidylinositol 3-kinase (PI3K). SOCS4 expression, in contrast, does not appear to be EPO inducible. Furthermore, we show differential stabilities of SOCS transcripts, with SOCS2 the longest-lived and SOCS1 and CIS the least stable, and provide evidence in support of EPO-independent expression of SOCS3 and SOCS4. In order to understand the effects of SOCS on EPO-mediated effects, we generated multiple stable cell lines that inducibly express particular SOCS proteins. Overexpression of SOCS1, SOCS3, or CIS negatively regulates EPO-mediated cell proliferation Stat5 phosphorylation, and activation of a Stat-dependent luciferase reporter. In contrast, SOCS2 is less effective, and SOCS4 is ineffective at counteracting EPO-mediated events. Thus, we have demonstrated differential regulation and function of various SOCS family members in EPO-dependent hematopoietic cells.
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Affiliation(s)
- Armin G Jegalian
- Molecular Biology Institute, UCLA School of Medicine, Los Angeles, CA 90095-1735, USA
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Jegalian AG, Wu H. Regulation of Socs gene expression by the proto-oncoprotein GFI-1B: two routes for STAT5 target gene induction by erythropoietin. J Biol Chem 2002; 277:2345-52. [PMID: 11696536 DOI: 10.1074/jbc.m105575200] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
SOCS proteins take part in a classical negative feedback loop to attenuate cytokine signaling. Although STAT family members positively modulate Socs gene expression, little else is known about Socs gene regulation. Here, we identify functional binding sites for GFI-1B, a proto-oncogenic transcriptional repressor, in the promoters of murine Socs1 and Socs3. Thus, mutating these sites relieved transcriptional repression, as determined by luciferase reporter assays of transiently transfected erythropoietin-responsive 32D-EpoR and HCD57 cells. Furthermore, cotransfection of Gfi-1B expression plasmid repressed reporter activity of wild-type (but not mutagenized) Socs1 and Socs3 promoters, strongly suggestive of direct GFI-1B binding to these promoters. In addition, overexpression of Gfi-1B resulted in reduced transcript levels of Socs1 and Socs3, but not Socs2 or Cis. Upon stimulation with erythropoietin, Socs transcripts were rapidly induced, whereas Gfi-1B mRNA was down-regulated. Interestingly, the latter effect appears to rely on STAT5 activity, but not on phosphoinositide 3-kinase or MAPK pathways. Thus, cytokine-mediated STAT5 activation allows relief of direct repression by GFI-1B of the Socs1 and Socs3 promoters, but apparently not of the Socs2 and Cis promoters. This constitutes a previously undescribed mode of controlling cytokine responsiveness, through the direct repression of a tumor suppressor (SOCS1) by a proto-oncoprotein (GFI-1B).
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Affiliation(s)
- Armin G Jegalian
- Molecular Biology Institute, the Department of Molecular, UCLA School of Medicine, Los Angeles, California 90095-1735, USA
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Brender C, Nielsen M, Kaltoft K, Mikkelsen G, Zhang Q, Wasik M, Billestrup N, Odum N. STAT3-mediated constitutive expression of SOCS-3 in cutaneous T-cell lymphoma. Blood 2001; 97:1056-62. [PMID: 11159537 DOI: 10.1182/blood.v97.4.1056] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
A characteristic feature of neoplastic transformation is the loss of external control by cytokines and extracellular matrix of cellular differentiation, migration, and mitogenesis. Because suppressors of cytokine signaling (SOCS) proteins are negative regulators of cytokine-induced signaling, it has been hypothesized that an aberrant SOCS expression plays a role in neoplastic transformation. This study reports on a constitutive SOCS-3 expression in cutaneous T-cell lymphoma (CTCL) cell lines. SOCS-3 protein is constitutively expressed in tumor cell lines (but not in nonmalignant T cells) obtained from affected skin from a patient with mycosis fungoides (MF) and from peripheral blood from a patient with Sezary syndrome (SS). In contrast, constitutive SOCS-3 expression is not found in the leukemic Jurkat T-cell line, the MOLT-4 acute lymphoblastic leukemia cell line, and the monocytic leukemic cell line U937. Expression of SOCS-3 coincides with a constitutive activation of STAT3 in CTCL tumor cells, and stable transfection of CTCL tumor cells with a dominant negative STAT3 strongly inhibits SOCS-3 expression, whereas transfection with wild-type STAT3 does not. Moreover, the reduced SOCS-3 expression in cells transfected with the dominant negative STAT3 is associated with an increased sensitivity to interferon-alpha (IFN-alpha). In conclusion, evidence is provided for a constitutive SOCS-3 expression in cancer cells obtained from patients with CTCL. Moreover, the findings indicate that the aberrant expression of SOCS-3 is mediated by a constitutive activation of STAT3 in CTCL cells and affects the IFN-alpha sensitivity of these cells. (Blood. 2001;97:1056-1062)
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MESH Headings
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/physiology
- Dimethyl Sulfoxide/pharmacology
- Enzyme Inhibitors/pharmacology
- Gene Expression Regulation, Neoplastic/physiology
- Genes, Dominant
- Humans
- Interferon-alpha/pharmacology
- Interferon-gamma/pharmacology
- Jurkat Cells/metabolism
- Leukemia-Lymphoma, Adult T-Cell/genetics
- Leukemia-Lymphoma, Adult T-Cell/metabolism
- Leukemia-Lymphoma, Adult T-Cell/pathology
- Mutation
- Mycosis Fungoides/genetics
- Mycosis Fungoides/metabolism
- Mycosis Fungoides/pathology
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/genetics
- Neoplasm Proteins/physiology
- Protein Biosynthesis
- Proteins/genetics
- Quinazolines
- RNA, Messenger/biosynthesis
- RNA, Neoplasm/biosynthesis
- Recombinant Fusion Proteins/physiology
- Repressor Proteins
- STAT3 Transcription Factor
- Sezary Syndrome/genetics
- Sezary Syndrome/metabolism
- Sezary Syndrome/pathology
- Skin Neoplasms/genetics
- Skin Neoplasms/metabolism
- Suppressor of Cytokine Signaling 3 Protein
- Suppressor of Cytokine Signaling Proteins
- Trans-Activators/genetics
- Trans-Activators/physiology
- Transcription Factors
- Transcription, Genetic
- Transfection
- Tumor Cells, Cultured/drug effects
- Tumor Cells, Cultured/metabolism
- Tyrphostins/pharmacology
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Affiliation(s)
- C Brender
- Institute of Medical Microbiology and Immunology, University of Copenhagen, Copenhagen, Denmark
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Monni R, Santos SC, Mauchauffe M, Berger R, Ghysdael J, Gouilleux F, Gisselbrecht S, Bernard O, Penard-Lacronique V. The TEL-Jak2 oncoprotein induces Socs1 expression and altered cytokine response in Ba/F3 cells. Oncogene 2001; 20:849-58. [PMID: 11314018 DOI: 10.1038/sj.onc.1204201] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2000] [Revised: 12/05/2000] [Accepted: 12/19/2000] [Indexed: 01/24/2023]
Abstract
The leukemia-associated TEL-Jak2 fusion protein possesses a constitutive tyrosine kinase activity and transforming properties in hematopoietic cell lines and animal models. In the murine pro-B Ba/F3 cell line, this fusion constitutively activates the Signal Transducer and Activator of Transcription 5 (Stat5) factors and, as a consequence, induces the sustained expression of various Stat5-target genes including the Cytokine Inducible SH2-containing protein (Cis) gene, which codes for a member of the Suppressor of Cytokine Signaling (Socs) protein family. In TEL-Jak2-transformed Ba/F3 cells, we also observed the upregulation of the Socs1 gene, whose product has been reported to negatively regulate the Jak kinase activity. In transient transfection experiments, Socs1 physically interacts with TEL-Jak2 and interferes with the TEL-Jak2-induced phosphorylation and activation of Stat5 factors, probably through the Socs1-induced proteasome-mediated degradation of the fusion protein. Interestingly, TEL-Jak2-expressing Ba/F3 cells were found to be resistant to the anti-proliferative activities of gamma interferon (IFN-gamma) seemingly as a consequence of Socs1 constitutive expression. These results indicate that the Socs1-dependent cytokine feedback loop, although active, is bypassed by the TEL-Jak2 fusion, but may play a role in the leukemogenic process by altering the cytokine responses of the leukemic cells. Our results also suggest that Socs1 plays a role in shutting down the signaling from the normally activated Jak2 kinase by inducing its proteasome-dependent degradation.
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Affiliation(s)
- R Monni
- INSERM U434, Centre d'Etude du Polymorphisme Humain (CEPH), 27 Rue Juliette Dodu, 75010 Paris, France
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Fang P, Wang Z, Sachs MS. Evolutionarily Conserved Features of the Arginine Attenuator Peptide Provide the Necessary Requirements for Its Function in Translational Regulation. J Biol Chem 2000. [DOI: 10.1016/s0021-9258(19)61434-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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