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Boasso A. Type I Interferon at the Interface of Antiviral Immunity and Immune Regulation: The Curious Case of HIV-1. SCIENTIFICA 2013; 2013:580968. [PMID: 24455433 PMCID: PMC3885208 DOI: 10.1155/2013/580968] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 12/10/2013] [Indexed: 06/03/2023]
Abstract
Type I interferon (IFN-I) play a critical role in the innate immune response against viral infections. They actively participate in antiviral immunity by inducing molecular mechanisms of viral restriction and by limiting the spread of the infection, but they also orchestrate the initial phases of the adaptive immune response and influence the quality of T cell immunity. During infection with the human immunodeficiency virus type 1 (HIV-1), the production of and response to IFN-I may be severely altered by the lymphotropic nature of the virus. In this review I consider the different aspects of virus sensing, IFN-I production, signalling, and effects on target cells, with a particular focus on the alterations observed following HIV-1 infection.
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Affiliation(s)
- Adriano Boasso
- Immunology Section, Chelsea and Westminster Hospital, 369 Fulham Road, London SW10 9NH, UK
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2
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Najjar I, Fagard R. STAT1 and pathogens, not a friendly relationship. Biochimie 2010; 92:425-44. [PMID: 20159032 PMCID: PMC7117016 DOI: 10.1016/j.biochi.2010.02.009] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Accepted: 02/09/2010] [Indexed: 12/21/2022]
Abstract
STAT1 belongs to the STAT family of transcription factors, which comprises seven factors: STAT1, STAT2, STAT3, STAT4, STAT5A, STAT5B and STAT6. STAT1 is a 91 kDa protein originally identified as the mediator of the cellular response to interferon (IFN) α, and thereafter found to be a major component of the cellular response to IFNγ. STAT1 is, in fact, involved in the response to several cytokines and to growth factors. It is activated by cytokine receptors via kinases of the JAK family. STAT1 becomes phosphorylated and forms a dimer which enters the nucleus and triggers the transcription of its targets. Although not lethal at birth, selective gene deletion of STAT1 in mice leads to rapid death from severe infections, demonstrating its major role in the response to pathogens. Similarly, in humans who do not express STAT1, there is a lack of resistance to pathogens leading to premature death. This indicates a key, non-redundant function of STAT1 in the defence against pathogens. Thus, to successfully infect organisms, bacterial, viral or parasitic pathogens must overcome the activity of STAT1, and almost all the steps of this pathway can be blocked or inhibited by proteins produced in infected cells. Interestingly, some pathogens, like the oncogenic Epstein–Barr virus, have evolved a strategy which uses STAT1 activation.
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Affiliation(s)
- Imen Najjar
- INSERM Unité 978, SMBH, 74 rue Marcel Cachin, Bobigny-cedex 93017, France.
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3
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Marijanovic Z, Ragimbeau J, vanderHeyden J, Uzé G, Pellegrini S. Comparable potency of IFNalpha2 and IFNbeta on immediate JAK/STAT activation but differential down-regulation of IFNAR2. Biochem J 2007; 407:141-51. [PMID: 17627610 PMCID: PMC2267396 DOI: 10.1042/bj20070605] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Type I IFNs (interferons) (IFNalpha/beta) form a family of related cytokines that control a variety of cellular functions through binding to a receptor composed of IFNAR (IFNalpha receptor subunit) 1 and 2. Among type I IFNs, the alpha2 and beta subtypes exhibit a large difference in their binding affinities to IFNAR1, and it was suggested that high concentrations of IFNAR1 may compensate for its low intrinsic binding affinity for IFNalpha2. We tested whether receptor-proximal signalling events are sensitive to IFNAR1 surface concentration by investigating the relationship between relative IFNAR1/IFNAR2 surface levels and IFNalpha2 and IFNbeta signalling potencies in several cell lines. For this, we monitored the activation profile of JAK (Janus kinase)/STAT (signal transducer and activator of transcription) proteins, measured basal and ligand-induced surface decay of each receptor subunit and tested the effect of variable IFNAR1 levels on IFNalpha2 signalling potency. Our data show that the cell-surface IFNAR1 level is indeed a limiting factor for assembly of the functional complex, but an increased concentration of it does not translate into an IFNalpha/beta differential JAK/STAT signalling nor does it change the dynamics of the engaged receptor. Importantly, however, our data highlight a differential effect upon routing of IFNAR2. Following binding of IFNalpha2, IFNAR2 is internalized, but, instead of being routed towards degradation as it is when complexed to IFNbeta, it recycles back to the cell surface. These observations suggest strongly that the stability and the intracellular lifetime of the ternary complex account for the differential control of IFNAR2. Moreover, the present study opens up the attractive possibility that endosomal-initiated signalling may contribute to IFNalpha/beta differential bioactivities.
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Affiliation(s)
- Zrinka Marijanovic
- *Unité de Signalisation des Cytokines, CNRS URA 1961, Institut Pasteur, 25 rue du Docteur Roux, Paris 75724
| | - Josiane Ragimbeau
- *Unité de Signalisation des Cytokines, CNRS URA 1961, Institut Pasteur, 25 rue du Docteur Roux, Paris 75724
| | | | - Gilles Uzé
- †CNRS UMR 5124, Montpellier 34095, France
| | - Sandra Pellegrini
- *Unité de Signalisation des Cytokines, CNRS URA 1961, Institut Pasteur, 25 rue du Docteur Roux, Paris 75724
- To whom correspondence should be addressed (email )
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4
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Tochizawa S, Muraguchi M, Ohmoto Y, Oga K, Mori T. Functional expression of human type I interferon receptors in the mouse liver. Biochem Biophys Res Commun 2006; 346:61-6. [PMID: 16750512 DOI: 10.1016/j.bbrc.2006.05.081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2006] [Accepted: 05/11/2006] [Indexed: 11/21/2022]
Abstract
We expressed human type I interferon (IFN) receptors (IFNAR) in mice and investigated their signaling. Using a hydrodynamics-based delivery method, vectors containing the genes for IFNAR1 and IFNAR2 were transferred into mice. Six hours after gene-transfer, mice were intravenously injected with human IFN-alpha at 10,000 IU. IFNAR1 and IFNAR2 were both expressed in the liver, but not spleen or lung. The receptors were coexpressed in single liver cells. One hour after IFN-alpha injection, the phosphorylation status of signal transducer and activator of transcription factor 1 (STAT1), a key molecule of IFN signaling, was determined. Phosphotyrosine-STAT1 (p-STAT1), localized to the nucleus of IFNAR-expressing cells, was increased in the livers of IFNAR gene-transferred mice but not in control vector-transferred animals. In conclusion, functional human IFNAR can be delivered to the mouse liver, resulting in an increase in p-STAT1 levels following human IFN-alpha stimulation.
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Affiliation(s)
- Shiro Tochizawa
- Research Institute of Pharmacological and Therapeutical Development, Otsuka Pharmaceutical Co., Ltd., Tokushima 771-0192, Japan.
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5
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Javed A, Reder AT. Therapeutic role of beta-interferons in multiple sclerosis. Pharmacol Ther 2006; 110:35-56. [PMID: 16229894 DOI: 10.1016/j.pharmthera.2005.08.011] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2005] [Accepted: 08/23/2005] [Indexed: 12/16/2022]
Abstract
Multiple sclerosis (MS) is an inflammatory disease of the central nervous system (CNS). In the last 12 years, there has been a proliferation of studies elucidating the immune mechanisms that mediate tissue damage in MS. Interferons (IFNs) have an important role in regulating innate and adaptive immune responses. They decrease pro-inflammatory responses such as the autoimmunity in MS, but other autoimmune responses such as systemic lupus erythematosus (SLE) may be exacerbated. This review offers a general overview of the biological properties of IFNs, effects on immune cells, and clinical effectiveness in MS treatment. IFN signaling is complex, from receptor binding events to the generation of effector mechanisms that dampen inflammation. Immune cell function is altered in MS. IFN treatment of MS patients ameliorates immune dysfunction, but not completely. The incomplete resolution of immune dysfunction by IFNs partly explains their significant, but modest therapeutic effects. This observation also suggests that there are immune mechanisms in MS that are resistant to IFN therapy. In MS, abnormalities may exist at several points along the IFN signaling pathway, including molecular defects in the IFN second messenger system. Currently, several studies are ongoing evaluating ways of potentiating IFN effects. IFNs were the first agents to show clinical efficacy in treatment of MS. More than a decade of experience with IFNs has showed continued clinical efficacy over time. In the near future, IFNs will continue to play a major role in MS.
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Affiliation(s)
- Adil Javed
- Department of Neurology, MC-2030, University of Chicago, 5841 South Maryland Avenue, IL 60637, USA
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6
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Clarke DTW, Irving AT, Lambley EH, Payne E, McMillan NAJ. A novel method for screening viral interferon-resistance genes. J Interferon Cytokine Res 2005; 24:470-7. [PMID: 15320960 DOI: 10.1089/1079990041689610] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Many viruses have evolved mechanisms to antagonize the interferon (IFN) system, targeting all the major components involved in receptor binding and signaling. Although a number of these vital proteins are homologous to cellular proteins involved in IFN downregulation (e.g., viral IFN regulatory factors [vIRFs]), many share little resemblance to known proteins. To determine the IFN-blocking properties of these proteins, functional assays are required. Here, we present a new and rapid functional screening method, based on the 2fTGH cell line, which is able to determine viral gene products that inhibit the IFN-alpha/Jak-Stat signaling pathway. Expression cloning of viral IFN-blocking genes into 2fTGH and consequent selection with IFN-alpha and 6-thioguanine result in the outgrowth of cells that are no longer responsive to IFN-alpha. We also demonstrate that selection occurs if members of the Jak-Stat signaling pathway are lost. To show the utility of our system, we have used a known suppressor of IFN signaling, the human papillomavirus (HPV) E7 gene. Expression of E7 causes the loss of ability of 2fTGH cells to respond to IFN-alpha treatment because of a functional disruption of the signaling pathway. This approach offers a new strategy for identifying novel viral genes or new functions of already described viral genes that have a role in IFN-alpha signaling inhibition.
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Affiliation(s)
- Daniel T W Clarke
- Centre for Immunology and Cancer Research, Princess Alexandra Hospital, University of Queensland, Brisbane, Australia
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7
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Ozaki T, Takahashi K, Kanasaki H, Iida K, Miyazaki K. Expression of the type I interferon receptor and the interferon-induced Mx protein in human endometrium during the menstrual cycle. Fertil Steril 2005; 83:163-70. [PMID: 15652903 DOI: 10.1016/j.fertnstert.2004.06.064] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2004] [Revised: 06/01/2004] [Accepted: 06/01/2004] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To investigate the expression of the type I interferon receptor (IFNAR) and interferon-induced Mx protein (Mx) in normal human endometrium throughout the menstrual cycle. DESIGN Prospective study. SETTING Medical university in Japan. PATIENT(S) Thirty-seven normal endometrial tissues from fertile women who had undergone hysterectomies for reasons other than endometrial disease. INTERVENTION(S) IFNAR-1, IFNAR-2, MxA, and MxB gene expression was analyzed by reverse transcription-real-time quantitative polymerase chain reaction. Moreover, localization of IFNAR-1 and IFNAR-2 were studied by immunohistochemistry. MAIN OUTCOME MEASURE(S) Expression of IFNAR-1, IFNAR-2, MxA, and MxB. RESULT(S) Expression of IFNAR-2 gene was significantly increased in the menstrual and midsecretory phase as compared with in the proliferative phase. Immunohistochemistry for IFNAR-1 and IFNAR-2 revealed weak staining of glandular epithelium and weak staining of stromal cells during the proliferative phase. However, an intense immunohistochemical staining of IFNAR-2 was observed on the surface and basement membrane of glands in the secretory phase. There was no statistical difference between MxA and MxB gene expression throughout the menstrual cycle. CONCLUSION(S) Our results suggest that IFNAR and Mx are expressed in the human endometrium and that the expression of IFNAR is cyclically changed during the menstrual cycle.
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Affiliation(s)
- Tomoya Ozaki
- Department of Obstetrics and Gynecology, Seirei Hamamatsu General Hospital, Hamamatsu, Japan
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8
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Wagner TC, Velichko S, Chesney SK, Biroc S, Harde D, Vogel D, Croze E. Interferon receptor expression regulates the antiproliferative effects of interferons on cancer cells and solid tumors. Int J Cancer 2004; 111:32-42. [PMID: 15185340 DOI: 10.1002/ijc.20236] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In addition to antiviral effects, Type I interferons (IFN) have potent antiproliferative and immunomodulatory activities. Because of these properties IFNs have been evaluated as therapeutics for the treatment of a number of human diseases, including cancer. Currently, IFNs have been shown to be efficacious for the treatment of only a select number of cancers. The reason for this is unclear. Recent evidence has demonstrated that some cancer cell types seem to be defective in their ability to respond to IFN. It has been suggested that defects in IFN signaling is one mechanism by which cancer cells escape responsiveness to Type I IFNs and growth control in general. We report that transfection and enhanced expression of the Type I IFN receptor chain (IFNAR2c) in 3 different human cancer cell lines markedly increases the sensitivity of these cells to the antiproliferative effects of IFNs. In cancer cells transfected with IFNAR2c, dose response curves demonstrate a significant decrease in the concentrations of IFN required to achieve maximum cell death. Furthermore, in these transfected cells, we observe a significant increase in the number of cells undergoing apoptosis, as measured by DNA fragmentation and Caspase 3 activation. In addition, using an in vivo xenograft tumor model we show an increase in the effectiveness of systemically delivered Betaseron in decreasing tumor burden in animals in which solid tumors were generated from IFNAR2c transfected cells. These data show that specific regulation of IFN receptor expression can play a major role in determining the clinical outcome of IFN-based cancer therapeutics by regulating the relative sensitivity of cancer cells to IFN-dependent growth control.
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Affiliation(s)
- T Charis Wagner
- Department of Immunology, Berlex Bioscience Inc., Richmond, CA 94804, USA
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9
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Cutrone EC, Langer JA. Identification of critical residues in bovine IFNAR-1 responsible for interferon binding. J Biol Chem 2001; 276:17140-8. [PMID: 11278538 DOI: 10.1074/jbc.m009663200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Interferons have antiviral, antigrowth and immunomodulatory effects. The human type I interferons, IFN-alpha, IFN-beta, and IFN-omega, induce somewhat different cellular effects but act through a common receptor complex, IFNAR, composed of subunits IFNAR-1 and IFNAR-2. Human IFNAR-2 binds all type I IFNs but with lower affinity and different specificity than the IFNAR complex. Human IFNAR-1 has low intrinsic binding of human IFNs but strongly affects the affinity and differential ligand specificity of the IFNAR complex. Understanding IFNAR-1 interactions with the interferons is critical to elucidating the differential ligand specificity and activation by type I IFNs. However, studies of ligand interactions with human IFNAR-1 are compromised by its low affinity. The homologous bovine IFNAR-1 serendipitously binds human IFN-alphas with nanomolar affinity. Exploiting its strong binding of human IFN-alpha2, we have identified residues important for ligand binding. Mutagenesis of any of five aromatic residues of bovine IFNAR-1 caused strong decreases in ligand binding, whereas mutagenesis of proximal neutral or charged residues had smaller effects. These residues were mapped onto a homology model of IFNAR-1 to identify the ligand-binding face of IFNAR-1, which is consistent with previous structure/function studies of human IFNAR-1. The topology of IFNAR-1/IFN interactions appears novel when compared with previously studied cytokine receptors.
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Affiliation(s)
- E C Cutrone
- Department of Molecular Genetics & Microbiology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA
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10
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Leszczyniecka M, Roberts T, Dent P, Grant S, Fisher PB. Differentiation therapy of human cancer: basic science and clinical applications. Pharmacol Ther 2001; 90:105-56. [PMID: 11578655 DOI: 10.1016/s0163-7258(01)00132-2] [Citation(s) in RCA: 228] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Current cancer therapies are highly toxic and often nonspecific. A potentially less toxic approach to treating this prevalent disease employs agents that modify cancer cell differentiation, termed 'differentiation therapy.' This approach is based on the tacit assumption that many neoplastic cell types exhibit reversible defects in differentiation, which upon appropriate treatment, results in tumor reprogramming and a concomitant loss in proliferative capacity and induction of terminal differentiation or apoptosis (programmed cell death). Laboratory studies that focus on elucidating mechanisms of action are demonstrating the effectiveness of 'differentiation therapy,' which is now beginning to show translational promise in the clinical setting.
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Affiliation(s)
- M Leszczyniecka
- Department of Urology, Herbert Irving Comprehensive Cancer Center, Columbia University, College of Physicians and Surgeons, New York, NY 10032, USA
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11
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Croze E, Usacheva A, Asarnow D, Minshall RD, Perez HD, Colamonici O. Receptor for activated C-kinase (RACK-1), a WD motif-containing protein, specifically associates with the human type I IFN receptor. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:5127-32. [PMID: 11046044 DOI: 10.4049/jimmunol.165.9.5127] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The cytoplasmic domain of the human type I IFN receptor chain 2 (IFNAR2c or IFN-alphaRbetaL) was used as bait in a yeast two-hybrid system to identify novel proteins interacting with this region of the receptor. We report here a specific interaction between the cytoplasmic domain of IFN-alphaRbetaL and a previously identified protein, RACK-1 (receptor for activated C kinase). Using GST fusion proteins encoding different regions of the cytoplasmic domain of IFN-alphaRbetaL, the minimum site for RACK-1 binding was mapped to aa 300-346. RACK-1 binding to IFN-alphaRbetaL did not require the first 91 aa of RACK-1, which includes two WD domains, WD1 and WD2. The interaction between RACK-1 and IFN-alphaRbetaL, but not the human IFN receptor chain 1 (IFNAR1 or IFN-alphaRalpha), was also detected in human Daudi cells by coimmunoprecipitation. RACK-1 was shown to be constitutively associated with IFN-alphaRbetaL, and this association was not effected by stimulation of Daudi cells with type I IFNs (IFN-beta1b). RACK-1 itself did not become tyrosine phosphorylated upon stimulation of Daudi cells with IFN-beta1b. However, stimulation of cells with either IFN-beta1b or PMA did result in an increase in detectable immunofluorescence and intracellular redistribution of RACK-1.
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MESH Headings
- Amino Acid Motifs/genetics
- Amino Acid Motifs/immunology
- Aspartic Acid
- Cell Line
- Enzyme Activation/genetics
- Enzyme Activation/immunology
- Humans
- Interferon Type I/metabolism
- Interferon Type I/pharmacology
- Intracellular Fluid/drug effects
- Intracellular Fluid/immunology
- Intracellular Fluid/metabolism
- Membrane Proteins
- Peptide Mapping
- Precipitin Tests
- Protein Binding/genetics
- Protein Binding/immunology
- Protein Kinase C/genetics
- Protein Kinase C/metabolism
- Receptor, Interferon alpha-beta
- Receptors for Activated C Kinase
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/isolation & purification
- Receptors, Cell Surface/metabolism
- Receptors, Interferon/genetics
- Receptors, Interferon/isolation & purification
- Receptors, Interferon/metabolism
- Repetitive Sequences, Amino Acid/genetics
- Repetitive Sequences, Amino Acid/immunology
- Saccharomyces cerevisiae/genetics
- Tetradecanoylphorbol Acetate/pharmacology
- Tryptophan
- Tumor Cells, Cultured
- Two-Hybrid System Techniques
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Affiliation(s)
- E Croze
- Department of Immunology, Berlex Biosciences, Richmond CA 94804, USA.
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12
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Russell-Harde D, Wagner TC, Rani MR, Vogel D, Colamonici O, Ransohoff RM, Majchrzak B, Fish E, Perez HD, Croze E. Role of the intracellular domain of the human type I interferon receptor 2 chain (IFNAR2c) in interferon signaling. Expression of IFNAR2c truncation mutants in U5A cells. J Biol Chem 2000; 275:23981-5. [PMID: 10825167 DOI: 10.1074/jbc.m002518200] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A human cell line (U5A) lacking the type I interferon (IFN) receptor chain 2 (IFNAR2c) was used to determine the role of the IFNAR2c cytoplasmic domain in regulating IFN-dependent STAT activation, interferon-stimulated gene factor 3 (ISGF3) and c-sis-inducible factor (SIF) complex formation, gene expression, and antiproliferative effects. A panel of U5A cells expressing truncation mutants of IFNAR2c on their cell surface were generated for study. Janus kinase (JAK) activation was detected in all mutant cell lines; however, STAT1 and STAT2 activation was observed only in U5A cells expressing full-length IFNAR2c and IFNAR2c truncated at residue 462 (R2.462). IFNAR2c mutants truncated at residues 417 (R2. 417) and 346 (R2.346) or IFNAR2c mutant lacking tyrosine residues in its cytoplasmic domain (R2.Y-F) render the receptor inactive. A similar pattern was observed for IFN-inducible STAT activation, STAT complex formation, and STAT-DNA binding. Consistent with these data, IFN-inducible gene expression was ablated in U5A, R2.Y-F, R2.417, and R2.346 cell lines. The implications are that tyrosine phosphorylation and the 462-417 region of IFNAR2c are independently obligatory for receptor activation. In addition, the distal 53 amino acids of the intracellular domain of IFNAR2c are not required for IFN-receptor mediated STAT activation, ISFG3 or SIF complex formation, induction of gene expression, and inhibition of thymidine incorporation. These data demonstrate for the first time that both tyrosine phosphorylation and a specific domain of IFNAR2c are required in human cells for IFN-dependent coupling of JAK activation to STAT phosphorylation, gene induction, and antiproliferative effects. In addition, human and murine cells appear to require different regions of the cytoplasmic domain of IFNAR2c for regulation of IFN responses.
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Affiliation(s)
- D Russell-Harde
- Berlex Biosciences, Richmond, California 94804, the Cleveland Clinic Foundation, Cleveland, Ohio, 44195, USA
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13
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Lu KP. Phosphorylation-dependent prolyl isomerization: a novel cell cycle regulatory mechanism. PROGRESS IN CELL CYCLE RESEARCH 2000; 4:83-96. [PMID: 10740817 DOI: 10.1007/978-1-4615-4253-7_8] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Protein phosphorylation by proline-directed protein kinases plays an essential role in triggering a programmed set of cell cycle events. We have recently isolated an essential and conserved mitotic regulator, Pin1. Pin1 is a phosphorylation-dependent prolyl isomerase that specifically isomerizes the phosphorylated serine/threonine-proline bond. Pin1 also binds and regulates the function of a conserved set of mitosis-specific phosphoproteins. These results suggest phosphorylation-dependent prolyl isomerization to be a novel cell cycle regulatory mechanism. This new post-translational regulation may allow the general increase in protein phosphorylation to be converted into the organised and programmed set of structural modifications that occur during mitosis. In addition, since inhibition of Pin1 induces mitotic arrest and apoptosis, Pin1 may be a potential new drug target.
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Affiliation(s)
- K P Lu
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
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14
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Chuntharapai A, Gibbs V, Lu J, Ow A, Marsters S, Ashkenazi A, De Vos A, Kim KJ. Determination of Residues Involved in Ligand Binding and Signal Transmission in the Human IFN-α Receptor 2. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.163.2.766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
The human IFN-α receptor (hIFNAR) is a complex composed of at least two chains, hIFNAR1 and hIFNAR2. We have performed a structure-function analysis of hIFNAR2 extracellular domain regions using anti-hIFNAR2 mAbs (1D3, 1F3, and 3B7) and several type I human IFNs. These mAbs block receptor activation, as determined by IFN-stimulated gene factor 3 formation, and block the antiviral cytopathic effects induced by type I IFNs. We generated alanine substitution mutants of hIFNAR2-IgG and determined that regions of hIFNAR2 are important for the binding of these blocking mAbs and hIFN-α2/α1. We further demonstrated that residues E78, W101, I104, and D105 are crucial for the binding of hIFN-α2/α1 and form a defined protrusion when these residues are mapped upon a structural model of hIFNAR2. To confirm that residues important for ligand binding are indeed important for IFN signal transduction, we determined the ability of mouse L929 cells expressing hIFNAR2 extracellular domain mutants to mediate hIFN signal. hIFN-α8, previously shown to signal a response in L929 cells expressing hIFNAR1, was unable to signal in L929 cells expressing hIFNAR2. Transfected cells expressing hIFNAR2 containing mutations at residues E78, W101, I104, or D105 were unresponsive to hIFN-α2, but remained responsive to hIFN-β. In summary, we have identified specific residues of hIFNAR2 important for the binding to hIFN-α2/1 and demonstrate that specific regions of the IFNAR interact with the subspecies of type I IFN in different manners.
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Affiliation(s)
- A. Chuntharapai
- *Departments of Antibody Technology, Molecular Oncology, and Protein Engineering, Genentech Inc., South San Francisco, CA 94080; and
| | - V. Gibbs
- †Department of Surgery, San Francisco Veterans Affairs Medical Center, San Francisco, CA 94121
| | - J. Lu
- *Departments of Antibody Technology, Molecular Oncology, and Protein Engineering, Genentech Inc., South San Francisco, CA 94080; and
| | - A. Ow
- †Department of Surgery, San Francisco Veterans Affairs Medical Center, San Francisco, CA 94121
| | - S. Marsters
- *Departments of Antibody Technology, Molecular Oncology, and Protein Engineering, Genentech Inc., South San Francisco, CA 94080; and
| | - A. Ashkenazi
- *Departments of Antibody Technology, Molecular Oncology, and Protein Engineering, Genentech Inc., South San Francisco, CA 94080; and
| | - A. De Vos
- *Departments of Antibody Technology, Molecular Oncology, and Protein Engineering, Genentech Inc., South San Francisco, CA 94080; and
| | - K. Jin Kim
- *Departments of Antibody Technology, Molecular Oncology, and Protein Engineering, Genentech Inc., South San Francisco, CA 94080; and
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15
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Balkan W, Oates EL, Howard GA, Roos BA. Testes exhibit elevated expression of calcitonin gene-related peptide receptor component protein. Endocrinology 1999; 140:1459-69. [PMID: 10067875 DOI: 10.1210/endo.140.3.6541] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Calcitonin gene-related peptide (CGRP) receptor component protein (RCP) is a novel protein that modulates CGRP responsiveness in a variety of cell types. Using probes based on the isolation of CGRP-RCP complementary DNA (cDNA) from a guinea pig organ of Corti cDNA library, we cloned human (h) and mouse (m) CGRP-RCP cDNAs, both of which encode 148-residue proteins that at the amino acid levels are approximately 88% identical to each other and to the 146-residue guinea pig CGRP-RCP. Northern blot analysis confirmed the presence of CGRP-RCP messenger RNA in all of the human and mouse tissues tested. In these human tissues, hCGRP-RCP messenger RNA (major band at approximately 3.1 kb, minor band at approximately 7.5 kb) was most prevalent in the testis. In the mouse, the highest abundance of CGRP-RCP RNA was clearly in the testis (major band at approximately 1.6 kb, minor band at approximately 1.1 kb). Based on this tissue distribution of RNA, we sought to identify the cells in the murine testis that contained CGRP-RCP protein. Numerous antisera generated against hCGRP-RCP, including one to recombinant hCGRP-RCP, exhibited strong immunoreactivity localized to the head region of spermatozoa. No CGRP-RCP immunoreactivity was observed in other cells at less mature stages of sperm maturation, in Sertoli or interstitial (Leydig) cells, or in human spermatozoa. Murine epididymal (mature) spermatozoa exhibited CGRP-RCP immunoreactivity identical to that of testicular spermatozoa. Spermatozoa that underwent an experimentally induced acrosome reaction (acrosomal discharge) lost their CGRP-RCP immunoreactivity. Therefore, it appears that CGRP-RCP is associated with the acrosome, suggesting that it may play an important role in reproduction.
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Affiliation(s)
- W Balkan
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, and Department of Medicine, University of Miami School of Medicine, Florida 33101, USA.
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16
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Russell-Harde D, Wagner TC, Perez HD, Croze E. Formation of a uniquely stable type I interferon receptor complex by interferon beta is dependent upon particular interactions between interferon beta and its receptor and independent of tyrosine phosphorylation. Biochem Biophys Res Commun 1999; 255:539-44. [PMID: 10049744 DOI: 10.1006/bbrc.1998.0105] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Human type I interferons (IFN) require two receptor chains, IFNAR1 and IFNAR2c for high affinity (pM) binding and biological activity. Our previous studies have shown that the ligand dependent assembly of the type I IFN receptor chains is not identical for all type I IFNs. IFNbeta appears unique in its ability to assemble a stable complex of receptor chains, as demonstrated by the observation that IFNAR2c co-immunoprecipitates with IFNAR1 when cells are stimulated with IFNbeta but not with IFNalpha. The characteristics of such a receptor complex are not well defined nor is it understood if differential signaling events can be mediated by variations in receptor assembly. To further characterize the factors required for formation of such a stable receptor complex we demonstrate using IFN stimulated Daudi cells that (1) IFNAR2c co-immunoprecipitates with IFNAR1 even when tyrosine phosphorylation of receptor chains is blocked with staurosporine, and (2) IFNbeta1b but not IFNalpha2, is present in the immunoprecipitated receptor complex. These results demonstrate that the unique IFNbeta induced assembly of type I IFN receptor chains is independent of receptor tyrosine phosphorylation and the recruitment of additional proteins to the receptor by such events. Furthermore, the presence of IFNbeta1b in the immunoprecipitated IFN receptor complex suggests that IFNbeta interacts and binds differently to the receptor than IFNalpha2. These results suggest that the specific assembly of type I IFN receptor chains is ligand dependent and may represent an early event which leads to the differential biological responses observed among type I IFNs.
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Affiliation(s)
- D Russell-Harde
- Department of Protein Biochemistry, Department of Immunology, Berlex Biosciences, Richmond, California 94804, USA
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17
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Goldman LA, Zafari M, Cutrone EC, Dang A, Brickelmeier M, Runkel L, Benjamin CD, Ling LE, Langer JA. Characterization of antihuman IFNAR-1 monoclonal antibodies: epitope localization and functional analysis. J Interferon Cytokine Res 1999; 19:15-26. [PMID: 10048764 DOI: 10.1089/107999099314379] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The type I interferon receptor (IFNAR) is composed of two subunits, IFNAR-1 and IFNAR-2, encoding transmembrane polypeptides. IFNAR-2 has a dominant role in ligand binding, but IFNAR-1 contributes to binding affinity and to differential ligand recognition. A panel of five monoclonal antibodies (mAb) to human IFNAR-1 (HuIFNAR-1) was produced and characterized. The reactivity of each mAb toward HuIFNAR-1 on native and transfected cells and in Western blot and ELISA formats was determined. In functional assays, one mAb, EA12, blocked IFN-a2 binding to human cells and interfered with Stat activation and antiviral activity. Epitopes for the mAb were localized to subdomains of the HuIFNAR-1 extracellular domain by differential reactivity of the mAb to a series of human/bovine IFNAR-1 chimeras. The antibody EA12 seems to require native HuIFNAR-1 for reactivity and does not map to a single subdomain, perhaps recognizing an epitope containing noncontiguous sequences in at least two subdomains. In contrast, the epitopes of the non-neutralizing mAb FB2, AA3, and GB8 mapped, respectively, to the first, second, and third subdomains of HuIFNAR-1. The mAb DB2 primarily maps to the fourth subdomain, although its reactivity may be affected by other determinants.
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Affiliation(s)
- L A Goldman
- Department of Molecular Genetics and Microbiology, UMDNJ-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
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18
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Abstract
Interferons play key roles in mediating antiviral and antigrowth responses and in modulating immune response. The main signaling pathways are rapid and direct. They involve tyrosine phosphorylation and activation of signal transducers and activators of transcription factors by Janus tyrosine kinases at the cell membrane, followed by release of signal transducers and activators of transcription and their migration to the nucleus, where they induce the expression of the many gene products that determine the responses. Ancillary pathways are also activated by the interferons, but their effects on cell physiology are less clear. The Janus kinases and signal transducers and activators of transcription, and many of the interferon-induced proteins, play important alternative roles in cells, raising interesting questions as to how the responses to the interferons intersect with more general aspects of cellular physiology and how the specificity of cytokine responses is maintained.
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Affiliation(s)
- G R Stark
- Lerner Research Institute, Cleveland Clinic Foundation, Ohio 44195, USA.
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19
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Goldman LA, Cutrone EC, Dang A, Hao X, Lim JK, Langer JA. Mapping human interferon-alpha (IFN-alpha 2) binding determinants of the type I interferon receptor subunit IFNAR-1 with human/bovine IFNAR-1 chimeras. Biochemistry 1998; 37:13003-10. [PMID: 9737881 DOI: 10.1021/bi980073j] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Type I interferons bind to a common receptor (IFNAR), composed of two transmembrane polypeptides, IFNAR-1 and IFNAR-2. Although human IFNAR-1 has a weak intrinsic affinity for human Type I interferons (IFNs), bovine IFNAR-1 binds human Type I IFNs with moderate (nM) affinity, and can be conveniently used to investigate the regions of IFNAR-1 involved in ligand binding. We have constructed 14 bovine/human IFNAR-1 chimeras by exchanging homologous subdomains in the extracellular portion of the receptor. These chimeras were expressed at very high levels on COS cells, and their ability to bind HuIFN-alpha2 was measured. No single bovine subdomain substituted into human IFNAR-1 could confer moderate-affinity ligand binding on the resulting chimera. Simultaneous substitution of bovine IFNAR-1 subdomains 2 and 3 for the homologous human subdomains resulted in a dramatic increase in the binding of IFN-alpha2, suggesting that critical determinants for moderate-affinity ligand binding by BoIFNAR-1 reside in these two subdomains. Bovine subdomains 1 and/or 4 each further enhanced IFN-alpha2 binding in the presence of bovine subdomains 2 and 3. Thus, the binding interactions of BoIFNAR-1 with IFNs appears to be more complex than that of other class II cytokine receptors with their ligands.
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Affiliation(s)
- L A Goldman
- Department of Molecular Genetics and Microbiology, UMDNJ-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA
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20
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Langer JA, Yang J, Carmillo P, Ling LE. Bovine type I interferon receptor protein BoIFNAR-1 has high-affinity and broad specificity for human type I interferons. FEBS Lett 1998; 421:131-5. [PMID: 9468293 DOI: 10.1016/s0014-5793(97)01550-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The type I interferon receptor (IFNAR) is composed of two transmembrane polypeptides, IFNAR-1 and IFNAR-2. Human IFNAR-1 has low intrinsic affinity for IFNs, but enhances the affinity for IFNs of the complex over that of HuIFNAR-2 alone, and modulates the ligand specificity. Bovine cells respond to human alpha interferons. The bovine homologue of HuIFNAR-1, BoIFNAR-1, when expressed in heterologous cells, confers high-affinity binding and broad specificity for human type I IFNs. A soluble fusion protein of the ectodomain of BoIFNAR-1 and an immunoglobulin Fc domain was produced. In contrast to HuIFNAR-1, this protein competes strongly with human cells for IFN binding, and directly binds a wide spectrum of human type I IFNs, including diverse IFN-alphas, IFN-beta and IFN-omega, with moderate to high affinity. This accounts for much of the specificity for human IFNs possessed by bovine cells, with several exceptions. The BoIFNAR-1 ectodomain, in contrast to HuIFNAR-1, may be useful for studies of binary and ternary complexes with IFNs and IFNAR-2, and for purification, assay and biological neutralization protocols.
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Affiliation(s)
- J A Langer
- Department of Molecular Genetics and Microbiology, Robert Wood Johnson Medical School-UMDNJ, Piscataway, NJ 08854, USA.
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21
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Gauzzi MC, Barbieri G, Richter MF, Uzé G, Ling L, Fellous M, Pellegrini S. The amino-terminal region of Tyk2 sustains the level of interferon alpha receptor 1, a component of the interferon alpha/beta receptor. Proc Natl Acad Sci U S A 1997; 94:11839-44. [PMID: 9342324 PMCID: PMC23625 DOI: 10.1073/pnas.94.22.11839] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Tyk2 belongs to the Janus kinase (JAK) family of receptor associated tyrosine kinases, characterized by a large N-terminal region, a kinase-like domain and a tyrosine kinase domain. It was previously shown that Tyk2 contributes to interferon-alpha (IFN-alpha) signaling not only catalytically, but also as an essential intracellular component of the receptor complex, being required for high affinity binding of IFN-alpha. For this function the tyrosine kinase domain was found to be dispensable. Here, it is shown that mutant cells lacking Tyk2 have significantly reduced IFN-alpha receptor 1 (IFNAR1) protein level, whereas the mRNA level is unaltered. Expression of the N-terminal region of Tyk2 in these cells reconstituted wild-type IFNAR1 level, but did not restore the binding activity of the receptor. Studies of mutant Tyk2 forms deleted at the N terminus indicated that the integrity of the N-terminal region is required to sustain IFNAR1. These studies also showed that the N-terminal region does not directly modulate the basal autophosphorylation activity of Tyk2, but it is required for efficient in vitro IFNAR1 phosphorylation and for rendering the enzyme activatable by IFN-alpha. Overall, these results indicate that distinct Tyk2 domains provide different functions to the receptor complex: the N-terminal region sustains IFNAR1 level, whereas the kinase-like domain provides a function toward high affinity ligand binding.
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Affiliation(s)
- M C Gauzzi
- Institut Pasteur, Institut National de la Santé et de la Recherche Médicale Unité 276, Paris 75724 Cedex 15, France
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22
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Owczarek CM, Hwang SY, Holland KA, Gulluyan LM, Tavaria M, Weaver B, Reich NC, Kola I, Hertzog PJ. Cloning and characterization of soluble and transmembrane isoforms of a novel component of the murine type I interferon receptor, IFNAR 2. J Biol Chem 1997; 272:23865-70. [PMID: 9295335 DOI: 10.1074/jbc.272.38.23865] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
This report describes the cloning of cDNAs encoding transmembrane and soluble isoforms of a novel chain of the murine type I interferon (IFN) receptor and characterization of its capability to bind ligand and transduce signals. The transmembrane receptor (murine IFNAR 2c) has an extracellular domain of 215 amino acids and an intracellular domain of 250 amino acids, with 48% amino acid and 71% nucleotide identity with human IFNAR 2c. The cDNA for the soluble murine receptor (IFNAR 2a) encodes a 221-amino acid polypeptide identical to the first 210 amino acids of IFNAR 2c plus a novel 11 amino acids. Northern blot analyses show that murine IFNAR 2 is expressed as two transcripts of 4 kilobases encoding the transmembrane isoform and 1.5 kilobases encoding the more abundant soluble isoform. Studies using primary murine cells that lack IFNAR 1 show that IFNAR 2 is expressed, and cells bind type I IFN ligand, but do not transduce signals as detected by electrophoretic mobility shift assays of ISGF3 or GAF complexes binding to their cognate oligonucleotides. These cells show no effects on the ability of IFNgamma to activate these complexes. These studies demonstrate that the IFNAR 2 transmembrane (2c) and soluble (2a) isoforms are conserved between the human and mouse and that IFNAR 2c has intrinsic ligand binding activity, but no intrinsic signal transducing activity as measured in this study.
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Affiliation(s)
- C M Owczarek
- Molecular Genetics and Development Group, Institute of Reproduction and Development, Monash University, Clayton Victoria 3168, Australia
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23
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Holland KA, Owczarek CM, Hwang SY, Tymms MJ, Constantinescu SN, Pfeffer LM, Kola I, Hertzog PJ. A type I interferon signaling factor, ISF21, encoded on chromosome 21 is distinct from receptor components and their down-regulation and Is necessary for transcriptional activation of interferon-regulated genes. J Biol Chem 1997; 272:21045-51. [PMID: 9261106 DOI: 10.1074/jbc.272.34.21045] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The type I interferons (IFNs) are a family of cytokines, comprising at least 17 subtypes, which exert pleiotropic actions by interaction with a multi-component cell surface receptor and at least one well characterized signal transduction pathway involving JAK/STAT (Janus kinase/signal transducer and activator of transcription) proteins. In a previous report, we showed that a signaling factor, encoded by a gene located on the distal portion of chromosome 21, distinct from the IFNAR-1 receptor, was necessary for 2'-5'-oligoadenylate synthetase activity and antiviral responses, but not for high affinity ligand binding. In the present studies using hybrid Chinese hamster ovary cell lines containing portions of human chromosome 21, we show that the type I IFN signaling molecule, designated herein as ISF21, is distinct from the second receptor component, IFNAR-2, which is expressed in signaling and non-signaling cell lines. The location of the gene encoding ISF21 is narrowed to a region between the 10;21 and the r21 breakpoints, importantly eliminating the Mx gene located at 21q22.3 (the product of which is involved in IFN-induced antiviral responses) as a candidate for the signaling factor. To characterize the action of this factor in the type I IFN signaling pathway, we show that it acts independently of receptor down-regulation following ligand binding, both of which occur equally in the presence or absence of the factor. In addition, we demonstrate that ISF21 is necessary for transcriptional activation of 2'-5'-oligoadenylate synthetase, 6-16, and guanylate-binding protein gene promoter reporter constructs, which are mediated by several signaling pathways. ISF21 represents a novel factor as the localization to chromosome 21, and the data presented in this study exclude any of the known type I IFN signal-transducing molecules.
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Affiliation(s)
- K A Holland
- Molecular Genetics and Development Group, Institute of Reproduction and Development, Monash University, Monash Medical Centre, Clayton, Victoria 3168, Australia
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24
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Pfeffer LM, Basu L, Pfeffer SR, Yang CH, Murti A, Russell-Harde D, Croze E. The short form of the interferon alpha/beta receptor chain 2 acts as a dominant negative for type I interferon action. J Biol Chem 1997; 272:11002-5. [PMID: 9110990 DOI: 10.1074/jbc.272.17.11002] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We have characterized the functional properties of the short form of the human interferon alpha/beta receptor chain 2 (IFNAR2), denoted IFNAR2.1. IFNAR2.1 contains a shortened cytoplasmic domain when compared with the recently cloned full-length IFNAR2 chain (IFNAR2. 2). We show that IFNalpha8 and IFNbeta1b induce antiviral and antiproliferative activity in mouse cell transfectants expressing the human IFNAR1 chain of the receptor and induce the formation of STAT1/STAT2 dimers in IFN-stimulated response element (ISRE)-dependent gel shift assays. In contrast, coexpression of IFNAR2.1 with IFNAR1 reduces the IFN-induced antiviral, antiproliferative and ISRE-dependent gel shift binding activity conferred by IFNAR1 alone. No antiviral or antiproliferative response to IFN, nor IFN-induced ISRE-dependent gel shift binding activity, was observed when IFNAR2.1 was expressed alone in murine cells. Therefore, IFNAR2.1 acts as a dominant negative for these IFN-induced activities. Our results suggest that IFNAR2.1 represents a nonfunctional version of the full-length chain (IFNAR2.2).
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Affiliation(s)
- L M Pfeffer
- Department of Pathology, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA.
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25
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Roberts RM, Liu L, Alexenko A. New and atypical families of type I interferons in mammals: comparative functions, structures, and evolutionary relationships. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1997; 56:287-325. [PMID: 9187057 DOI: 10.1016/s0079-6603(08)61008-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- R M Roberts
- Department of Veterinary Pathobiology and Animal Sciences, University of Missouri, Columbia 65211, USA
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26
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Affiliation(s)
- A M Fry
- Department of Molecular Biology, University of Geneva, Switzerland
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27
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Croze E, Russell-Harde D, Wagner TC, Pu H, Pfeffer LM, Perez HD. The human type I interferon receptor. Identification of the interferon beta-specific receptor-associated phosphoprotein. J Biol Chem 1996; 271:33165-8. [PMID: 8969169 DOI: 10.1074/jbc.271.52.33165] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
We used specific antibodies recognizing the receptor 1 (IFNAR1) and the recently cloned receptor 2.2 (IFNAR2.2) chains of the human type I interferon receptor complex to demonstrate that the interferon beta (IFN-beta)-specific receptor-associated phosphoprotein is IFNAR2.2 and not an unknown or additional receptor component. Immunoprecipitation experiments demonstrated that IFNAR2.2 is present in Daudi cells as a cell surface protein of approximately 90-100 kDa, which is tyrosine-phosphorylated and associated with IFNAR1, upon stimulation of cells with IFN-beta. IFNAR2.2 was not detected associated with IFNAR1 in cells stimulated with IFN-alpha, suggesting differences in receptor interaction between the two type I interferons. Both IFNAR1 and IFNAR2.2 undergo tyrosine phosphorylation upon induction by either IFN-alpha or IFN-beta. Therefore, it is unclear as to why IFNAR2.2 is not detectable in IFNAR1 immunoprecipitates in IFN-beta-treated cells. These data suggest that, although IFN-alpha and IFN-beta may utilize similar receptor chains, they interact with IFNAR1 and IFNAR2.2 in different ways.
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Affiliation(s)
- E Croze
- Department of Protein Biochemistry and Biophysics, Berlex Biosciences, Richmond, California 94804, USA.
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28
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Abstract
The type-I interferon receptor is a multisubunit receptor of the cytokine receptor superfamily. The production of specific monoclonal antibodies against the receptor and the cloning of different receptor subunits have contributed to understanding the type-I interferon receptor structure and function. The present article analyzes these new advances and the role of the different receptor subunits in type-I interferon signaling.
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Affiliation(s)
- P Domanski
- Department of Pathology, University of Tennessee, Memphis 38163, USA
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29
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Luebke AE, Dahl GP, Roos BA, Dickerson IM. Identification of a protein that confers calcitonin gene-related peptide responsiveness to oocytes by using a cystic fibrosis transmembrane conductance regulator assay. Proc Natl Acad Sci U S A 1996; 93:3455-60. [PMID: 8622957 PMCID: PMC39630 DOI: 10.1073/pnas.93.8.3455] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
An expression-cloning strategy was used to isolate a cDNA that encodes a protein that confers calcitonin gene-related peptide (CGRP) responsiveness to Xenopus laevis oocytes. A guinea pig organ of Corti (the mammalian hearing organ) cDNA library was screened by using an assay based on the cystic fibrosis transmembrane conductance regulator (CFTR). The CFTR is a chloride channel that is activated upon phosphorylation; this channel activity was used as a sensor for CGRP-induced activation of intracellular kinases. A cDNA library from guinea pig organ of Corti was screened by using this oocyte-CFTR assay. A cDNA was identified that contained an open reading frame coding for a small hydrophilic protein that is presumed to be either a CGRP receptor or a component of a CGRP receptor complex. This CGRP receptor component protein confers CGRP-specific activation to the CFTR assay, as no activation was detected upon application of calcitonin, amylin, neuropeptide Y, vasoactive intestinal peptide, or beta-endorphin. In situ hybridization demonstrated that the CGRP receptor component protein is expressed in outer hair cells of the organ of Corti and is colocalized with CGRP-containing efferent nerve terminals.
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Affiliation(s)
- A E Luebke
- Department of Physiology and Biophysics, Veterans Affairs Medical Center, University of Miami School of Medicine, FL 33101, USA
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