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Fleskens V, Minutti CM, Wu X, Wei P, Pals CEGM, McCrae J, Hemmers S, Groenewold V, Vos HJ, Rudensky A, Pan F, Li H, Zaiss DM, Coffer PJ. Nemo-like Kinase Drives Foxp3 Stability and Is Critical for Maintenance of Immune Tolerance by Regulatory T Cells. Cell Rep 2019; 26:3600-3612.e6. [PMID: 30917315 PMCID: PMC6444001 DOI: 10.1016/j.celrep.2019.02.087] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 12/06/2018] [Accepted: 02/21/2019] [Indexed: 12/22/2022] Open
Abstract
The Foxp3 transcription factor is a crucial determinant of both regulatory T (TREG) cell development and their functional maintenance. Appropriate modulation of tolerogenic immune responses therefore requires the tight regulation of Foxp3 transcriptional output, and this involves both transcriptional and post-translational regulation. Here, we show that during T cell activation, phosphorylation of Foxp3 in TREG cells can be regulated by a TGF-β activated kinase 1 (TAK1)-Nemo-like kinase (NLK) signaling pathway. NLK interacts and phosphorylates Foxp3 in TREG cells, resulting in the stabilization of protein levels by preventing association with the STUB1 E3-ubiquitin protein ligase. Conditional TREG cell NLK-knockout (NLKΔTREG) results in decreased TREG cell-mediated immunosuppression in vivo, and NLK-deficient TREG cell animals develop more severe experimental autoimmune encephalomyelitis. Our data suggest a molecular mechanism, in which stimulation of TCR-mediated signaling can induce a TAK1-NLK pathway to sustain Foxp3 transcriptional activity through the stabilization of protein levels, thereby maintaining TREG cell suppressive function.
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Affiliation(s)
- Veerle Fleskens
- Center for Molecular Medicine, Division of Pediatrics, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Carlos M Minutti
- Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Ashworth Laboratories, Edinburgh, UK
| | - Xingmei Wu
- ENT Department, Affiliated Eye and ENT Hospital, Fudan University, Shanghai, China
| | - Ping Wei
- Department of Otolaryngology, The Children's Hospital of Chongqing Medical University, 136 Zhongshaner Road, Chongqing 400014, China
| | - Cornelieke E G M Pals
- Center for Molecular Medicine, Division of Pediatrics, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands; Regenerative Medicine Center, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands
| | - James McCrae
- Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Ashworth Laboratories, Edinburgh, UK
| | - Saskia Hemmers
- Immunology Program, Howard Hughes Medical Institute, and Ludwig Center, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Vincent Groenewold
- Hubrecht Institute, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Harm-Jan Vos
- Proteins at Work, UMC Utrecht, Utrecht, the Netherlands
| | - Alexander Rudensky
- Immunology Program, Howard Hughes Medical Institute, and Ludwig Center, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Fan Pan
- Immunology and Hematopoiesis Division, Department of Oncology, Bloomberg-Kimmel Institute, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Huabin Li
- ENT Department, Affiliated Eye and ENT Hospital, Fudan University, Shanghai, China.
| | - Dietmar M Zaiss
- Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Ashworth Laboratories, Edinburgh, UK.
| | - Paul J Coffer
- Center for Molecular Medicine, Division of Pediatrics, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands; Regenerative Medicine Center, University Medical Centre Utrecht, Utrecht University, Utrecht, the Netherlands.
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2
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Recombinant Brugia malayi pepsin inhibitor (rBm33) exploits host signaling events to regulate inflammatory responses associated with lymphatic filarial infections. Microb Pathog 2017; 112:195-208. [PMID: 28942176 DOI: 10.1016/j.micpath.2017.09.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Revised: 08/13/2017] [Accepted: 09/11/2017] [Indexed: 11/23/2022]
Abstract
Prolonged existence of filarial parasites and their molecules within the host modulate the host immune system to instigate their survival and induce inflammatory responses that contribute to disease progression. Recombinant Brugia malayi pepsin inhibitor (rBm33) modulates the host immune responses by skewing towards Th1 responses characterized by secretion of inflammatory molecules such as TNF-α, IL-6, nitric oxide (NO). Here we also specified the molecular signaling events triggered by rBm33 in peripheral blood mononuclear cells (PBMCs) of filarial endemic normals (EN). rBm33 predominantly enhanced the levels of nitric oxide in cultured PBMCs but did not result in oxidative stress to the host cells. Further, rBm33 treatment of human PBMCs resulted in higher GSH/GSSG levels. MYD88 dependent activation was found to be associated with rBm33 specific inflammatory cytokine production. rBm33 triggered intracellular signaling events also involved JNK activation in host PBMCs. In addition, c-Fos and not NF-κB was identified as the transcription factor regulating the expression of inflammatory cytokines in rBm33 stimulated PBMCs. rBm33 marked its role in filarial pathology by altered levels of growth factors but did not have a significant impact on matrix metalloproteinases (MMPs), tissue inhibitors of matrix metalloproteinases (TIMPs) activity of host PBMCs. Thus, the study outlines the signaling network of rBm33 induced inflammatory responses within the host immune cells.
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3
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van den Berg MCW, van Gogh IJA, Smits AMM, van Triest M, Dansen TB, Visscher M, Polderman PE, Vliem MJ, Rehmann H, Burgering BMT. The small GTPase RALA controls c-Jun N-terminal kinase-mediated FOXO activation by regulation of a JIP1 scaffold complex. J Biol Chem 2013; 288:21729-41. [PMID: 23770673 DOI: 10.1074/jbc.m113.463885] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
FOXO (forkhead box O) transcription factors are tumor suppressors and increase the life spans of model organisms. Cellular stress, in particular oxidative stress caused by an increase in levels of reactive oxygen species (ROS), activates FOXOs through JNK-mediated phosphorylation. Importantly, JNK regulation of FOXO is evolutionarily conserved. Here we identified the pathway that mediates ROS-induced JNK-dependent FOXO regulation. Following increased ROS, RALA is activated by the exchange factor RLF (RalGDS-like factor), which is in complex with JIP1 (C-Jun-amino-terminal-interacting protein 1) and JNK. Active RALA consequently regulates assembly and activation of MLK3, MKK4, and JNK onto the JIP1 scaffold. Furthermore, regulation of FOXO by RALA and JIP1 is conserved in C. elegans, where both ral-1 and jip-1 depletion impairs heat shock-induced nuclear translocation of the FOXO orthologue DAF16.
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Affiliation(s)
- Maaike C W van den Berg
- Molecular Cancer Research, University Medical Center Utrecht, Utrecht, 3584 CG, The Netherlands
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4
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Yang N, Ray DW, Matthews LC. Current concepts in glucocorticoid resistance. Steroids 2012; 77:1041-9. [PMID: 22728894 DOI: 10.1016/j.steroids.2012.05.007] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 05/24/2012] [Accepted: 05/29/2012] [Indexed: 01/04/2023]
Abstract
Glucocorticoids (GCs) are the most potent anti-inflammatory agents known. A major factor limiting their clinical use is the wide variation in responsiveness to therapy. The high doses of GC required for less responsive patients means a high risk of developing very serious side effects. Variation in sensitivity between individuals can be due to a number of factors. Congenital, generalized GC resistance is very rare, and is due to mutations in the glucocorticoid receptor (GR) gene, the receptor that mediates the cellular effects of GC. A more common problem is acquired GC resistance. This localized, disease-associated GC resistance is a serious therapeutic concern and limits therapeutic response in patients with chronic inflammatory disease. It is now believed that localized resistance can be attributed to changes in the cellular microenvironment, as a consequence of chronic inflammation. Multiple factors have been identified, including alterations in both GR-dependent and -independent signaling downstream of cytokine action, oxidative stress, hypoxia and serum derived factors. The underlying mechanisms are now being elucidated, and are discussed here. Attempts to augment tissue GC sensitivity are predicted to permit safe and effective use of low-dose GC therapy in inflammatory disease.
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Affiliation(s)
- Nan Yang
- Endocrine Sciences Research Group, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK
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5
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Ito K, Chung KF, Adcock IM. Update on glucocorticoid action and resistance. J Allergy Clin Immunol 2006; 117:522-43. [PMID: 16522450 DOI: 10.1016/j.jaci.2006.01.032] [Citation(s) in RCA: 278] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2006] [Revised: 01/25/2006] [Accepted: 01/25/2006] [Indexed: 12/11/2022]
Abstract
Extensive development of inhaled and oral glucocorticoids has resulted in highly potent molecules that have been optimized to target activity to the lung and minimize systemic exposure. These have proved highly effective for most asthmatic subjects, but despite these developments, there are a number of subjects with asthma who fail to respond to even high doses of inhaled or even oral glucocorticoids. Advances in delineating the fundamental mechanisms of glucocorticoid pharmacology, especially the concepts of transactivation and transrepression and cofactor recruitment, have resulted in better understanding of the molecular mechanisms whereby glucocorticoids suppress inflammation. The existence of multiple mechanisms underlying glucocorticoid insensitivity raises the possibility that this might indeed reflect different diseases with a common phenotype, and studies examining the efficacy of potential new agents should be targeted toward subgroups of patients with severe corticosteroid-resistant asthma who clearly require effective new drugs and other approaches to improved asthma control.
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Affiliation(s)
- Kazuhiro Ito
- Cell and Molecular Biology, Airways Disease Section, National Heart and Lung Institute, Imperial College London, UK
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6
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Essers MAG, Weijzen S, de Vries-Smits AMM, Saarloos I, de Ruiter ND, Bos JL, Burgering BMT. FOXO transcription factor activation by oxidative stress mediated by the small GTPase Ral and JNK. EMBO J 2004; 23:4802-12. [PMID: 15538382 PMCID: PMC535088 DOI: 10.1038/sj.emboj.7600476] [Citation(s) in RCA: 602] [Impact Index Per Article: 30.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2004] [Accepted: 10/13/2004] [Indexed: 12/30/2022] Open
Abstract
Forkhead transcription factors of the FOXO class are negatively regulated by PKB/c-Akt in response to insulin/IGF signalling, and are involved in regulating cell cycle progression and cell death. Here we show that, in contrast to insulin signalling, low levels of oxidative stress generated by treatment with H2O2 induce the activation of FOXO4. Upon treatment of cells with H2O2, the small GTPase Ral is activated and this results in a JNK-dependent phosphorylation of FOXO4 on threonine 447 and threonine 451. This Ral-mediated, JNK-dependent phosphorylation is involved in the nuclear translocation and transcriptional activation of FOXO4 after H2O2 treatment. In addition, we show that this signalling pathway is also employed by tumor necrosis factor alpha to activate FOXO4 transcriptional activity. FOXO members have been implicated in cellular protection against oxidative stress via the transcriptional regulation of manganese superoxide dismutase and catalase gene expression. The results reported here, therefore, outline a homeostasis mechanism for sustaining cellular reactive oxygen species that is controlled by signalling pathways that can convey both negative (PI-3K/PKB) and positive (Ras/Ral) inputs.
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Affiliation(s)
- Marieke A G Essers
- Department of Physiological Chemistry, Centre for Biomedical Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Sanne Weijzen
- Department of Physiological Chemistry, Centre for Biomedical Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Alida M M de Vries-Smits
- Department of Physiological Chemistry, Centre for Biomedical Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Ingrid Saarloos
- Department of Physiological Chemistry, Centre for Biomedical Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Nancy D de Ruiter
- Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA, USA
| | - Johannes L Bos
- Department of Physiological Chemistry, Centre for Biomedical Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Boudewijn M T Burgering
- Department of Physiological Chemistry, Centre for Biomedical Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
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7
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Abstract
Hematopoiesis is the cumulative result of intricately regulated signal transduction cascades that are mediated by cytokines and their cognate receptors. Proper culmination of these diverse signaling pathways forms the basis for an orderly generation of different cell types and aberrations in these pathways is an underlying cause for diseases such as leukemias and other myeloproliferative and lymphoproliferative disorders. Over the past decade, downstream signal transduction events initiated upon cytokine/growth factor stimulation have been a major focus of basic and applied biomedical research. As a result, several key concepts have emerged allowing a better understanding of the complex signaling processes. A group of transcription factors, termed signal transducers and activators of transcription (STATs) appear to orchestrate the downstream events propagated by cytokine/growth factor interactions with their cognate receptors. Similarly, cytoplasmic Janus protein tyrosine kinases (JAKs) and Src family of kinases seem to play a critical role in diverse signal transduction pathways that govern cellular survival, proliferation, differentiation and apoptosis. Accumulating evidence suggests that STAT protein activation may be mediated by members of both JAK and Src family members following cytokine/growth factor stimulation. In addition, JAK kinases appear to be essential for the phosphorylation of the cytokine receptors which results in the creation of docking sites on the receptors for binding of SH2-containing proteins such as STATs, Src-kinases and other signaling intermediates. Cell and tissue-specificity of cytokine action appears to be determined by the nature of signal transduction pathways activated by cytokine/receptor interactions. The integration of these diverse signaling cues from active JAK kinases, members of the Src-family kinases and STAT proteins, leads to cell proliferation, cell survival and differentiation, the end-point of the cytokine/growth factor stimulus.
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Affiliation(s)
- Sushil G Rane
- Laboratory of Cell Regulation & Carcinogenesis, NCI, NIH, Bldg. 41, C629, 41 Library Drive, Bethesda, Maryland, MD 20892, USA
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8
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Affiliation(s)
- C Luberto
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston 29425, USA
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9
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de Ruiter ND, Wolthuis RM, van Dam H, Burgering BM, Bos JL. Ras-dependent regulation of c-Jun phosphorylation is mediated by the Ral guanine nucleotide exchange factor-Ral pathway. Mol Cell Biol 2000; 20:8480-8. [PMID: 11046144 PMCID: PMC102154 DOI: 10.1128/mcb.20.22.8480-8488.2000] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The transcription factor c-Jun is critically involved in the regulation of proliferation and differentiation as well as cellular transformation induced by oncogenic Ras. The signal transduction pathways that couple Ras activation to c-Jun phosphorylation are still partially elusive. Here we show that an activated version of the Ras effector Rlf, a guanine nucleotide exchange factor (GEF) of the small GTPase Ral, can induce the phosphorylation of serines 63 and 73 of c-Jun. In addition, we show that growth factor-induced, Ras-mediated phosphorylation of c-Jun is abolished by inhibitory mutants of the RalGEF-Ral pathway. These results suggest that the RalGEF-Ral pathway plays a major role in Ras-dependent c-Jun phosphorylation. Ral-dependent regulation of c-Jun phosphorylation includes JNK, a still elusive JNKK, and possibly Src.
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Affiliation(s)
- N D de Ruiter
- Department of Physiological Chemistry and Centre for Biomedical Genetics, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands
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10
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Reddy EP, Korapati A, Chaturvedi P, Rane S. IL-3 signaling and the role of Src kinases, JAKs and STATs: a covert liaison unveiled. Oncogene 2000; 19:2532-47. [PMID: 10851052 DOI: 10.1038/sj.onc.1203594] [Citation(s) in RCA: 183] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Hematopoiesis is the cumulative result of intricately regulated signal transduction cascades that are mediated by cytokines and their cognate receptors. Proper culmination of these diverse signaling pathways forms the basis for an orderly generation of different cell types and aberrations in these pathways is an underlying cause for diseases such as cancer. Over the past several years, downstream events initiated upon cytokine/growth factor stimulation have been a major focus of biomedical research. As a result, several key concepts have emerged allowing a better understanding of the complex signaling processes. A group of novel transcription factors, termed signal transducers and activators of transcription (STATs) appear to orchestrate the downstream events propagated by cytokine/growth factor interactions with their cognate receptors. Until recently, the JAK proteins were considered to be the tyrosine kinases, which dictated the levels of phosphorylation and activation of STAT proteins, forming the basis of the JAK-STAT model. However, over the past few years, increasing evidence has accumulated which indicates that at least some of the STAT protein activation may be mediated by members of the Src gene family following cytokine/growth factor stimulation. Studies have demonstrated that the Src-family of tyrosine kinases can phosphorylate and activate certain STAT proteins, in lieu of JAK kinases. In such a scenario, JAK kinases may be more crucial to phosphorylation of the cytokine/growth factor receptors and in the process create docking sites on the receptors for binding of SH2-containing proteins such as STATs, Src-kinases and other signaling intermediates. Tyrosine phosphorylation and activation of STAT proteins can be achieved either by JAKs or Src-kinases depending on the nature of STAT that is being activated. This forms the basis for the JAK-Src-STAT model proposed in this review. The concerted action of JAK kinases, members of the Src-kinase family and STAT proteins, leads to cell proliferation and cell survival, the end-point of the cytokine/growth factor stimulus. Oncogene (2000).
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Affiliation(s)
- E P Reddy
- Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, 3307 N Broad Street, Philadelphia, Pennsylvania, PA 19140, USA
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11
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Abstract
The receptor for interleukin 5 (IL-5) consists of a cytokine-specific chain (IL-5R) and a signaling β chain, which is shared with interleukin 3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF). These 3 cytokines can act in eosinophil development and activation in vitro, but gene deletion or antibody blocking of IL-5 largely ablates eosinophilic responses in models of allergic disease or helminth infection. We investigated factors acting in differential IL-5R gene splicing to generate either the membrane-anchored isoform (TM-IL-5R) which associates with the common β chain to allow IL-5 responsiveness, or a secreted, antagonist variant (SOL-IL-5R). In a murine myeloid cell line (FDC-P1), transfected with minigenes allowing expression of either IL-5R variant, IL-5 itself, but not IL-3 or GM-CSF, stimulated a reversible switch toward expression of TM-IL-5R. A switch from predominantly soluble isoform to TM-IL-5R messenger RNA (mRNA) expression was also seen during IL-5-driven eosinophil development from human umbilical cord blood-derived CD34+ cells; this was accompanied by surface expression of IL-5R and acquisition of functional responses to IL-5. IL-3 and GM-CSF also supported eosinophil development and up-regulation of TM-IL-5R mRNA in this system, but this was preceded by expression of IL-5 mRNA and was inhibited by monoclonal antibody to IL-5. These data suggest IL-5-specific signaling, not shared by IL-3 and GM-CSF, leading to a switch toward up-regulation of functional IL-5R and, furthermore, that IL-3 and GM-CSF-driven eosinophil development is dependent on IL-5, providing an explanation for the selective requirement of IL-5 for expansion of the eosinophil lineage.
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12
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Phosphatidylcholine-Preferring Phospholipase C from B. cereus. Function, Structure, and Mechanism. Top Curr Chem (Cham) 2000. [DOI: 10.1007/3-540-45035-1_5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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13
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Kaye KM, Izumi KM, Li H, Johannsen E, Davidson D, Longnecker R, Kieff E. An Epstein-Barr virus that expresses only the first 231 LMP1 amino acids efficiently initiates primary B-lymphocyte growth transformation. J Virol 1999; 73:10525-30. [PMID: 10559372 PMCID: PMC113109 DOI: 10.1128/jvi.73.12.10525-10530.1999] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
An Epstein-Barr virus (EBV) recombinant (MS231) that expresses the first 231 amino acids (aa) of LMP1 and is truncated 155 aa before the carboxyl terminus transformed resting B lymphocytes into lymphoblastoid cell lines (LCLs) only when the infected cells were grown on fibroblast feeder cells (K. M. Kaye et al., J. Virol. 69:675-683, 1995). Higher-titer MS231 virus has now been compared to wild-type (WT) EBV recombinants for the ability to cause resting primary B-lymphocyte transformation. Unexpectedly, MS231 is as potent as WT EBV recombinants in causing infected B lymphocytes to proliferate in culture for up to 5 weeks. When more than one transforming event is initiated in a microwell, the MS231 recombinant supports efficient long-term LCL outgrowth and fibroblast feeder cells are not required. However, with limited virus input, MS231-infected cells differed in their growth from WT virus-infected cells as early as 6 weeks after infection. In contrast to WT virus-infected cells, most MS231-infected cells could not be grown into long-term LCLs. Thus, the LMP1 amino-terminal 231 aa are sufficient for initial growth transformation but the carboxyl-terminal 155 aa are necessary for efficient long-term outgrowth. Despite the absence of the carboxyl-terminal 155 aa, MS231- and WT-transformed LCLs are similar in latent EBV gene expression, in ICAM-1 and CD23 expression, and in NF-kappaB and c-jun N-terminal kinase activation. MS231 recombinant-infected LCLs, however, require 16- to 64-fold higher cell density than WT-infected LCLs for regrowth after limiting dilution. These data indicate that the LMP1 carboxyl-terminal 155 aa are important for growth at lower cell density and appear to reduce dependence on paracrine growth factors.
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Affiliation(s)
- K M Kaye
- Department of Medicine, Harvard Medical School, Channing Laboratory, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.
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14
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Geijsen N, Spaargaren M, Raaijmakers JA, Lammers JW, Koenderman L, Coffer PJ. Association of RACK1 and PKCbeta with the common beta-chain of the IL-5/IL-3/GM-CSF receptor. Oncogene 1999; 18:5126-30. [PMID: 10490850 DOI: 10.1038/sj.onc.1202896] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Granulocyte macrophage colony stimulating factor (GM-CSF), interleukin-3 (IL-3) and interleukin-5 (IL-5 belong to a family of cytokines that regulate proliferation, differentiation and function of haematopoietic cells. Their receptor consists of a ligand specific alpha-chain and a signal transducing beta-chain (betac). While, the role of phosphotyrosine residues in the betac as mediators of downstream signalling cascades has been established, little is known about non-phosphotyrosine mediated events. To identify proteins interacting with betac, we screened a yeast two-hybrid library with the intracellular domain of betac. We found that RACK1, a molecule associating with activated PKC, PLCgamma and Src kinases, associated with the membrane proximal region of betac in both yeast two-hybrid, immunoprecipitation and GST-pull-down assays. The association of RACK1 was constitutive, demonstrating no alteration upon cellular stimulation. Furthermore, upon stimulation of cells with IL-5 or PMA, a complex of betac and PKCbeta was found. Together, these findings suggest a novel role for RACK1 as a possible adapter molecule associating with the intracellular domain of cytokine receptors.
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Affiliation(s)
- N Geijsen
- Department of Pulmonary Diseases, University Hospital Utrecht, Heidelberglaan 100, 3508 GA Utrecht, The Netherlands
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15
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van Dijk TB, Baltus B, Raaijmakers JAM, Lammers JWJ, Koenderman L, de Groot RP. A Composite C/EBP Binding Site Is Essential for the Activity of the Promoter of the IL-3/IL-5/Granulocyte-Macrophage Colony-Stimulating Factor Receptor βc Gene. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.163.5.2674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
The common β-chain (βc) is the main signaling component of the heterodimeric receptors for IL-3, IL-5, and GM-CSF and is primarily expressed on myeloid cells. The proximal βc promoter is regulated by GGAA binding proteins, including PU.1, a hemopoietic specific member of the Ets family. However, it is not likely that PU.1 alone accounts for the myeloid-restricted expression of the βc subunit. Here we describe the identification of a C/EBP binding enhancer that is located 2 kb upstream of the transcription start site. The enhancer contains two elements that bind C/EBPα and -β in U937 cells, while C/EBPε is also bound in extracts of HL-60 cells. Importantly, deletion of the enhancer or mutation of either of one of the C/EBP sites results in a complete loss of promoter activity in cell lines as well as in primary cells, showing the importance of C/EBP members in βc gene activation. We further show that PU.1 has to cooperate with C/EBP proteins to induce βc transcription. Since the βc is already expressed on CD34+ cells, these results demonstrate that both C/EBP and PU.1 are not only important for the myeloid-specific gene regulation at later stages of myeloid differentiation.
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Affiliation(s)
- Thamar B. van Dijk
- Department of Pulmonary Diseases, University Hospital Utrecht, Utrecht, The Netherlands
| | - Belinda Baltus
- Department of Pulmonary Diseases, University Hospital Utrecht, Utrecht, The Netherlands
| | - Jan A. M. Raaijmakers
- Department of Pulmonary Diseases, University Hospital Utrecht, Utrecht, The Netherlands
| | - Jan-Willem J. Lammers
- Department of Pulmonary Diseases, University Hospital Utrecht, Utrecht, The Netherlands
| | - Leo Koenderman
- Department of Pulmonary Diseases, University Hospital Utrecht, Utrecht, The Netherlands
| | - Rolf P. de Groot
- Department of Pulmonary Diseases, University Hospital Utrecht, Utrecht, The Netherlands
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16
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Han JS, Hyun BC, Kim JH, Shin I. Fas-mediated activation of phospholipase D is coupled to the stimulation of phosphatidylcholine-specific phospholipase C in A20 cells. Arch Biochem Biophys 1999; 367:233-9. [PMID: 10395739 DOI: 10.1006/abbi.1999.1250] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The activation of phospholipase D in murine B cell lymphoma A20 cells treated with anti-Fas monoclonal antibody has been investigated. Fas cross-linking resulted in a both dose- and time-dependent increases in phospholipase D activity. There was a nearly maximum saturated rise in phospholipase D activity at the dose of 200 ng/ml anti-Fas monoclonal antibody showing a fourfold increase within 3 h. Fas activation also caused an approximately twofold increase of phosphatidylcholine-specific phospholipase C activity and 1,2-diacylglycerol release, which could be blocked by 30 min pretreatment with the phosphatidylcholine-specific phospholipase C inhibitor D609 (50 microgram/ml). Pretreatment of D609 also effectively inhibited the translocation of protein kinase C betaI and betaII from the cytosol to the membrane and the activation of phospholipase D induced by Fas cross-linking, suggesting that 1, 2-diacylglycerol released from the cellular phosphatidylcholine pool through phosphatidylcholine-specific phospholipase C plays a major role in protein kinase C/phospholipase D activation. Anti-Fas monoclonal antibody failed to elicit phosphoinositide-specific phospholipase C activation and any changes in the intracellular Ca2+ level in A20 cells, indicating that the phosphoinositide-mediated pathway is not involved in this Fas signaling. Therefore, these results suggest that Fas-mediated phospholipase D activation may be a consequence of primary stimulation of phosphatidylcholine-specific phospholipase C and that phospholipase D may play a role in Fas cross-linking signaling downstream from phosphatidylcholine-specific phospholipase C.
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Affiliation(s)
- J S Han
- College of Medicine, Hanyang University, Seoul, 133-791, Korea.
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17
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Dijkers PF, van Dijk TB, de Groot RP, Raaijmakers JA, Lammers JW, Koenderman L, Coffer PJ. Regulation and function of protein kinase B and MAP kinase activation by the IL-5/GM-CSF/IL-3 receptor. Oncogene 1999; 18:3334-42. [PMID: 10362354 DOI: 10.1038/sj.onc.1202678] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Interleukin (IL)-3, IL-5 and granulocyte-macrophage colony-stimulating factor (GM-CSF) regulate proliferation, differentiation and apoptosis of target cells. Receptors for these cytokines consist of a cytokine-specific alpha subunit and a common shared beta c subunit. Tyrosine phosphorylation of the beta c is thought to play a critical role in mediating signal transduction events. We have examined the effect of mutation of beta c tyrosines on the activation of multiple signal transduction pathways. Activation of protein kinase B (PKB) required JAK2 and was inhibited by dominant-negative phosphatidylinositol 3-kinase (P13K). Overexpression of JAK2 was sufficient to activate both protein kinase B (PKB) and extracellular regulated kinase-1 (ERK1). Tyrosine 577 and 612 were found to be critical for the activation of PKB and ERK1, but not activation of STAT transcription factors. Activation of both PKB and ERK have been implicated in the regulation of proliferation and apoptosis. We generated GM-CSFR stable cell lines expressing receptor mutants to evaluate their effect on these processes. Activation of both PKB and ERK was perturbed, while STAT activation remained unaffected. Tyrosines 577 and 612 were necessary for optimal proliferation, however, mutation of these tyrosine residues did not affect GM-CSF mediated rescue from apoptosis. These data demonstrate that while phosphorylation of beta c tyrosine residues 577 and 612 are important for optimal cell proliferation, rescue from apoptosis can be mediated by alternative signalling routes apparently independent of PKB or ERK activation.
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Affiliation(s)
- P F Dijkers
- Department of Pulmonary Diseases, University Hospital Utrecht, The Netherlands
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18
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Lane SJ, Adcock IM, Richards D, Hawrylowicz C, Barnes PJ, Lee TH. Corticosteroid-resistant bronchial asthma is associated with increased c-fos expression in monocytes and T lymphocytes. J Clin Invest 1998; 102:2156-64. [PMID: 9854051 PMCID: PMC509170 DOI: 10.1172/jci2680] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Unstimulated peripheral blood mononuclear cells (PBMCs) from corticosteroid-resistant (CR) but not corticosteroid-sensitive (CS) asthmatics demonstrate increased activating peptide-1 (AP-1)- and decreased glucocorticoid receptor (GR)-DNA binding. We test whether these abnormalities are associated with excessive generation of c-fos, the inducible component of AP-1. The c-fos transcription rate, mRNA and protein levels, and GR-DNA binding were quantitated in PBMCs, T cells, and monocytes from CS, CR, and nonasthmatic subjects. There was a 1.7-, 4.2-, and 2.3-fold greater increase in the baseline c-fos transcription rate, mRNA expression, and protein levels, respectively, in PBMCs derived from CR compared with CS patients. At optimal stimulation with PMA, there was a 5.7-, 3.4-, and 2-fold greater increase in the c-fos transcription rate, mRNA accumulation, and protein levels, respectively, in CR compared with CS PBMCs. These abnormalities were detected in both the T cell and monocyte subpopulations. PMA stimulation converted PBMCs from a CS to a CR phenotype and was associated with direct interaction between c-Fos and the GR. Pretreatment of PBMCs from CR patients with c-fos antisense oligonucleotides enhanced GR-DNA binding activity in CR PBMCs stimulated with dexamethasone. We suggest that increased c-fos synthesis provides a major mechanism for the increased AP-1- and decreased GR- DNA binding seen in CR asthma.
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Affiliation(s)
- S J Lane
- Departments of Respiratory Medicine and Allergy, Guy's Hospital, London SE1 9RT, United Kingdom
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19
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Cloning and Characterization of the Human Interleukin-3 (IL-3)/IL-5/ Granulocyte-Macrophage Colony-Stimulating Factor Receptor βc Gene: Regulation by Ets Family Members. Blood 1998. [DOI: 10.1182/blood.v92.10.3636] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractHigh-affinity receptors for interleukin-3 (IL-3), IL-5, and granulocyte-macrophage colony-stimulating factor (GM-CSF) are composed of two distinct subunits, a ligand-specific chain and a common β chain (βc). Whereas the mouse has two homologous β subunits (βc and βIL-3), in humans, only a single β chain is identified. We describe here the isolation and characterization of the gene encoding the human IL-3/IL-5/GM-CSF receptor β subunit. The gene spans about 25 kb and is divided into 14 exons, a structure very similar to that of the murine βc/βIL-3 genes. Surprisingly, we also found the remnants of a second βc chain gene directly downstream of βc. We identified a functional promoter that is active in the myeloid cell lines U937 and HL-60, but not in HeLa cells. The proximal promoter region, located from −103 to +33 bp, contains two GGAA consensus binding sites for members of the Ets family. Single mutation of those sites reduces promoter activity by 70% to 90%. The 5′ element specifically binds PU.1, whereas the 3′ element binds a yet-unidentified protein. These findings, together with the observation that cotransfection of PU.1 and other Ets family members enhances βc promoter activity in fibroblasts, reinforce the notion that GGAA elements play an important role in myeloid-specific gene regulation.
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20
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Cloning and Characterization of the Human Interleukin-3 (IL-3)/IL-5/ Granulocyte-Macrophage Colony-Stimulating Factor Receptor βc Gene: Regulation by Ets Family Members. Blood 1998. [DOI: 10.1182/blood.v92.10.3636.422k45_3636_3646] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
High-affinity receptors for interleukin-3 (IL-3), IL-5, and granulocyte-macrophage colony-stimulating factor (GM-CSF) are composed of two distinct subunits, a ligand-specific chain and a common β chain (βc). Whereas the mouse has two homologous β subunits (βc and βIL-3), in humans, only a single β chain is identified. We describe here the isolation and characterization of the gene encoding the human IL-3/IL-5/GM-CSF receptor β subunit. The gene spans about 25 kb and is divided into 14 exons, a structure very similar to that of the murine βc/βIL-3 genes. Surprisingly, we also found the remnants of a second βc chain gene directly downstream of βc. We identified a functional promoter that is active in the myeloid cell lines U937 and HL-60, but not in HeLa cells. The proximal promoter region, located from −103 to +33 bp, contains two GGAA consensus binding sites for members of the Ets family. Single mutation of those sites reduces promoter activity by 70% to 90%. The 5′ element specifically binds PU.1, whereas the 3′ element binds a yet-unidentified protein. These findings, together with the observation that cotransfection of PU.1 and other Ets family members enhances βc promoter activity in fibroblasts, reinforce the notion that GGAA elements play an important role in myeloid-specific gene regulation.
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21
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de Groot RP, Coffer PJ, Koenderman L. Regulation of proliferation, differentiation and survival by the IL-3/IL-5/GM-CSF receptor family. Cell Signal 1998; 10:619-28. [PMID: 9794243 DOI: 10.1016/s0898-6568(98)00023-0] [Citation(s) in RCA: 169] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The receptors for the I1-3/IL-5/GM-CSF cytokine family are composed of a heterodimeric complex of a cytokine-specific alpha chain and a common beta chain (betac). Binding of IL-3/IL-5/GM-CSF to their respective receptors rapidly induces activation of multiple intracellular signalling pathways, including the Ras-Raf-ERK, the JAK/STAT, the phosphatidylinositol 3-kinase PKB, and the JNK/SAPK and p38 signalling pathways. This review focuses on recent advancements in understanding how these different signalling pathways are activated by IL-3/IL-5/GM-CSF receptors, and how the individual pathways contribute to the pleiotropic effects of IL-3/IL-5/GM-CSF on their target cells, including proliferation, differentiation, survival, and effector functions.
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Affiliation(s)
- R P de Groot
- Department of Pulmonary Diseases, University Hospital Utrecht, The Netherlands.
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22
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Abstract
Cytokines are important regulators of hematopoiesis. They exert their actions by binding to specific receptors on the cell surface. Interleukin-5 (IL-5) is a critical cytokine that regulates the growth, activation, and survival of eosinophils. Because eosinophils play a seminal role in the pathogenesis of asthma and allergic diseases, an understanding of the signal transduction mechanism of IL-5 is of paramount importance. The IL-5 receptor is a heterodimer of alpha- and beta-subunits. The alpha-subunit is specific, whereas the beta-subunit is common to IL-3, IL-5, and granulocyte/macrophage colony-stimulating factor (GM-CSF) receptors and is crucial for signal transduction. It has been shown that there are two major signaling pathways of IL-5 in eosinophils. IL-5 activates Lyn, Syk, and JAK2 and propagates signals through the Ras-MAPK and JAK-STAT pathways. Studies suggest that Lyn, Syk, and JAK2 tyrosine kinases and SHP-2 tyrosine phosphatase are important for eosinophil survival. In contrast to their survival-promoting activity, Lyn and JAK2 appear to have no role in eosinophil degranulation or expression of surface adhesion molecules. Raf-1 kinase, on the other hand, is critical for eosinophil degranulation and adhesion molecule expression. Btk is involved in IL-5 stimulation of B cell function. However, it does not appear to be important for eosinophil function. Thus a clear segregation of signaling molecules based on their functional importance is emerging. This review describes the signal transduction mechanism of the IL-3/GM-CSF/IL-5 receptor system and compares and contrasts IL-5 signaling between eosinophils and B cells.
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Affiliation(s)
- T Adachi
- The University of Texas Medical Branch, Division of Allergy and Immunology, Department of Internal Medicine, Galveston, Texas 77555-0762, USA
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23
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Miralles F, Parra M, Caelles C, Nagamine Y, Félez J, Muñoz-Cánoves P. UV irradiation induces the murine urokinase-type plasminogen activator gene via the c-Jun N-terminal kinase signaling pathway: requirement of an AP1 enhancer element. Mol Cell Biol 1998; 18:4537-47. [PMID: 9671463 PMCID: PMC109039 DOI: 10.1128/mcb.18.8.4537] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/1997] [Accepted: 05/01/1998] [Indexed: 02/08/2023] Open
Abstract
UV irradiation leads to severe damage, such as cutaneous inflammation, immunosuppression, and cancer, but it also results in a gene induction protective response termed the UV response. The signal triggering the UV response was thought to originate from DNA damage; recent findings, however, have shown that it is initiated at or near the cell membrane and transmitted via cytoplasmic kinase cascades to induce gene transcription. Urokinase-type plasminogen activator (uPA) was the first protein shown to be UV inducible in xeroderma pigmentosum DNA repair-deficient human cells. However, the underlying molecular mechanisms responsible for the induction were not elucidated. We have found that the endogenous murine uPA gene product is transcriptionally upregulated by UV in NIH 3T3 fibroblast and F9 teratocarcinoma cells. This induction required an activator protein 1 (AP1) enhancer element located at -2.4 kb, since deletion of this site abrogated the induction. We analyzed the contribution of the three different types of UV-inducible mitogen-activated protein (MAP) kinases (ERK, JNK/SAPK, and p38) to the activation of the murine uPA promoter by UV. MEKK1, a specific JNK activator, induced transcription from the uPA promoter in the absence of UV treatment, whereas coexpression of catalytically inactive MEKK1(K432M) and of cytoplasmic JNK inhibitor JIP-1 inhibited UV-induced uPA transcriptional activity. In contrast, neither dominant negative MKK6 (or SB203580) nor PD98059, which specifically inhibit p38 and ERK MAP kinase pathways, respectively, could abrogate the UV-induced effect. Moreover, our results indicated that wild-type N-terminal c-Jun, but not mutated c-Jun (Ala-63/73), was able to mediate UV-induced uPA transcriptional activity. Taken together, we show for the first time that kinases of the JNK family can activate the uPA promoter. This activation links external UV stimulation and AP1-dependent uPA transcription, providing a transcription-coupled signal transduction pathway for the induction of the murine uPA gene by UV.
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Affiliation(s)
- F Miralles
- Institut de Recerca Oncològica, Facultat de Farmacia, Universitat de Barcelona, Barcelona, Spain
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24
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van Dijk MC, van Blitterswijk WJ. Lipid metabolism in fibroblast growth factor-stimulated L6 myoblasts: a receptor mutation (Y766F) abrogates phospholipase D and diacylglycerol kinase activities. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1391:273-9. [PMID: 9555056 DOI: 10.1016/s0005-2760(98)00016-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Phosphatidylcholine (PC) hydrolysis induced by basic fibroblast growth factor (bFGF) was studied in rat L6 myoblasts expressing the wild-type FGF receptor-1 (FGFR-1) or a mutant (Y766F) that is incapable of activating phospholipase C-gamma (PLCgamma). Stimulation of FGFR-1 activated phospholipase D (PLD) rapidly and transiently, but did not induce PC-specific PLC activity. Downregulation of protein kinase C blocked bFGF-induced PLD activation but not phosphatidic acid formation by diacylglycerol (DG) kinase. Only phosphoinositide (PI)-derived DG, not PC-derived DG, appeared to be a substrate for DG kinase. Stimulation of FGFR-1(Y766F) did not activate PLD or DG kinase, both of which apparently require initial PLCgamma activation. The Y766F mutation reduced mitogen-activated protein kinase activation but not cell proliferation. We conclude that both PI turnover and PC hydrolysis are dispensable for bFGF-induced mitogenesis.
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Affiliation(s)
- M C van Dijk
- Division of Cellular Biochemistry, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, Netherlands
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25
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The Role of Transcription Factor PU.I in the Activity of the Intronic Enhancer of the Eosinophil-Derived Neurotoxin (RNS2) Gene. Blood 1998. [DOI: 10.1182/blood.v91.6.2126] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractEosinophil-derived neurotoxin (EDN) found in the granules of human eosinophils is a cationic ribonuclease toxin. Expression of the EDN gene (RNS2) in eosinophils is dependent on proximal promoter sequences in combination with an enhancer located in the first intron. We further define here the active region of the intron using transfections in differentiated eosinophilic HL60 cells. We show that a region containing a tandem PU.I binding site is important for intronic enhancer activity. This region binds multiple forms of transcription factor PU.I as judged by gel-shift analysis and DNA affinity precipitation. Importantly, introducing point mutations in the PU.I site drastically reduces the intronic enhancer activity, showing the importance of PU.I for expression of EDN in cells of the eosinophilic lineage.
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26
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The Role of Transcription Factor PU.I in the Activity of the Intronic Enhancer of the Eosinophil-Derived Neurotoxin (RNS2) Gene. Blood 1998. [DOI: 10.1182/blood.v91.6.2126.2126_2126_2132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Eosinophil-derived neurotoxin (EDN) found in the granules of human eosinophils is a cationic ribonuclease toxin. Expression of the EDN gene (RNS2) in eosinophils is dependent on proximal promoter sequences in combination with an enhancer located in the first intron. We further define here the active region of the intron using transfections in differentiated eosinophilic HL60 cells. We show that a region containing a tandem PU.I binding site is important for intronic enhancer activity. This region binds multiple forms of transcription factor PU.I as judged by gel-shift analysis and DNA affinity precipitation. Importantly, introducing point mutations in the PU.I site drastically reduces the intronic enhancer activity, showing the importance of PU.I for expression of EDN in cells of the eosinophilic lineage.
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27
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Orchansky PL, Ayres SD, Hilton DJ, Schrader JW. An interleukin (IL)-13 receptor lacking the cytoplasmic domain fails to transduce IL-13-induced signals and inhibits responses to IL-4. J Biol Chem 1997; 272:22940-7. [PMID: 9278458 DOI: 10.1074/jbc.272.36.22940] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Interleukin (IL)-13 is a pleiotropic immunoregulatory cytokine that shares many, although not all, of the biological activities of IL-4. The overlapping biological properties of IL-4 and IL-13 appear to be due to the existence of shared components of the receptors, and we and others showed that the IL-4 receptor-alpha is involved in signal transduction paths activated by both. We show here that expression of the IL-13 receptor-alpha in two factor-dependent cell lines, the premyeloid FD5 and the T lymphoid CT4.S, conferred the ability to grow continuously in response to IL-13; to respond to IL-13 with tyrosine phosphorylation of JAK1, Tyk2, IL-4Ralpha, IRS-2, and STAT6; and to respond to IL-4 with tyrosine phosphorylation of Tyk2 in addition to those induced in parental cell lines. Expression of a truncated IL-13 receptor-alpha that lacked the cytoplasmic domain demonstrated that this domain was essential for IL-13-dependent growth and phosphorylation of the above substrates. Expression of this truncated IL-13 receptor also resulted in an inhibition of biochemical and biological responses to IL-4 that was exacerbated by the presence of IL-13. These dominant inhibitory effects indicate that the extracellular domain of the truncated IL-13 receptor competes with gammac for complexes of IL-4 and the IL-4 receptor-alpha, or, when itself bound to IL-13, competes with IL-4 for the IL-4 receptor-alpha.
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Affiliation(s)
- P L Orchansky
- The Biomedical Research Centre, 2222 Health Sciences Mall, University of British Columbia, Vancouver V6T 1Z3, Canada.
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28
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van Dijk TB, Caldenhoven E, Raaijmakers JA, Lammers JW, Koenderman L, de Groot RP. Multiple tyrosine residues in the intracellular domain of the common beta subunit of the interleukin 5 receptor are involved in activation of STAT5. FEBS Lett 1997; 412:161-4. [PMID: 9257712 DOI: 10.1016/s0014-5793(97)00768-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In contrast to the general model of cytokine-induced JAK/STAT signaling, tyrosine phosphorylation of the IL-5R beta chain seems to be dispensable for STAT activation in cells overexpressing exogenous STAT proteins. In this study we expressed IL-5 receptor mutants in 293 cells and studied IL-5-induced endogenous STAT-dependent transcription. Our results indicate that: (a) tyrosine phosphorylation of the IL-5R beta chain is required for endogenous STAT5 activation, (b) multiple tyrosine residues are phosphorylated upon IL-5 stimulation, including Tyr577, Tyr612, Tyr695, and Tyr750, and (c) Tyr612, Tyr695, and Tyr750 are all capable of inducing activation of STAT5, demonstrating a high level of functional redundancy within the IL-5R beta chain.
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Affiliation(s)
- T B van Dijk
- Department of Pulmonary Diseases, University Hospital Utrecht, Netherlands
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29
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Affiliation(s)
- P J Coffer
- Department of Pulmonary Diseases, University Hospital Utrecht, The Netherlands
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