1
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Zhou T, Gao B, Fan Y, Liu Y, Feng S, Cong Q, Zhang X, Zhou Y, Yadav PS, Lin J, Wu N, Zhao L, Huang D, Zhou S, Su P, Yang Y. Piezo1/2 mediate mechanotransduction essential for bone formation through concerted activation of NFAT-YAP1-ß-catenin. eLife 2020; 9:52779. [PMID: 32186512 PMCID: PMC7112954 DOI: 10.7554/elife.52779] [Citation(s) in RCA: 171] [Impact Index Per Article: 42.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 03/17/2020] [Indexed: 12/15/2022] Open
Abstract
Mechanical forces are fundamental regulators of cell behaviors. However, molecular regulation of mechanotransduction remain poorly understood. Here, we identified the mechanosensitive channels Piezo1 and Piezo2 as key force sensors required for bone development and osteoblast differentiation. Loss of Piezo1, or more severely Piezo1/2, in mesenchymal or osteoblast progenitor cells, led to multiple spontaneous bone fractures in newborn mice due to inhibition of osteoblast differentiation and increased bone resorption. In addition, loss of Piezo1/2 rendered resistant to further bone loss caused by unloading in both bone development and homeostasis. Mechanistically, Piezo1/2 relayed fluid shear stress and extracellular matrix stiffness signals to activate Ca2+ influx to stimulate Calcineurin, which promotes concerted activation of NFATc1, YAP1 and ß-catenin transcription factors by inducing their dephosphorylation as well as NFAT/YAP1/ß-catenin complex formation. Yap1 and ß-catenin activities were reduced in the Piezo1 and Piezo1/2 mutant bones and such defects were partially rescued by enhanced ß-catenin activities.
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Affiliation(s)
- Taifeng Zhou
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, Boston, United States.,Department of Orthopaedic Surgery, Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, First Affiliated Hospital of Sun Yat-sen University, Sun Yat-sen University, Guangzhou, China
| | - Bo Gao
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, Boston, United States.,Department of Spine Surgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yi Fan
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, Boston, United States
| | - Yuchen Liu
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, Boston, United States
| | - Shuhao Feng
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, Boston, United States.,Department of Orthopedic Surgery, Nanfang Hospital, Southern Medical University, Guangdong, China
| | - Qian Cong
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, Boston, United States
| | - Xiaolei Zhang
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, Boston, United States.,Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Yaxing Zhou
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, Boston, United States
| | - Prem S Yadav
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, Boston, United States
| | - Jiachen Lin
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, Boston, United States.,Department of Orthopedic Surgery and Beijing Key Laboratory for Genetic Research of Skeletal Deformity, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Nan Wu
- Department of Orthopedic Surgery and Beijing Key Laboratory for Genetic Research of Skeletal Deformity, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Liang Zhao
- Department of Orthopedic Surgery, Nanfang Hospital, Southern Medical University, Guangdong, China
| | - Dongsheng Huang
- Department of Spine Surgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Shuanhu Zhou
- Department of Orthopedic Surgery, Brigham and Women's Hospital, Boston, United States
| | - Peiqiang Su
- Department of Orthopaedic Surgery, Guangdong Provincial Key Laboratory of Orthopedics and Traumatology, First Affiliated Hospital of Sun Yat-sen University, Sun Yat-sen University, Guangzhou, China
| | - Yingzi Yang
- Department of Developmental Biology, Harvard School of Dental Medicine, Harvard Stem Cell Institute, Boston, United States
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2
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Pachulec E, Neitzke-Montinelli V, Viola JPB. NFAT2 Regulates Generation of Innate-Like CD8 + T Lymphocytes and CD8 + T Lymphocytes Responses. Front Immunol 2016; 7:411. [PMID: 27766099 PMCID: PMC5052263 DOI: 10.3389/fimmu.2016.00411] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 09/22/2016] [Indexed: 11/13/2022] Open
Abstract
Nuclear factor of activated T cells (NFAT) 2 null mutant mice die in utero of cardiac failure, precluding analysis of the role of NFAT2 in lymphocyte responses. Only the NFAT2-/-/Rag-1-/- chimeric mice model gave insight into the role of NFAT2 transcription factor in T lymphocyte development, activation, and differentiation. As reports are mainly focused on the role of NFAT2 in CD4+ T lymphocytes activation and differentiation, we decided to investigate NFAT2's impact on CD8+ T lymphocyte responses. We report that NFAT2 is phosphorylated and inactive in the cytoplasm of naive CD8+ T cells, and upon TCR stimulation, it is dephosphorylated and translocated into the nucleus. To study the role of NFAT2 in CD8+ T responses, we employed NFAT2fl/flCD4-Cre mice with NFAT2 deletion specifically in T cells. Interestingly, the absence of NFAT2 in T cells resulted in increased percentage of non-conventional innate-like CD8+ T cells. These cells were CD122+, rapid producer of interferon gamma (IFN-γ) and had characteristics of conventional memory CD8+ T cells. We also observed an expansion of PLZF+ expressing CD3+ thymocyte population in the absence of NFAT2 and increased IL-4 production. Furthermore, we found that CD8+ T lymphocytes deficient in NFAT2 had reduced activation, proliferation, and IFN-γ and IL-2 production at suboptimal TCR strength. NFAT2 absence did not significantly influence differentiation of CD8+ T cells into cytotoxic effector cells but reduced their IFN-γ production. This work documents NFAT2 as a negative regulator of innate-like CD8+ T cells development. NFAT2 is required for complete CD8+ T cell responses at suboptimal TCR stimulation and regulates IFN-γ production by cytotoxic CD8+ T cells in vitro.
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Affiliation(s)
- Emilia Pachulec
- Program of Cellular Biology, Brazilian National Cancer Institute (INCA) , Rio de Janeiro , Brazil
| | | | - João P B Viola
- Program of Cellular Biology, Brazilian National Cancer Institute (INCA) , Rio de Janeiro , Brazil
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3
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Wang K, Zhang DL, Long B, An T, Zhang J, Zhou LY, Liu CY, Li PF. NFAT4-dependent miR-324-5p regulates mitochondrial morphology and cardiomyocyte cell death by targeting Mtfr1. Cell Death Dis 2015; 6:e2007. [PMID: 26633713 PMCID: PMC4720883 DOI: 10.1038/cddis.2015.348] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 10/10/2015] [Accepted: 11/02/2015] [Indexed: 12/19/2022]
Abstract
Emerging evidence suggest that the abnormal mitochondrial fission participates in pathogenesis of cardiac diseases, including myocardial infarction and heart failure. However, the molecular components regulating mitochondrial network in heart remain largely unidentified. Here we report that NFAT4, miR-324-5p and mitochondrial fission regulator 1 (Mtfr1) function in one signaling axis that regulates mitochondrial morphology and cardiomyocyte cell death. Knocking down Mtfr1 suppresses mitochondrial fission, apoptosis and myocardial infarction. Mtfr1 is a direct target of miR-324-5p, and miR-324-5p attenuates mitochondrial fission, cardiomyocyte apoptosis and myocardial infarction by suppressing Mtfr1 translation. Finally, we show that transcription factor NFAT4 inhibits miR-324-5p expression. Knockdown of NFAT4 suppresses mitochondrial fission and protects cardiomyocyte from apoptosis and myocardial infarction. Our study defines the NFAT4/ miR-324-5p/Mtfr1 axis, which participates in the regulation of mitochondrial fission and cardiomyocyte apoptosis, and suggests potential new treatment avenues for cardiac diseases.
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Affiliation(s)
- K Wang
- Center for Developmental Cardiology, Institute for Translational Medicine, College of Medicine, Qingdao University, Qingdao, China
| | - D-L Zhang
- Department of Cardiology, Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China
| | - B Long
- Laboratory of Molecular Medicine, Central Research Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - T An
- State Key Laboratory of Cardiovascular Disease, Heart Failure Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - J Zhang
- State Key Laboratory of Cardiovascular Disease, Heart Failure Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - L-Y Zhou
- Center for Developmental Cardiology, Institute for Translational Medicine, College of Medicine, Qingdao University, Qingdao, China
| | - C-Y Liu
- Center for Developmental Cardiology, Institute for Translational Medicine, College of Medicine, Qingdao University, Qingdao, China
| | - P-F Li
- Center for Developmental Cardiology, Institute for Translational Medicine, College of Medicine, Qingdao University, Qingdao, China
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4
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Yamamoto S, Nagao Y, Kuroiwa K, Hakamata Y, Ichida M, Saito-Ohara F, Tominaga K, Endo H. Rapid selection of XO embryonic stem cells using Y chromosome-linked GFP transgenic mice. Transgenic Res 2014; 23:757-65. [PMID: 25008421 DOI: 10.1007/s11248-014-9813-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 06/30/2014] [Indexed: 10/25/2022]
Abstract
We developed a transgenic mouse line with Y chromosome-linked green fluorescent protein expressing transgenes (Y-GFP) by the conventional microinjection into the pronucleus of C57BL/6J fertilized oocytes. Embryonic stem (ES) cells derived from Y-GFP mice enabled not only sexing but also the identification of 39, XO karyotype by the lack of Y chromosome. Actually, when fluorescence activated cell sorting (FACS) was applied to Y-GFP ES cells, non-fluorescent ES cells were conveniently collected and showed the lack of Y chromosome by PCR genotyping and Southern blot analysis. FACS analysis revealed Y chromosome loss occurred at 2.9 % of 40, XY ES cells after five passages. These Y-GFP ES cells are potentially applicable to reduce the time, cost and effort needed to generate the gene-targeted mice by the production of male and female mice derived from the same ES cell clone.
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Affiliation(s)
- Satoshi Yamamoto
- Department of Biochemistry, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke, Tochigi, 329-0498, Japan
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5
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Abstract
Cyclosporin A and tacrolimus have been used as immunosuppressive agents initially in organ transplantation after their discovery, and are also used for treatment of the autoimmune disease, providing an excellent therapeutic effect. These agents act targeting on intracellular phosphatase calcineurin (CN), and subsequently inhibit activation of nuclear factor of activated T cells (NFAT), a key regulator of stimulation-dependent gene activation. The CN-NFAT system is involved not only in the immunoregulation including activation and development of helper T cells, regulatory T cells and NKT cells, but in a variety of cellular and developmental events other than immune system. CN inhibitors also affect organs outside of immune system leading to adverse effects, including nephrotoxicity and glucose intolerance. We review recent findings in CN-NFAT system, as well as development of potential CN inhibitors.
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Affiliation(s)
- Yoshiharu Amasaki
- The Center for Rheumatic Diseases/Tonan Hospital, KKR Sapporo Medical Center, Japan
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6
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Estrogen receptor signaling and its relationship to cytokines in systemic lupus erythematosus. J Biomed Biotechnol 2010; 2010:317452. [PMID: 20617147 PMCID: PMC2896666 DOI: 10.1155/2010/317452] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Revised: 03/18/2010] [Accepted: 03/31/2010] [Indexed: 01/19/2023] Open
Abstract
Dysregulation of cytokines is among the main abnormalities in Systemic Lupus Erythematosus (SLE). However, although, estrogens, which are known to be involved in lupus disease,
influence cytokine production, the underlying molecular mechanisms remain poorly defined.
Recent evidence demonstrates the presence of estrogen receptor in various cell types of the
immune system, while divergent effects of estrogens on the cytokine regulation are thought to be
implicated. In this paper, we provide an overview of the current knowledge as to how estrogen-induced
modulation of cytokine production in SLE is mediated by the estrogen receptor while
simultaneously clarifying various aspects of estrogen receptor signaling in this disease. The
estrogen receptor subtypes, their structure, and the mode of action of estrogens by gene activation
and via extranuclear effects are briefly presented. Results regarding the possible correlation
between estrogen receptor gene polymorphisms and quantitative changes in the receptor protein
to SLE pathology and cytokine production are reviewed.
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7
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Abstract
cADPR (cyclic ADP-ribose) is a universal Ca2+ mobilizing second messenger. In T-cells cADPR is involved in sustained Ca2+ release and also in Ca2+ entry. Potential mechanisms for the latter include either capacitative Ca2+ entry, secondary to store depletion by cADPR, or direct activation of the non-selective cation channel TRPM2 (transient receptor potential cation channel, subfamily melastatin, member 2). Here we characterize the molecular target of the newly-described membrane-permeant cADPR agonist 8-Br-N1-cIDPR (8-bromo-cyclic IDP-ribose). 8-Br-N1-cIDPR evoked Ca2+ signalling in the human T-lymphoma cell line Jurkat and in primary rat T-lymphocytes. Ca2+ signalling induced by 8-Br-N1-cIDPR consisted of Ca2+ release and Ca2+ entry. Whereas Ca2+ release was sensitive to both the RyR (ryanodine receptor) blocker RuRed (Ruthenium Red) and the cADPR antagonist 8-Br-cADPR (8-bromo-cyclic ADP-ribose), Ca2+ entry was inhibited by the Ca2+ entry blockers Gd3+ (gadolinium ion) and SKF-96365, as well as by 8-Br-cADPR. To unravel a potential role for TRPM2 in sustained Ca2+ entry evoked by 8-Br-N1-cIDPR, TRPM2 was overexpressed in HEK (human embryonic kidney)-293 cells. However, though activation by H2O2 was enhanced dramatically in those cells, Ca2+ signalling induced by 8-Br-N1-cIDPR was almost unaffected. Similarly, direct analysis of TRPM2 currents did not reveal activation or co-activation of TRPM2 by 8-Br-N1-cIDPR. In summary, the sensitivity to the Ca2+ entry blockers Gd3+ and SKF-96365 is in favour of the concept of capacitative Ca2+ entry, secondary to store depletion by 8-Br-N1-cIDPR. Taken together, 8-Br-N1-cIDPR appears to be the first cADPR agonist affecting Ca2+ release and secondary Ca2+ entry, but without effect on TRPM2.
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8
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Glud SZ, Sørensen AB, Andrulis M, Wang B, Kondo E, Jessen R, Krenacs L, Stelkovics E, Wabl M, Serfling E, Palmetshofer A, Pedersen FS. A tumor-suppressor function for NFATc3 in T-cell lymphomagenesis by murine leukemia virus. Blood 2005; 106:3546-52. [PMID: 16051745 PMCID: PMC1895049 DOI: 10.1182/blood-2005-02-0493] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Nuclear factor of activated T cell (NFAT) transcription factors play a central role in differentiation, activation, and elimination of lymphocytes. We here report on the finding of provirus integration into the Nfatc3 locus in T-cell lymphomas induced by the murine lymphomagenic retrovirus SL3-3 and show that NFATc3 expression is repressed in these lymphomas. The provirus insertions are positioned close to the Nfatc3 promoter or a putative polyadenylated RNA (polyA) region. Furthermore, we demonstrate that NFATc3-deficient mice infected with SL3-3 develop T-cell lymphomas faster and with higher frequencies than wild-type mice or NFATc2-deficient mice. These results identify NFATc3 as a tumor suppressor for the development of murine T-cell lymphomas induced by the retrovirus SL3-3.
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9
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Zaichuk TA, Shroff EH, Emmanuel R, Filleur S, Nelius T, Volpert OV. Nuclear factor of activated T cells balances angiogenesis activation and inhibition. ACTA ACUST UNITED AC 2004; 199:1513-22. [PMID: 15184502 PMCID: PMC2211785 DOI: 10.1084/jem.20040474] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
It has been demonstrated that vascular endothelial cell growth factor (VEGF) induction of angiogenesis requires activation of the nuclear factor of activated T cells (NFAT). We show that NFATc2 is also activated by basic fibroblast growth factor and blocked by the inhibitor of angiogenesis pigment epithelial–derived factor (PEDF). This suggests a pivotal role for this transcription factor as a convergence point between stimulatory and inhibitory signals in the regulation of angiogenesis. We identified c-Jun NH2-terminal kinases (JNKs) as essential upstream regulators of NFAT activity in angiogenesis. We distinguished JNK-2 as responsible for NFATc2 cytoplasmic retention by PEDF and JNK-1 and JNK-2 as mediators of PEDF-driven NFAT nuclear export. We identified a novel NFAT target, caspase-8 inhibitor cellular Fas-associated death domain–like interleukin 1β–converting enzyme inhibitory protein (c-FLIP), whose expression was coregulated by VEGF and PEDF. Chromatin immunoprecipitation showed VEGF-dependent increase of NFATc2 binding to the c-FLIP promoter in vivo, which was attenuated by PEDF. We propose that one possible mechanism of concerted angiogenesis regulation by activators and inhibitors may be modulation of the endothelial cell apoptosis via c-FLIP controlled by NFAT and its upstream regulator JNK.
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Affiliation(s)
- Tetiana A Zaichuk
- Department of Urology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
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10
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Wilkins BJ, De Windt LJ, Bueno OF, Braz JC, Glascock BJ, Kimball TF, Molkentin JD. Targeted disruption of NFATc3, but not NFATc4, reveals an intrinsic defect in calcineurin-mediated cardiac hypertrophic growth. Mol Cell Biol 2002; 22:7603-13. [PMID: 12370307 PMCID: PMC135666 DOI: 10.1128/mcb.22.21.7603-7613.2002] [Citation(s) in RCA: 200] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
A calcineurin-nuclear factor of activated T cells (NFAT) regulatory pathway has been implicated in the control of cardiac hypertrophy, suggesting one mechanism whereby alterations in intracellular calcium handling are linked to the expression of hypertrophy-associated genes. Although recent studies have demonstrated a necessary role for calcineurin as a mediator of cardiac hypertrophy, the potential involvement of NFAT transcription factors as downstream effectors of calcineurin signaling has not been evaluated. Accordingly, mice with targeted disruptions in NFATc3 and NFATc4 genes were characterized. Whereas the loss of NFATc4 did not compromise the ability of the myocardium to undergo hypertrophic growth, NFATc3-null mice demonstrated a significant reduction in calcineurin transgene-induced cardiac hypertrophy at 19 days, 26 days, 6 weeks, 8 weeks, and 10 weeks of age. NFATc3-null mice also demonstrated attenuated pressure overload- and angiotensin II-induced cardiac hypertrophy. These results provide genetic evidence that calcineurin-regulated responses require NFAT effectors in vivo.
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Affiliation(s)
- Benjamin J Wilkins
- Division of Molecular Cardiovascular Biology, Department of Pediatrics, Children's Hospital Medical Center, Cincinnati Ohio 45229-3039, USA
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11
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Gomez MF, Stevenson AS, Bonev AD, Hill-Eubanks DC, Nelson MT. Opposing actions of inositol 1,4,5-trisphosphate and ryanodine receptors on nuclear factor of activated T-cells regulation in smooth muscle. J Biol Chem 2002; 277:37756-64. [PMID: 12145283 DOI: 10.1074/jbc.m203596200] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The nuclear factor of activated T-cells (NFAT), originally identified in T-cells, has since been shown to play a role in mediating Ca(2+)-dependent gene transcription in diverse cell types outside of the immune system. We have previously shown that nuclear accumulation of NFATc3 is induced in ileal smooth muscle by platelet-derived growth factor in a manner that depends on Ca(2+) influx through L-type, voltage-dependent Ca(2+) channels. Here we show that NFATc3 is also the predominant NFAT isoform expressed in cerebral artery smooth muscle and is induced to accumulate in the nucleus by UTP and other G(q/11)-coupled receptor agonists. This induction is mediated by calcineurin and is dependent on sarcoplasmic reticulum Ca(2+) release through inositol 1,4,5-trisphosphate receptors and extracellular Ca(2+) influx through L-type, voltage-dependent Ca(2+) channels. Consistent with results obtained in ileal smooth muscle, depolarization-induced Ca(2+) influx fails to induce NFAT nuclear accumulation in cerebral arteries. We also provide evidence that Ca(2+) release by ryanodine receptors in the form of Ca(2+) sparks may exert an inhibitory influence on UTP-induced NFATc3 nuclear accumulation and further suggest that UTP may act, in part, by inhibiting Ca(2+) sparks. These results are consistent with a multifactorial regulation of NFAT nuclear accumulation in smooth muscle that is likely to involve several intracellular signaling pathways, including local effects of sarcoplasmic reticulum Ca(2+) release and effects attributable to global elevations in intracellular Ca(2+).
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Affiliation(s)
- Maria F Gomez
- Department of Pharmacology, University of Vermont, Burlington, Vermont 05405, USA
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12
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Amasaki Y, Adachi S, Ishida Y, Iwata M, Arai N, Arai KI, Miyatake S. A constitutively nuclear form of NFATx shows efficient transactivation activity and induces differentiation of CD4(+)CD8(+) T cells. J Biol Chem 2002; 277:25640-8. [PMID: 11997392 DOI: 10.1074/jbc.m201860200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Ca(2+) signal facilitates nuclear translocation of NFAT through the dephosphorylation of clustered serine residues in the calcium regulatory domain by the Ca(2+)/calmodulin-dependent phosphatase calcineurin. The conformation of dephosphorylated NFAT exposes the nuclear localization signal for translocation into the nucleus and masks the nuclear export sequence to keep the protein in the nucleus. It has been reported that deletion of some serine-rich motifs masking the nuclear localization signal results in the translocation of NFAT into the nucleus, but that the nuclear export sequence located at the N terminus also needs to be deleted for NFATx (NFAT4/NFATc3) to exert efficient transactivation function. Here, we report that deletion of the critical serine-rich motifs of NFATx leads to a conformation that efficiently exposes the nuclear localization signal and that has stronger transcription activity compared with the fully activated wild-type protein in the presence of the nuclear export sequence. This also suggests that the regulation of the transactivation domain by phosphorylation observed in NFAT1 may not contribute significantly to the transcription activity of NFATx. The expression of this constitutively nuclear form of NFATx in the CD4(+)CD8(+) T cell line facilitates differentiation into the CD4 single-positive stage upon stimulation with phorbol ester. Our data suggest that NFATx is involved in the regulation of co-receptor expression during differentiation into the CD4 single-positive stage.
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Affiliation(s)
- Yoshiharu Amasaki
- Department of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo, Japan
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13
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Liu J, Arai K, Arai N. Inhibition of NFATx activation by an oligopeptide: disrupting the interaction of NFATx with calcineurin. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:2677-87. [PMID: 11509611 DOI: 10.4049/jimmunol.167.5.2677] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Calcium-dependent phosphatase calcineurin (CN) regulates the activation and nuclear translocation of NFAT. We identify here a novel CN-binding motif in one member of the NFAT family, NFATx, and a peptide based on this motif, Pep3. Pep3 binds CN and competes with wild-type NFATx for CN interaction. Amino acid mutations within Pep3 show that multiple amino acid residues are required for the effective functions of Pep3. Ectopic expression of Pep3 in a Th clone via a retrovirus-mediated gene transfer could selectively block the nuclear translocation of endogenous NFATx, whereas it had little effect on the nuclear translocation of another member of the NFAT family, NFATp. Furthermore, in transfection experiments, Pep3 also blocked the nuclear translocation of transfected NFATx, but not NFATp, in the B cell line M12, demonstrating specific inhibition of Pep3 for NFATx. Importantly, several cytokines produced by the T cell clone were severely repressed by ectopic Pep3, and indeed, the production of these cytokines was enhanced by the expression of wild-type NFATx. Our results show selective inhibition of NFATx activation and cytokine expression by Pep3 and suggest a new approach for studying the biology of each NFAT family member. This approach may provide an opportunity for pharmacological targeting of Ca(2+)-dependent signaling events.
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Affiliation(s)
- J Liu
- Department of Immunology, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304, USA
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14
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Abstract
This review discusses the rapidly progressing field of cardiomyocyte signal transduction and the regulation of the hypertrophic response. When stimulated by a wide array of neurohumoral factors or when faced with an increase in ventricular-wall tension, individual cardiomyocytes undergo hypertrophic growth as an adaptive response. However, sustained cardiac hypertrophy is a leading predictor of future heart failure. A growing number of intracellular signaling pathways have been characterized as important transducers of the hypertrophic response, including specific G protein isoforms, low-molecular-weight GTPases (Ras, RhoA, and Rac), mitogen-activated protein kinase cascades, protein kinase C, calcineurin, gp130-signal transducer and activator of transcription, insulin-like growth factor I receptor pathway, fibroblast growth factor and transforming growth factor beta receptor pathways, and many others. Each of these signaling pathways has been implicated as a hypertrophic transducer, which collectively suggests an emerging paradigm whereby multiple pathways operate in concert to orchestrate a hypertrophic response
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Affiliation(s)
- J D Molkentin
- Department of Pediatrics, Division of Molecular Cardiovascular Biology, Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio 45229-3039, USA.
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15
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López-Rodríguez C, Aramburu J, Rakeman AS, Copeland NG, Gilbert DJ, Thomas S, Disteche C, Jenkins NA, Rao A. NF-AT5: the NF-AT family of transcription factors expands in a new direction. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2001; 64:517-26. [PMID: 11233530 DOI: 10.1101/sqb.1999.64.517] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- C López-Rodríguez
- Center for Blood Research and the Department of Pathology, Harvard Medical School, Boston, Massachusetts 02115, USA
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16
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Abstract
In response to increased ventricular wall tension or neurohumoral stimuli, the myocardium undergoes an adaptive hypertrophy response that temporarily augments pump function. Although initially beneficial, sustained cardiac hypertrophy can lead to decompensation and cardiomyopathy. Recent studies have focused on characterizing the molecular mechanisms that underlie cardiac hypertrophy. An increasing number of signal transduction pathways have been identified as important regulators of the hypertrophic response, including the low-molecular weight GTPases (Ras, RhoA, and Rac), mitogen-activated protein kinases, protein kinase C, and calcineurin. This review will discuss an emerging body of evidence that implicates the calcium-calmodulin-activated protein phosphatase calcineurin as a physiological regulator of the cardiac hypertrophic response. Although the sufficiency of calcineurin to promote cardiomyocyte hypertrophy in vivo and in vitro is established, its overall necessity as a hypertrophic mediator is currently an area of ongoing debate. The use of the calcineurin-inhibitory agents cyclosporine A and FK506 have suggested a necessary role for calcineurin in many, but not all, animal models of hypertrophy or cardiomyopathy. The evidence implicating a role for calcineurin signaling in the heart will be weighed against a growing body of literature suggesting necessary roles for a diverse array of intracellular signaling pathways, highlighting the multifactorial nature of the hypertrophic program.
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Affiliation(s)
- J D Molkentin
- Department of Pediatrics, University of Cincinnati, Division of Molecular Cardiovascular Biology, Children's Hospital Medical Center, Cincinnati, Ohio, USA.
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Valencia TG, Roberts LD, Zeng H, Grant SR. Tetracycline-inducible CaM kinase II silences hypertrophy-sensitive gene expression in rat neonate cardiomyocytes. Biochem Biophys Res Commun 2000; 274:803-10. [PMID: 10924357 DOI: 10.1006/bbrc.2000.3239] [Citation(s) in RCA: 10] [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
Recent work from this laboratory both in rat primary cardiomyocytes and in ventricular tissue of transgenic mouse models of induced hypertrophy has identified two Ca(2+)/calmodulin-dependent nuclear signaling cascades. The first involves the phosphatase calcineurin (CaN). The second is the CaM kinase kinase cascade which involves CaM kinase I and CaM kinase IV. Each of these signaling cascades strongly up-regulate transcription of hypertrophy-sensitive genes in the rat ventricular cardiomyocyte. We have documented that over-expression of an active form of CaM kinase II silenced transcriptional induction of hypertrophy-sensitive genes. The purpose of this study was to generate an inducible CaM kinase II expression system and correlate its expression with the silencing of hypertrophic-sensitive reporters. A truncated form of CaM KII, CaM KII (1-290) was subcloned downstream and proximal to a promoter under transcriptional control (induction) of the tetracycline-regulated transcription factor, tet-TransActivator (tTA). Hypertrophy-sensitive reporter activity in primary cardiomyocytes was silenced when tet-inducible CaM KII was co-expressed with plasmids harboring active forms of CaN, CaM KI or CaM KIV. For instance, induced CaM KII expression silenced CaN, CaM kinase I, or CaM kinase IV driven ANF reporter activity 4.9-, 2.9-, and 6.9-fold below their maximal values, respectively. Myocyte exposure to doxycycline (DOX) blocked tTA-driven CaM KII expression and restored CaN/CaM KI or CaN/CaM KIV driven reporter activation. This study demonstrates, for the first time, that active CaM KII silences Ca(2+)-sensitive nuclear signaling cascades for transcriptional up-regulation of cardiomyocyte hypertrophy.
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Affiliation(s)
- T G Valencia
- Laboratory of Cardiac and Vascular Molecular Genetics, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas, 76107, USA
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18
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Amasaki Y, Miyatake S, Arai N, Arai K. Regulation of nuclear factor of activated T-cell family transcription factors during T-cell development in the thymus. J Allergy Clin Immunol 2000; 106:S1-9. [PMID: 10887328 DOI: 10.1067/mai.2000.106061] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND T lymphocytes undergo a series of developmental events in the thymus, and signaling through the T-cell antigen receptor is crucial in this differential program. The nuclear factor of activated T cells (NFATs) may be involved in transcriptional induction of cytokine genes and other immunoregulatory genes in T cells. OBJECTIVES We have examined the distribution of 3 NFAT family members (NFAT1, NFATc, and NFATx) in human fetal thymocytes, by using semiquantitative RT-PCR and electrophoretic mobility shift assay. RESULTS The messenger RNA of NFATx was expressed in all T-lymphocyte subsets tested, and expression was highest in CD4(+)CD8(+) thymocytes. Conversely, mRNA of NFAT1 was preferentially expressed in mature CD4(+) single-positive cells. NFATc mRNA was present at low levels in all subsets but was strongly induced by treatment with phorbol ester plus calcium ionophore. Using electrophoretic mobility shift assay, we observed stimulation-dependent NFAT-DNA binding in CD4(+)CD8(+) thymocytes, which was largely dependent on NFATx protein. This DNA-binding activity was inhibited by cyclosporin A, which indicated that NFATx nuclear translocation in CD4(+)CD8(+) thymocytes was regulated by calcineurin phosphatase. In contrast, NFAT1 and NFATc (and to some extent NFATx) were responsible for NFAT DNA binding in the CD4(+) cells. CONCLUSIONS Expression of NFAT family members is differentially regulated during T-cell development, and NFATx may be involved in T-cell antigen receptor/calcineurin-dependent signaling in CD4(+)CD8(+) thymocytes.
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Affiliation(s)
- Y Amasaki
- Department of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo, Japan
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Adachi S, Amasaki Y, Miyatake S, Arai N, Iwata M. Successive expression and activation of NFAT family members during thymocyte differentiation. J Biol Chem 2000; 275:14708-16. [PMID: 10799559 DOI: 10.1074/jbc.275.19.14708] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Differentiation of immature CD4(+)CD8(+) thymocytes to mature CD4(+) or CD8(+) T cells is induced by positive selection and appears to involve calcineurin-dependent activation of NFAT, a family of transcription factors. NFATx is predominantly expressed in CD4(+)CD8(+) thymocytes, whereas NFATp and NFATc are expressed at much lower levels in the thymus than in mature T cells. However, how or when each NFAT member is involved in the differentiation pathway is unclear. Using an in vitro model system where isolated CD4(+)CD8(+) thymocytes can survive and differentiate into semi-mature CD4-lineage T cells, we suggest that low calcineurin activity sustained for approximately 20 h is required for cell survival and differentiation. Accordingly, the DNA binding activity of NFAT slowly increased during the stimulation of 20 h to induce the differentiation. NFATx significantly contributed to the early rise, but the late increase was mostly due to NFATc activation. Meanwhile, the expression of NFATx mRNA decreased and that of NFATc mRNA increased. The DNA-binding activity of NFATp was detectable but low throughout the stimulation. NFATp became dominantly active after the semi-mature T cells differentiated into mature and activated CD4 T cells. These findings suggest that NFATx and NFATc successively play roles in T cell development.
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Affiliation(s)
- S Adachi
- Integrative Projects, Mitsubishi Kasei Institute of Life Sciences, Machida-shi, Tokyo 194-8511, Japan
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Liu J, Masuda ES, Tsuruta L, Arai N, Arai KI. Two Independent Calcineurin-Binding Regions in the N-Terminal Domain of Murine NF-ATx1 Recruit Calcineurin to Murine NF-ATx1. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.8.4755] [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
Intracellular calcium regulates events controlling nuclear translocation of nuclear factor of activated T cells (NF-AT). Calcium-dependent phosphatase calcineurin (CN) plays a central role in this process. Structural and functional analyses of the N-terminal domain of murine NF-ATx1, a member of the NF-AT family, have defined two distinct CN binding regions (CNBRs), CNBR1 and CNBR2, which are located in the region preceding the SP boxes of serine/proline-rich sequences and the region between the SP boxes and Rel similarity domain, respectively. The binding of murine NF-ATx1 (mNF-ATx1) to CN was abolished by deletion of these two regions, yet was unaffected by the individual deletion. In contrast, the nuclear translocation of mNF-ATx1 was much reduced when only CNBR2 was removed. Luciferase assay revealed that both regions are required for mNF-ATx1-dependent activation of the murine IL-2 promoter. Most importantly, recombinant CNBR2 bound CN with a higher affinity, and when expressed in Jurkat cells, it functioned as a dominant negative mutant that prevented the transcription driven by exogenous mNF-ATx1, probably by interfering with the function of CN. We propose that activation of mNF-ATx1 can be modulated through two distinct CN target regions. Our findings provide a new opportunity for pharmacological intervention with Ca2+-dependent signaling events.
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Affiliation(s)
- Jie Liu
- *Department of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo, Shirokane-dai, Minato-ku, Tokyo, Japan
| | - Esteban S. Masuda
- †Department of Molecular Biology, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304; and
| | - Lisako Tsuruta
- *Department of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo, Shirokane-dai, Minato-ku, Tokyo, Japan
| | - Naoko Arai
- †Department of Molecular Biology, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304; and
| | - Ken-ichi Arai
- *Department of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo, Shirokane-dai, Minato-ku, Tokyo, Japan
- ‡Core Research for Evolutional Science and Technology (CREST), Hon-cho, Kawaguchi, Saitama, Japan
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21
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Zhu J, McKeon F. NF-AT activation requires suppression of Crm1-dependent export by calcineurin. Nature 1999; 398:256-60. [PMID: 10094050 DOI: 10.1038/18473] [Citation(s) in RCA: 147] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Nuclear import of the NF-AT transcription factors during T-cell activation requires the calcium-activated phosphatase calcineurin, which unmasks nuclear-location signals on NF-AT. We show here that the nuclear import of NF-ATs is not sufficient to activate NF-AT target genes, as NF-ATs are subject to a futile cycling across the nuclear envelope owing to engagement with the exportin protein Crm1. Calcineurin suppresses this futile cycling by a non-catalytic mechanism involving the masking of nuclear export signals on NF-AT targeted by Crm1. This clustering of binding sites for calcineurin and Crml on NF-AT establishes an inherent competition between these molecules that imparts exquisite calcium sensitivity to the shuttling dynamics of the NF-AT transcription factors. Such a balance between nuclear import and export may regulate the action of other transcription factors.
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Affiliation(s)
- J Zhu
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
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22
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Rider V, Foster RT, Evans M, Suenaga R, Abdou NI. Gender differences in autoimmune diseases: estrogen increases calcineurin expression in systemic lupus erythematosus. CLINICAL IMMUNOLOGY AND IMMUNOPATHOLOGY 1998; 89:171-80. [PMID: 9787119 DOI: 10.1006/clin.1998.4604] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Systemic lupus erythematosus (SLE) predominantly affects women (9:1 compared to men) of childbearing age and often decreases its intensity in postmenopausal women, suggesting that sex hormones play a role in its pathogenesis. Comparison of steady-state levels of calcineurin mRNA using RNase protection assays revealed increased calcineurin expression in response to estradiol in cultured T cells from nine female lupus patients. Calcineurin mRNA levels did not increase significantly in T cells from eight age-matched normal control female volunteers. Estrogen-dependent calcineurin mRNA increased in a dose-dependent fashion, while progesterone and dexamethasone did not increase calcineurin mRNA in patient cells. Lupus T cell calcineurin mRNA increased in response to estradiol at 6 h but not at 3 h. Calcineurin phosphatase activity increased in lupus T cell extracts after incubation of cells with estradiol, while phosphatase activity in normal T cells was unaffected by estrogen. Calcineurin expression in T cells from patients with vasculitis and rheumatoid arthritis taking medications similar to those taken by the lupus patients was unaffected by estradiol. This study provides the first evidence for a molecular marker of estrogen action in lupus patients and suggests that estrogen-dependent changes in lupus T cell calcineurin could alter proinflammatory cytokine gene regulation and T-B cell interactions.
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Affiliation(s)
- V Rider
- School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri, 64110, USA
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23
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Abstract
The nuclear factor of activated T cells (NFAT) plays an important role in T-cell biology. Activation of T cells results in the rapid calcineurin-dependent translocation of NFAT transcription factors from the cytoplasm to the nucleus. This translocation process coupled to the subsequent active maintenance of NFAT in the nucleus compartment is critical for the induction of expression of several genes encoding cytokines and membrane proteins that modulate immune responses. The molecular cloning of the NFAT family of transcription factors has facilitated rapid progress in the understanding of the signalling mechanisms that control the activity of NFAT.
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Affiliation(s)
- E S Masuda
- Department of Cell Signalling, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304, USA.
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Imamura R, Masuda ES, Naito Y, Imai SI, Fujino T, Takano T, Arai KI, Arai N. Carboxyl-Terminal 15-Amino Acid Sequence of NFATx1 Is Possibly Created by Tissue-Specific Splicing and Is Essential for Transactivation Activity in T Cells. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.161.7.3455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Abstract
NFAT regulates transcription of a number of cytokine and other immunoregulatory genes. We have isolated NFATx, which is one of four members of the NFAT family of transcription factors and is preferentially expressed in the thymus and peripheral blood leukocytes, and an isoform of NFATx, NFATx1. Here we provide evidence showing that 15 amino acids in the carboxyl-terminal end of NFATx1 are required for its maximum transactivation activity in Jurkat T cells. A fusion between these 15 amino acids and the GAL4 DNA binding domain was capable of transactivating reporters driven by the GAL4 DNA binding site. Interestingly, this 15-amino acid transactivation sequence is well conserved in NFAT family proteins, although the sequences contiguous to the carboxyl-terminal regions of the NFAT family are much less conserved. We also report three additional isoforms of NFATx, designated NFATx2, NFATx3, and NFATx4. This transactivation sequence is altered by tissue-specific alternative splicing in newly isolated NFATx isoforms, resulting in lower transactivation activity in Jurkat T cells. NFATx1 is expressed predominantly in the thymus and peripheral blood leukocyte, while the skeletal muscle expressed primarily NFATx2. In Jurkat cells, transcription from the NFAT site of the IL-2 promoter is activated strongly by NFATx1 but only weakly by NFATx2. These data demonstrate that the 15-amino acid sequence of NFATx1 is a major transactivation sequence required for induction of genes by NFATx1 in T cells and possibly regulates NFAT activity through tissue-specific alternative splicing.
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Affiliation(s)
- Ryu Imamura
- *Department of Cell Signaling, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304
| | - Esteban S. Masuda
- *Department of Cell Signaling, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304
| | - Yoshiyuki Naito
- *Department of Cell Signaling, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304
| | - Shin-ichiro Imai
- †Department of Microbiology, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan; and
| | - Tadahiro Fujino
- †Department of Microbiology, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan; and
| | - Toshiya Takano
- †Department of Microbiology, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan; and
| | - Ken-ichi Arai
- ‡Department of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Naoko Arai
- *Department of Cell Signaling, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304
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25
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Amasaki Y, Masuda ES, Imamura R, Arai KI, Arai N. Distinct NFAT Family Proteins Are Involved in the Nuclear NFAT-DNA Binding Complexes from Human Thymocyte Subsets. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.160.5.2324] [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 nuclear factor of activated T cells (NFAT) is involved in the transcriptional induction of cytokine and other immunoregulatory genes during an immune response. Among four distinct NFAT family members identified to date, mRNAs of NFAT1, NFATc, and NFATx are expressed in the thymus. Here, we report the distribution of these three NFAT family members in human fetal thymocyte subsets and in peripheral mature T cells. We show that NFATx mRNA was expressed in all T lymphocyte subsets tested and was highest in CD4+CD8+ double positive (DP) thymocytes. Conversely, NFAT1 mRNA was preferentially expressed in the mature CD4+ single positive (SP) populations. NFATc mRNA was present at low levels in all subsets but strongly induced upon treatment with phorbol ester and calcium ionophore. Interestingly, we detected NFAT-DNA binding complexes in DP thymocytes, albeit at lower levels than in CD4 SP cells. Corresponding to the mRNA expression, we observed that NFATx was responsible for the NFAT-DNA binding in DP thymocytes. Moreover, this DNA binding was inhibited by cyclosporin A, indicating that NFATx nuclear translocation was regulated by the calcineurin phosphatase in DP thymocytes. For the CD4 SP populations, NFAT1 and NFATc, and to some extent NFATx, were responsible for the NFAT-DNA binding complexes. These results indicate that NFAT family members are differentially regulated during the development of T cells, and that NFATx may play a distinct role in calcineurin-dependent signaling in DP thymocytes.
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Affiliation(s)
- Yoshiharu Amasaki
- *Department of Cell Signaling, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304; and
| | - Esteban S. Masuda
- *Department of Cell Signaling, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304; and
| | - Ryu Imamura
- *Department of Cell Signaling, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304; and
| | - Ken-ichi Arai
- †Department of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Naoko Arai
- *Department of Cell Signaling, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304; and
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26
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Yoshida H, Nishina H, Takimoto H, Marengère LE, Wakeham AC, Bouchard D, Kong YY, Ohteki T, Shahinian A, Bachmann M, Ohashi PS, Penninger JM, Crabtree GR, Mak TW. The transcription factor NF-ATc1 regulates lymphocyte proliferation and Th2 cytokine production. Immunity 1998; 8:115-24. [PMID: 9462517 DOI: 10.1016/s1074-7613(00)80464-1] [Citation(s) in RCA: 281] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
NF-ATc1 is a member of a family of genes that encodes the cytoplasmic component of the nuclear factor of activated T cells (NF-AT). In activated T cells, nuclear NF-AT binds to the promoter regions of multiple cytokine genes and induces their transcription. The role of NF-ATc1 was investigated in recombination activating gene-1 (RAG-1)-deficient blastocyst complementation assays using homozygous NF-ATc1-/- mutant ES cell lines. NF-ATc1-/-/RAG-1-/- chimeric mice showed reduced numbers of thymocytes and impaired proliferation of peripheral lymphocytes, but normal production of IL-2. Induction in vitro of Th2 responses, as demonstrated by a decrease in IL-4 and IL-6 production, was impaired in mutant T cells. These data indicate that NF-ATc1 plays roles in the development of T lymphocytes and in the differentiation of the Th2 response.
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Affiliation(s)
- H Yoshida
- The Amgen Institute, Department of Medical Biophysics, University of Toronto, Ontario, Canada
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27
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Masuda ES, Liu J, Imamura R, Imai SI, Arai KI, Arai N. Control of NFATx1 nuclear translocation by a calcineurin-regulated inhibitory domain. Mol Cell Biol 1997; 17:2066-75. [PMID: 9121455 PMCID: PMC232054 DOI: 10.1128/mcb.17.4.2066] [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: 02/07/2023] Open
Abstract
The nuclear factor of activated T cells (NFAT) regulates cytokine gene expression in T cells through cis-acting elements located in the promoters of several cytokine genes. NFATx1, which is preferentially expressed in the thymus and peripheral blood leukocytes, is one of four members of the NFAT family of transcription factors. We have performed domain analysis of NFATx1 by examining the effects of deletion mutations. We found that NFATx1 DNA binding activity and interaction with AP-1 polypeptides were dependent on its central Rel similarity region and that transcriptional activation was reduced by deletions of either its N-terminal domain or its C-terminal domain, suggesting the presence of intrinsic transcriptional activation motifs in both regions. We also identified a potent inhibitory sequence within its N-terminal domain. We show that the inactivation of the inhibition was dependent on the activity of calcineurin, a calcium-calmodulin-dependent phosphatase. We also show that calcineurin associated with the N-terminal domain of NFATx1 at multiple docking sites and caused a reduction of size, indicative of dephosphorylation, in NFATx1. We have mapped the inhibitory activity to less than 60 residues, containing motifs that are conserved in all NFAT proteins. Finally, we demonstrate that deletion in NFATx1 of the mapped 60 residues leads to its nuclear translocation independent of calcium signaling. Our results support the model proposing that the N-terminal domain confers calcium-signaling dependence on NFATx1 transactivation activity by regulating its intracellular localization through a protein module that associates with calcineurin and is a target of its phosphatase activity.
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Affiliation(s)
- E S Masuda
- Department of Cell Signaling, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, California 94304, USA
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