Calcium oscillations in T-cells: mechanisms and consequences for gene expression

2003 ◽  
Vol 31 (5) ◽  
pp. 925-929 ◽  
Author(s):  
R.S. Lewis
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Nuclear Factor Κb ◽  
Cellular Mechanism ◽  
Calcium Oscillations ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Crac Channels ◽  
Kinetics Of ◽  
Ca2 Channels

[Ca2+]i (intracellular Ca2+ concentration) oscillations play a central role in the activation of T-lymphocytes by antigen. Oscillations in T-cells are absolutely dependent on Ca2+ influx through store-operated CRAC channels (Ca2+-release-activated Ca2+ channels), and evidence suggests that they arise from delayed interactions between these channels and Ca2+ stores. Their potential functions have been explored by creating controlled [Ca2+]i oscillations with pulses of Ca2+ entry or pulses of Ins(1,4,5)P3. Oscillations enhance both the efficiency and specificity of signalling through the Ca2+-dependent transcription factors nuclear factor of activated T-cells (NFAT), Oct/Oap and nuclear factor κB (NFκB) in ways that are consistent with each factor's Ca2+ dependence and kinetics of activation and deactivation. These studies show how [Ca2+]i oscillations may enhance signalling to the nucleus, and suggest a possible cellular mechanism for extracting information encoded in oscillation frequency.

scholarly journals STIM2 targets Orai1/STIM1 to the AKAP79 signaling complex and confers coupling of Ca2+entry with NFAT1 activation

2020 ◽  
Vol 117 (28) ◽  
pp. 16638-16648 ◽  
Author(s):  
Ga-Yeon Son ◽  
Krishna Prasad Subedi ◽  
Hwei Ling Ong ◽  
Lucile Noyer ◽  
Hassan Saadi ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Unique Role ◽  
Signaling Complex ◽  
Contact Sites ◽  
Channel Function

The Orai1 channel is regulated by stromal interaction molecules STIM1 and STIM2 within endoplasmic reticulum (ER)-plasma membrane (PM) contact sites. Ca2+signals generated by Orai1 activate Ca2+-dependent gene expression. When compared with STIM1, STIM2 is a weak activator of Orai1, but it has been suggested to have a unique role in nuclear factor of activated T cells 1 (NFAT1) activation triggered by Orai1-mediated Ca2+entry. In this study, we examined the contribution of STIM2 in NFAT1 activation. We report that STIM2 recruitment of Orai1/STIM1 to ER-PM junctions in response to depletion of ER-Ca2+promotes assembly of the channel with AKAP79 to form a signaling complex that couples Orai1 channel function to the activation of NFAT1. Knockdown of STIM2 expression had relatively little effect on Orai1/STIM1 clustering or local and global [Ca2+]iincreases but significantly attenuated NFAT1 activation and assembly of Orai1 with AKAP79. STIM1ΔK, which lacks the PIP2-binding polybasic domain, was recruited to ER-PM junctions following ER-Ca2+depletion by binding to Orai1 and caused local and global [Ca2+]iincreases comparable to those induced by STIM1 activation of Orai1. However, in contrast to STIM1, STIM1ΔK induced less NFAT1 activation and attenuated the association of Orai1 with STIM2 and AKAP79. Orai1-AKAP79 interaction and NFAT1 activation were recovered by coexpressing STIM2 with STIM1ΔK. Replacing the PIP2-binding domain of STIM1 with that of STIM2 eliminated the requirement of STIM2 for NFAT1 activation. Together, these data demonstrate an important role for STIM2 in coupling Orai1-mediated Ca2+influx to NFAT1 activation.

B-cell antigen receptor activates transcription factors NFAT (nuclear factor of activated T-cells) and NF-κB (nuclear factor κB) via a mechanism that involves diacylglycerol

2004 ◽  
Vol 32 (1) ◽  
pp. 113-115 ◽  
Author(s):  
P. Antony ◽  
J.B. Petro ◽  
G. Carlesso ◽  
N.P. Shinners ◽  
J. Lowe ◽  
...  
Keyword(s):  
T Cells ◽  
Transcription Factors ◽  
B Cell ◽  
Antigen Receptor ◽  
Nuclear Factor Κb ◽  
B Cell Antigen Receptor ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Cell Antigen Receptor ◽  
Cell Antigen

Engagement of the B-cell antigen receptor (BCR) induces the activation of various transcription factors, including NFAT (nuclear factor of activated T-cells) and NF-κB (nuclear factor κB), which participate in long-term biological responses such as proliferation, survival and differentiation of B-lymphocytes. We addressed the biochemical basis of this process using the DT40 chicken B-cell lymphoma. We discovered that Bruton's tyrosine kinase (BTK) and phospholipase C-γ2 (PLC-γ2) are required to activate NFAT and NF-κB, and to produce the lipid second messenger diacylglycerol in response to BCR cross-linking. Therefore the functional integrity of the BTK/PLC-γ2/diacylglycerol signalling axis is crucial for BCR-directed activation of both transcription factors NFAT and NF-κB.

PKCθ-regulated signalling in health and disease

2014 ◽  
Vol 42 (6) ◽  
pp. 1484-1489 ◽  
Author(s):  
Pulak R. Nath ◽  
Noah Isakov
Keyword(s):  
Signal Transduction ◽  
T Cells ◽  
T Cell ◽  
Immunological Synapse ◽  
Cell Types ◽  
Cell Receptor ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Health And Disease

Protein kinase Cθ (PKCθ) is a key enzyme in T-lymphocytes where it plays an important role in signal transduction downstream of the activated T-cell receptor (TCR) and the CD28 co-stimulatory receptor. Antigenic stimulation of T-cells triggers PKCθ translocation to the centre of the immunological synapse (IS) at the contact site between antigen-specific T-cells and antigen-presenting cells (APCs). The IS-residing PKCθ phosphorylates and activates effector molecules that transduce signals into distinct subcellular compartments and activate the transcription factors, nuclear factor κB (NF-κB), nuclear factor of activated T-cells (NFAT) and activating protein 1 (AP-1), which are essential for the induction of T-cell-mediated responses. Besides its major biological role in T-cells, PKCθ is expressed in several additional cell types and is involved in a variety of distinct physiological and pathological phenomena. For example, PKCθ is expressed at high levels in platelets where it regulates signal transduction from distinct surface receptors, and is required for optimal platelet activation and aggregation, as well as haemostasis. In addition, PKCθ is involved in physiological processes regulating insulin resistance and susceptibility to obesity, and is expressed at high levels in gastrointestinal stromal tumours (GISTs), although the functional importance of PKCθ in these processes and cell types is not fully clear. The present article briefly reviews selected topics relevant to the biological roles of PKCθ in health and disease.

scholarly journals A potential role for nuclear factor of activated T-cells in receptor tyrosine kinase and G-protein-coupled receptor agonist-induced cell proliferation

2002 ◽  
Vol 368 (1) ◽  
pp. 183-190 ◽  
Author(s):  
Chandrahasa R. YELLATURU ◽  
Salil K. GHOSH ◽  
R.K. RAO ◽  
Lisa K. JENNINGS ◽  
Aviv HASSID ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Dna Synthesis ◽  
G Protein ◽  
Receptor Tyrosine Kinase ◽  
Binding Activity ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Dna Binding Activity ◽  
G Protein Coupled

We have studied the role of nuclear factor of activated T-cells (NFAT) transcription factors in the induction of vascular smooth muscle cell (VSMC) growth by platelet-derived growth factor-BB (PDGF-BB) and thrombin, the receptor tyrosine kinase (RTK) and G-protein-coupled receptor (GPCR) agonists, respectively. NFATc1 but not NFATc2 or NFATc3 was translocated from the cytoplasm to the nucleus upon treatment of VSMCs with PDGF-BB or thrombin. Translocation of NFATc1 was followed by an increase in NFAT—DNA binding activity and NFAT-dependent reporter gene expression. Cyclosporin A (CsA), a potent and specific inhibitor of calcineurin, a calcium/calmodulin-dependent serine phosphatase involved in the dephosphorylation and activation of NFATs, blocked NFAT—DNA binding activity and NFAT-dependent reporter gene expression induced by PDGF-BB and thrombin. CsA also completely inhibited PDGF-BB- and thrombin-induced VSMC growth, as measured by DNA synthesis and cell number. In addition, forced expression of the NFAT-competing peptide VIVIT for calcineurin binding significantly attenuated the DNA synthesis induced by PDGF-BB and thrombin in VSMCs. Together, these findings for the first time demonstrate a role for NFATs in RTK and GPCR agonist-induced growth in VSMCs.

Suppression of Nuclear Translocation of Nuclear Factor‐κB and Nuclear Factor of Activated T Cells by Younggaechulgam‐Tang

2004 ◽  
Vol 26 (4) ◽  
pp. 545-558
Author(s):  
Hye‐Young Shin ◽  
Yung‐Sun Song ◽  
Chung‐Yeon Hwang ◽  
Tae‐Yong Shin ◽  
Hyung‐Min Kim
Keyword(s):  
T Cells ◽  
Nuclear Translocation ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Activated T Cells
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