Molecular mechanisms for Kv1.3 potassium channel current inhibition by CD3/CD28 stimulation in Jurkat T cells

Matsushita, Yuichiro; Ohya, Susumu; Itoda, Haruna; Kimura, T.; Yamamura, Hisao; Imaizumi, Yuji

doi:10.1016/j.bbrc.2008.06.118

Cited by 3 publications

(4 citation statements)

References 26 publications

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“…Thus, Kv1.3 channels may be part of a signaling complex at the IS consisting of TCR/CD3, protein kinases, and integrin β1 [ 11 , 17 ]. Redistribution of Kv1.3 into the IS affects its function: its inactivation kinetics is accelerated probably due to modulation of its phosphorylation state, whereas its activation kinetics is slowed down likely because of partitioning into specific membrane domains [ 18 , 19 ].…”

Section: Introductionmentioning

confidence: 99%

Role of C-Terminal Domain and Membrane Potential in the Mobility of Kv1.3 Channels in Immune Synapse Forming T Cells

Sebestyén

Nagy

Mocsár

et al. 2022

IJMS

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Voltage-gated Kv1.3 potassium channels are essential for maintaining negative membrane potential during T-cell activation. They interact with membrane-associated guanylate kinases (MAGUK-s) via their C-terminus and with TCR/CD3, leading to enrichment at the immunological synapse (IS). Molecular interactions and mobility may impact each other and the function of these proteins. We aimed to identify molecular determinants of Kv1.3 mobility, applying fluorescence correlation spectroscopy on human Jurkat T-cells expressing WT, C-terminally truncated (ΔC), and non-conducting mutants of mGFP-Kv1.3. ΔC cannot interact with MAGUK-s and is not enriched at the IS, whereas cells expressing the non-conducting mutant are depolarized. Here, we found that in standalone cells, mobility of ΔC increased relative to the WT, likely due to abrogation of interactions, whereas mobility of the non-conducting mutant decreased, similar to our previous observations on other membrane proteins in depolarized cells. At the IS formed with Raji B-cells, mobility of WT and non-conducting channels, unlike ΔC, was lower than outside the IS. The Kv1.3 variants possessing an intact C-terminus had lower mobility in standalone cells than in IS-engaged cells. This may be related to the observed segregation of F-actin into a ring-like structure at the periphery of the IS, leaving much of the cell almost void of F-actin. Upon depolarizing treatment, mobility of WT and ΔC channels decreased both in standalone and IS-engaged cells, contrary to non-conducting channels, which themselves caused depolarization. Our results support that Kv1.3 is enriched at the IS via its C-terminal region regardless of conductivity, and that depolarization decreases channel mobility.

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Section: Introductionmentioning

confidence: 99%

Role of C-Terminal Domain and Membrane Potential in the Mobility of Kv1.3 Channels in Immune Synapse Forming T Cells

Sebestyén

Nagy

Mocsár

et al. 2022

IJMS

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“…1A). The application of 10 nM margatoxin, a selective blocker of Kv1.3 channel (15), reduced the outward current by over 80%, confirming that Kv1.3 current was the predominant component of the outward current (25). In this study, margatoxin was added at the end of each experiment to evaluate Kv1.3 current.…”

Section: Effects Of Pip 2 and Pip 3 On Kv13 Current In Jurkat Cellsmentioning

confidence: 76%

“…Membrane currents were measured in Jurkat cells using standard whole cell voltage clamping (14,25), using an amplifier (CEZ-2300, Nihon Kohden, Tokyo, Japan). The pipette resistance ranged from 2 to 4 M⍀ when filled with the pipette solution.…”

Section: Methodsmentioning

confidence: 99%

Inhibition of Kv1.3 potassium current by phosphoinositides and stromal-derived factor-1α in Jurkat T cells

Matsushita¹,

Ohya²,

Itoda³

et al. 2009

American Journal of Physiology-Cell Physiology

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The activation of Kv1.3 potassium channel has obligatory roles in immune responses of T lymphocytes. Stromal cell-derived factor-1alpha (SDF-1alpha) binds to C-X-C chemokine receptor type 4, activates phosphoinositide 3-kinase, and plays essential roles in cell migration of T lymphocytes. In this study, the effects of phosphoinositides and SDF-1alpha on Kv1.3 current activity were examined in the Jurkat T cell line using whole cell patch-clamp techniques. The internal application of 10 microM phosphatidylinositol 4,5-bisphosphate (PIP(2)) or 10 microM phosphatidylinositol-3,4,5-trisphosphate (PIP(3)) significantly reduced Kv1.3 current, but that of 10 microM phosphatidylinositol-4-monophosphate (PIP) did not. The coapplication of 10 microg/ml anti-PIP(3) antibody with PIP(2) from the pipette did not change the reduction of Kv1.3 current by PIP(2), but the coapplication of the antibody with PIP(3) eliminated the reduction. The heat-inactivated anti-PIP(3) antibody had no effect on PIP(3)-induced inhibition. These results suggest that PIP(2) per se can reduce Kv1.3 current as well as PIP(3). External application of 1 muM Akt-kinase inhibitor VIII did not reverse the effect of intracellular PIP(3). External application of 10 and 30 ng/ml SDF-1alpha significantly reduced Kv1.3 current. Internal application of anti-PIP(3) antibody reversed the SDF-1alpha-induced reduction. These results suggest that, in Jurkat T cells, PIP(2), PIP(3), and SDF-1alpha reduce Kv1.3 channel activity and that the reduction by SDF-1alpha may be mediated by the enhancement of PIP(3) production. These novel inhibitory effects of phosphoinositides and SDF-1alpha on Kv1.3 current may have a significant function as a downregulation mechanism of Kv1.3 activity for the maintenance of T lymphocyte activation in immune responses.

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“…Kv1.3 is a voltage‐gated channel that is functionally coupled to the activation of inflammation‐related cells when plasma membrane depolarizes (Chandy et al ., ). It is activated by membrane depolarization over −60 mV, and their open probability steeply increases with more positive membrane potentials (Matsushita et al ., ). Our results indicate that curcumin (5–100 μM) significantly inhibited hKv1.3 currents at each positive potential from 0 to +60 mV.…”

Section: Discussionmentioning

confidence: 97%

Curcumin Serves as a Human Kv1.3 Blocker to Inhibit Effector Memory T Lymphocyte Activities

Lian

Yang

Wang

et al. 2012

Phytotherapy Research

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Curcumin, the principal active component of turmeric, has long been used to treat various diseases in India and China. Recent studies show that curcumin can serve as a therapeutic agent for autoimmune diseases via a variety of mechanisms. Effector memory T cells (T(EM), CCR7⁻ CD45RO⁺ T lymphocyte) have been demonstrated to play a crucial role in the pathogenesis of T cell-mediated autoimmune diseases, such as multiple sclerosis (MS) or rheumatoid arthritis (RA). Kv1.3 channels are predominantly expressed in T(EM) cells and control T(EM) activities. In the present study, we examined the effect of curcumin on human Kv1.3 (hKv1.3) channels stably expressed in HEK-293 cells and its ability to inhibit proliferation and cytokine secretion of T(EM) cells isolated from patients with MS or RA. Curcumin exhibited a direct blockage of hKv1.3 channels in a time-dependent and concentration-dependent manner. Moreover, the activation curve was shifted to a more positive potential, which was consistent with an open-channel blockade. Paralleling hKv1.3 inhibition, curcumin significantly inhibited proliferation and interferon-γ secretion of T(EM) cells. Our findings demonstrate that curcumin is able to inhibit proliferation and proinflammatory cytokine secretion of T(EM) cells probably through inhibition of hKv1.3 channels, which contributes to the potency of curcumin for the treatment of autoimmune diseases. This is probably one of pharmacological mechanisms of curcumin used to treat autoimmune diseases.

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Molecular mechanisms for Kv1.3 potassium channel current inhibition by CD3/CD28 stimulation in Jurkat T cells

Cited by 3 publications

References 26 publications

Role of C-Terminal Domain and Membrane Potential in the Mobility of Kv1.3 Channels in Immune Synapse Forming T Cells

Role of C-Terminal Domain and Membrane Potential in the Mobility of Kv1.3 Channels in Immune Synapse Forming T Cells

Inhibition of Kv1.3 potassium current by phosphoinositides and stromal-derived factor-1α in Jurkat T cells

Curcumin Serves as a Human Kv1.3 Blocker to Inhibit Effector Memory T Lymphocyte Activities

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