HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Supplemental Movie All Versions of this Article: 292/4/C1431    most recent 00376.2006v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (9) Citing Articles via Google Scholar Google Scholar Articles by Nicolaou, S. A. Articles by Conforti, L. Search for Related Content PubMed PubMed Citation Articles by Nicolaou, S. A. Articles by Conforti, L.

MEMBRANE TRANSPORTERS, ION CHANNELS, AND PUMPS

The Ca²⁺-activated K⁺ channel KCa3.1 compartmentalizes in the immunological synapse of human T lymphocytes

¹Department of Internal Medicine and ³Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, Ohio; and ²Department of Cell Biology and Physiology, University of Pittsburgh, Pittsburgh, Pennsylvania

Submitted 10 July 2006 ; accepted in final form 29 November 2006

T cell receptor engagement results in the reorganization of intracellular and membrane proteins at the T cell-antigen presenting cell interface forming the immunological synapse (IS), an event required for Ca²⁺ influx. KCa3.1 channels modulate Ca²⁺ signaling in activated T cells by regulating the membrane potential. Nothing is known regarding KCa3.1 membrane distribution during T cell activation. Herein, we determined whether KCa3.1 translocates to the IS in human T cells using YFP-tagged KCa3.1 channels. These channels showed electrophysiological and pharmacological properties identical to wild-type channels. IS formation was induced by either anti-CD3/CD28 antibody-coated beads for fixed microscopy experiments or Epstein-Barr virus-infected B cells for fixed and live cell microscopy. In fixed microscopy experiments, T cells were also immunolabeled for F-actin or CD3, which served as IS formation markers. The distribution of KCa3.1 was determined with confocal and fluorescence microscopy. We found that, upon T cell activation, KCa3.1 channels localize with F-actin and CD3 to the IS but remain evenly distributed on the cell membrane when no stimulus is provided. Detailed imaging experiments indicated that KCa3.1 channels are recruited in the IS shortly after antigen presentation and are maintained there for at least 15–30 min. Interestingly, pretreatment of activated T cells with the specific KCa3.1 blocker TRAM-34 blocked Ca²⁺ influx, but channel redistribution to the IS was not prevented. These results indicate that KCa3.1 channels are a part of the signaling complex that forms at the IS upon antigen presentation.

T cell activation; ion channels; membrane distribution

This article has been cited by other articles:

				S. Srivastava, L. Di, O. Zhdanova, Z. Li, S. Vardhana, Q. Wan, Y. Yan, R. Varma, J. Backer, H. Wulff, et al. The Class II Phosphatidylinositol 3 kinase C2{beta} Is Required for the Activation of the K+ Channel KCa3.1 and CD4 T-Cells Mol. Biol. Cell, September 1, 2009; 20(17): 3783 - 3791. [Abstract] [Full Text] [PDF]

				M. I. Lioudyno, J. A. Kozak, A. Penna, O. Safrina, S. L. Zhang, D. Sen, J. Roos, K. A. Stauderman, and M. D. Cahalan Orai1 and STIM1 move to the immunological synapse and are up-regulated during T cell activation PNAS, February 12, 2008; 105(6): 2011 - 2016. [Abstract] [Full Text] [PDF]