The patch-clamp recording technique and RNApolymerase chain reaction were used to identify the voltage-dependent K channels expressed by murine fetal and adult CD4CD8 thymocytes. Two distinct currents, encoded by the genes Kv1.1 and Kv1.3 were identified based upon their biophysical and pharmacologic characteristics and confirmed with RNA-polymerase chain reaction. Peptide blockers of Kv1.1 and Kv1.3 gene products were also applied to a murine fetal thymic organ culture system to investigate the developmental role of these K channels. Dendrotoxin (DTX) and charybdotoxin (CTX), antagonists of Kv1.1 and Kv1.3 channels, respectively, decreased thymocyte yields in organ culture without affecting thymocyte viability. DTX-treated thymi contained 56 ± 8% (n = 8 experiments), and CTX-treated thymi contained 74 ± 4% (n = 7 experiments) as many thymocytes as untreated lobes. DTX and CTX also altered the developmental progression of thymocytes in fetal organ culture. These data provide the first evidence of Kv1.1 expression in a lymphoid cell and indicate that thymocyte voltage-dependent K channels are critical to thymocyte preclonal expansion and/or maturation.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				L. E. Pereira, F. Villinger, H. Wulff, A. Sankaranarayanan, G. Raman, and A. A. Ansari Pharmacokinetics, Toxicity, and Functional Studies of the Selective Kv1.3 Channel Blocker 5-(4-Phenoxybutoxy)Psoralen in Rhesus Macaques Experimental Biology and Medicine, November 1, 2007; 232(10): 1338 - 1354. [Abstract] [Full Text] [PDF]

				C. Beeton and K. G. Chandy Potassium Channels, Memory T Cells, and Multiple Sclerosis Neuroscientist, December 1, 2005; 11(6): 550 - 562. [Abstract] [PDF]

				R. Vicente, A. Escalada, M. Coma, G. Fuster, E. Sanchez-Tillo, C. Lopez-Iglesias, C. Soler, C. Solsona, A. Celada, and A. Felipe Differential Voltage-dependent K+ Channel Responses during Proliferation and Activation in Macrophages J. Biol. Chem., November 21, 2003; 278(47): 46307 - 46320. [Abstract] [Full Text] [PDF]

				P. A. Koni, R. Khanna, M. C. Chang, M. D. Tang, L. K. Kaczmarek, L. C. Schlichter, and R. A. Flavell Compensatory Anion Currents in Kv1.3 Channel-deficient Thymocytes J. Biol. Chem., October 10, 2003; 278(41): 39443 - 39451. [Abstract] [Full Text] [PDF]

				Q.-H. Liu, B. K. Fleischmann, B. Hondowicz, C. C. Maier, L. A. Turka, K. Yui, M. I. Kotlikoff, A. D. Wells, and B. D. Freedman Modulation of Kv Channel Expression and Function by TCR and Costimulatory Signals during Peripheral CD4+ Lymphocyte Differentiation J. Exp. Med., October 7, 2002; 196(7): 897 - 909. [Abstract] [Full Text] [PDF]

				X. Guo, J. N. Rao, L. Liu, M. Rizvi, D. J. Turner, and J.-Y. Wang Polyamines regulate beta -catenin tyrosine phosphorylation via Ca2+ during intestinal epithelial cell migration Am J Physiol Cell Physiol, September 1, 2002; 283(3): C722 - C734. [Abstract] [Full Text] [PDF]

				J. N. Rao, L. Li, V. A. Golovina, O. Platoshyn, E. D. Strauch, J. X.-J. Yuan, and J.-Y. Wang Ca2+-RhoA signaling pathway required for polyamine-dependent intestinal epithelial cell migration Am J Physiol Cell Physiol, April 1, 2001; 280(4): C993 - C1007. [Abstract] [Full Text] [PDF]

				J.-Y. Wang, J. Wang, V. A. Golovina, L. Li, O. Platoshyn, and J. X.-J. Yuan Role of K+ channel expression in polyamine-dependent intestinal epithelial cell migration Am J Physiol Cell Physiol, February 1, 2000; 278(2): C303 - C314. [Abstract] [Full Text] [PDF]

				L. Wang, B. Xu, R. E. White, and L. Lu Growth factor-mediated K+ channel activity associated with human myeloblastic ML-1 cell proliferation Am J Physiol Cell Physiol, November 1, 1997; 273(5): C1657 - C1665. [Abstract] [Full Text] [PDF]

				J. N. Rao, O. Platoshyn, L. Li, X. Guo, V. A. Golovina, J. X.-J. Yuan, and J.-Y. Wang Activation of K+ channels and increased migration of differentiated intestinal epithelial cells after wounding Am J Physiol Cell Physiol, April 1, 2002; 282(4): C885 - C898. [Abstract] [Full Text] [PDF]