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Acta Physiologica 2006; Volume 186, Supplement 650
Joint Meeting of The German Society of Physiology and The Federation of European Physiological Societies 2006
3/26/2006-3/29/2006
Ludwig-Maximilians-University, Munich
INTERACTIONS OF N-TERMINAL AND C-TERMINAL PARTS OF THE SMALL CONDUCTANCE CA2+ ACTIVATED K+ CHANNEL, HSK3 CHANGE EBIO-SENSITIVITY.
Abstract number: PT06A-1
Frei1 E, Spindler1 I, Lehmann-Horn1 F, Grissmer1 S, Jager1 H
1Department of Applied Physiology, University of Ulm, Germany
Using the yeast two hybrid technique, we found an interaction between N- and C-terminal parts of the Ca2+-activated K+ channel, SK3 (Frei et al., 2003, Biophys J 84:236a). The C-terminal part of SK channels confers EBIO sensitivity (Pedarzani et al., 2001, J Biol Chem 276: 9762). Therefore N-C interactions of SK3 channels might influence EBIO sensitivity. To test this hypothesis we expressed SK31-299 together with endogenous SK3 channels in PC12 cells and measured SK3 currents with the whole cell mode of the patch clamp technique. If SK31-299 interacts with the C-terminal part of SK3 channels EBIO sensitivity might be changed. SK3 currents were elicited with 0.5mM free Ca 2+ in the pipette. In control experiments 0.2, 0.3 and 0.5mM EBIO activated 36, 56 and 82% of the SK3 channels which were activated by 1mM EBIO, respectively. In SK31-299 expressing cells 0.2, 0.3 and 0.5mM EBIO activated only 16, 28 and 50% of the channels which were activated by 1mM EBIO, respectively. These data clearly indicate that N-C interactions in SK3 channels modify EBIO sensitivity.
Further experiments will show if also Ca2+ sensitivity of SK3 channels is influenced by N-C interactions.
Supported by the Wilhelm Sander Stiftung (2004.046.1) and grants from the 4SC AG (Martinsried).
To cite this abstract, please use the following information:
Acta Physiologica 2006; Volume 186, Supplement 650 :PT06A-1