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) All Versions of this Article: 568/3/737    most recent jphysiol.2005.090142v1 Services Email this article to a friend Similar articles in this journal 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 Google Scholar Google Scholar Articles by Ottschytsch, N. Articles by Snyders, D. J Search for Related Content PubMed PubMed Citation Articles by Ottschytsch, N. Articles by Snyders, D. J

¹ Laboratory for Molecular Biophysics, Physiology and Pharmacology, Department of Biomedical Sciences, University of Antwerp, Belgium
² Laboratory of Cell Biology and Histology, Department of Biomedical Sciences, University of Antwerp, Belgium

The subunit Kv6.3 encodes a voltage-gated potassium channel belonging to the group of electrically silent Kv subunits, i.e. subunits that do not form functional homotetrameric channels. The lack of current, caused by retention in the endoplasmic reticulum (ER), was overcome by coexpression with Kv2.1. To investigate whether a specific section of Kv6.3 was responsible for ER retention, we constructed chimeric subunits between Kv6.3 and Kv2.1, and analysed their subcellular localization and functionality. The results demonstrate that the ER retention of Kv6.3 is not caused by the N-terminal A and B box (NAB) domain nor the intracellular N- or C-termini, but rather by the S1–S6 core protein. Introduction of individual transmembrane segments of Kv6.3 in Kv2.1 was tolerated, with the exception of S6. Indeed, introduction of the S6 domain of Kv6.3 in Kv2.1 was enough to cause ER retention, which was due to the C-terminal section of S6. The S4 segment of Kv6.3 could act as a voltage sensor in the Kv2.1 context, albeit with a major hyperpolarizing shift in the voltage dependence of activation and inactivation, apparently caused by the presence of a tyrosine in Kv6.3 instead of a conserved arginine. This study suggests that the silent behaviour of Kv6.3 is largely caused by the C-terminal part of its sixth transmembrane domain that causes ER retention of the subunit.

(Received 23 June 2005; accepted after revision 5 August 2005; first published online 11 August 2005)
Corresponding author D. J. Snyders: Laboratory for Molecular Biophysics, Physiology and Pharmacology, Department of Biomedical Sciences, University of Antwerp (CDE), Universiteitsplein 1, T4.21, 2610 Antwerp, Belgium. Email: dirk.snyders{at}ua.ac.be

This article has been cited by other articles:

				R. H. Pineda and A. B. Ribera Dorsal-Ventral Gradient for Neuronal Plasticity in the Embryonic Spinal Cord J. Neurosci., April 2, 2008; 28(14): 3824 - 3834. [Abstract] [Full Text] [PDF]