Distributed structures underlie gating differences between the Kin channel KAT1 and the Kout channel SKOR

Riedelsberger, J., Sharma, T., Gonzalez, W., Gajdanowicz, P., Morales-Navarro, S. E., Garcia-Mata, C., Mueller-Roeber, B., Gonzalez-Nilo, F. D., Blatt, M. R. and Dreyer, I. (2010) Distributed structures underlie gating differences between the Kin channel KAT1 and the Kout channel SKOR. Molecular Plant, 3(1), pp. 236-245. (doi:10.1093/mp/ssp096)

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Publisher's URL: http://dx.doi.org/10.1093/mp/ssp096

Abstract

The family of voltage-gated (Shaker-like) potassium channels in plants includes both inward-rectifying (Kin) channels that allow plant cells to accumulate K+ and outward-rectifying (Kout) channels that mediate K+ efflux. Despite their close structural similarities, Kin and Kout channels differ in their gating sensitivity towards voltage and the extracellular K+ concentration. We have carried out a systematic program of domain swapping between the Kout channel SKOR and the Kin channel KAT1 to examine the impacts on gating of the pore regions, the S4, S5, and the S6 helices. We found that, in particular, the N-terminal part of the S5 played a critical role in KAT1 and SKOR gating. Our findings were supported by molecular dynamics of KAT1 and SKOR homology models. In silico analysis revealed that during channel opening and closing, displacement of certain residues, especially in the S5 and S6 segments, is more pronounced in KAT1 than in SKOR. From our analysis of the S4-S6 region, we conclude that gating (and K+-sensing in SKOR) depend on a number of structural elements that are dispersed over this similar to 145-residue sequence and that these place additional constraints on configurational rearrangement of the channels during gating

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Blatt, Professor Michael and Garcia-Mata, Dr Carlos
Authors: Riedelsberger, J., Sharma, T., Gonzalez, W., Gajdanowicz, P., Morales-Navarro, S. E., Garcia-Mata, C., Mueller-Roeber, B., Gonzalez-Nilo, F. D., Blatt, M. R., and Dreyer, I.
Subjects:Q Science > QH Natural history > QH301 Biology
College/School:College of Medical Veterinary and Life Sciences > Institute of Molecular Cell and Systems Biology
Journal Name:Molecular Plant
Publisher:Oxford University Press
ISSN:1674-2052
ISSN (Online):1752-9867
Published Online:10 December 2009

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
301211Structural Analysis of K+ Dependent Gating in the Yeast Model YKCL K+ ChannelMichael BlattBiotechnology and Biological Sciences Research Council (BBSRC)17/C13599Institute of Molecular Cell and Systems Biology
378211Signalling and functional analysis of KCO1 channel interactions in ArabidopsisMichael BlattBiotechnology and Biological Sciences Research Council (BBSRC)BB/C500595/1Institute of Molecular Cell and Systems Biology
403581Co-operative gating interactions in the yeast TOK1 K+ channelMichael BlattBiotechnology and Biological Sciences Research Council (BBSRC)BB/D001528/1Institute of Molecular Cell and Systems Biology