Small vertical movement of a K+ channel voltage sensor measured with luminescence energy transfer

David J. Posson, Pinghua Ge, Christopher Miller, Francisco Bezanilla and Paul R. Selvin ()
Additional contact information
David J. Posson: University of Illinois at Urbana-Champaign
Pinghua Ge: University of Illinois at Urbana-Champaign
Christopher Miller: Brandeis University
Francisco Bezanilla: UCLA School of Medicine
Paul R. Selvin: University of Illinois at Urbana-Champaign

Nature, 2005, vol. 436, issue 7052, 848-851

Abstract: Abstract Voltage-gated ion channels open and close in response to voltage changes across electrically excitable cell membranes1. Voltage-gated potassium (Kv) channels are homotetramers with each subunit constructed from six transmembrane segments, S1–S6 (ref. 2). The voltage-sensing domain (segments S1–S4) contains charged arginine residues on S4 that move across the membrane electric field2,3, modulating channel open probability. Understanding the physical movements of this voltage sensor is of fundamental importance and is the subject of controversy. Recently, the crystal structure of the KvAP4 channel motivated an unconventional ‘paddle model’ of S4 charge movement, indicating that the segments S3b and S4 might move as a unit through the lipid bilayer with a large (15–20-Å) transmembrane displacement5. Here we show that the voltage-sensor segments do not undergo significant transmembrane translation. We tested the movement of these segments in functional Shaker K+ channels by using luminescence resonance energy transfer to measure distances between the voltage sensors and a pore-bound scorpion toxin. Our results are consistent with a 2-Å vertical displacement of S4, not the large excursion predicted by the paddle model. This small movement supports an alternative model in which the protein shapes the electric field profile, focusing it across a narrow region of S4 (ref. 6).

Date: 2005
References: Add references at CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
https://www.nature.com/articles/nature03819 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:436:y:2005:i:7052:d:10.1038_nature03819

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/nature03819

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().