Back to Search
Start Over
Coupling of Voltage Sensing to Channel Opening Reflects Intrasubunit Interactions in Kv Channels
- Source :
- The journal of general physiology, The Journal of General Physiology
- Publication Year :
- 2004
- Publisher :
- Rockefeller University Press, 2004.
-
Abstract
- Voltage-gated K+ channels play a central role in the modulation of excitability. In these channels, the voltage-dependent movement of the voltage sensor (primarily S4) is coupled to the (S6) gate that opens the permeation pathway. Because of the tetrameric structure, such coupling could occur within each subunit or between adjacent subunits. To discriminate between these possibilities, we analyzed various combinations of a S4 mutation (R401N) and a S6 mutation (P511G) in hKv1.5, incorporated into tandem constructs to constrain subunit stoichiometry. R401N shifted the voltage dependence of activation to negative potentials while P511G did the opposite. When both mutations were introduced in the same α-subunit of the tandem, the positive shift of P511G was compensated by the negative shift of R401N. With each mutation in a separate subunit of a tandem, this compensation did not occur. This suggests that for Kv channels, the coupling between voltage sensing and gating reflects primarily an intrasubunit interaction.
- Subjects :
- Physiology
Protein subunit
Analytical chemistry
hKv1.5
Plasma protein binding
Gating
Article
S6 gate
Membrane Potentials
dimers
Kv1.5 Potassium Channel
Structure-Activity Relationship
03 medical and health sciences
0302 clinical medicine
Humans
030304 developmental biology
Membrane potential
S4 segment
0303 health sciences
Binding Sites
Tandem
Chemistry
Recombinant Proteins
Coupling (electronics)
Protein Subunits
Amino Acid Substitution
Potassium Channels, Voltage-Gated
Modulation
gating
Mutation (genetic algorithm)
Mutagenesis, Site-Directed
Biophysics
Human medicine
Ion Channel Gating
030217 neurology & neurosurgery
Protein Binding
Subjects
Details
- ISSN :
- 15407748 and 00221295
- Volume :
- 125
- Database :
- OpenAIRE
- Journal :
- Journal of General Physiology
- Accession number :
- edsair.doi.dedup.....2d99e9139e7c2e216704e09d35ea6ac1
- Full Text :
- https://doi.org/10.1085/jgp.200409194