Evidence map›Paper›PMID 26200862›Full record

ArticleBiophysical journal2015

Subconductance gating and voltage sensitivity of sarcoplasmic reticulum K(+) channels: a modeling approach.

Antoni Matyjaszkiewicz, Elisa Venturi, Fiona O'Brien, Tsunaki Iida, Miyuki Nishi, Hiroshi Takeshima, Krasimira Tsaneva-Atanasova, Rebecca Sitsapesan

Open access · hybridAbstract read
In one paragraph

Article in Biophysical journal, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
0.8field-weighted citation impact, top 28% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed, 8 citations in OpenAlex.

  1. Article
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors at 4 institutions in 2 countries.

Antoni MatyjaszkiewiczBristol Centre for Complexity Sciences, University of Bristol, Bristol, United Kingdom; Department of Engineering Mathematics, University of Bristol, Bristol, United Kingdom. Electronic address: antoni.matyjaszkiewicz@bristol.ac.uk.
Elisa VenturiDepartment of Pharmacology, University of Oxford, Oxford, United Kingdom.
Fiona O'BrienDepartment of Pharmacology, University of Oxford, Oxford, United Kingdom.
Tsunaki IidaGraduate School of Pharmaceutical Sciences, Kyoto University, Yoshidahonmachi, Sakyo Ward, Kyoto, Japan.
Miyuki NishiGraduate School of Pharmaceutical Sciences, Kyoto University, Yoshidahonmachi, Sakyo Ward, Kyoto, Japan.
Hiroshi TakeshimaGraduate School of Pharmaceutical Sciences, Kyoto University, Yoshidahonmachi, Sakyo Ward, Kyoto, Japan.
Krasimira Tsaneva-AtanasovaCollege of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, United Kingdom.
Rebecca SitsapesanDepartment of Pharmacology, University of Oxford, Oxford, United Kingdom. Electronic address: rebecca.sitsapesan@pharm.ox.ac.uk.
Kyoto University · JPUniversity of Oxford · GBUniversity of Bristol · GBUniversity of Exeter · GB

Funding

British Heart Foundation FS/11/31/28790British Heart Foundation RG/10/14/28576
6 · The paper itself

Abstract

Sarcoplasmic reticulum (SR) K(+) channels are voltage-regulated channels that are thought to be actively gating when the membrane potential across the SR is close to zero as is expected physiologically. A characteristic of SR K(+) channels is that they gate to subconductance open states but the relevance of the subconductance events and their contribution to the overall current flowing through the channels at physiological membrane potentials is not known. We have investigated the relationship between subconductance and full conductance openings and developed kinetic models to describe the voltage sensitivity of channel gating. Because there may be two subtypes of SR K(+) channels (TRIC-A and TRIC-B) present in most tissues, to conduct our study on a homogeneous population of SR K(+) channels, we incorporated SR vesicles derived from Tric-a knockout mice into artificial membranes to examine the remaining SR K(+) channel (TRIC-B) function. The channels displayed very low open probability (Po) at negative potentials (≤0 mV) and opened predominantly to subconductance open states. Positive holding potentials primarily increased the frequency of subconductance state openings and thereby increased the number of subsequent transitions into the full open state, although a slowing of transitions back to the sublevels was also important. We investigated whether the subconductance gating could arise as an artifact of incomplete resolution of rapid transitions between full open and closed states; however, we were not able to produce a model that could fit the data as well as one that included multiple distinct current amplitudes. Our results suggest that the apparent subconductance openings will provide most of the K(+) flux when the SR membrane potential is close to zero. The relative contribution played by openings to the full open state would increase if negative charge developed within the SR thus increasing the capacity of the channel to compensate for ionic imbalances.

Indexed as

AnimalsComputer SimulationIon ChannelsKineticsLipid BilayersMembrane PotentialsMice, KnockoutModels, BiologicalMuscle, SkeletalPatch-Clamp TechniquesPhosphatidylethanolaminesSarcoplasmic ReticulumIon ChannelsLipid BilayersphosphatidylethanolaminePhosphatidylethanolaminesTRIC-A protein, mouseTRIC-B protein, mouse

Identifiers

PMID26200862
PMCPMC4623209
OpenAlexW2163052036

What OpenQuestion holds

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LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.