Evidence map›Paper›PMID 9591643›Full record

ArticleBiophysical journal1998

A novel crystallization method for visualizing the membrane localization of potassium channels.

A N Lopatin, E N Makhina, C G Nichols

Open access · bronzeAbstract read
In one paragraph

Article in Biophysical journal, 1998. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
0.1field-weighted citation impact, top 55% 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

1 citing paper in PubMed, 12 citations in OpenAlex.

  1. Article
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

3 authors at 1 institution in 1 country.

A N LopatinDepartment of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA. anatoli@cellbio.wustl.edu
E N Makhina
C G Nichols
Washington University in St. Louis · US

Funding

Rectification &Block of Ion Channel CurrentsR01HL054171 · NHLBI · WASHINGTON UNIVERSITY · PI NICHOLS, COLIN G · 1995 to 2017
$4.5M
NHLBI NIH HHS HL54171
6 · The paper itself

Abstract

The high permeability of K+ channels to monovalent thallium (Tl+) ions and the low solubility of thallium bromide salt were used to develop a simple yet very sensitive approach to the study of membrane localization of potassium channels. K+ channels (Kir1.1, Kir2.1, Kir2.3, Kv2.1), were expressed in Xenopus oocytes and loaded with Br ions by microinjection. Oocytes were then exposed to extracellular thallium. Under conditions favoring influx of Tl+ ions (negative membrane potential under voltage clamp, or high concentration of extracellular Tl+), crystals of TlBr, visible under low-power microscopy, formed under the membrane in places of high density of K+ channels. Crystals were not formed in uninjected oocytes, but were formed in oocytes expressing as little as 5 microS K+ conductance. The number of observed crystals was much lower than the estimated number of functional channels. Based on the pattern of crystal formation, K+ channels appear to be expressed mostly around the point of cRNA injection when injected either into the animal or vegetal hemisphere. In addition to this pseudopolarized distribution of K+ channels due to localized microinjection of cRNA, a naturally polarized (animal/vegetal side) distribution of K+ channels was also frequently observed when K+ channel cRNA was injected at the equator. A second novel "agarose-hemiclamp" technique was developed to permit direct measurements of K+ currents from different hemispheres of oocytes under two-microelectrode voltage clamp. This technique, together with direct patch-clamping of patches of membrane in regions of high crystal density, confirmed that the localization of TlBr crystals corresponded to the localization of functional K+ channels and suggested a clustered organization of functional channels. With appropriate permeant ion/counterion pairs, this approach may be applicable to the visualization of the membrane distribution of any functional ion channel.

Indexed as

Potassium Channels, Inwardly RectifyingPotassium Channels, Voltage-GatedAnimalsBiophysicsBromidesCell MembraneCrystallizationDelayed Rectifier Potassium ChannelsFemaleModels, TheoreticalOocytesPatch-Clamp TechniquesPotassium ChannelsPotassium CompoundsSensitivity and SpecificityShab Potassium ChannelsBromidesDelayed Rectifier Potassium ChannelsKCNJ4 protein, humanpotassium bromidePotassium ChannelsPotassium Channels, Inwardly RectifyingPotassium Channels, Voltage-GatedPotassium CompoundsShab Potassium Channels

Identifiers

PMID9591643
PMCPMC1299559
OpenAlexW2054912972

What OpenQuestion holds

Textmetadata
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.