Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
???displayArticle.abstract???
A cloned human voltage-sensitive K+ channel HLK3 which is present in T-lymphocytes and in the brain was expressed in Xenopus oocytes and after permanent transfection of a human B-lymphocyte cell line (IM9). Injections of low cRNA concentrations into Xenopus oocytes led to the expression of a transient K+ current, with saturating current-voltage (I-V) relationship, which was abolished by repetitive stimulations due to a slow recovery from inactivation. This transient K+ channel current was fully inhibited by 10 nM charybdotoxin. Injection of high concentrations of the same RNA led to a non-inactivating K+ current, with linear I-V curve, which did not undergo use-dependent inactivation and was hardly sensitive to 10 nM charybdotoxin. Intermediate behaviour due to changing proportions of these two types of K+ channel expression were observed at intermediate RNA concentrations. Transient and non-inactivating K+ currents were also observed by both whole-cell and single channel patch-clamp recording from HLK3 transfected IM9 cells. The main conductance of the channel in the two different modes (inactivating and charybdotoxin-sensitive or non-inactivating and charybdotoxin-resistant) is the same (12-14 pS). Destruction of the cytoskeletal elements with cytochalasin D, colchicine or botulinum C2 toxin in oocyte experiments prevented expression of the sustained mode of the K+ channel. The results suggest that the sustained mode obtained at high RNA concentrations corresponds to channel clustering involving cytoskeletal elements. This differential functional expression of K+ channels associated with different levels of mRNA appears as a new important factor to explain the biophysical and pharmacological diversity of voltage-sensitive K+ channels.
Attali,
Cloning, functional expression, and regulation of two K+ channels in human T lymphocytes.
1992, Pubmed,
Xenbase
Attali,
Cloning, functional expression, and regulation of two K+ channels in human T lymphocytes.
1992,
Pubmed
,
Xenbase Betz,
Homology and analogy in transmembrane channel design: lessons from synaptic membrane proteins.
1990,
Pubmed Chandy,
Simplified gene nomenclature.
1991,
Pubmed Cooper,
Effects of cytochalasin and phalloidin on actin.
1987,
Pubmed Douglass,
Characterization and functional expression of a rat genomic DNA clone encoding a lymphocyte potassium channel.
1990,
Pubmed
,
Xenbase Folander,
Cloning and expression of the delayed-rectifier IsK channel from neonatal rat heart and diethylstilbestrol-primed rat uterus.
1990,
Pubmed
,
Xenbase Froehner,
The submembrane machinery for nicotinic acetylcholine receptor clustering.
1991,
Pubmed Froehner,
The postsynaptic 43K protein clusters muscle nicotinic acetylcholine receptors in Xenopus oocytes.
1990,
Pubmed
,
Xenbase Grimminger,
Suppression of cytoskeletal rearrangement in activated human neutrophils by botulinum C2 toxin. Impact on cellular signal transduction.
1991,
Pubmed Grissmer,
Expression and chromosomal localization of a lymphocyte K+ channel gene.
1990,
Pubmed
,
Xenbase Hamill,
Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches.
1981,
Pubmed Honoré,
Cloning, expression, pharmacology and regulation of a delayed rectifier K+ channel in mouse heart.
1991,
Pubmed
,
Xenbase Hymel,
Purified skeletal muscle 1,4-dihydropyridine receptor forms phosphorylation-dependent oligomeric calcium channels in planar bilayers.
1988,
Pubmed Isacoff,
Evidence for the formation of heteromultimeric potassium channels in Xenopus oocytes.
1990,
Pubmed
,
Xenbase Jan,
How might the diversity of potassium channels be generated?
1990,
Pubmed
,
Xenbase Jasmin,
Compartmentalization of cold-stable and acetylated microtubules in the subsynaptic domain of chick skeletal muscle fibre.
1990,
Pubmed Kirsch,
The 93-kDa glycine receptor-associated protein binds to tubulin.
1991,
Pubmed Kordeli,
An isoform of ankyrin is localized at nodes of Ranvier in myelinated axons of central and peripheral nerves.
1990,
Pubmed MacKinnon,
Using mutagenesis to study potassium channel mechanisms.
1991,
Pubmed Miller,
Voltage-sensitive Ca2+ channels.
1992,
Pubmed Moczydlowski,
An emerging pharmacology of peptide toxins targeted against potassium channels.
1988,
Pubmed Peter,
The polarized distribution of poly(A+)-mRNA-induced functional ion channels in the Xenopus oocyte plasma membrane is prevented by anticytoskeletal drugs.
1991,
Pubmed
,
Xenbase Philipson,
A small K+ channel looms large.
1992,
Pubmed Rehm,
Molecular aspects of neuronal voltage-dependent K+ channels.
1991,
Pubmed Rehm,
Purification and subunit structure of a putative K+-channel protein identified by its binding properties for dendrotoxin I.
1988,
Pubmed Rudy,
Diversity and ubiquity of K channels.
1988,
Pubmed Schindler,
Different channel properties of Torpedo acetylcholine receptor monomers and dimers reconstituted in planar membranes.
1984,
Pubmed Srinivasan,
Ankyrin and spectrin associate with voltage-dependent sodium channels in brain.
1988,
Pubmed Stühmer,
Molecular basis of functional diversity of voltage-gated potassium channels in mammalian brain.
1989,
Pubmed
,
Xenbase Stühmer,
Structure-function studies of voltage-gated ion channels.
1991,
Pubmed Sugimoto,
Immunohistochemical study of a rat membrane protein which induces a selective potassium permeation: its localization in the apical membrane portion of epithelial cells.
1990,
Pubmed
,
Xenbase Takumi,
Cloning of a membrane protein that induces a slow voltage-gated potassium current.
1988,
Pubmed
,
Xenbase Wei,
K+ current diversity is produced by an extended gene family conserved in Drosophila and mouse.
1990,
Pubmed
,
Xenbase
