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.
Comparison of cloned Kir2 channels with native inward rectifier K+ channels from guinea-pig cardiomyocytes.
Liu GX
,
Derst C
,
Schlichthörl G
,
Heinen S
,
Seebohm G
,
Brüggemann A
,
Kummer W
,
Veh RW
,
Daut J
,
Preisig-Müller R
.
???displayArticle.abstract???
The aim of the study was to compare the properties of cloned Kir2 channels with the properties of native rectifier channels in guinea-pig (gp) cardiac muscle. The cDNAs of gpKir2.1, gpKir2.2, gpKir2.3 and gpKir2.4 were obtained by screening a cDNA library from guinea-pig cardiac ventricle. A partial genomic structure of all gpKir2 genes was deduced by comparison of the cDNAs with the nucleotide sequences derived from a guinea-pig genomic library. The cell-specific expression of Kir2 channel subunits was studied in isolated cardiomyocytes using a multi-cell RT-PCR approach. It was found that gpKir2.1, gpKir2.2 and gpKir2.3, but not gpKir2.4, are expressed in cardiomyocytes. Immunocytochemical analysis with polyclonal antibodies showed that expression of Kir2.4 is restricted to neuronal cells in the heart. After transfection in human embryonic kidney cells (HEK293) the mean single-channel conductance with symmetrical K+ was found to be 30.6 pS for gpKir2.1, 40.0 pS for gpKir2.2 and 14.2 pS for Kir2.3. Cell-attached measurements in isolated guinea-pig cardiomyocytes (n = 351) revealed three populations of inwardly rectifying K+ channels with mean conductances of 34.0, 23.8 and 10.7 pS. Expression of the gpKir2 subunits in Xenopus oocytes showed inwardly rectifying currents. The Ba2+ concentrations required for half-maximum block at -100 mV were 3.24 M for gpKir2.1, 0.51 M for gpKir2.2, 10.26 M for gpKir2.3 and 235 M for gpKir2.4. Ba2+ block of inward rectifier channels of cardiomyocytes was studied in cell-attached recordings. The concentration and voltage dependence of Ba2+ block of the large-conductance inward rectifier channels was virtually identical to that of gpKir2.2 expressed in Xenopus oocytes. Our results suggest that the large-conductance inward rectifier channels found in guinea-pig cardiomyocytes (34.0 pS) correspond to gpKir2.2. The intermediate-conductance (23.8 pS) and low-conductance (10.7 pS) channels described here may correspond to gpKir2.1 and gpKir2.3, respectively.
Chomczynski,
Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction.
1987, Pubmed
Chomczynski,
Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction.
1987,
Pubmed
Doupnik,
The inward rectifier potassium channel family.
1995,
Pubmed
Fakler,
Strong voltage-dependent inward rectification of inward rectifier K+ channels is caused by intracellular spermine.
1995,
Pubmed
,
Xenbase
Ficker,
Spermine and spermidine as gating molecules for inward rectifier K+ channels.
1994,
Pubmed
,
Xenbase
Goldin,
Maintenance of Xenopus laevis and oocyte injection.
1992,
Pubmed
,
Xenbase
HALL,
Current-voltage relations of Purkinje fibres in sodium-deficient solutions.
1963,
Pubmed
HODGKIN,
The effect of sodium ions on the electrical activity of giant axon of the squid.
1949,
Pubmed
Ishihara,
Gating mechanism of the cloned inward rectifier potassium channel from mouse heart.
1994,
Pubmed
,
Xenbase
Ishihara,
A repolarization-induced transient increase in the outward current of the inward rectifier K+ channel in guinea-pig cardiac myocytes.
1998,
Pubmed
Ishii,
Cloning and functional expression of a cardiac inward rectifier K+ channel.
1994,
Pubmed
,
Xenbase
Josephson,
Inwardly rectifying single-channel and whole cell K+ currents in rat ventricular myocytes.
1986,
Pubmed
Krapivinsky,
A novel inward rectifier K+ channel with unique pore properties.
1998,
Pubmed
Kubo,
Primary structure and functional expression of a mouse inward rectifier potassium channel.
1993,
Pubmed
,
Xenbase
Kummer,
Catecholamines and catecholamine-synthesizing enzymes in guinea-pig sensory ganglia.
1990,
Pubmed
Lerche,
Molecular cloning and functional expression of KCNQ5, a potassium channel subunit that may contribute to neuronal M-current diversity.
2000,
Pubmed
,
Xenbase
Lopatin,
Potassium channel block by cytoplasmic polyamines as the mechanism of intrinsic rectification.
1994,
Pubmed
,
Xenbase
Makhina,
Cloning and expression of a novel human brain inward rectifier potassium channel.
1994,
Pubmed
,
Xenbase
Mederos y Schnitzler,
ATP-sensitive potassium channels in capillaries isolated from guinea-pig heart.
2000,
Pubmed
Methfessel,
Patch clamp measurements on Xenopus laevis oocytes: currents through endogenous channels and implanted acetylcholine receptor and sodium channels.
1986,
Pubmed
,
Xenbase
Morishige,
Molecular cloning and functional expression of a novel brain-specific inward rectifier potassium channel.
1994,
Pubmed
,
Xenbase
Nakamura,
Inhibition of rat ventricular IK1 with antisense oligonucleotides targeted to Kir2.1 mRNA.
1998,
Pubmed
,
Xenbase
Neher,
Correction for liquid junction potentials in patch clamp experiments.
1992,
Pubmed
Nehring,
Neuronal inwardly rectifying K(+) channels differentially couple to PDZ proteins of the PSD-95/SAP90 family.
2000,
Pubmed
Nichols,
Inward rectification and implications for cardiac excitability.
1996,
Pubmed
Nichols,
Inward rectifier potassium channels.
1997,
Pubmed
Omori,
Inwardly rectifying potassium channels expressed by gene transfection into the green Monkey kidney cell line COS-1.
1997,
Pubmed
Owen,
Effect of extracellular cations on the inward rectifying K+ channels Kir2.1 and Kir3.1/Kir3.4.
1999,
Pubmed
,
Xenbase
Preisig-Müller,
Separation of cardiomyocytes and coronary endothelial cells for cell-specific RT-PCR.
1999,
Pubmed
Périer,
Primary structure and characterization of a small-conductance inwardly rectifying potassium channel from human hippocampus.
1994,
Pubmed
,
Xenbase
Raab-Graham,
Molecular cloning and expression of a human heart inward rectifier potassium channel.
1994,
Pubmed
,
Xenbase
Rajan,
TASK-3, a novel tandem pore domain acid-sensitive K+ channel. An extracellular histiding as pH sensor.
2000,
Pubmed
,
Xenbase
Rakusan,
Regional capillary supply in the normal and hypertrophied rat heart.
1980,
Pubmed
Sakmann,
Conductance properties of single inwardly rectifying potassium channels in ventricular cells from guinea-pig heart.
1984,
Pubmed
Shieh,
Interaction of Ba2+ with the pores of the cloned inward rectifier K+ channels Kir2.1 expressed in Xenopus oocytes.
1998,
Pubmed
,
Xenbase
Shimoni,
Role of an inwardly rectifying potassium current in rabbit ventricular action potential.
1992,
Pubmed
Shioya,
Fast and slow blockades of the inward-rectifier K+ channel by external divalent cations in guinea-pig cardiac myocytes.
1993,
Pubmed
Takahashi,
Molecular cloning and functional expression of cDNA encoding a second class of inward rectifier potassium channels in the mouse brain.
1994,
Pubmed
,
Xenbase
Tang,
Cloning a novel human brain inward rectifier potassium channel and its functional expression in Xenopus oocytes.
1994,
Pubmed
,
Xenbase
Töpert,
Kir2.4: a novel K+ inward rectifier channel associated with motoneurons of cranial nerve nuclei.
1998,
Pubmed
,
Xenbase
Veh,
Immunohistochemical localization of five members of the Kv1 channel subunits: contrasting subcellular locations and neuron-specific co-localizations in rat brain.
1995,
Pubmed
Wang,
Differential distribution of inward rectifier potassium channel transcripts in human atrium versus ventricle.
1998,
Pubmed
Welling,
Primary structure and functional expression of a cortical collecting duct Kir channel.
1997,
Pubmed
,
Xenbase
Wible,
Cloning and functional expression of an inwardly rectifying K+ channel from human atrium.
1995,
Pubmed
,
Xenbase
Wood,
Cloning and functional expression of a human gene, hIRK1, encoding the heart inward rectifier K+-channel.
1995,
Pubmed
,
Xenbase
Woodhull,
Ionic blockage of sodium channels in nerve.
1973,
Pubmed
Zhu,
Effects of intra- and extracellular acidifications on single channel Kir2.3 currents.
1999,
Pubmed
,
Xenbase
