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.
Pflugers Arch
2007 May 01;4542:195-207. doi: 10.1007/s00424-006-0203-1.
Show Gene links
Show Anatomy links
Molecular and functional characterization of Kv4.2 and KChIP2 expressed in the porcine left ventricle.
Schultz JH
,
Volk T
,
Bassalaý P
,
Hennings JC
,
Hübner CA
,
Ehmke H
.
???displayArticle.abstract???
Recent studies showed that the Ca(2+)-independent transient outward current (I (to)) is very small or even not detectable in the porcine leftventricle. We investigated whether an altered molecular expression or function of voltage-dependent potassium channels belonging to the Kv4 sub-family and their ancillary Ca(2+)-binding beta sub-unit KChIP2, which contribute to the major fraction of I (to )in other species, may underlie this lack of a significant I (to) in the porcine leftventricle. RT-PCR analysis with degenerate primers showed that both Kv4 mRNA and KChIP2 mRNA are expressed in porcine left ventricular tissue and in isolated ventricular myocytes. PCR cloning and sequence analysis predicted proteins with >98% identity to rat and human Kv4.2 and >99% identity to rat and human KChIP2. Heterologous expression of porcine Kv4.2 in Xenopus laevis oocytes gave rise to currents with characteristic properties of rat and human Kv4.2, and co-expression with its KChIP2 sub-unit increased current density (tenfold), slowed inactivation (twofold) and accelerated recovery from inactivation (tenfold). Kv4.2 immunohistochemistry in porcine left ventricular tissue revealed a predominant membrane-bound signal. Relative quantification of gene expression indicated that Kv4.2 and KChIP2 mRNA and protein are expressed at comparable ratios in porcine and rat left ventricular tissues, which displays a large I (to). Collectively, these data demonstrate that the lack of a significant I (to) in the porcine leftventricle does not result from dysfunctional or insufficiently expressed Kv4.2 and KChIP2 sub-units.
An,
Modulation of A-type potassium channels by a family of calcium sensors.
2000, Pubmed,
Xenbase
An,
Modulation of A-type potassium channels by a family of calcium sensors.
2000,
Pubmed
,
Xenbase
Apkon,
Characterization of two distinct depolarization-activated K+ currents in isolated adult rat ventricular myocytes.
1991,
Pubmed
Bailly,
Regional alteration of the transient outward current in human left ventricular septum during compensated hypertrophy.
1997,
Pubmed
Barry,
Differential expression of voltage-gated K+ channel subunits in adult rat heart. Relation to functional K+ channels?
1995,
Pubmed
Birnbaum,
Structure and function of Kv4-family transient potassium channels.
2004,
Pubmed
Bähring,
Conserved Kv4 N-terminal domain critical for effects of Kv channel-interacting protein 2.2 on channel expression and gating.
2001,
Pubmed
Chomczynski,
Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction.
1987,
Pubmed
Clark,
Heterogeneity of action potential waveforms and potassium currents in rat ventricle.
1993,
Pubmed
Greenstein,
Role of the calcium-independent transient outward current I(to1) in shaping action potential morphology and duration.
2000,
Pubmed
Gómez,
Modulation of electrical heterogeneity by compensated hypertrophy in rat left ventricle.
1997,
Pubmed
Hamill,
Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches.
1981,
Pubmed
Hess,
Calcium channel types in cardiac myocytes: modulation by dihydropyridines and beta-adrenergic stimulation.
1986,
Pubmed
Inoue,
Masking of A-type K+ channel in guinea pig cardiac cells by extracellular Ca2+.
1993,
Pubmed
Isbrandt,
Gene structures and expression profiles of three human KCND (Kv4) potassium channels mediating A-type currents I(TO) and I(SA).
2000,
Pubmed
Lacroix,
Repolarization abnormalities and their arrhythmogenic consequences in porcine tachycardia-induced cardiomyopathy.
2002,
Pubmed
Li,
Calcium-activated transient outward chloride current and phase 1 repolarization of swine ventricular action potential.
2003,
Pubmed
Litovsky,
Transient outward current prominent in canine ventricular epicardium but not endocardium.
1988,
Pubmed
Liu,
Ionic bases for electrophysiological distinctions among epicardial, midmyocardial, and endocardial myocytes from the free wall of the canine left ventricle.
1993,
Pubmed
Livak,
Analysis of relative gene expression data using real-time quantitative PCR and the 2(-Delta Delta C(T)) Method.
2001,
Pubmed
Macianskiene,
Channels involved in transient currents unmasked by removal of extracellular calcium in cardiac cells.
2002,
Pubmed
Matsuda,
Sodium conductance in calcium channels of guinea-pig ventricular cells induced by removal of external calcium ions.
1986,
Pubmed
Mukherjee,
Changes in L-type calcium channel abundance and function during the transition to pacing-induced congestive heart failure.
1998,
Pubmed
Nerbonne,
Genetic manipulation of cardiac K(+) channel function in mice: what have we learned, and where do we go from here?
2001,
Pubmed
Näbauer,
Regional differences in current density and rate-dependent properties of the transient outward current in subepicardial and subendocardial myocytes of human left ventricle.
1996,
Pubmed
Patel,
Heterogeneous expression of KChIP2 isoforms in the ferret heart.
2002,
Pubmed
,
Xenbase
Patel,
Elucidating KChIP effects on Kv4.3 inactivation and recovery kinetics with a minimal KChIP2 isoform.
2002,
Pubmed
,
Xenbase
Roberds,
Cloning and tissue-specific expression of five voltage-gated potassium channel cDNAs expressed in rat heart.
1991,
Pubmed
Rosati,
Concordant expression of KChIP2 mRNA, protein and transient outward current throughout the canine ventricle.
2003,
Pubmed
Rosati,
Regulation of KChIP2 potassium channel beta subunit gene expression underlies the gradient of transient outward current in canine and human ventricle.
2001,
Pubmed
,
Xenbase
Schram,
Differential distribution of cardiac ion channel expression as a basis for regional specialization in electrical function.
2002,
Pubmed
Schultz,
Heterogeneity of Kv2.1 mRNA expression and delayed rectifier current in single isolated myocytes from rat left ventricle.
2001,
Pubmed
Sheng,
Subcellular segregation of two A-type K+ channel proteins in rat central neurons.
1992,
Pubmed
,
Xenbase
Shibata,
A fundamental role for KChIPs in determining the molecular properties and trafficking of Kv4.2 potassium channels.
2003,
Pubmed
Volk,
Relationship between transient outward K+ current and Ca2+ influx in rat cardiac myocytes of endo- and epicardial origin.
1999,
Pubmed
Wettwer,
Transient outward current in human and rat ventricular myocytes.
1993,
Pubmed
Wettwer,
Transient outward current in human ventricular myocytes of subepicardial and subendocardial origin.
1994,
Pubmed
Xu,
Four kinetically distinct depolarization-activated K+ currents in adult mouse ventricular myocytes.
1999,
Pubmed
