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.
KCNE2 modulates current amplitudes and activation kinetics of HCN4: influence of KCNE family members on HCN4 currents.
Decher N
,
Bundis F
,
Vajna R
,
Steinmeyer K
.
???displayArticle.abstract???
The HCN4 gene encodes a hyperpolarization-activated cation current contributing to the slow components of the pacemaking currents I(f) in the sinoatrial node and I(h) or I(q) in the thalamus. Heterologous expression studies of individual HCN channels have, however, failed to reproduce fully the diversity of native I(f/h/q) currents, suggesting the presence of modulating auxiliary subunits. Consistent with this is the recent description of KCNE2, which is highly expressed in the sinoatrial node, as a beta-subunit of rapidly activating HCN1 and HCN2 channels. To determine whether KCNE2 can also modulate the slow component of native I(f/h/q) currents, we co-expressed KCNE2 with HCN4 in Xenopus oocytes and in Chinese hamster ovary (CHO) cells and analysed the resulting currents using two-electrode voltage-clamp and patch-clamp techniques, respectively. In both cell types, co-expressed KCNE2 enhanced HCN4-generated current amplitudes, slowed the activation kinetics and shifted the voltage for half-maximal activation of currents to more negative voltages. In contrast, the related family members KCNE1, KCNE3 and KCNE4 did not change current characteristics of HCN4. Consistent with these electrophysiological results, the carboxy-terminal tail of KCNE2, but not of other KCNE subunits, interacted with the carboxy-terminal tail of HCN4 in yeast two-hybrid assays. KCNE2, by modulating I(f) or I(h) currents, might thus contribute to the electrophysiological diversity of known pacemaking currents in the heart and brain.
Abbott,
Do all voltage-gated potassium channels use MiRPs?
2001, Pubmed,
Xenbase
Abbott,
Do all voltage-gated potassium channels use MiRPs?
2001,
Pubmed
,
Xenbase
Abbott,
MiRP1 forms IKr potassium channels with HERG and is associated with cardiac arrhythmia.
1999,
Pubmed
,
Xenbase
Abbott,
MiRP2 forms potassium channels in skeletal muscle with Kv3.4 and is associated with periodic paralysis.
2001,
Pubmed
,
Xenbase
Barhanin,
K(V)LQT1 and lsK (minK) proteins associate to form the I(Ks) cardiac potassium current.
1996,
Pubmed
,
Xenbase
Cerbai,
The properties of the pacemaker current I(F)in human ventricular myocytes are modulated by cardiac disease.
2001,
Pubmed
Cui,
Analysis of the cyclic nucleotide binding domain of the HERG potassium channel and interactions with KCNE2.
2001,
Pubmed
Denyer,
Pacemaking in rabbit isolated sino-atrial node cells during Cs+ block of the hyperpolarization-activated current if.
1990,
Pubmed
DiFrancesco,
Properties of the current if in the sino-atrial node of the rabbit compared with those of the current iK, in Purkinje fibres.
1980,
Pubmed
Franco,
Divergent expression of delayed rectifier K(+) channel subunits during mouse heart development.
2001,
Pubmed
Ishii,
Molecular characterization of the hyperpolarization-activated cation channel in rabbit heart sinoatrial node.
1999,
Pubmed
Kuruma,
A hyperpolarization- and acid-activated nonselective cation current in Xenopus oocytes.
2000,
Pubmed
,
Xenbase
Lerche,
Molecular cloning and functional expression of KCNQ5, a potassium channel subunit that may contribute to neuronal M-current diversity.
2000,
Pubmed
,
Xenbase
Lorenz,
Heteromultimeric CLC chloride channels with novel properties.
1996,
Pubmed
,
Xenbase
Ludwig,
A family of hyperpolarization-activated mammalian cation channels.
1998,
Pubmed
Ludwig,
Two pacemaker channels from human heart with profoundly different activation kinetics.
1999,
Pubmed
Monteggia,
Cloning and localization of the hyperpolarization-activated cyclic nucleotide-gated channel family in rat brain.
2000,
Pubmed
Moosmang,
Cellular expression and functional characterization of four hyperpolarization-activated pacemaker channels in cardiac and neuronal tissues.
2001,
Pubmed
Proenza,
Pacemaker channels produce an instantaneous current.
2002,
Pubmed
Sanguinetti,
Coassembly of K(V)LQT1 and minK (IsK) proteins to form cardiac I(Ks) potassium channel.
1996,
Pubmed
,
Xenbase
Santoro,
Identification of a gene encoding a hyperpolarization-activated pacemaker channel of brain.
1998,
Pubmed
,
Xenbase
Santoro,
Molecular and functional heterogeneity of hyperpolarization-activated pacemaker channels in the mouse CNS.
2000,
Pubmed
,
Xenbase
Santoro,
Interactive cloning with the SH3 domain of N-src identifies a new brain specific ion channel protein, with homology to eag and cyclic nucleotide-gated channels.
1997,
Pubmed
Schroeder,
A constitutively open potassium channel formed by KCNQ1 and KCNE3.
2000,
Pubmed
,
Xenbase
Seebohm,
Dependence of I(Ks) biophysical properties on the expression system.
2001,
Pubmed
,
Xenbase
Seifert,
Molecular characterization of a slowly gating human hyperpolarization-activated channel predominantly expressed in thalamus, heart, and testis.
1999,
Pubmed
Shi,
Distribution and prevalence of hyperpolarization-activated cation channel (HCN) mRNA expression in cardiac tissues.
1999,
Pubmed
Tinel,
M-type KCNQ2-KCNQ3 potassium channels are modulated by the KCNE2 subunit.
2000,
Pubmed
Tinel,
KCNE2 confers background current characteristics to the cardiac KCNQ1 potassium channel.
2000,
Pubmed
,
Xenbase
Tzounopoulos,
Induction of endogenous channels by high levels of heterologous membrane proteins in Xenopus oocytes.
1995,
Pubmed
,
Xenbase
Ulens,
Functional heteromerization of HCN1 and HCN2 pacemaker channels.
2001,
Pubmed
,
Xenbase
Vaccari,
The human gene coding for HCN2, a pacemaker channel of the heart.
1999,
Pubmed
Villmann,
Kainate binding proteins possess functional ion channel domains.
1997,
Pubmed
,
Xenbase
Weerapura,
A comparison of currents carried by HERG, with and without coexpression of MiRP1, and the native rapid delayed rectifier current. Is MiRP1 the missing link?
2002,
Pubmed
,
Xenbase
Yanagihara,
Potassium current during the pacemaker depolarization in rabbit sinoatrial node cell.
1980,
Pubmed
Yasui,
I(f) current and spontaneous activity in mouse embryonic ventricular myocytes.
2001,
Pubmed
Yu,
MinK-related peptide 1: A beta subunit for the HCN ion channel subunit family enhances expression and speeds activation.
2001,
Pubmed
,
Xenbase
Zhang,
minK-related peptide 1 associates with Kv4.2 and modulates its gating function: potential role as beta subunit of cardiac transient outward channel?
2001,
Pubmed
,
Xenbase
van Ginneken,
Voltage clamp measurements of the hyperpolarization-activated inward current I(f) in single cells from rabbit sino-atrial node.
1991,
Pubmed
