| 1995 |
Kv1.5 protein localizes to intercalated disk regions in human atrial and ventricular myocytes, as determined by co-localization with connexin and N-cadherin antibodies; NH2-terminal antibodies additionally stained vascular smooth muscle, suggesting differential epitope accessibility between cardiac and vascular myocytes. |
Immunofluorescence with two distinct anti-channel antibodies, co-localization with connexin and N-cadherin markers |
The Journal of clinical investigation |
Medium |
7615797
|
| 1996 |
The Kvβ2.1 subunit co-assembles with hKv1.5 alpha subunit, shifting the midpoints for activation (~14 mV negative) and inactivation (~12 mV negative) and increasing the extent of slow inactivation, thereby altering Kv1.5 gating kinetics. |
Molecular cloning, immunopurification, Western blot, whole-cell patch-clamp in HEK293 and L-cells |
The Journal of biological chemistry |
High |
8576199
|
| 1997 |
Kv1.5 protein expression is reduced by >50% in both left and right atrial appendages of patients with chronic atrial fibrillation, in parallel with a reduction in sustained (IKsus/IKur) outward K+ current density, consistent with Kv1.5 underlying IKur. |
Quantitative Western blot, nystatin-perforated patch-clamp recordings of atrial myocytes |
Circulation research |
Medium |
9168779
|
| 1998 |
Co-expression of human Kvβ3.1 with Kv1.5 in Chinese hamster ovary cells produces a novel fast-inactivating (A-type) outward current, demonstrating that Kvβ3.1 confers rapid inactivation on Kv1.5. |
Heterologous co-expression in CHO cells, whole-cell patch-clamp |
The Journal of biological chemistry |
Medium |
9857044
|
| 1999 |
PKA phosphorylation of serine-24 on the Kvβ1.3 NH2-terminus reduces Kvβ1.3-induced fast inactivation of Kv1.5; substitution of serine-24 with a negatively charged residue mimics phosphorylation (reduces inactivation) while a positively charged residue enhances inactivation. |
Site-directed mutagenesis of Kvβ1.3 serine-24, patch-clamp in Xenopus oocytes and HEK293 cells, PKA activation/inhibition |
The Journal of biological chemistry |
High |
10318802
|
| 1999 |
Slow inactivation of hKv1.5 is regulated by intracellular ion occupancy: intracellular K+ (or Cs+) concentration modulates inactivation with low affinity (Kd ~34–43 mM), and this is more potent than extracellular ion effects; the inactivation mechanism is not classical C-type but is closely coupled to ion permeation through the pore. |
Whole-cell patch-clamp with varied intra- and extracellular cation concentrations, including symmetric reduction experiments and gating current analysis |
The Journal of physiology |
Medium |
10050000
|
| 2000 |
Kv1.5 is associated with Src family protein tyrosine kinases in astrocytes (demonstrated by co-immunoprecipitation); Src-mediated tyrosine phosphorylation of Kv1.5 is required for full channel activity and astrocyte proliferation, and this phosphorylation is downregulated during differentiation. |
Co-immunoprecipitation, antisense oligodeoxynucleotides, Src-specific inhibitor PP2, constitutively active Src transfection, whole-cell patch-clamp |
The Journal of neuroscience |
Medium |
10884308
|
| 2001 |
Alpha-actinin-2 binds to a discrete region (amino acids 73–148) of the Kv1.5 N-terminus via its internal spectrin repeats, as demonstrated by yeast two-hybrid and in vitro binding assays; this interaction does not occur with Kv1.1, Kv1.2, or Kv1.3 N-termini. |
Yeast two-hybrid analysis, in vitro binding assays, deletion analysis |
FEBS letters |
Medium |
11389904
|
| 2001 |
SAP97 co-localizes and co-immunoprecipitates with Kv1.5 in cardiac myocytes at intercalated disks and lateral membranes; the C-terminal PDZ-binding motif (TDL) of Kv1.5 is required for this interaction, and SAP97 co-expression augments Kv1.5 currents in Xenopus oocytes. |
Co-immunoprecipitation, immunocytochemistry, site-directed mutagenesis (TDL→AAA), functional expression in Xenopus oocytes |
American journal of physiology. Heart and circulatory physiology |
Medium |
11709425
|
| 2001 |
Heteromultimeric Kv1.2/Kv1.5 channels underlie the 4-AP-sensitive delayed rectifier K+ current in rabbit portal vein vascular myocytes; tandem-coupled [Kv1.5/Kv1.2]2 heterotetramers reproduced the characteristic voltage-dependent shift in activation seen in native channels but absent in Kv1.5 homotetramers. |
Patch-clamp of native vascular myocytes, heterologous expression of homo- and heterotetramers (including tandem constructs) in mammalian cells, pharmacological characterization |
Circulation research |
Medium |
11717161
|
| 2002 |
External H+ and Zn2+ inhibit hKv1.5 by stabilizing an inactivated state; this inhibition requires histidine H463 (in the channel turret) and R487 (near the outer pore mouth), and is relieved by extracellular K+ through a non-competitive mechanism. |
Site-directed mutagenesis (H463Q, R487V), whole-cell patch-clamp, gating current analysis in non-conducting mutant hKv1.5 W472F, varied extracellular [K+] |
The Journal of physiology |
High |
12015417
|
| 2002 |
PKA activity is required to maintain Kv1.5 current levels; inhibition of PKA reduces Kv1.5 currents by revealing endogenous phosphatase activity, and this regulation requires an intact actin cytoskeleton and alpha-actinin-2 (antisense knockdown of alpha-actinin-2 abolishes the effect). |
Xenopus oocyte expression, PKA activators/inhibitors, cytochalasin (actin disruption), phalloidin, antisense oligonucleotides against alpha-actinin-2, alkaline phosphatase injection, orthovanadate |
Molecular pharmacology |
Medium |
11809852
|
| 2002 |
PKC activation (via PMA) markedly reduces Kv1.5 current only when Kv1.5 is co-expressed with Kvβ1.2 (but not Kvβ1.3); all three proteins (Kv1.5, Kvβ1.2, Kvβ1.3) are substrates for PKC phosphorylation, and Kv1.5 assembles in vivo with both beta subunits. |
Co-expression in HEK293 cells, whole-cell patch-clamp, phorbol ester activation, PKC inhibitors, in vivo assembly demonstrated |
The Journal of pharmacology and experimental therapeutics |
Medium |
12130714
|
| 2003 |
Kv1.5 is the molecular basis of IKur in canine atrial myocytes; a Kv1.5-selective compound (not affecting Kv3.1, hERG, or sodium channels) fully suppressed IKur tail currents and prolonged atrial action potentials, while Kv3.1 protein was undetectable in atrial membrane fractions. |
RT-PCR, Western blot of cytosolic and membrane fractions, confocal immunostaining, voltage-clamp, action potential recordings in isolated canine atrial myocytes |
Circulation research |
High |
14500335
|
| 2003 |
Different SAP97 isoforms differentially regulate Kv1.5: the cardiac isoform lacking I1A insert increases Kv1.5 current (215%) and promotes surface membrane clustering, while the isoform containing I1A abolishes this effect; both isoforms co-immunoprecipitate with Kv1.5. |
RT-PCR isoform cloning, co-immunoprecipitation, confocal imaging of GFP-tagged channels, patch-clamp in CHO cells, W623F SH3-domain mutation |
The Journal of biological chemistry |
Medium |
12970345
|
| 2003 |
SAP97 increases hKv1.5 current through an indirect mechanism dependent on the Kv1.5 N-terminus (not the C-terminal PDZ-binding motif); no physical interaction between SAP97 and Kv1.5 could be detected by co-IP, co-localization, or yeast two-hybrid in most experiments. |
Deletion mutagenesis of Kv1.5 N- and C-termini, yeast two-hybrid, co-IP from HEK cells and rat ventricular myocytes, co-localization in cardiac myocytes, Xenopus oocyte functional expression |
FEBS letters |
Medium |
12860415
|
| 2005 |
Kv1.5 surface expression is regulated by retrograde trafficking via the dynein motor complex: disruption of dynein-dynactin (by p50/dynamitin overexpression), inhibition of endocytosis (dynamin inhibitory peptide), or microtubule depolymerization (nocodazole) all increase Kv1.5 current density and redistribute channels to the plasma membrane; Kv1.5 co-immunoprecipitates with the dynein motor complex in an interaction requiring the N-terminal SH3-binding domain. |
Overexpression of p50/dynamitin, dynamin inhibitory peptide, nocodazole, Proteinase K surface accessibility assay, co-immunoprecipitation, confocal imaging in HEK cells and rat atrial myocytes, patch-clamp |
Circulation research |
High |
16051887
|
| 2006 |
Kv1.5 is internalized upon activation of 5-HT2A receptors by serotonin via a pathway involving phospholipase C, protein kinase C, tyrosine kinases, and caveolae-mediated endocytosis; 5-HT2A receptors and caveolin-1 co-immunoprecipitate with Kv1.5 channels in pulmonary artery homogenates. |
Co-immunoprecipitation, pharmacological inhibitors (ketanserin, U73122, Gö6976, genistein, tyrphostin 23, beta-cyclodextrin, concanavalin A), patch-clamp, confocal imaging of channel internalization in rat PASMC and Ltk- cells stably expressing hKv1.5 |
Circulation research |
Medium |
16527989
|
| 2006 |
Kv1.5 and Kv1.3 form functional heterotetramers in macrophages; co-expression of Kv1.5 positively shifts K+ current half-activation voltage, both subunits co-immunoprecipitate and co-localize at the membrane, and FRET studies confirm heterotetrameric assembly; TNF-α activation increases Kv1.3 without changing Kv1.5, altering the pharmacological profile. |
Co-immunoprecipitation, co-localization by microscopy, FRET, Xenopus oocyte co-expression with varied subunit ratios, HEK293 co-expression, electrophysiology, pharmacology |
The Journal of biological chemistry |
High |
17038323
|
| 2006 |
A nonsense mutation (E375X) in KCNA5 truncates Kv1.5 at the S4-S6 voltage sensor, pore, and C-terminus; heterologously expressed E375X fails to generate IKur and exerts a dominant-negative effect on wild-type current, leading to action potential prolongation and early afterdepolarizations in human atrial myocytes. Aminoglycoside-induced translational read-through of the premature stop codon rescues channel function. |
Genomic DNA scanning, heterologous expression, whole-cell patch-clamp, action potential recordings in human atrial myocytes, murine in vivo model, aminoglycoside read-through rescue |
Human molecular genetics |
High |
16772329
|
| 2006 |
AVE0118 blocks Kv1.5 by binding to the inner cavity of the channel pore; alanine-scanning mutagenesis identified Thr479, Thr480, Val505, Ile508, Val512, and Val516 (facing the central cavity) and Ile502 and Leu510 (facing away from cavity) as key binding residues; block is open-state preferring and slows current deactivation ('foot-in-the-door' mechanism). |
Alanine-scanning mutagenesis of the pore domain, two-microelectrode voltage-clamp in Xenopus oocytes, homology model docking |
Molecular pharmacology |
High |
16835355
|
| 2007 |
Kv1.5 is post-translationally modified by SUMO-1, -2, and -3 at two membrane-proximal cytoplasmic SUMO consensus sites; Kv1.5 interacts specifically with the SUMO-conjugating enzyme Ubc9 and serves as a substrate in a minimal in vitro reconstituted SUMOylation reaction; disruption of SUMOylation sites or expression of SUMO protease SENP2 causes a ~15 mV hyperpolarizing shift in the voltage dependence of steady-state inactivation. |
In vitro reconstituted SUMOylation assay, in vivo SUMOylation with SUMO-specific protease deconjugation (SENP2, Ulp1), mutagenesis of SUMO target motifs, whole-cell patch-clamp |
Proceedings of the National Academy of Sciences of the United States of America |
High |
17261810
|
| 2007 |
Rab4- and Rab11-dependent endosomal recycling pathways regulate steady-state Kv1.5 surface levels in atrial myocytes: Kv1.5 internalizes to EEA1-positive early endosomes and recycles back to the plasma membrane; dominant-negative Rab4S22N and Rab11S25N decrease surface Kv1.5 levels while GTPase-deficient Rab4Q67L and Rab11Q70L increase them; Rab11 co-immunoprecipitates with Kv1.5. |
Kinetic internalization assays, co-localization with endosomal markers, co-immunoprecipitation, dominant-negative and constitutively active Rab GTPase mutants, live-cell surface labeling, electrophysiology in HL-1 mouse atrial myocytes |
The Journal of biological chemistry |
High |
17673464
|
| 2007 |
S-acylation (palmitoylation) of Kv1.5 on COOH-terminal cysteines via hydroxylamine-sensitive thioester bonds is required for normal surface expression; pharmacological inhibition of S-acylation decreases surface Kv1.5 and targets it for proteasomal degradation; S-acylation occurs in the biosynthetic pathway of nascent channel protein. |
Hydroxylamine treatment, inhibitors of S-acylation, proteasome inhibitors, COOH-terminal cysteine mutation, confocal microscopy, Western blot in transfected fibroblasts |
American journal of physiology. Cell physiology |
Medium |
17344312
|
| 2007 |
Caveolin is required for trafficking of Kv1.5 to cholesterol-rich lipid raft microdomains; in cells lacking endogenous caveolin, Kv1.5 association with low-density detergent-resistant membranes requires exogenous caveolin co-expression; caveolin-trafficking mutants sequester Kv1.5 in intracellular compartments, reducing surface channel expression; caveolin co-expression induces depolarizing shifts in Kv1.5 activation and inactivation analogous to elevated cholesterol effects. |
Sucrose gradient fractionation, co-expression with caveolin and caveolin trafficking mutants, whole-cell patch-clamp, confocal microscopy |
Molecular pharmacology |
Medium |
18045854
|
| 2007 |
Membrane cholesterol depletion (via methyl-β-cyclodextrin) causes redistribution of Kv1.5 subunits from cholesterol-enriched microdomains into larger clusters throughout the plasma membrane, increasing IKur current; Kv1.5 subunits are concentrated in cholesterol-rich microdomains distinct from caveolae in rat atrial cardiomyocytes. |
Methyl-β-cyclodextrin treatment, GFP-tagged Kv1.5 imaging in live neonatal cardiomyocytes, sucrose gradient fractionation, patch-clamp in rat atrial myocytes, cholesterol loading with LDL |
The Journal of physiology |
Medium |
17525113
|
| 2008 |
SAP97 retains and immobilizes Kv1.5 subunits in the plasma membrane of cardiac myocytes, increasing IKur current density and reducing channel mobility (FRAP); SAP97 overexpression clusters endogenous Kv1.5 at myocyte-myocyte contacts. |
Adenovirus-mediated SAP97 overexpression in rat neonatal cardiomyocytes and CHO cells, FRAP, immunocytochemistry, whole-cell patch-clamp, cell-attached patch recordings |
American journal of physiology. Heart and circulatory physiology |
Medium |
18245566
|
| 2008 |
After internalization, Kv1.5 rapidly associates with Rab5- and Rab4-positive early endosomes (fast recycling pathway), and a fraction is targeted to Rab7-positive late endosomes for degradation; Rab5DN increases Kv1.5 current ~2-fold, Rab4DN similarly increases currents, Rab7 overexpression decreases currents in H9c2 myoblasts; Rab11-positive perinuclear recycling is slow and only evident after 24 h. |
Dominant-negative and constitutively active Rab GTPase mutants, post-internalization trafficking assays, co-localization with endosomal markers, whole-cell patch-clamp in H9c2 myoblasts and HEK293 cells |
The Journal of physiology |
Medium |
18755741
|
| 2008 |
The C-terminal domain of Kv1.5 (specifically Arg543-Val583) interacts with Kvβ subunits in a pyridine-nucleotide-dependent manner: NADPH accelerates Kvβ3-induced inactivation while NADP+ reverses it; deletion of the C-terminus abolishes nucleotide-sensitive Kvβ regulation; a GST-C-terminal fusion protein binds Kvβ2:NADPH with higher affinity than Kvβ2:NADP+. |
C-terminal deletion mutagenesis, GST pull-down with brain lysates, patch-clamp with intrapipette nucleotide infusion, co-expression in COS-7 cells |
Pflugers Archiv |
Medium |
22426702
|
| 2008 |
Four-and-a-half LIM protein 1 (FHL1) physically interacts with the Kv1.5/KCNA5 C-terminal domain in human atrium; co-expression of FHL1 markedly increases Kv1.5 current density and shifts activation to more positive potentials, and increases the extent and rate of slow inactivation. |
GST-KCNA5 C-terminal pull-down with mass spectrometry, co-immunoprecipitation from human atrium and CHO cells, confocal microscopy, patch-clamp in CHO cells |
Cardiovascular research |
High |
18281375
|
| 2008 |
Kv1.3 association modifies Kv1.5 trafficking: Kv1.3/Kv1.5 heterotetramers (confirmed by FRET) target to distinct surface microdomains with higher lateral mobility than Kv1.3 homotetramers; immunoprecipitation shows heteromeric channels associate with caveolar raft domains differently from Kv1.3 homomers; FRAP reveals higher mobility for hybrid channels. |
FRET, FRAP, co-immunoprecipitation, cholesterol depletion, caveolae co-localization, pharmacology in HEK cells and LPS-activated macrophages |
The Journal of biological chemistry |
Medium |
18218624
|
| 2009 |
Cholesterol regulates Kv1.5 surface expression by modulating trafficking through the Rab11-associated recycling endosome: cholesterol depletion promotes exocytosis of Kv1.5 from a Rab11-positive intracellular pool; dominant-negative Rab11 (but not Rab4) prevents the cholesterol depletion-induced increase in IKur; Rab11 co-immunoprecipitates with hKv1.5-EGFP. |
Whole-cell patch-clamp, single-channel recordings, FRAP, 3D microscopy, co-immunoprecipitation, dominant-negative Rab11 and Rab4 mutants, NEM and GTP-γ-S inhibitors in rat adult atrial myocytes |
Proceedings of the National Academy of Sciences of the United States of America |
High |
19706553
|
| 2010 |
A novel 33-bp coding region deletion in the Kv1.5 N-terminus (removing 11 amino acids including an SH3-domain binding site for Src-family tyrosine kinases) causes ~60% reduction in IKur and a dominant-negative effect; pretreatment with Src inhibitor PP2 prevents v-Src from suppressing wild-type current, whereas the mutant channel is unresponsive to v-Src, implicating tyrosine kinase signaling through the N-terminal SH3-binding domain in Kv1.5 regulation. |
Site-directed mutagenesis, transfection in cells, whole-cell patch-clamp, Src inhibitor PP2, v-Src kinase treatment |
Heart rhythm |
Medium |
20638934
|
| 2012 |
Oxidative stress leads to sulfenic acid modification of Kv1.5 on a single C-terminal cysteine (C581); this modification is necessary and sufficient to reduce channel surface expression, promote internalization, and block recycling; under prolonged oxidative stress, sulfenic acid modification triggers channel degradation. Sulfenic acid-modified proteins including Kv1.5 are elevated in human atrial fibrillation. |
Sulfenic acid-specific probe (DAz) labeling with Western blot, site-directed mutagenesis of C581, live-cell immunofluorescence, whole-cell voltage-clamp, Western blot in human AF tissue |
Circulation research |
High |
22843785
|
| 2012 |
AMPK activation (wild-type and constitutively active γR70Q, but not inactive αK45R mutant) significantly reduces Kv1.5-mediated K+ currents and decreases Kv1.5 protein abundance in the cell membrane; Nedd4-2 co-expression similarly downregulates Kv1.5 currents, suggesting AMPK acts in part via Nedd4-2. |
Xenopus oocyte injection with Kv1.5 ± AMPK constructs, two-electrode voltage-clamp, chemiluminescence and confocal microscopy for membrane protein abundance |
Cellular physiology and biochemistry |
Medium |
23221389
|
| 2012 |
PKC activity is required for Kvβ1.3-induced fast inactivation of Kv1.5; PKC inhibition (calphostin C or siRNA knockdown of all PKC isoforms) abolishes fast inactivation without dissociating Kv1.5 from Kvβ1.3 (co-IP and co-localization preserved); a Kv1.5 channelosome comprising Kv1.5, Kvβ1.3, RACK1, PKCβI, PKCβII, and PKCθ was identified by co-immunoprecipitation in HEK293 cells and rat ventricular tissue. |
Co-immunoprecipitation, immunocytochemistry, siRNA knockdown of PKC isoforms, calphostin C inhibition, whole-cell patch-clamp, rat ventricular and atrial tissue |
The Journal of biological chemistry |
High |
22547057
|
| 2012 |
Novel gain-of-function (E48G, A305T, D322H) and loss-of-function (Y155C, D469E, P488S) mutations in KCNA5 were identified in patients with early-onset lone atrial fibrillation; loss-of-function mutants showed decreased surface expression by confocal microscopy, while gain-of-function mutants showed preserved surface expression with increased IKur. |
Sequencing of KCNA5, confocal microscopy for surface expression, whole-cell patch-clamp in transfected cells |
European heart journal |
Medium |
23264583
|
| 2015 |
Kv1.5 channels in vascular smooth muscle are required for coronary metabolic dilation: Kv1.5-null mice show impaired myocardial blood flow and tissue oxygen tension during cardiac stress despite elevated cardiac work; smooth muscle-specific re-expression of Kv1.5 in the null background rescues metabolic dilation; isolated arteries from Kv1.5-null mice show impaired relaxation to H2O2 but normal responses to adenosine and acetylcholine. |
Kv1.5 knockout mice, inducible smooth muscle-specific Kv1.5 rescue transgene, in vivo hemodynamic and blood flow measurements (micromanometer catheters), myocardial tissue oxygen tension, isolated artery vasoreactivity studies |
Circulation research |
High |
26224794
|
| 2015 |
Urate taken up intracellularly via URATv1 increases Kv1.5 protein expression and IKur in HL-1 atrial myocytes through NADPH oxidase-derived reactive oxygen species and ERK phosphorylation; the ERK inhibitor PD98059 and antioxidants (NAC, apocynin) abolish the urate-induced increase in Kv1.5. |
URATv1 inhibitor (benzbromarone), ABCG2 inhibitor (KO143), N-acetylcysteine, apocynin, ERK inhibitor PD98059, ROS flow cytometry, RT-PCR, immunoblot, patch-clamp in HL-1 cells |
Circulation journal |
Medium |
26477273
|
| 2015 |
DNA methylation of the KCNA5 promoter epigenetically silences Kv1.5 channel expression in Ewing sarcoma cells; treatment with the DNA methylation inhibitor decitabine restores Kv1.5 expression and inhibits Ewing sarcoma cell proliferation. |
Promoter methylation analysis, decitabine treatment, Kv1.5 expression assays, cell proliferation assays |
Molecular cancer research |
Medium |
26573141
|
| 2005 |
Kv1.5 is degraded by the proteasome: proteasome inhibitors (MG132, ALLN, lactacystine) prolong Kv1.5 half-life (~6.7 h), increase ubiquitinated Kv1.5 levels, and increase IKur by stabilizing channel protein in the ER/Golgi; lysosomal inhibition has no effect; this degradation pathway was also demonstrated in endogenous Kv1.5 in rat atrial cells. |
Pulse-chase analysis, proteasome and lysosomal inhibitors, immunofluorescence, patch-clamp, brefeldin A and colchicine treatment in COS cells and rat atrial cells |
Biochemical and biophysical research communications |
Medium |
16185660
|
| 2006 |
Kv1.5 does not localize to caveolae in rat and canine cardiac myocytes: co-immunoprecipitation of Kv1.5 with caveolin-3 was not detected (though caveolin-3/eNOS and caveolin-3/β-dystroglycan interactions were), and wide-field/deconvolution microscopy showed <12% co-localization of Kv1.5 with caveolin-3 in atrial myocytes; in HEK293 cells Kv1.5 does not partition into low-buoyancy raft fractions. |
Co-immunoprecipitation, wide-field microscopy with deconvolution, immunoelectron microscopy, sucrose gradient fractionation in rat and canine cardiac tissue and HEK293 cells |
FEBS letters |
Medium |
17054951
|
| 1993 |
Dexamethasone (glucocorticoid) rapidly induces Kv1.5 gene transcription in GH3 pituitary cells, increasing Kv1.5 mRNA and ~3-fold increasing Kv1.5 protein (76 kDa, t1/2 ~4 hr) within 12 h, which is associated with increased noninactivating voltage-gated K+ current; Kv1.5 mRNA turnover (t1/2 ~0.5 hr) is not affected. |
Nuclear run-on transcription assay, mRNA stability assay, immunoblot, whole-cell patch-clamp in GH3 cells |
Neuron |
Medium |
8352944
|