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Kv1.5

potassium voltage-gated channel, shaker-related subfamily, member 5
Synonyms: Kv1.5 kcna5 . Symbol: Kcna5

Introductions


Potassium voltage-gated channel, shaker-related subfamily, member 5, also known as KCNA5 or Kv1.5 is a protein which in humans is encoded by the KCNA5 gene. [1585] Kv1.5 underlies the cardiac ultra-rapid delayed rectifier potassium current (IKur) in humans. In addition, Kv1.5 channels are also expressed in many other organs, such as pulmonary arteries, brain, skeletal muscle, and have crucial function in cell cycle regulation. Since IKur is expressed in the cardiac atrial, but scarcely in the ventricular cells in human, thus IKur has important roles in controlling action potential (AP) shape and contractility in the human atrium [1573]

Genes


Kcna5 : potassium voltage-gated channel, shaker-related subfamily, member 5

RGD ID Chromosome Position Species
2953 4 162896283-162898091 Rat
10832 6 126482569-126485573 Mouse
731065 12 5153085-5155949 Human

Transcripts


Acc No Sequence Length Source
NM_012972 NCBI
NM_145983 NCBI
NM_002234 NCBI

Ontologies


Accession Name Definition Evidence
GO:0005794 Golgi apparatus A compound membranous cytoplasmic organelle of eukaryotic cells, consisting of flattened, ribosome-free vesicles arranged in a more or less regular stack. The Golgi apparatus differs from the endoplasmic reticulum in often having slightly thicker membranes, appearing in sections as a characteristic shallow semicircle so that the convex side (cis or entry face) abuts the endoplasmic reticulum, secretory vesicles emerging from the concave side (trans or exit face). In vertebrate cells there is usually one such organelle, while in invertebrates and plants, where they are known usually as dictyosomes, there may be several scattered in the cytoplasm. The Golgi apparatus processes proteins produced on the ribosomes of the rough endoplasmic reticulum; such processing includes modification of the core oligosaccharides of glycoproteins, and the sorting and packaging of proteins for transport to a variety of cellular locations. Three different regions of the Golgi are now recognized both in terms of structure and function: cis, in the vicinity of the cis face, trans, in the vicinity of the trans face, and medial, lying between the cis and trans regions. IEA
GO:0016021 integral to membrane Penetrating at least one phospholipid bilayer of a membrane. May also refer to the state of being buried in the bilayer with no exposure outside the bilayer. When used to describe a protein, indicates that all or part of the peptide sequence is embedded in the membrane. IEA
GO:0008076 voltage-gated potassium channel complex A protein complex that forms a transmembrane channel through which potassium ions may cross a cell membrane in response to changes in membrane potential. IMP
GO:0005886 plasma membrane The membrane surrounding a cell that separates the cell from its external environment. It consists of a phospholipid bilayer and associated proteins. IEA
GO:0016020 membrane Double layer of lipid molecules that encloses all cells, and, in eukaryotes, many organelles; may be a single or double lipid bilayer; also includes associated proteins. IEA

Interactions


Mutation

The related Kv1.5 channel, which does not undergo intrinsic N-type inactivation, also exhibits enhanced slow inactivation when the H463 residue in the S5-P-loop linker structure known as the turret is mutated to a glycine (H463G) [1588]

ALA

α-linolenic acid (ALA), a vegetable marine n-3 polyunsaturated fatty acid, blocked Kv1.5 channels in a time- and voltage-dependent manner. [122]

TEA

Kv1.5 is insensitive to TEA [1575]

Kvβ and Drug competition

Drug binding in the inner cavity of the Kv1.5 channel pore can compete with binding of β-subunits because there is partial overlap in the residues involved in either binding [1574]

Kvβ subunits

Interaction of Kvβ subunits with Kv1.5 controls channel trafficking and integration into the plasma membrane, and modulates activation and inactivation kinetics of the current [1574]

KChIP1/2

co-expression of KChIP2 (or KChIP1) decreases Kv1.5-encoded K(+) currents. Although current densities are reduced, KChIP2 (or KChIP1) co-expression does not affect the time- or voltage-dependent properties of heterologously expressed Kv1.5-encoded K(+) currents [1577]

Kvβ1.2, Kvβ1.3, and Kvβ2.1

These are most widely expressed in the heart. When co-expressed with Kv1.5, they shift the steady-state activation and inactivation curves to more negative potentials [1574]

Kvβ3.1

The heterologous coexpression of human Kv1.5 and Kvβ3.1 subunits in Chinese hamster ovary cells yielded a novel Kv channel mediating very fast inactivating (A-type) outward currents upon depolarization. Thus, the expression of Kvβ3.1 subunits potentially extends the possibilities to express diverse A-type Kv channels in the human brain [1579]

PKA and PKC

In human atria, phosphorylation induced by stimulation of β-adrenoceptors and activation of PKA increases, whereas PKC-mediated phosphorylation decreases IKur amplitude. Stimulation of PKC has little effect on expressed Kv1.5 channels alone; however, co-assembly of Kvβ1.2 with Kv1.5 enhances the response of the channel to PKC activation with a reduction in the K+ current [1574]

Nitric Oxide

Kv1.5 channels are also regulated by NO via a cGMP/PKG-dependent pathway. NO donors such as SNAP (S-nitroso-N-acetylpenicillamine) and L-arginine concentration-dependently decrease IKv1.5 in an expression system, and elevate the plateau in mouse ventricular cells (which unlike human ventricular cardiomyocytes do endogenously express Kv1.5) [1574]

DPO

Diphenyl phosphine oxide (DPO) compounds that are potent frequency-dependent inhibitors of cloned human Kv1.5 (hKv1.5) channels. DPO inhibited hKv1.5 expressed in Chinese hamster ovary cells in a concentration-dependent manner preferentially during channel activation and slowed the deactivating tail current, consistent with a predominant open-channel blocking mechanism. Near complete recovery from washout [1584]

Proteins and Lipids

It has been reported that several regulatory proteins and lipids, such as SAP97, half LIM protein 1, b-accessory protein KChIP2, eicosapentaenoic acid and an antiarrhythmic drug, quinidine, regulate Kv1.5 expression and intracellular trafficking processes [1573]

Bisindolylmaleimide, a blocker of Kv1.5

BIM (V) also did not alter the peak current at low concentrations (0.3, 1 μM) but did at high concentrations (3, 10 μM). High concentrations of BIM, the peak amplitude of current was affected much less than the steady-state current amplitude at the end of the 250-ms depolarizing pulse. The washout of BIM (I) and BIM (V) by perfusion of drug-free solution was obtained within 3 min, and currents were recovered to 84.02 ± 0.04% (n = 6) and 87.11 ± 0.11% (n = 5) of control, respectively [1580]

Vernakalant

Of many recent drugs, Vernakalant (RSD1235) is of special interest because it has recently been approved by the European drug agencies for intravenous conversion of recent onset of AF.101,102. It produces a strong, positive frequency-dependent IKur block with an IC50 of 13 µM at 1 Hz in stably expressed hKv1.5 channels, whereas three-fold higher concentrations are required albeit at 0.25 Hz for open-channel block of expressed hNav1.5 channels [1574]

S9947

A novel Kv1.5 channel blocker, S9947 (2′-(benzyloxycarbonylaminometh- yl)biphenyl-2-carboxylic acid 2-(2-pyridyl)ethyl amide) inhibited the cloned human cardiac potassium channel Kv1.5 expressed in Xenopus oocytes and CHO cells with IC50 values of ~0.6 μM and ~0.4 μM, respectively. Heterologous expression of hKv1.5 in CHO cells and Xenopus oocytes revealed differences in the inactivation of the current (fig 2). This could be due, at least in part, to the higher temperature [1581]

AVE0118

One of the first intensely studied Kv1.5 blockers, AVE0118, shortened APs in preparations from patients in sinus rhythm (SR), and only prolonged the dramatically altered AP in preparations from patients in chronic atrial fibrillation [1585]

Loratadine

Loratadine is a long-acting non-sedating histamine H1-receptor antagonist widely prescribed for treating acute coryza and chronic allergic rhinitis and skin disorders. Loratadine inhibited in a concentration-dependent manner the hKv1.5 current, the apparent affinity being 1.2±0.2 μM. The blockade increased steeply between −30 and 0 mV which corresponded with the voltage range for channel opening, thus suggesting that the drug binds preferentially to the open state of the channel. Excellent washout was also observed [1582]

Local Anaesthetics

The effects of local anaesthetics (Ropivacaine, (R/+) Mepivacaine, and (S/-) Mepivacaine) was tested on Kv1.5. While Ropivacine conveyed concentration dependent block, R/+ and S/- Mepivacine block displayed no apparent time-dependence due to a very fast dissociation rate constant [1583]

Channel trafficking by myosins

Myosin-V motor proteins regulate Kv1.5 channel trafficking in cardiac myocytes. MYO5A and MYO5B mediate functionally distinct and isoform-specific steps in surface trafficking of Kv1.5 channels determining cellular exitibility. [2022]

Antiarrhythmic compound, AVE 0118

The antiarrhythmic compound, AVE 0118, elicits an sympathetic effect in rat small mesenteric arteries. This effect was found to be at least in part mediated by AVE 0118 blocking of neuronal Kv1.5 channels in the medio-adventitial layer [2023]

PKC isoform βII

Protein kinases are involved in the regulation of cardiac ion channels. PKC-dependent regulation of Kv1.5/ Kvβ1.2 channels in the heart is specifically regulated by the PKC isoform βII [2028]

Synapse-associated protein 97 and cortactin

Structural remodeling that includes ion channels is supposed to underlie the abnormal action potentials of Purkinje cells (PC) of the infarcted zone. Synapse-associated protein 97 and actin-binding protein cortactin were found to maintain and normalize Kv1.5 channel conductance of arrythmogenic PCs [2029]

SPAK and OSR1

SPS1-related proline/alanine-rich kinase (SPAK) and oxidative stress-responsive kinase 1 (OSR1) regulate membrane proteins including ion channels. A coexpression study in xenopus oocytes demostrated that both SPAK and OSR1 decrease the surface expression and activity of Kv1.5 channels [2030]

Midazolam

The benzodiazepine Midazolam used in anesthesia may elicit cardiac side effects via Kv1.5 channels. Studies on heterologously expressed Kv1.5 channels revealed Midazolam as an open channel inhibitor of cardiac Kv1.5 channels, exerting an fast onset of block without frequency dependence [2031]

Cortisone and hydrocortisone

The glucocorticoids cortisone and hydrocortisone were shown to rapidly and irreversibly suppress the amplitude of Kv1.5 channel current. However, inhibition properties of cortisone and hydrocortisone differed across the voltage range indicating that they inhibit the Kv1.5 channel differently. Altogether, Kv1.5 channels showed more sensitivity to hydrocortisone than to cortisone [2032]

PKC and AMPK regulation of surface expression

PKC and AMPK activation was shown to reduce Kv1.5 current in heterologous expression assays. These experiments demonstrated that PKC and AMPK kinases both reduce surface expression of Kv1.5 but rely on different molecular mechanisms [2034]

Janus kinase3

Janus kinase 3 was shown to negatively regulate Kv1.5 protein abundance and activity. Being sensitive to ouabain, this reduction was suggested to be mediated by the Na+K+ ATPase [2035]

Propofol

The anesthetic propofol affects a variety of ion channels. Whole-cell patch-clamp recording of CHO cells expressing different hKv1.5 mutants revealed that propofol blocks hKv1.5 by directly interacting with specific amino acids near the selectivity filter or the S6 domain [2037]

Intracellular urate

Urate can be taken up by the cell through the uric acid transporter (UAT). Intracellular urate was shown to enhance Kv1.5 protein expression and activity in cultured mouse atrial myocytes [2038]

Paroxetine

The selective serotonin reuptake inhibitor (SSRI) paroxetine reduces currents of rat Kv1.5 channels expressed in CHO cells. The properties of Kv1.5 current alteration suggest that paroxetine acts as an open-channel blocker [2041]

SGK3

The serum glucocorticoid inducible kinase isoform SGK3 regulates membrane transporters and ion channels. In Xenopus oocytes expressing KCNA5, SGK3 enhanced voltage gated currents. Additional SKG3 expression was found to offset downregulation of Kv1.5 currents by coexpressed Nedd4-2. Together, this indicates SGK3 as a positive regulator of Kv1.5 channel currents [2042]

Sertraline

Sertraline, a selective serotonin reuptake inhibitor (SSRI) may elicit cardiac toxicity via Kv1.5 channels. Whole cell patch clamp recording of CHO cells expressing rat Kv1.5 channels expressed in CHO cells suggest that sertraline acts as an open-channel blocker [2044]

Proteins


Kv1.5

Low temperature exposure increases the protein expression levels of hKv1.5 [1573]

Structures


Crystal structure

Kv4.1 Kv4.1

The homology model of Kv1.5 is structurally more or less identical to the template, i.e., the pore region of the crystal structure of Kv1.2 (PDB accession code 2A79), which is not surprising, given the very high sequence identity in this region [1576]

Each Kv1.5 α-subunit consists of six transmembrane spanning segments (S1–S6) with intracellular amino- and carboxy-termini. The extracellular linker between S5 and S6 dips back into the membrane. Together with the linkers from the other three α-subunits, this P-region lines the centrally located hydrophilic pore that is responsible for ion selectivity and permeation [1574]

The beta-subunits of the Kv channels (Kvb1–4) are cytosolic proteins that bind to the cytoplasmic T1 domain of the membrane spanning Kv1 and Kv4 proteins [589].

Distributions


Anti-FLAG staining revealed the localization of Kv1.5-FLAG in a reticular pattern throughout the cytosol and in a perinuclear pattern throughout the nuclear envelope, indicating its presence in the endoplasmic reticulum (ER) [1589]

Expressions


Expression in Human Tissue

Kv1.5 channels are also expressed in many other organs, such as pulmonary arteries, brain, skeletal muscle [1574]

Expression of Kv1.5 in Heart

The voltage-gated K+ channel Kv1.5 is expressed in the human heart, including the atria [582], [583] and ventricles [582], brain [582], macrophages [584], as well as vascular [585], intesti- nal, and airway [586] smooth muscle. [123].

Expression of Kv1.5 in Rat

Northern blot analysis revealed that in rat Kv1.5 mRNA is expressed in many different tissues, for example, heart, kidney, skeletal muscle, lung, brain, pituitary and aorta. In cardiac tissue Kv1.5 is much more abundantly expressed in atrium than in ventricle [1585]

Interestingly, although Kv1.5 was abundantly found in the central nervous system, it stained no peripheral nerves (PNS) [348]

Morphine

Chronic morphine administration enhances the expression of Kv1.5 and Kv1.6 voltage-gated K+ channels in rat spinal cord [1762]

Aldosterone

In Wistar rats the application of aldosterone downregulated KCNA5 and other left-ventricular mRNAs coding for Kv4.2, Kv4.3, Kir2.1, Kir2.3 and Cav1.2. Expression of Kv1.5, Kir2.3 and Cav1.2 channels was significantly decreased by aldosterone administration [2018]

Functionals


Atria Specific

Kv1.5 channels are atria-specific and have thus been proposed as pharmacological targets for antiarrhythmic drugs effective on supraventricular arrhythmias, such as atrial fibrillation. [122]

Human Kv1.5 (hKv1.5) is encoded by KCNA5 and KCNA5 loss-of-function mutations have been reported to produce kindred atrial arrhythmia, which suggest that the genetic alteration of hKv1.5 may substantially enhance arrhythmia susceptibility [1573]

IKur blockers have been shown to affect human atrial AP repolarization in vitro, and selectively increase atrial refractoriness and terminate atrial arrhythmias in several animal species in vivo [426]

Cell Cycle Regulation

Kv1.5 has a crucial function in cell cycle regulation. Kv1.5 subunit is up-regulated during G1 phase of the cell cycle, it is conceivable that this subunit plays a relatively minor role when compared with Kv1.3 in OP G1/S cell cycle progression [1575]

In the heart, Kv1.5 contributes to the repolarization of the cardiac action potential [587] and is responsible for the ultrarapid delayed rectifier current [588].

Kv1.5 also plays an important role in cell membrane potential regulation [1587]

Spermatozoa

Kv1.5, minK and TASK2 were localized to various regions of the spermatozoa. Although Kv1.4, Kv1.7, TASK2 and TASK3 channels may have important roles in human spermatozoa, Kv1.5 and minK appear to be the most likely candidates for human sperm RVD, serving as targets for non-hormonal contraception [1653]

Disease

(PULMONARY HYPERTENSION) Overexpression of Kv1.5 in cultured PASMCs (Pulmonary artery smooth muscle cells) could offset hypoxia-induced cell proliferation and hypoxia-inhibited Kv currents in the IUGR group. These results suggest that the inhibited expression of Kv1.5 in PASMCs contribute to the development of exaggerated CH-PHT (Chronic hypoxia pulmonary hypertension) in rats during adulthood [1586]

(HYPOTHYROIDISM) Kv1.5 is markedly decreased by hypothyroidism and deletion of the Kv1.5-partner kcne2, which impairs channel expression, triggers cardiopathies with a marked form of hypothyroidism with deleterious results in neonates [348]

(CARDIAC ARREST) Low temperature exposure stabilizes the protein in the cellular organelles or on the plasma membrane, and modulates its maturation and trafficking, thus enhancing the currents of hKv1.5 (CARDIAC CHANNEL) and its trafficking defect mutants [1573]

(HYPOXIA PULMONARY VASOCONSTRICTION) Molecular identification of the role of voltage-gated K+ channels, Kv1.5 and Kv2.1, in hypoxic pulmonary vasoconstriction and control of resting membrane potential in rat pulmonary artery myocytes [1825]

B-cell proliferation

Kv1.5 channels were identified as determinants of human B-lymphocyte proliferation and migration. The abundance of Kv1.5 channel expression was shown to inversely correlate with the clinical aggressiveness of lymphoma [2017]

Chronic hypoxia pulmonary hypertension

Inhibited expression of Kv1.5 in pulmonary artery smooth muscle cells (PASMCs) contributes to the development of chronic hypoxia pulmonary hypertension. Kv1.5 overexpression in PAMSCs was able to compensate hypoxia-induced cell proliferation in the rat model [1586]

Atrial fibrillation

Kv1.5 channels underlie the voltage-gated atrial-specific potassium current Ikur. Gain-of-function and loss-of-function mutation studies provided evidence that both increased and decreased Kv1.5 channel activity can increase atrial fibrillation (AF) susceptibility. The high prevalence of these deleterious variants of KCNA5 in were reported for AF patients [2019]

Obesity-induced electrophysiological remodeling

Obesity-induced electrophysiological remodeling of the heart was reported to involve protein kinase D-mediated reduction of c-AMP response element-binding protein (CREB). In turn, CREB reduction elicits a decrease of cardiaque Kv1.5 channel expression [2020]

Chronic mechanical stress

Chronic mechanical stress may increase Kv1.5 channel expression in atrial myocytes. The upregulation of Kv1.5 channel expression was suggested to be provoked by the overactivation of integrin signaling upon shear stress [2021]

Adaption of exitable cells

The adaption of excitable cells can occur due to various pathological or physiological challenges. In preoptic GABAergic neurons this electrical remodeling was shown to rely on the upregulation of conduction through Kv1.5 channels.[2024]

Cancer cell survival

Survival of cancer cells under stress depends on the suppression of Kv1.5 subunits. The repression of KCNA5 depends on polycomb group (PcG) proteins BMI-1 and EZH2. Inhibition of these PcGs restores Kv1.5 expression and favors stress-induced death [2025]

Hyperoxia

Cardiotoxic effects of hyperoxia involve the downregulation of Kv1.5 and Kvβ subunit expression. The decrease in cardiac Kv1.5 expression is possibly mediated by SiRT1 [2026]

Hypoxia and 15-LOX

Hypoxia can cause Kv1.5 and Kv2.1 suppression. This effect was suggested to be mediated by increased 15-lipoxygenase (15-LOX) expression. This is supported by the finding that inhibition of 15-lipoxygenase can reverse hypoxia-induced down-regulation of Kv1.5 and Kv2.1 channels in rat cardiac myocytes [2027]

Low temperature stabilization

Low temperature exposure of CHO cells was shown to stabilize the Kv1.5 subunits in organelles or the membrane and to enhance hKv1.5 currents [1573]

Cardiac VSM cells, blood flow and metabolism

A KCNA5 knockout study revealed that Kv1.5 channels, expressed in vascular smooth muscle cells, play a critical role in coupling myocardial blood flow to cardiac metabolism [2036]

Osteosarcoma

Kv1.5 is expressed in osteosarcoma. Silencing of Kv1.5 channels suppressed osteosarcoma progression through multiple signaling pathways [2039]

Ewing sarcoma

The promoter of KCNA5 was found to be methylated in Ewing sarcoma cells. Epigenetic silencing of Kv1.5 expression was found to promote tumor cell proliferation, supporting a role of ion channel dysregulation in tumorigenesis [2040]

Kinetics


Effect of Temperature on Kinetics

Kv1.5

Reduced-temperature (even at 34C) culture substantially enhanced the hKv1.5 currents, which is associated with stabilization of the channel protein, slower degradation of its immature protein and the accumulation of mature protein on the plasma membrane [1573]

Though the Kv1.5 current can be regarded as a ‘sustained’ current at room temperature, inactivation proceeds much faster at more physiological temperature. Moreover, the time course of recovery from inactivation is also faster at higher temperatures [1574]

Kv1.5 Kv1.5 currents at 24°C and 37°C from mouse fibroblasts (ltk-) permanently transfected with human HK2 channel. Voltage-clamp experiments. (a) Original current recordings at 23°C. Voltage clamp protocol see inset, protocol repeated at 0.2 Hz. Cell c96, Cm 19 pF. (b) Current recordings at 37°C from same cell as in (a), same protocol as in (a). A significant change in inactivation was observed [1585]

Single Channel Current

Kv1.5

the single channel Kvl.5 currents recorded in the cell attached mode.The cell was bathed with the K+-rich solution (140mM K+),and the pipette contained the external medium(4mM K+).The linear slope conductance was 8pS. Single-channel currents illustrated here were recorded at+60mV [1578]


Kv1.5 Expressed in CHO cells

Kv3.1 When expressed in CHO cells, wild-type Kv1.5 channels exhibited only a slow C-type inactivation during test pulses to +60 mV. We attached the proximal 40 amino acid residues of the Kv4.2 N-terminus to Kv1.5 to generate Kv1.5(+4.2N40) channels. In contrast to Kv1.5, Kv1.5(+4.2N40) channels yielded rapidly inactivating outward currents. The results demonstrated that the Kv4.2 inactivating domain conferred a rapid inactivation to Kv1.5 channels. [1807]

Kv1.5 currents in Xenopus oocytes and effect of corticoids

Kv1.5 currents were recorded using the two-microelectrode voltage clamp technique. A series of voltage pulses of 2s were applied from −80 mV to +50 mV in 10mV steps from a holding potential of −100 mV. Application of cortisone or hydrocortisone inhibited peak and steady-state currents.[2032]

Kv1.5 currents in Xenopus oocytes

Kv1.5 currents were measured in Xenopus oocytes using the double-electrode voltage-clamp technique. Using 10mV voltage steps of -90 to 50 mV from a holding potential of – 80 mV, Kv1.5 channels elicited rapidly activating currrents and slow inactivating currents.[2031]

hKv1.5 currents recorded in CHO cells

Membrane currents of hKv1.5 channels expressed in CHO cells were recorded with the whole-cell patch-clamp technique. A series of test potentials from −50 to +50 mV lasting 300-ms in 10 mV steps were applied from a holding potential of −80 mV and a return potential of −40 mV. Fast activation of hKv1.5 currents was elicited at potentials above −20 mV.[2037]

Kv1.5 currents and inactivation kinetics in CHO cells

Traces of Kv1.5 currents were recorded by whole-cell patch-clamp technique in CHO cells. Depolarizing pulses of 250ms from -80 to +50 mV were applied that elicited rapid activation and very slow inactivation. Inactivation kinetics were recorded after a 250ms depolarizing pulse of +50ms and by applying a 250-ms repolarizing pulse at -40 mV, using a holding potential of -80 mV. The fast decline of the tail current had a time constant of 16.2±2.0 ms.[2041]

Kv1.5 activation and inactivation kinetics in HEK cells

KCNA5 was expressed in HEK cells. After 200ms pre-pulses from -50 to +50 mV, Kv1.5 peak currents were quantified during a -60 mV test-pulse. A two-pulse protocol was used to study Kv1.5 inactivation kinetics with test pulses to +70 mV and 200 ms that were applied after a 1 s pre-pulse of -60 to +40 mV.[2042]

Models


Five State Kv1.5 markov model

Kv4.1

Under the assumption that transition rates between the open and closed conformations of a subunit are independent of the state of the other subunits and that all four subunits operate in an identical manner, the Kv1.5 channel can be represented by the five-state model in Fig. 1A. It has four closed, nonconducting states, C1-C1, and an open, conducting state, O. Here, α and β are the forward and reverse rate constants of the transition to the open conformation, respectively [426]

Kv1.5 blockers are selectively blocking only the activated or open state of Kv1.5 channels and important features of the drug-ion channel interaction such as use- and voltage-dependence are not easily implemented in the Hodgkin-Huxley[426]

[1] Kv1.5 (Model ID = 21)

AnimalHuman 89
CellType Oocyte
Age 0 Days
Temperature9.0°C
Reversal -90.0 mV
Ion K +
Ligand ion
Reference L H Philipson et. al; Proc. Natl. Acad. Sci. U.S.A. 1991 Jan 1
mpower 1.0
mInf 1.0000/(1+ exp((v - -6.0000)/-6.4000))
mTau (-0.1163 * v) + 8.3300 If v lt 50
mTau 2 If v gteq 50
hpower 1.0
hInf 1.0000/(1+ exp((v - -25.3000)/3.5000))
hTau (-15.5000 * v) + 1620.0000 If v lt 100
hTau 50 If v gteq 100

MOD xml channelML

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Credits


Editor : Admin.

Contributors : Rajnish Ranjan, Michael Schartner, Nitin Khanna

To cite : [Editor], [Contributors]. Accessed on [Date] Channelpedia , http://channelpedia.epfl.ch/ionchannels/5