Intracellular intermediate conductance calcium activated potassium channels. Medical search. Frequent questions

Potassium intermediate/small conductance calcium-activated channel, subfamily N, member 4, also known as KCNN4, is a human gene encoding the KCa3.1 protein. (wikipedia.org)
This gene is similar to other KCNN family potassium channel genes, but it differs enough to possibly be considered as part of a new subfamily. (wikipedia.org)

elevation, while cation channel blockers, free radical scavengers, low extracellular [Ca2+], transition metal chelators, and removal of the cell wall inhibit this reaction. (deepdyve.com)

however, the mechanisms that coordinate photosynthesis and stomatal conductance have yet to be identified. (nature.com)
Similarly, across the lines, drought stress decreased stomatal conductance (37%), transpiration rate (42%), photosynthetic rate (40%), photosystem II quantum yield (20%), photochemical quenching (44%), and total dry matter production (34%) than irrigated control. (preprints.org)

Activation is followed by membrane hyperpolarization, which promotes calcium influx. (wikipedia.org)
Exogenous ascorbate also induces a moderate increase in programmed cell death symptoms in intact roots, but it does not activate Ca2+ influx currents in patch-clamped root protoplasts. (deepdyve.com)
Knockout of the beta1 subunit results in BK channels that fail to open, increased calcium influx and increased tone. (americanasthmafoundation.org)
This neurotoxicity appears also to be mediated by Zn 2+ influx, in large part through voltage-gated Ca 2+ channels and also through NMDA receptor-gated channels ( Koh and Choi, 1994 ) and Ca 2+ -permeable AMPA/kainate receptor-gated channels ( Yin and Weiss, 1995 ). (jneurosci.org)
In kidneys suffering from ischemia-reperfusion and in renal tubular epithelial cells subjected to hypoxia/reoxygenation, NCX extrudes Na + in exchange for Ca 2+ influx, resulting in intracellular Ca 2+ overload and tubular epithelial cell injury (Yamashita J, S Kita, T Iwamoto et al. (cellphysiolbiochem.com)
Nevertheless, they coordinately facilitate Na + influx, intracellular alkalinization, and ultimately Ca 2+ loading of the sarcoplasmic reticulum for excitation-contraction coupling (Garciarena CD et al. (cellphysiolbiochem.com)

These conclusions were, however, apparently contradicted by elegant experiments done on internally-perfused snail neurons, in which neither the injection of calmodulin, nor of the calmodulin-antagonist, trifluoperazine, were able to modify Ca-activated K currents ( Levitan and Levitan, 1986 ). (conicyt.cl)
On the other hand, these recent studies apparently also support the lack of involvement of calmodulin in the gating of the BK channels studied in Helix neurons by Levitan and Levitan (1986) . (conicyt.cl)
In hypothalamic neurons, modulators such as neuropeptide Y (NPY) and adenosine depress glutamatergic transmission by either a pertussis toxin (PTx)-sensitive G-protein-coupled pathway or by inhibition of voltage-activated calcium channels (VACCs). (jneurosci.org)
Effects of calcium-activated potassium channel modulators on afterhyperpolarizing potentials in identified motor and mechanosensory neurons of the medicinal leech. (harvard.edu)
We used the ratioable fluorescent dye mag-fura-5 to measure intracellular free Zn 2+ ([Zn 2+ ] i ) in cultured neocortical neurons exposed to neurotoxic concentrations of Zn 2+ in concert with depolarization or glutamate receptor activation and identified four routes of Zn 2+ entry. (jneurosci.org)
The kainate-induced increase was highly sensitive to Gd 3+ or Na + removal in most neurons but insensitive in a minority subpopulation ("cobalt-positive cells"), suggesting that a fourth route of neuronal Zn 2+ entry is through the Ca 2+ -permeable channels gated by certain subtypes of AMPA or kainate receptors. (jneurosci.org)
Although it would be useful to understand how neurons regulate intracellular cytosolic free Zn 2+ concentrations ([Zn 2+ ] i ), at present, the tools available for measuring dynamic changes in [Zn 2+ ] i are limited. (jneurosci.org)

Up-regulation of the IKCa1 potassium channel during T-cell activation. (wikipedia.org)

The KCa3.1 protein is part of a potentially heterotetrameric voltage-independent potassium channel that is activated by intracellular calcium. (wikipedia.org)
The encoded protein may be part of the predominant calcium-activated potassium channel in T-lymphocytes. (wikipedia.org)
On the other hand, BK channels have an aspartate-rich Ca-sensing region (a «calcium bowl») in the channel protein itself, which confers most of the Ca-sensitivity to the channel, although a second Ca-sensor also seems to be present ( Schreiber and Salkoff, 1997 ). (conicyt.cl)
The inhibition could be mimicked by the L-type calcium channel blocker nimodipine (1 μ m ) as well as by protein kinase C (PKC) activators phorbol 12,13-dibutyrate (10 μ m ) and phorbol 12-myristate 13-acetate (500 n m ), and blocked by the PKC inactivator (±)-1-(5-isoquinolinesulfonyl)-2-methylpiperazine (200 μ m ), suggesting a mechanism involving PKC modulation of L-type calcium channels. (jneurosci.org)
Neuromodulatory transmitters engage G-protein coupled receptors (GPCRs), activating intracellular signaling cascades that then can directly activate or modify the properties of ion channels. (frontiersin.org)
Smooth muscle cells express Kv7.4 and Kv7.5 voltage-dependent potassium channels, which have each been implicated as regulators of smooth muscle contractility, though they display different sensitivities to signaling via cAMP/protein kinase A (PKA) and protein kinase C (PKC). (aspetjournals.org)
Although there are many remaining uncertainties, this review highlights the idea that Best1 is a multifunctional protein, functioning as an anion channel with unique properties as well as a key regulator of various important brain functions. (en-journal.org)

9 As would be predicted from their known abilities to couple through pertussis toxin-sensitive G-proteins, all of the cloned opioid receptors possess the same general structure of an extracellular N-terminal region, seven transmembrane domains and intracellular C-terminal tail structure. (opioids.wiki)
This active transport creates a concentration gradient that favors the extracellular diffusion of potassium ions. (medscape.com)
The process restores the excess of intracellular potassium and extracellular sodium and reinstates the negative resting membrane potential. (medscape.com)
The NMDA-induced increase was only partly sensitive to Gd 3+ or to removal of extracellular Na + , consistent with a third route of entry directly through NMDA receptor-gated channels. (jneurosci.org)

Intermediate duration LTP (LTP 2) was associated with Ca increase in dendritic branches, due to activation of NMDA receptors and local IP3 receptors (IP3Rs). (yale.edu)

Best1 has intracellular N-termini and 4 transmembrane domains which are highly conserved between species. (en-journal.org)

The concentration gradients are maintained by the sodium/potassium ATP pump (in an energy-dependent process) that transports sodium ions out of the cell and potassium ions into the cell. (medscape.com)
In addition, because the nerve membrane is permeable to potassium ions and impermeable to sodium ions, 95% of the ionic leak in excitable cells is caused by K + ions in the form of an outward flux, accounting for the negative resting potential. (medscape.com)
Once membrane depolarization is complete, the membrane becomes impermeable to sodium ions again, and the conductance of potassium ions into the cell increases. (medscape.com)
Hyperaldosteronism is characterized by excessive secretion of aldosterone, which causes increases in sodium reabsorption and loss of potassium and hydrogen ions. (medscape.com)
Kv7 family channels mediate a voltage-dependent outward flux of potassium ions, which contributes to the establishment of negative membrane potentials in many cell types. (aspetjournals.org)
The essential metal ions for humans are the bulk metals sodium, potassium, calcium and magnesium and the trace metals manganese, iron, cobalt, copper, zinc and molybdenum, and, after outlining why they are required, we summarise the circumstances in which certain of them can be toxic. (rsc.org)

EPR spectroscopy measurements demonstrate that salinity (NaCl) triggers the accumulation of root apoplastic ascorbyl radicals in an A9C-dependent manner, confirming that l-ascorbate leaks through anion channels under depolarization. (deepdyve.com)
It is hypothesized that depolarization or block of potassium channels allows recruitment of voltage-dependent calcium channels (VDCCs) and increased contraction. (americanasthmafoundation.org)
Upon membrane depolarization, the KCNQ1 potassium channel opens at the intermediate (IO) and activated (AO) states of the stepwise voltage-sensing domain (VSD) activation. (elifesciences.org)
During membrane depolarization, the S4 segment moves outward from its resting state to the intermediate state to trigger the IO state opening. (elifesciences.org)

This study demonstrates that, in Arabidopsis roots, exogenous l-ascorbic acid triggers a transient increase of the cytosolic free calcium activity ([Ca2+]cyt. (deepdyve.com)

The recently identified 2-pore domain potassium (K2P) channels are believed to be responsible for leak K + currents. (medscape.com)
Apamin-sensitive calcium-activated potassium currents in rabbit ventricles with chronic myocardial infarction. (harvard.edu)
Cerebellar ataxia by enhanced Ca(V)2.1 currents is alleviated by Ca2+-dependent K+-channel activators in Cacna1a(S218L) mutant mice. (harvard.edu)
ML277 provides insights and a tool to investigate the gating mechanism of KCNQ1 channels, and our study reveals a new strategy for treating long QT syndrome by specifically enhancing the AO state of native I Ks currents. (elifesciences.org)

The presence in human red blood cells (RBCs) of a K permeability that was greatly enhanced by calcium was first reported by Gardós (1958) . (conicyt.cl)

The principal regulators of aldosterone synthesis and secretion are the renin-angiotensin system and the potassium ion concentration. (medscape.com)
Severe hypokalemia may require intravenous (IV) correction if the potassium concentration is less than 2.5 mmol/L or if the patient is clinically symptomatic. (medscape.com)
Note that inhibition of K V 7 channels is a downstream consequence of Ca V 3.2 modulation due to changes in intracellular calcium concentration. (frontiersin.org)

Unexpected down-regulation of the hIK1 Ca2+-activated K+ channel by its opener 1-ethyl-2-benzimidazolinone in HaCaT keratinocytes. (wikipedia.org)

In ventricular myocytes, intracellular Na + is centrally involved in regulation of cardiac Ca 2+ and contractility by the way of an Na +/ H + exchanger (NHE1), NCX, and Na + channel (Despa S et al. (cellphysiolbiochem.com)

Previously, we had shown that the BK channel accessory beta1 subunit is required for BK channel function in vascular smooth muscle and bladder smooth muscle. (americanasthmafoundation.org)
Finally, it seems appropriate to consider the "sodium channel syndrome" (mutations in the gene of the α subunit of the sodium channel, SCN5A gene) as a single clinical entity that may manifest in a wide range of phenotypes, to thus have a better insight on these cardiac syndromes and potential outcomes for their clinical treatment. (bvsalud.org)

The channel is also named Gardos channel because of its discoverer. (wikipedia.org)

We expressed chimeric channels composed of different components of the Kv7.4 and Kv7.5 α -subunits in vascular smooth muscle cells to determine which components are essential for enhancement or inhibition of channel activity. (aspetjournals.org)
CBC1/CBC2 redundantly stimulate stomatal opening by inhibition of S-type anion channels in response to both BL and low concentrations of CO 2 . (nature.com)

Based on differences in unitary conductances, sensitivity to drugs, and voltage-dependence, this allowed the classification of the channels as small (SK), with unitary conductances of 4 - 14 pS that are blocked by apamin and are insensitive to voltage. (conicyt.cl)
Intriguingly, the replacement of gluconate with ascorbate in the patch-clamp pipette reveals a large ascorbate efflux current, which shows sensitivity to the anion channel blocker, anthracene-9-carboxylic acid (A9C), indicative of the ascorbate release via anion channels. (deepdyve.com)
Forskolin treatment reduced the sensitivity of Kv7.5 channels to Ciona intestinalis voltage-sensing phosphatase (Ci-VSP)-induced PIP 2 depletion, whereas activation of PKC with phorbol-12-myristate-13-acetate potentiated the Ci-VSP-induced decline in Kv7.5 current amplitude. (aspetjournals.org)
The prominence of Kv7 channels as regulators of electrical excitability may be ascribed to their unique properties, such as a very negative threshold of activation (negative to −50 mV), absence of time-dependent inactivation, and high sensitivity to signal transduction pathways that influence their probability of opening, either positively or negatively ( Delmas and Brown, 2005 ). (aspetjournals.org)

Functional states of the sodium channel (closed, open, and inactivated) and their structure help to understand the cardiac regulation processes. (bvsalud.org)
Cervical vertebrae 1,2, …?Ca: Calcium?Ca: Cancer?Ca: Carcinoma?Ca: Cardiac arrest?Ca: Coronary artery?CA-125: A tumor marker for ovarian cancer?CAB: Cellulose acetate butyrate?CABG: Coronary artery bypass graft?CACI: Computer-Assisted Continuous Infusion?CAD: Coronary artery disease?CAG: ?CAH: Chronic active hepatitis?CAH: Congenital adrenal hyperplasia?calid. (kuwaitpharmacy.com)

Sodium (Na V ), potassium (K V ), and calcium (Ca V ) permeable voltage-gated ion channels are shown in red, blue, and green, respectively. (frontiersin.org)

SIGNIFICANCE STATEMENT Kv7.4 and Kv7.5 channels are known signal transduction intermediates and drug targets for regulation of smooth muscle tone. (aspetjournals.org)

The large conductance calcium-activated (BK type) potassium channel is activated by calcium and voltage, and so this channel is an ideal negative-feedback regulator of VDCCs. (americanasthmafoundation.org)

This was better defined when recordings were made of single channels in many different preparations in combination with the use of selective blockers. (conicyt.cl)

Simulating the volume of the tissue activated, we confirm that the proposed targets are reported as optimal targets (sweet spots) to be beneficial for the improvement of motor symptoms. (frontiersin.org)

We showed previously that cytoplasmic release of mtDNA activates the cGAS STING TBK1 pathway resulting in interferon-stimulated gene (ISG) expression that promotes antiviral immunity4. (regenerativemedicine.net)

Although airway smooth muscle (ASM) contraction is initiated by calcium release from intracellular stores, there is considerable evidence that the control of membrane potential by potassium channels is an important factor in regulating ASM constriction. (americanasthmafoundation.org)

In the heart, KCNQ1 associates with KCNE1 subunits to form I Ks channels that regulate heart rhythm. (elifesciences.org)

We studied modulation of glutamate-evoked calcium rises in primary astrocyte cultures using fura-2 ratiometric digital calcium imaging. (jneurosci.org)
It was already known that GrC of vestibulo-cerebellum are specialized to slow-down firing modulation based on the expression of low-threshold Ca 2+ channels 27 . (nature.com)
Here, we review cellular mechanisms and signaling pathways involved in axonal ion channel modulation and examine how changes to ion channel function affect AP initiation, AP propagation, and the release of neurotransmitter. (frontiersin.org)

Very recently, the sequencing of the genes that code for SK, IK and BK channels has allowed a definition of the mechanisms of channel gating and of the participation of calmodulin in it. (conicyt.cl)
Kv7 channels are encoded by KCNQ genes (1 through 5). (aspetjournals.org)

Intermediate (IK) channels, on the other hand, have conductances of 11- 40 pS, are voltage-independent, may be blocked by iberiotoxin and charybdotoxin (Ch Tx), and are found in red and white blood cells, colon, lung, pancreas, and other tissues. (conicyt.cl)
The type III mGluR agonist l -2-amino-4-phosphonobutyrate consistently inhibited 5HT-evoked calcium rises, whereas in a smaller number of cells quisqualate and L-CCG-I showed both inhibitory and additive effects. (jneurosci.org)
Case Report on: Very Early Afterdepolarizations in HiPSC-Cardiomyocytes-An Artifact by Big Conductance Calcium Activated Potassium Current (Ibk,Ca). Cells. (harvard.edu)
Malate is synthesized in guard cells via starch degradation that is induced by the activated H + -ATPase 27 . (nature.com)

Ca(2+)-activated K(+) channel-3.1 blocker TRAM-34 attenuates airway remodeling and eosinophilia in a murine asthma model. (harvard.edu)

The present studies identify distinct functional domains that confer differential sensitivities of Kv7.4 and Kv7.5 to stimulatory and inhibitory signaling and reveal structural features of the channel subunits that determine their biophysical properties. (aspetjournals.org)
functional channels form as homo- or hetero-tetramers of α -subunits ( Delmas and Brown, 2005 ). (aspetjournals.org)
Heart relaxation also stands out as an active process, dependent on the energetic output and on specific ion and enzymatic actions, with the role of sodium channel being outstanding in the functional process. (bvsalud.org)

Changes in intracellular calcium not only modify glial physiology, but they also seem to be involved in complex intercellular communication networks (for review, see Finkbeiner, 1993 ). (jneurosci.org)
These findings may improve our understanding of the roles of these channels in smooth muscle physiology and disease, particularly in conditions where Kv7.4 and Kv7.5 are differentially expressed. (aspetjournals.org)

Later experiments, in which six different calmodulin-inhibitory drugs were tested on the Ca-activated K conductance of human RBCs, showed that all were potent inhibitors of this conductance and that their effect showed a correlation coefficient of 0.98 with that found on RBC Ca-ATPase, a membrane enzyme known to be activated by calmodulin ( Lackington and Orrego, 1981 ). (conicyt.cl)
All these findings thus seemed to firmly support a role for calmodulin in the gating of these Ca-activated K channels. (conicyt.cl)
At the time, this seemed to tip the balance against a participation of calmodulin in these channels. (conicyt.cl)

Calcium plays a key role as a second messenger system in astrocytes, both in regulation of many subcellular processes and in long distance intercellular signaling. (jneurosci.org)
Neuromodulatory regulation of ion channels affects how ion channels respond to voltage deflections on short and long time scales, thus affecting how certain features of synaptic input are transformed into neuronal output. (frontiersin.org)

however, the signaling components connecting the phototropins, the H + -ATPase, and the anion channels remain unknown. (nature.com)

This mechanism may underlie ascorbate release, signalling phenomena, apoplastic redox reactions, iron acquisition, and control the ionic and electrical equilibrium (together with K+ efflux via GORK channels). (deepdyve.com)
Now, eight transporters were found to control the uptake and efflux of calcium. (mdpi.com)

Subsequent movement of the S4 helix from the intermediate state to the activated state then triggers conformational change of the pore from the IO state to the AO state. (elifesciences.org)

Of these, four: sodium, potassium, calcium and magnesium, can be considered as 'bulk elements', and together constitute approximately 99% of the metal ion content of the human body. (rsc.org)

From a physiological and pathophysiological point of view, the conformational states of the sodium channel during heart function constitute a significant aspect for the diagnosis and treatment of heart diseases. (bvsalud.org)

The channel activity was first described in 1958 by György Gárdos in human erythrocytes. (wikipedia.org)

BK channel opening hyperpolarizes membranes, deactivates VDCCs and thereby opposes contraction. (americanasthmafoundation.org)
1989), however, suggested that there is no NCX in basolateral membranes in proximal tubules but that instead, intracellular calcium pools within the mitochondria and elsewhere contribute to Na + /Ca 2+ exchange. (cellphysiolbiochem.com)

Recent advances, including the ability to more directly interrogate ion channel function in small axonal compartments, has improved our understanding of how channel function is regulated in these compartments. (frontiersin.org)
as a result, the output spike pattern of a neuron is highly sensitive to the neuromodulation of the small fraction of ion channels localized to the AIS. (frontiersin.org)

Potassium channels whose activation is dependent on intracellular calcium concentrations. (harvard.edu)

The authors used 2-photon microscopy to obtain high resolution images of calcium signals in the apical dendrites while activating Schaffer collateral inputs to induce long-term potentiation (LTP) of different durations. (yale.edu)

pathological vitamin are less almost added than their inner basophils, and are proteolytically classified as neonatal activated on their adhesion of beginning by MAPKK site channels. (evakoch.com)

Instead, a specific subset of ISGs that includes Parp9 remains activated by the unphosphorylated form of ISGF3 that enhances nDNA damage and repair responses. (regenerativemedicine.net)

Though these calcium transporters have been identified through genome-wide analysis, only a few of them were functionally verified. (mdpi.com)

In contrast, mGluRs modulated serotonin (5HT)-evoked calcium rises through a different mechanism. (jneurosci.org)
This observation not just supported that conductance tuning would allow the emergence of a richness of electroresponsive properties, but also implied the presence of yet unrecognized ionic mechanism causing firing acceleration. (nature.com)

Anatomy27

Organisms16

Diseases3

Chemicals and Drugs151

Analytical, Diagnostic and Therapeutic Techniques and Equipment12

Psychiatry and Psychology1

Phenomena and Processes41

Disciplines and Occupations4

Technology, Industry, Agriculture1

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Subfamily2

Cation channel1

Stomatal conductance2

Influx6

Neurons7

IKCa11

Protein7

Extracellular4

Receptors1

Transmembrane1

Ions6

Depolarization4

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HIK11

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Targets1

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Regulate1

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19581

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Transporters1

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