keyword
MENU ▼
Read by QxMD icon Read
search

BK channel

keyword
https://www.readbyqxmd.com/read/29237755/differential-contribution-of-ca2-sources-to-day-and-night-bk-current-activation-in-the-circadian-clock
#1
Joshua P Whitt, Beth A McNally, Andrea L Meredith
Large conductance K+ (BK) channels are expressed widely in neurons, where their activation is regulated by membrane depolarization and intracellular Ca2+ (Ca2+i). To enable this regulation, BK channels functionally couple to both voltage-gated Ca2+ channels (VGCCs) and channels mediating Ca2+ release from intracellular stores. However, the relationship between BK channels and their specific Ca2+ source for particular patterns of excitability is not well understood. In neurons within the suprachiasmatic nucleus (SCN)-the brain's circadian clock-BK current, VGCC current, and Ca2+i are diurnally regulated, but paradoxically, BK current is greatest at night when VGCC current and Ca2+i are reduced...
December 13, 2017: Journal of General Physiology
https://www.readbyqxmd.com/read/29217678/hrpu-2-a-homologue-of-mammalian-hnrnp-u-regulates-synaptic-transmission-by-controlling-the-expression-of-slo-2-potassium-channel-in-c-elegans
#2
Ping Liu, Sijie Jason Wang, Zhao-Wen Wang, Bojun Chen
Slo2 channels are large-conductance potassium channels abundantly expressed in the nervous system. However, it is unclear how their expression level in neurons is regulated. Here we report that HRPU-2, an RNA-binding protein homologous to mammalian hnRNP U, plays an important role in regulating the expression of SLO-2 (a homologue of mammalian Slo2) in C. elegans Loss-of-function (lf) mutants of hrpu-2 were isolated in a genetic screen for suppressors of a sluggish phenotype caused by a hyperactive SLO-2. In hrpu-2(lf) mutants, SLO-2-mediated delayed outward currents in neurons are greatly decreased, and neuromuscular synaptic transmission is enhanced...
December 7, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/29211339/%C3%AE-3-adrenoceptor-agonists-inhibit-carbachol-evoked-ca2-oscillations-in-murine-detrusor-myocytes
#3
Caoimhin S Griffin, Eamonn Bradley, Mark A Hollywood, Noel G McHale, Keith D Thornbury, Gerard P Sergeant
OBJECTIVE: To test if carbachol-evoked Ca2+ oscillations in freshly isolated murine detrusor myocytes were affected by β3-adrenoceptor modulators. MATERIAL & METHODS: Isometric tension recordings were made from strips of murine detrusor and intracellular Ca2+ measurements were made from isolated detrusor myocytes using confocal microscopy. Transcriptional expression of β-AR sub-types in detrusor strips and isolated detrusor myocytes was assessed using RT-PCR and real-time quantitative PCR...
December 6, 2017: BJU International
https://www.readbyqxmd.com/read/29204711/voltage-sensitive-potassium-channels-of-the-bk-type-and-their-coding-genes-are-alcohol-targets-in-neurons
#4
Alex M Dopico, Anna N Bukiya, Jill C Bettinger
Among all members of the voltage-gated, TM6 ion channel superfamily, the proteins that constitute calcium- and voltage-gated potassium channels of large conductance (BK) and their coding genes are unique for their involvement in ethanol-induced disruption of normal physiology and behavior. Moreover, in vitro studies document that BK activity is modified by ethanol with an EC50~23 mM, which is near blood alcohol levels considered legal intoxication in most states of the USA (0.08 g/dL = 17.4 mM). Following a succinct introduction to our current understanding of BK structure and function in central neurons, with a focus on neural circuits that contribute to the neurobiology of alcohol use disorders (AUD), we review the modifications in organ physiology by alcohol exposure via BK and the different molecular elements that determine the ethanol response of BK in alcohol-naïve systems, including the role of an ethanol-recognizing site in the BK-forming slo1 protein, modulation of accessory BK subunits, and their coding genes...
December 5, 2017: Handbook of Experimental Pharmacology
https://www.readbyqxmd.com/read/29188803/activation-of-human-smooth-muscle-bk-channels-by-hydrochlorothiazide-requires-cell-integrity-and-the-presence-of-bk-%C3%AE-1-subunit
#5
Pedro Martín, Melisa Moncada, Guruprasad Kuntamallappanavar, Alex M Dopico, Verónica Milesi
Thiazide-like diuretics are the most commonly used drugs to treat arterial hypertension, with their efficacy being linked to their chronic vasodilatory effect. Previous studies suggest that activation of the large conductance voltage- and Ca2+-dependent K+ (BK) channel (Slo 1, MaxiK channel) is responsible for the thiazide-induced vasodilatory effect. But the direct electrophysiological evidence supporting this claim is lacking. BK channels can be associated with one small accessory β-subunit (β1-β4) that confers specific biophysical and pharmacological characteristics to the current phenotype...
November 30, 2017: Acta Pharmacologica Sinica
https://www.readbyqxmd.com/read/29163049/tagging-of-endogenous-bk-channels-with-a-fluorogen-activating-peptide-reveals-%C3%AE-4-mediated-control-of-channel-clustering-in-cerebellum
#6
Christopher P Pratt, Dika A Kuljis, Gregg E Homanics, Jianjun He, Dmytro Kolodieznyi, Srikanth Dudem, Mark A Hollywood, Alison L Barth, Marcel P Bruchez
BK channels are critical regulators of neuronal activity, controlling firing, neurotransmitter release, cerebellar function, and BK channel mutations have been linked to seizure disorders. Modulation of BK channel gating is well characterized, regulated by accessory subunit interactions, intracellular signaling pathways, and membrane potential. In contrast, the role of intracellular trafficking mechanisms in controlling BK channel function, especially in live cells, has been less studied. Fluorogen-activating peptides (FAPs) are well-suited for trafficking and physiological studies due to the binding of malachite green (MG)-based dyes with sub-nanomolar affinity to the FAP, resulting in bright, photostable, far-red fluorescence...
2017: Frontiers in Cellular Neuroscience
https://www.readbyqxmd.com/read/29160573/activation-of-voltage-dependent-k-channels-strongly-limits-hypoxia-induced-elevation-of-ca-2-i-in-rat-carotid-body-glomus-cells
#7
Jiaju Wang, Donghee Kim
Large-conductance KCa (BK) and other voltage-dependent K(+) channels (Kv) are highly expressed in carotid body (CB) glomus cells, but their role in hypoxia-induced excitation is still not well defined and remains controversial. We addressed this issue by studying the effects of inhibitors of BK (IBTX) and BK/Kv (TEA/4-AP) on [Ca(2+) ]i responses to a wide range of hypoxia at different levels of resting cell Em. IBTX and TEA/4-AP did not affect the basal [Ca(2+) ]i in isolated glomus cells bathed in 5 mm KClo , but elicited transient increases in [Ca(2+) ]i in cells that were moderately depolarized (11-20 mV) by elevation of [KCl]o (12-20 mm)...
November 21, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/29152668/the-role-of-astrocytic-calcium-and-trpv4-channels-in-neurovascular-coupling
#8
Allanah Kenny, Michael J Plank, Tim David
Neuronal activity evokes a localised change in cerebral blood flow in a response known as neurovascular coupling (NVC). Although NVC has been widely studied the exact mechanisms that mediate this response remain unclear; in particular the role of astrocytic calcium is controversial. Mathematical modelling can be a useful tool for investigating the contribution of various signalling pathways towards NVC and for analysing the underlying cellular mechanisms. The lumped parameter model of a neurovascular unit with both potassium and nitric oxide (NO) signalling pathways and comprised of neurons, astrocytes, and vascular cells has been extended to include the glutamate induced astrocytic calcium pathway with epoxyeicosatrienoic acid (EET) signalling and the stretch dependent TRPV4 calcium channel on the astrocytic endfoot...
November 20, 2017: Journal of Computational Neuroscience
https://www.readbyqxmd.com/read/29145442/downregulation-of-kcnmb4-expression-and-changes-in-bk-channel-subtype-in-hippocampal-granule-neurons-following-seizure-activity
#9
Luke E Whitmire, Ling Ling, Vladslav Bugay, Chase M Carver, Santosh Timilsina, Hui-Hsiu Chuang, David B Jaffe, Mark S Shapiro, Jose E Cavazos, Robert Brenner
A major challenge is to understand maladaptive changes in ion channels that sets neurons on a course towards epilepsy development. Voltage- and calcium-activated K+ (BK) channels contribute to early spike timing in neurons, and studies indicate that the BK channel plays a pathological role in increasing excitability early after a seizure. Here, we have investigated changes in BK channels and their accessory β4 subunit (KCNMB4) in dentate gyrus (DG) granule neurons of the hippocampus, key neurons that regulate excitability of the hippocampus circuit...
2017: PloS One
https://www.readbyqxmd.com/read/29144974/double-nanodomain-coupling-of-calcium-channels-ryanodine-receptors-and-bk-channels-controls-the-generation-of-burst-firing
#10
Tomohiko Irie, Laurence O Trussell
Action potentials clustered into high-frequency bursts play distinct roles in neural computations. However, little is known about ionic currents that control the duration and probability of these bursts. We found that, in cartwheel inhibitory interneurons of the dorsal cochlear nucleus, the likelihood of bursts and the interval between their spikelets were controlled by Ca2+ acting across two nanodomains, one between plasma membrane P/Q Ca2+ channels and endoplasmic reticulum (ER) ryanodine receptors and another between ryanodine receptors and large-conductance, voltage- and Ca2+-activated K+ (BK) channels...
November 15, 2017: Neuron
https://www.readbyqxmd.com/read/29136290/the-role-of-ca-2-dependent-k-channels-at-the-rat-corticostriatal-synapses-revealed-by-paired-pulse-stimulation
#11
Angel A Robles G, Ana V Vega, Carolina Gonzalez-Sandoval, Jaime Barral
Potassium channels play an important role in modulating synaptic activity both at presynaptic and postsynaptic levels. We have shown before that presynaptically located KV and KIR channels modulate the strength of corticostriatal synapses in rat brain, but the role of other types of potassium channels at these synapses remains largely unknown. Here we show that calcium-dependent potassium channels BK-type but not SK-type channels are located presynaptically in corticostriatal synapses. We stimulated cortical neurons in rat brain slices and recorded postsynaptic excitatory potentials (EPSP) in medium spiny neurons (MSN) in dorsal neostriatum...
November 14, 2017: Synapse
https://www.readbyqxmd.com/read/29051185/cgmp-elevating-compounds-and-ischemic-conditioning-provide-cardioprotection-against-ischemia-and-reperfusion-injury-via-cardiomyocyte-specific-bk-channels
#12
Sandra Frankenreiter, Piotr Bednarczyk, Angelina Kniess, Nadja Bork, Julia Straubinger, Piotr Koprowski, Antoni Wrzosek, Eva Mohr, Angela Logan, Michael P Murphy, Meinrad Gawaz, Thomas Krieg, Adam Szewczyk, Viacheslav O Nikolaev, Peter Ruth, Robert Lukowski
Background -The nitric oxide-sensitive guanylyl cyclase (NO-GC)/cyclic guanosine-3',5'-monophosphate (cGMP)/cGMP-dependent protein kinase type I (cGKI)-signaling pathway can afford protection against the ischemia and reperfusion (I/R) injury that occurs during myocardial infarction (MI). Reportedly, voltage and Ca(2+)-activated K(+) channels of the BK-type are stimulated by cGMP/cGKI and recent ex-vivo studies implicated that increased BK activity favors the survival of the myocardium at I/R. It remains unclear, however, whether the molecular events downstream of cGMP involve BK channels present in cardiomyocytes (CMs) or in other cardiac cell types...
October 19, 2017: Circulation
https://www.readbyqxmd.com/read/29050967/role-of-k-channels-in-regulating-spontaneous-activity-in-the-muscularis-mucosae-of-guinea-pig-bladder
#13
Ken Lee, Ayu Isogai, Minori Antoh, Shunichi Kajioka, Masatoshi Eto, Hikaru Hashitani
To explore the roles of various K(+) channels in regulating the spontaneous activity of bladder muscularis mucosae (MM) that is considered to play an important role in maintaining mucosal function. Effects of K(+) channel modulators on electrical and contractile activity in the guinea-pig bladder MM were examined using intracellular microelectrode and isometric tension recording. The MM predominately generated bursting spontaneous action potentials (SAPs) and phasic contractions (SPCs) that were blocked by nifedipine (1µM)...
October 16, 2017: European Journal of Pharmacology
https://www.readbyqxmd.com/read/29040972/regulation-of-coronary-arterial-large-conductance-ca2-activated-k-channel-protein-expression-and-function-by-n-3-polyunsaturated-fatty-acids-in-diabetic-rats
#14
Xu Tang, Ling-Ling Qian, Ru-Xing Wang, Yong Yao, Shi-Peng Dang, Ying Wu, Wen Wang, Yuan Ji, Man-Qing Sun, Da-Yun Xia, Xiao-Yu Liu, Dai-Min Zhang, Qiang Chai, Tong Lu
AIM: The objective of this study was to examine the effects of n-3 polyunsaturated fatty acids (n-3 PUFAs) on coronary arterial large conductance Ca2+-activated K+ (BK) channel function in coronary smooth muscle cells (SMCs) of streptozotocin-induced diabetic rats. METHODS: The effects of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on coronary BK channel open probabilities were determined using the patch clamp technique. The mRNA and protein expressions of BK channel subunits were measured using qRT-PCR and Western blots...
October 18, 2017: Journal of Vascular Research
https://www.readbyqxmd.com/read/29025867/threading-the-biophysics-of-mammalian-slo1-channels-onto-structures-of-an-invertebrate-slo1-channel
#15
REVIEW
Yu Zhou, Huanghe Yang, Jianmin Cui, Christopher J Lingle
For those interested in the machinery of ion channel gating, the Ca(2+) and voltage-activated BK K(+) channel provides a compelling topic for investigation, by virtue of its dual allosteric regulation by both voltage and intracellular Ca(2+) and because its large-single channel conductance facilitates detailed kinetic analysis. Over the years, biophysical analyses have illuminated details of the allosteric regulation of BK channels and revealed insights into the mechanism of BK gating, e.g., inner cavity size and accessibility and voltage sensor-pore coupling...
November 6, 2017: Journal of General Physiology
https://www.readbyqxmd.com/read/29016852/potassium-channel-dysfunction-underlies-purkinje-neuron-spiking-abnormalities-in-spinocerebellar-ataxia-type-2
#16
James M Dell'Orco, Stefan M Pulst, Vikram G Shakkottai
Alterations in Purkinje neuron firing often accompany ataxia, but the molecular basis for these changes is poorly understood. In a mouse model of spinocerebellar ataxia type 2 (SCA2), a progressive reduction in Purkinje neuron firing frequency accompanies cell atrophy. We investigated the basis for altered Purkinje neuron firing in SCA2. A reduction in the expression of large-conductance calcium-activated potassium (BK) channels and Kv3.3 voltage-gated potassium channels accompanies the inability of Purkinje neurons early in disease to maintain repetitive spiking...
October 15, 2017: Human Molecular Genetics
https://www.readbyqxmd.com/read/28986465/dendritic-and-axonal-l-type-calcium-channels-cooperate-to-enhance-motoneuron-firing-output-during-drosophila-larval-locomotion
#17
Dimitrios Kadas, Aylin Klein, Niklas Krick, Jason W Worrell, Stefanie Ryglewski, Carsten Duch
Behaviorally adequate neuronal firing patterns are critically dependent on the specific types of ion channel expressed and on their subcellular localization. This study combines in situ electrophysiology with genetic and pharmacological intervention in larval Drosophila melanogaster of both sexes to address localization and function of L-type like calcium channels in motoneurons. We demonstrate that Dmca1D (Cav1 homolog) L-type like calcium channels localize to both, the somatodendritic and the axonal compartment of larval crawling motoneurons...
October 6, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28979317/the-role-of-bk-channels-in-antiseizure-action-of-the-cb1-receptor-agonist-acea-in-maximal-electroshock-and-pentylenetetrazole-models-of-seizure-in-mice
#18
Sina Asaadi, Mohammad Jahanbakhshi, Mahmoud Lotfinia, Nima Naderi
The anticonvulsant effect of cannabinoid compound has been shown in various models of seizure. On the other hand, there are controversial findings about the role of large conductance calcium-activated potassium (BK) channels in the pathogenesis of epilepsy. Also, there is no data regarding the effect of co-administration of cannabinoid type 1 (CB1) receptor agonists and BK channels antagonists in the acute models of seizure in mice. In this study, the effect of arachidonyl-2'-chloroethylamide (ACEA), a CB1 receptor agonist, and a BK channel antagonist, paxilline, either alone or in combination was investigated...
2017: Iranian Journal of Pharmaceutical Research: IJPR
https://www.readbyqxmd.com/read/28966112/functional-validation-of-ca-2-binding-residues-from-the-crystal-structure-of-the-bk-ion-channel
#19
Aravind S Kshatri, Alberto J Gonzalez-Hernandez, Teresa Giraldez
BK channels are dually regulated by voltage and Ca(2+), providing a cellular mechanism to couple electrical and chemical signalling. Intracellular Ca(2+) concentration is sensed by a large cytoplasmic region in the channel known as "gating ring", which is formed by four tandems of regulator of conductance for K(+) (RCK1 and RCK2) domains. The recent crystal structure of the full-length BK channel from Aplysia californica has provided new information about the residues involved in Ca(2+) coordination at the high-affinity binding sites located in the RCK1 and RCK2 domains, as well as their cooperativity...
September 29, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28955251/molecular-mechanisms-underlying-renin-angiotensin-aldosterone-system-mediated-regulation-of-bk-channels
#20
REVIEW
Zhen-Ye Zhang, Ling-Ling Qian, Ru-Xing Wang
Large-conductance calcium-activated potassium channels (BK channels) belong to a family of Ca(2+)-sensitive voltage-dependent potassium channels and play a vital role in various physiological activities in the human body. The renin-angiotensin-aldosterone system is acknowledged as being vital in the body's hormone system and plays a fundamental role in the maintenance of water and electrolyte balance and blood pressure regulation. There is growing evidence that the renin-angiotensin-aldosterone system has profound influences on the expression and bioactivity of BK channels...
2017: Frontiers in Physiology
keyword
keyword
14409
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"