keyword
MENU ▼
Read by QxMD icon Read
search

Bk channels

keyword
https://www.readbyqxmd.com/read/28818302/mitochondrial-ca-2-activated-k-channels-and-their-role-in-cell-life-and-death-pathways
#1
REVIEW
Inge E Krabbendam, Birgit Honrath, Carsten Culmsee, Amalia M Dolga
Ca(2+)-activated K(+) channels (KCa) are expressed at the plasma membrane and in cellular organelles. Expression of all KCa channel subtypes (BK, IK and SK) has been detected at the inner mitochondrial membrane of several cell types. Primary functions of these mitochondrial KCa channels include the regulation of mitochondrial ROS production, maintenance of the mitochondrial membrane potential and preservation of mitochondrial calcium homeostasis. These channels are therefore thought to contribute to cellular protection against oxidative stress through mitochondrial mechanisms of preconditioning...
July 22, 2017: Cell Calcium
https://www.readbyqxmd.com/read/28754781/nongenomic-modulation-of-the-large-conductance-voltage-and-ca-2-activated-k-channels-by-estrogen-a-novel-regulatory-mechanism-in-human-detrusor-smooth-muscle
#2
Kiril L Hristov, Shankar P Parajuli, Aaron Provence, Eric S Rovner, Georgi V Petkov
Estrogens have an important role in regulating detrusor smooth muscle (DSM) function. However, the underlying molecular and cellular mechanisms by which estrogens control human DSM excitability and contractility are not well known. Here, we used human DSM specimens from open bladder surgeries on 27 patients to elucidate the mechanism by which 17β-estradiol regulates large conductance voltage- and Ca(2+)-activated K(+) (BK) channels, the most prominent K(+) channels in human DSM We employed single BK channel recordings on inside-out excised membrane patches, perforated whole-cell patch-clamp on freshly isolated DSM cells, and isometric tension recordings on DSM-isolated strips to investigate the mechanism by which 17β-estradiol activates BK channels...
July 2017: Physiological Reports
https://www.readbyqxmd.com/read/28732502/chronic-glucocorticoid-exposure-activates-bk-nlrp1-signal-involving-in-hippocampal-neuron-damage
#3
Biqiong Zhang, Yaodong Zhang, Wenning Wu, Tanzhen Xu, Yanyan Yin, Junyan Zhang, Dake Huang, Weizu Li
BACKGROUND: Neuroinflammation mediated by NLRP1 (nucleotide-binding oligomerization domain (NOD)-like receptor protein 1) inflammasome plays an important role in many neurological diseases such as Parkinson's disease (PD) and Alzheimer's disease (AD). Our previous studies showed that chronic glucocorticoid (GC) exposure increased brain inflammation via NLRP1 inflammasome and induce neurodegeneration. However, little is known about the mechanism of chronic GC exposure on NLRP1 inflammasome activation in hippocampal neurons...
July 21, 2017: Journal of Neuroinflammation
https://www.readbyqxmd.com/read/28719636/the-non-diuretic-hypotensive-effects-of-thiazides-are-enhanced-during-volume-depletion-states
#4
Saeed Alshahrani, Robert M Rapoport, Kamyar Zahedi, Min Jiang, Michelle Nieman, Sharon Barone, Andrea L Meredith, John N Lorenz, Jack Rubinstein, Manoocher Soleimani
Thiazide derivatives including Hydrochlorothiazide (HCTZ) represent the most common treatment of mild to moderate hypertension. Thiazides initially enhance diuresis via inhibition of the kidney Na+-Cl- Cotransporter (NCC). However, chronic volume depletion and diuresis are minimal while lowered blood pressure (BP) is maintained on thiazides. Thus, a vasodilator action of thiazides is proposed, likely via Ca2+-activated K+ (BK) channels in vascular smooth muscles. This study ascertains the role of volume depletion induced by salt restriction or salt wasting in NCC KO mice on the non-diuretic hypotensive action of HCTZ...
2017: PloS One
https://www.readbyqxmd.com/read/28696251/endothelin-1-stimulates-vasoconstriction-through-rab11a-serine-177-phosphorylation
#5
Xue Zhai, Marie D Leo, Jonathan H Jaggar
Rationale: Large-conductance calcium (Ca(2+))-activated potassium channels (BK) are composed of pore-forming BKα and auxiliary β1 subunits in arterial smooth muscle cells (myocytes). Vasoconstrictors, including endothelin-1 (ET-1), inhibit myocyte BK channels, leading to contraction, but mechanisms involved are unclear. Recent evidence indicates that BKα is primarily plasma membrane-localized, whereas the cellular location of β1 can be rapidly altered by Rab11A-positive recycling endosomes. Whether vasoconstrictors regulate the multi-subunit composition of surface BK channels to stimulate contraction is unclear...
July 10, 2017: Circulation Research
https://www.readbyqxmd.com/read/28693898/nanosecond-pulsed-electric-fields-depolarize-transmembrane-potential-via-voltage-gated-k-ca-2-and-trpm8-channels-in-u87-glioblastoma-cells
#6
Ryan C Burke, Sylvia M Bardet, Lynn Carr, Sergii Romanenko, Delia Arnaud-Cormos, Philippe Leveque, Rodney P O'Connor
Nanosecond pulsed electric fields (nsPEFs) have a variety of applications in the biomedical and biotechnology industries. Cancer treatment has been at the forefront of investigations thus far as nsPEFs permeabilize cellular and intracellular membranes leading to apoptosis and necrosis. nsPEFs may also influence ion channel gating and have the potential to modulate cell physiology without poration of the membrane. This phenomenon was explored using live cell imaging and a sensitive fluorescent probe of transmembrane voltage in the human glioblastoma cell line, U87 MG, known to express a number of voltage-gated ion channels...
July 8, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28665272/proximal-clustering-between-bk-and-cav1-3-channels-promotes-functional-coupling-and-bk-channel-activation-at-low-voltage
#7
Oscar Vivas, Claudia M Moreno, Luis F Santana, Bertil Hille
CaV-channel dependent activation of BK channels is critical for feedback control of both calcium influx and cell excitability. Here we addressed the functional and spatial interaction between BK and CaV1.3 channels, unique CaV1 channels that activate at low voltages. We found that when BK and CaV1.3 channels were co-expressed in the same cell, BK channels started activating near -50 mV, ~30 mV more negative than for activation of co-expressed BK and high-voltage activated CaV2.2 channels. In addition, single-molecule localization microscopy revealed striking clusters of CaV1...
June 30, 2017: ELife
https://www.readbyqxmd.com/read/28600454/the-slo-w-path-to-identifying-the-mitochondrial-channels-responsible-for-ischemic-protection
#8
REVIEW
Charles Owen Smith, Keith Nehrke, Paul S Brookes
Mitochondria play an important role in tissue ischemia and reperfusion (IR) injury, with energetic failure and the opening of the mitochondrial permeability transition pore being the major causes of IR-induced cell death. Thus, mitochondria are an appropriate focus for strategies to protect against IR injury. Two widely studied paradigms of IR protection, particularly in the field of cardiac IR, are ischemic preconditioning (IPC) and volatile anesthetic preconditioning (APC). While the molecular mechanisms recruited by these protective paradigms are not fully elucidated, a commonality is the involvement of mitochondrial K(+) channel opening...
June 9, 2017: Biochemical Journal
https://www.readbyqxmd.com/read/28596131/control-of-anterior-pituitary-cell-excitability-by-calcium-activated-potassium-channels
#9
REVIEW
Michael J Shipston
In anterior pituitary endocrine cells, large (BK), small (SK) and intermediate (IK) conductance calcium activated potassium channels are key determinants in shaping cellular excitability in a cell type- and context-specific manner. Indeed, these channels are targeted by multiple signaling pathways that stimulate or inhibit cellular excitability. BK channels can, paradoxically, both promote electrical bursting as well as terminate bursting and spiking dependent upon intrinsic BK channel properties and proximity to voltage gated calcium channels in somatotrophs, lactotrophs and corticotrophs...
June 5, 2017: Molecular and Cellular Endocrinology
https://www.readbyqxmd.com/read/28571761/the-temperature-dependence-of-the-bk-channel-activity-kinetics-thermodynamics-and-long-range-correlations
#10
Agata Wawrzkiewicz-Jałowiecka, Beata Dworakowska, Zbigniew J Grzywna
Large-conductance, voltage dependent, Ca(2+)-activated potassium channels (BK) are transmembrane proteins that regulate many biological processes by controlling potassium flow across cell membranes. Here, we investigate to what extent temperature (in the range of 17-37°C with ΔT=5°C step) is a regulating parameter of kinetic properties of the channel gating and memory effect in the series of dwell-time series of subsequent channel's states, at membrane depolarization and hyperpolarization. The obtained results indicate that temperature affects strongly the BK channels' gating, but, counterintuitively, it exerts no effect on the long-range correlations, as measured by the Hurst coefficient...
May 29, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28550175/chronic-hypoxia-attenuates-the-vasodilator-efficacy-of-protein-kinase-g-in-fetal-and-adult-ovine-cerebral-arteries
#11
Richard B Thorpe, Margaret C Hubbell, Jinjutha Silpanisong, James M Williams, William J Pearce
Long-term hypoxia (LTH) attenuates nitric oxide-induced vasorelaxation in ovine middle cerebral arteries. Because cGMP-dependent protein kinase (PKG) is an important mediator of NO signaling in vascular smooth muscle, we tested the hypothesis that LTH diminishes the ability of PKG to interact with target proteins and cause vasorelaxation. Prominent among proteins that regulate vascular tone is the large-conductance Ca(2+)-sensitive K(+) (BK) channel, which is a substrate for PKG and is responsive to phosphorylation on multiple serine/threonine residues...
July 1, 2017: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/28546434/behavioral-deficits-following-withdrawal-from-chronic-ethanol-are-influenced-by-slo-channel-function-in-caenorhabditis-elegans
#12
Luisa L Scott, Scott J Davis, Rachel C Yen, Greg J Ordemann, Sarah K Nordquist, Deepthi Bannai, Jonathan T Pierce
Symptoms of withdrawal from chronic alcohol use are a driving force for relapse in alcohol dependence. Thus, uncovering molecular targets to lessen their severity is key to breaking the cycle of dependence. Using the nematode Caenorhabditis elegans, we tested whether one highly conserved ethanol target, the large-conductance, calcium-activated potassium channel (known as the BK channel or Slo1), modulates ethanol withdrawal. Consistent with a previous report, we found that C. elegans displays withdrawal-related behavioral impairments after cessation of chronic ethanol exposure...
July 2017: Genetics
https://www.readbyqxmd.com/read/28487419/membrane-depolarization-activates-bk-channels-through-rock-mediated-%C3%AE-1-subunit-surface-trafficking-to-limit-vasoconstriction
#13
M Dennis Leo, Xue Zhai, Padmapriya Muralidharan, Korah P Kuruvilla, Simon Bulley, Frederick A Boop, Jonathan H Jaggar
Membrane depolarization of smooth muscle cells (myocytes) in the small arteries that regulate regional organ blood flow leads to vasoconstriction. Membrane depolarization also activates large-conductance calcium (Ca(2+))-activated potassium (BK) channels, which limits Ca(2+) channel activity that promotes vasoconstriction, thus leading to vasodilation. We showed that in human and rat arterial myocytes, membrane depolarization rapidly increased the cell surface abundance of auxiliary BK β1 subunits but not that of the pore-forming BKα channels...
May 9, 2017: Science Signaling
https://www.readbyqxmd.com/read/28487418/science-signaling-podcast-for-9-may-2017-trafficking-of-bk-channel-subunits-in-arterial-myocytes
#14
Jonathan H Jaggar, Annalisa M VanHook
This Podcast features a conversation with Jonathan Jaggar, senior author of a Research Article that appears in the 9 May 2017 issue of Science Signaling, about trafficking of big potassium (BK) channel subunits in arterial myocytes. Depolarization of the arterial myocyte membrane causes a rise in intracellular calcium that stimulates the cell to contract, which leads to vasoconstriction. Membrane depolarization also activates BK channels, which allow potassium to flow out of the cell, thus repolarizing the membrane and promoting vasodilation...
May 9, 2017: Science Signaling
https://www.readbyqxmd.com/read/28481415/large-conductance-ca-2-activated-k-channel-activation-by-apical-p2y-receptor-agonists-requires-hydrocortisone-in-differentiated-airway-epithelium
#15
Nathan A Zaidman, Angela Panoskaltsis-Mortari, Scott M O'Grady
KEY POINTS: Hydrocortisone (HC) is required for activation of large-conductance Ca(2+) -activated K(+) current (BK) by purinergic receptor agonists. HC reduces insertion of the stress-regulated exon (STREX) in the KCNMA1 gene, permitting protein kinase C (PKC)-dependent channel activation. Overlapping and unique purinergic signalling regions exist at the apical border of differentiated surface cells. BK channels localize in the cilia of surface cells. ABSTRACT: In the present study we investigated the role of hydrocortisone (HC) on uridine-5'-triphosphate (UTP)-stimulated ion transport in differentiated, pseudostratified epithelia derived from normal human bronchial basal cells...
July 15, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/28469792/large-conductance-voltage-and-ca-2-activated-k-channels-affect-the-physiological-characteristics-of-human-urine-derived-stem-cells
#16
Qingqing Wang, Jiang Zhao, Chao Wu, Zhenxing Yang, Xingyou Dong, Qian Liu, Bishao Sun, Chen Wei, Xiaoyan Hu, Longkun Li
We investigated the current characteristics of large conductance voltage and Ca(2+)-activated K(+) (BK) channels in human urine-derived stem cells (hUSCs) and the effect of BK channels on proliferation and differentiation of hUSCs. Fresh human urine (n=6) was collected from healthy donors to isolate hUSCs. Human KCNMA1 gene silencing U6 shRNA was used to down regulate the expression of BK in hUSCs. IBTX (BK channel antagonist) and NS1619 (BK channel agonist) were used to examine the effect of BK channels on hUSCs...
2017: American Journal of Translational Research
https://www.readbyqxmd.com/read/28468834/a-voltage-dependent-k-channel-in-the-lysosome-is-required-for-refilling-lysosomal-ca-2-stores
#17
Wuyang Wang, Xiaoli Zhang, Qiong Gao, Maria Lawas, Lu Yu, Xiping Cheng, Mingxue Gu, Nirakar Sahoo, Xinran Li, Ping Li, Stephen Ireland, Andrea Meredith, Haoxing Xu
The resting membrane potential (Δψ) of the cell is negative on the cytosolic side and determined primarily by the plasma membrane's selective permeability to K(+) We show that lysosomal Δψ is set by lysosomal membrane permeabilities to Na(+) and H(+), but not K(+), and is positive on the cytosolic side. An increase in juxta-lysosomal Ca(2+) rapidly reversed lysosomal Δψ by activating a large voltage-dependent and K(+)-selective conductance (LysoKVCa). LysoKVCa is encoded molecularly by SLO1 proteins known for forming plasma membrane BK channels...
June 5, 2017: Journal of Cell Biology
https://www.readbyqxmd.com/read/28465407/role-of-nrf2-signaling-in-the-regulation-of-vascular-bk-channel-beta-1-subunit-expression-and-bk-channel-function-in-high-fat-diet-induced-diabetic-mice
#18
Tong Lu, Xiaojing Sun, Yong Li, Qiang Chai, Xiao-Li Wang, Hon-Chi Lee
The large conductance Ca(2+)-activated K(+) (BK) channel β1 subunit (BK-β1) is a key modulator of BK channel electrophysiology and the downregulation of BK-β1 protein expression in vascular smooth muscle cells (SMCs) underlies diabetic vascular dysfunction. In this study, we hypothesized that the nuclear factor erythroid-2-related factor 2 (Nrf2) signaling pathway plays a significant role in the regulation of coronary BK channel function and vasodilation in high fat diet (HFD)-induced obese/diabetic mice...
May 2, 2017: Diabetes
https://www.readbyqxmd.com/read/28455309/molecular-structure-and-function-of-big-calcium-activated-potassium-channels-in-skeletal-muscle-pharmacological-perspectives
#19
Fatima Maqoud, Michela Cetrone, Antonietta Mele, Domenico Tricarico
The large-conductance Ca(2+)-activated K(+) (BK) channel is broadly expressed in various mammalian cells and tissues such as neurons, skeletal muscles (sarco-BK), and smooth muscles. These channels are activated by changes in membrane electrical potential and by increases in the concentration of intracellular calcium ion (Ca(2+)). The large-conductance Ca(2+)-activated K(+) (BK) channel is subjected to many mechanisms that add diversity to the BK channel α subunit gene. These channels are indeed subject to alternative splicing, auxiliary subunits modulation, post-translational modifications and protein-protein interactions...
April 28, 2017: Physiological Genomics
https://www.readbyqxmd.com/read/28429615/regulation-of-vascular-large-conductance-calcium-activated-potassium-channels-by-nrf2-signalling
#20
Yong Li, Xiao-Li Wang, Xiaojing Sun, Qiang Chai, Jingchao Li, Benjamin Thompson, Win-Kuang Shen, Tong Lu, Hon-Chi Lee
BK channels are major ionic determinants of vasodilation. BK channel function is impaired in diabetic vessels due to accelerated proteolysis of its beta-1 (BK-β1) subunits in response to increased oxidative stress. The nuclear factor E2-related factor-2 (Nrf2) signalling pathway has emerged as a master regulator of cellular redox status, and we hypothesized that it plays a central role in regulating BK channel function in diabetic vessels. We found that Nrf2 expression was markedly reduced in db/db diabetic mouse aortas, and this was associated with significant downregulation of BK-β1...
April 1, 2017: Diabetes & Vascular Disease Research
keyword
keyword
98306
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"