keyword
MENU ▼
Read by QxMD icon Read
search

Kv2

keyword
https://www.readbyqxmd.com/read/27916464/subtype-specific-block-of-voltage-gated-k-channels-by-%C3%AE-conopeptides
#1
Enrico Leipold, Florian Ullrich, Markus Thiele, Alesia A Tietze, Heinrich Terlau, Diana Imhof, Stefan H Heinemann
The neurotoxic cone snail peptide μ-GIIIA specifically blocks skeletal muscle voltage-gated sodium (NaV1.4) channels. The related conopeptides μ-PIIIA and μ-SIIIA, however, exhibit a wider activity spectrum by also inhibiting the neuronal NaV channels NaV1.2 and NaV1.7. Here we demonstrate that those μ-conopeptides with a broader target range also antagonize select subtypes of voltage-gated potassium channels of the KV1 family: μ-PIIIA and μ-SIIIA inhibited KV1.1 and KV1.6 channels in the nanomolar range, while being inactive on subtypes KV1...
December 1, 2016: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/27884958/activity-dependent-redistribution-of-kv2-1-ion-channels-on-rat-spinal-motoneurons
#2
Shannon H Romer, Adam S Deardorff, Robert E W Fyffe
Homeostatic plasticity occurs through diverse cellular and synaptic mechanisms, and extensive investigations over the preceding decade have established Kv2.1 ion channels as key homeostatic regulatory elements in several central neuronal systems. As in these cellular systems, Kv2.1 channels in spinal motoneurons (MNs) localize within large somatic membrane clusters. However, their role in regulating motoneuron activity is not fully established in vivo. We have previously demonstrated marked Kv2.1 channel redistribution in MNs following in vitro glutamate application and in vivo peripheral nerve injury (Romer et al...
November 2016: Physiological Reports
https://www.readbyqxmd.com/read/27810559/interaction-site-for-the-inhibition-of-tarantula-jingzhaotoxin-xi-on-voltage-gated-potassium-channel-kv2-1
#3
Huai Tao, Xia Chen, Meichun Deng, Yucheng Xiao, Yuanyuan Wu, Zhonghua Liu, Sainan Zhou, Yingchun He, Songping Liang
Jingzhaotoxin-XI (JZTX-XI) is a 34-residue peptide from the Chinese tarantula Chilobrachys jingzhao venom that potently inhibits both voltage-gated sodium channel Nav1.5 and voltage-gated potassium channel Kv2.1. In the present study, we further showed that JZTX-XI blocked Kv2.1 currents with the IC50 value of 0.39 ± 0.06 μM. JZTX-XI significantly shifted the current-voltage (I-V) curves and normalized conductance-voltage (G-V) curves of Kv2.1 channel to more depolarized voltages. Ala-scanning mutagenesis analyses demonstrated that mutants I273A, F274A, and E277A reduced toxin binding affinity by 10-, 16-, and 18-fold, respectively, suggesting that three common residues (I273, F274, E277) in the Kv2...
December 15, 2016: Toxicon: Official Journal of the International Society on Toxinology
https://www.readbyqxmd.com/read/27798188/oxidation-of-kcnb1-potassium-channels-causes-neurotoxicity-and-cognitive-impairment-in-a-mouse-model-of-traumatic-brain-injury
#4
Wei Yu, Randika Parakramaweera, Shavonne Teng, Manasa Gowda, Yashsavi Sharad, Smita Thakker-Varia, Janet Alder, Federico Sesti
: The delayed rectifier potassium (K(+)) channel KCNB1 (Kv2.1), which conducts a major somatodendritic current in cortex and hippocampus, is known to undergo oxidation in the brain, but whether this can cause neurodegeneration and cognitive impairment is not known. Here, we used transgenic mice harboring human KCNB1 wild-type (Tg-WT) or a nonoxidable C73A mutant (Tg-C73A) in cortex and hippocampus to determine whether oxidized KCNB1 channels affect brain function. Animals were subjected to moderate traumatic brain injury (TBI), a condition characterized by extensive oxidative stress...
October 26, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/27760355/extracellular-linkers-completely-transplant-the-voltage-dependence-from-kv1-2-ion-channels-to-kv2-1
#5
Fredrik Elinder, Michael Madeja, Hugo Zeberg, Peter Århem
The transmembrane voltage needed to open different voltage-gated K (Kv) channels differs by up to 50 mV from each other. In this study we test the hypothesis that the channels' voltage dependences to a large extent are set by charged amino-acid residues of the extracellular linkers of the Kv channels, which electrostatically affect the charged amino-acid residues of the voltage sensor S4. Extracellular cations shift the conductance-versus-voltage curve, G(V), by interfering with these extracellular charges...
October 18, 2016: Biophysical Journal
https://www.readbyqxmd.com/read/27734968/the-anticonvulsant-retigabine-suppresses-neuronal-kv2-mediated-currents
#6
Jeroen I Stas, Elke Bocksteins, Camilla S Jensen, Nicole Schmitt, Dirk J Snyders
Enhancement of neuronal M-currents, generated through KV7.2-KV7.5 channels, has gained much interest for its potential in developing treatments for hyperexcitability-related disorders such as epilepsy. Retigabine, a KV7 channel opener, has proven to be an effective anticonvulsant and has recently also gained attention due to its neuroprotective properties. In the present study, we found that the auxiliary KCNE2 subunit reduced the KV7.2-KV7.3 retigabine sensitivity approximately 5-fold. In addition, using both mammalian expression systems and cultured hippocampal neurons we determined that low μM retigabine concentrations had 'off-target' effects on KV2...
October 13, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27729411/functional-antagonism-of-voltage-gated-k-channel-%C3%AE-subunits-in-the-developing-brain-ventricular-system
#7
Hongyuan Shen, Elke Bocksteins, Igor Kondrychyn, Dirk Snyders, Vladimir Korzh
The brain ventricular system is essential for neurogenesis and brain homeostasis. Its neuroepithelial lining effects these functions, but the underlying molecular pathways remain to be understood. We found that the potassium channels expressed in neuroepithelial cells determine the formation of the ventricular system. The phenotype of a novel zebrafish mutant characterized by denudation of neuroepithelial lining of the ventricular system and hydrocephalus is mechanistically linked to Kcng4b, a homologue of the 'silent' voltage-gated potassium channel α-subunit Kv6...
November 15, 2016: Development
https://www.readbyqxmd.com/read/27677211/targeted-deletion-of-the-kv6-4-subunit-causes-male-sterility-due-to-disturbed-spermiogenesis
#8
Glenn Regnier, Elke Bocksteins, Waleed F Marei, Isabel Pintelon, Jean-Pierre Timmermans, Jo L M R Leroy, Dirk J Snyders
Electrically silent voltage-gated potassium (KvS) channel subunits (i.e. Kv5-Kv6 and Kv8-Kv9) do not form functional homotetrameric Kv channels, but co-assemble with Kv2 subunits, generating functional heterotetrameric Kv2--KvS channel complexes in which the KvS subunits modulate the Kv2 channel properties. Several KvS subunits are expressed in testis tissue but knowledge about their contribution to testis physiology is lacking. Here, we report that the targeted deletion of Kv6.4 in a transgenic mouse model (Kcng4-/-) causes male sterility as offspring from homozygous females were only obtained after mating with wild-type (WT) or heterozygous males...
September 28, 2016: Reproduction, Fertility, and Development
https://www.readbyqxmd.com/read/27638047/comparison-of-voltage-gated-k-currents-in-arterial-myocytes-with-heterologously-expressed-k-v-subunits
#9
Robert H Cox, Samantha Fromme
We have shown that three components contribute to functional voltage gated K(+) (K v) currents in rat small mesenteric artery myocytes: (1) Kv1.2 plus Kv1.5 with Kvβ1.2 subunits, (2) Kv2.1 probably associated with Kv9.3 subunits, and (3) Kv7.4 subunits. To confirm and address subunit stoichiometry of the first two, we have compared the biophysical properties of K v currents in small mesenteric artery myocytes with those of Kv subunits heterologously expressed in HEK293 cells using whole cell voltage clamp methods...
September 16, 2016: Cell Biochemistry and Biophysics
https://www.readbyqxmd.com/read/27562026/physiological-roles-of-kv2-channels-in-entorhinal-cortex-layer-ii-stellate-cells-revealed-by-guangxitoxin-1e
#10
Christoph Hönigsperger, Maximiliano J Nigro, Johan F Storm
KEY POINTS: Kv2 channels underlie delayed-rectifier potassium currents in various neurons, although their physiological roles often remain elusive. Almost nothing is known about Kv2 channel functions in medial entorhinal cortex (mEC) neurons, which are involved in representing space, memory formation, epilepsy and dementia. Stellate cells in layer II of the mEC project to the hippocampus and are considered to be space-representing grid cells. We used the new Kv2 blocker Guangxitoxin-1E (GTx) to study Kv2 functions in these neurons...
August 26, 2016: Journal of Physiology
https://www.readbyqxmd.com/read/27320844/dromedary-immune-response-and-specific-kv2-1-antibody-generation-using-a-specific-immunization-approach
#11
Rym Hassiki, Alain J Labro, Zakaria Benlasfar, Cécile Vincke, Mahmoud Somia, Mohamed El Ayeb, Serge Muyldermans, Dirk J Snyders, Balkiss Bouhaouala-Zahar
Voltage-gated potassium (Kv) channels form cells repolarizing power and are commonly expressed in excitable cells. In non-excitable cells, Kv channels such as Kv2.1 are involved in cell differentiation and growth. Due to the involvement of Kv2.1 in several physiological processes, these channels are promising therapeutic targets. To develop Kv2.1 specific antibody-based channel modulators, we applied a novel approach and immunized a dromedary with heterologous Ltk- cells that overexpress the mouse Kv2.1 channel instead of immunizing with channel protein fragments...
June 16, 2016: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/27300868/revealing-nonergodic-dynamics-in-living-cells-from-a-single-particle-trajectory
#12
Yann Lanoiselée, Denis S Grebenkov
We propose the improved ergodicity and mixing estimators to identify nonergodic dynamics from a single particle trajectory. The estimators are based on the time-averaged characteristic function of the increments and can thus capture additional information on the process as compared to the conventional time-averaged mean-square displacement. The estimators are first investigated and validated for several models of anomalous diffusion, such as ergodic fractional Brownian motion and diffusion on percolating clusters, and nonergodic continuous-time random walks and scaled Brownian motion...
May 2016: Physical Review. E
https://www.readbyqxmd.com/read/27262624/toxicology-of-potassium-channel-directed-compounds-in-mosquitoes
#13
Nicholas R Larson, Paul R Carlier, Aaron D Gross, Rafique M Islam, Ming Ma, Baonan Sun, Maxim M Totrov, Roopali Yadav, Jeffrey R Bloomquist
Potential targets for new vector control insecticides are nerve and muscle potassium channels. In this study, the activities of known potassium channel blockers (4-aminopyridine, quinidine, and tetraethylammonium) and the insecticide propoxur were compared to three experimental catechols and several other compounds against Anopheles gambiae and Aedes aegypti mosquitoes. Experimental catechol 1 was the most toxic experimental compound in all of the mortality assays conducted, but was at least 100-fold and 39-fold less toxic than propoxur against Ae...
June 1, 2016: Neurotoxicology
https://www.readbyqxmd.com/read/27218229/alterations-of-voltage-dependent-k-channels-in-the-mesenteric-artery-during-the-early-and-chronic-phases-of-diabetes
#14
Da Hye Hong, Hongliang Li, Hye Won Kim, Han Sol Kim, Youn Kyoung Son, Se-Ran Yang, Jeong-Ran Park, Kwon-Soo Ha, Eun-Taek Han, Seok-Ho Hong, Amy L Firth, Sung Hun Na, Won Sun Park
This study investigated the alteration of voltage-dependent K(+) (Kv) channels in mesenteric arterial smooth muscle cells from control (Long-Evans Tokushima Otsuka [LETO]) and diabetic (Otsuka Long-Evans Tokushima Fatty [OLETF]) rats during the early and chronic phases of diabetes. We demonstrated alterations in the mesenteric Kv channels during the early and chronic phase of diabetes using the patch-clamp technique, the arterial tone measurement system, and RT-PCR in Long-Evans Tokushima (LETO; for control) and Otsuka Long-Evans Tokushima Fatty (OLETF; for diabetes) type 2 diabetic model rats...
September 2016: Clinical and Experimental Pharmacology & Physiology
https://www.readbyqxmd.com/read/27164420/a-comparison-of-the-delayed-outward-potassium-current-between-the-nucleus-ambiguus-and-hippocampus-sensitivity-to-paeonol
#15
Chin-Tsang Yang, Yuk-Man Leung, Sheng-Feng Hsu, Iona MacDonald, Mei-Ling Wang, Jaung-Geng Lin, Shih-Ya Hung, Yi-Hung Chen
Whole-cell patch-clamp recordings investigated the electrophysiological effects of 2'-hydroxy-4'-methoxyacetophenone (paeonol), one of the major components of Moutan Cortex, in hippocampal CA1 neurons and nucleus ambiguus (NA) neurons from neonatal rats as well as in lung epithelial H1355 cells expressing Kv2.1 or Kv1.2. Extracellular application of paeonol at 100μM did not significantly affect the spontaneous action potential frequency, whereas paeonol at 300μM increased the frequency of spontaneous action potentials in hippocampal CA1 neurons...
August 5, 2016: European Journal of Pharmacology
https://www.readbyqxmd.com/read/27148689/sp6616-as-a-new-kv2-1-channel-inhibitor-efficiently-promotes-%C3%AE-cell-survival-involving-both-pkc-erk1-2-and-cam-pi3k-akt-signaling-pathways
#16
T T Zhou, L L Quan, L P Chen, T Du, K X Sun, J C Zhang, L Yu, Y Li, P Wan, L L Chen, B H Jiang, L H Hu, J Chen, X Shen
Kv2.1 as a voltage-gated potassium (Kv) channel subunit has a pivotal role in the regulation of glucose-stimulated insulin secretion (GSIS) and pancreatic β-cell apoptosis, and is believed to be a promising target for anti-diabetic drug discovery, although the mechanism underlying the Kv2.1-mediated β-cell apoptosis is obscure. Here, the small molecular compound, ethyl 5-(3-ethoxy-4-methoxyphenyl)-2-(4-hydroxy-3-methoxybenzylidene)-7-methyl-3-oxo-2,3-dihydro-5H-[1,3]thiazolo[3,2-a]pyrimidine-6-carboxylate (SP6616) was discovered to be a new Kv2...
2016: Cell Death & Disease
https://www.readbyqxmd.com/read/27114846/oxidation-of-k-channels-in-aging-and-neurodegeneration
#17
REVIEW
Federico Sesti
Reversible regulation of proteins by reactive oxygen species (ROS) is an important mechanism of neuronal plasticity. In particular, ROS have been shown to act as modulatory molecules of ion channels-which are key to neuronal excitability-in several physiological processes. However ROS are also fundamental contributors to aging vulnerability. When the level of excess ROS increases in the cell during aging, DNA is damaged, proteins are oxidized, lipids are degraded and more ROS are produced, all culminating in significant cell injury...
March 2016: Aging and Disease
https://www.readbyqxmd.com/read/27114559/gdf-15-enhances-intracellular-ca2-by-increasing-cav1-3-expression-in-rat-cerebellar-granule-neurons
#18
Jun-Mei Lu, Chang-Ying Wang, Changlong Hu, Yan-Jia Fang, Yan-Ai Mei
GDF-15 (growth/differentiation factor 15) is a novel member of the TGF (transforming growth factor)-β superfamily that has critical roles in the central and peripheral nervous systems. We reported previously that GDF-15 increased delayed rectifier outward K(+) currents and Kv2.1 α subunit expression through TβRII (TGF-β receptor II) to activate Src kinase and Akt/mTOR (mammalian target of rapamycin) signalling in rat CGNs (cerebellar granule neurons). In the present study, we found that treatment of CGNs with GDF-15 for 24 h increased the intracellular Ca(2+) concentration ([Ca(2+)]i) in response to membrane depolarization, as determined by Ca(2+) imaging...
July 1, 2016: Biochemical Journal
https://www.readbyqxmd.com/read/27046646/genome-wide-dna-hydroxymethylation-identifies-potassium-channels-in-the-nucleus-accumbens-as-discriminators-of-methamphetamine-addiction-and-abstinence
#19
J L Cadet, C Brannock, I N Krasnova, S Jayanthi, B Ladenheim, M T McCoy, D Walther, A Godino, M Pirooznia, R S Lee
Epigenetic consequences of exposure to psychostimulants are substantial but the relationship of these changes to compulsive drug taking and abstinence is not clear. Here, we used a paradigm that helped to segregate rats that reduce or stop their methamphetamine (METH) intake (nonaddicted) from those that continue to take the drug compulsively (addicted) in the presence of footshocks. We used that model to investigate potential alterations in global DNA hydroxymethylation in the nucleus accumbens (NAc) because neuroplastic changes in the NAc may participate in the development and maintenance of drug-taking behaviors...
April 5, 2016: Molecular Psychiatry
https://www.readbyqxmd.com/read/27045173/molecular-interactions-between-tarantula-toxins-and-low-voltage-activated-calcium-channels
#20
Autoosa Salari, Benjamin S Vega, Lorin S Milescu, Mirela Milescu
Few gating-modifier toxins have been reported to target low-voltage-activated (LVA) calcium channels, and the structural basis of toxin sensitivity remains incompletely understood. Studies of voltage-gated potassium (Kv) channels have identified the S3b-S4 "paddle motif," which moves at the protein-lipid interface to drive channel opening, as the target for these amphipathic neurotoxins. Voltage-gated calcium (Cav) channels contain four homologous voltage sensor domains, suggesting multiple toxin binding sites...
2016: Scientific Reports
keyword
keyword
22958
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"