Immunolocalization suggests a role of the histamine‐gated chloride channel PxHCLB in spectral opponent processing in butterfly photoreceptors

2018 ◽  
Vol 527 (4) ◽  
pp. 753-766 ◽  
Author(s):  
Pei‐Ju Chen ◽  
Atsuko Matsushita ◽  
Motohiro Wakakuwa ◽  
Kentaro Arikawa
Keyword(s):  
Chloride Channel ◽  
Opponent Processing

scholarly journals The Role of Serum Chloride in Acute and Chronic Heart Failure: A Narrative Review

2021 ◽  
Vol 11 (2) ◽  
pp. 87-98
Author(s):  
Frederick Berro Rivera ◽  
Pia Alfonso ◽  
Jem Marie Golbin ◽  
Kevin Lo ◽  
Edgar Lerma ◽  
...  
Keyword(s):  
Heart Failure ◽  
Chloride Channel ◽  
Chloride Channels ◽  
Prognostic Value ◽  
Diuretic Therapy ◽  
Juxtaglomerular Apparatus ◽  
Sodium Chloride Cotransporter ◽  
Serum Chloride ◽  
And Function

Clinical guidelines include diuretics for the treatment of heart failure (HF), not to decrease mortality but to decrease symptoms and hospitalizations. More attention has been paid to the worse outcomes, including mortality, associated with continual diuretic therapy due to hypochloremia. Studies have revealed a pivotal role for serum chloride in the pathophysiology of HF and is now a target of treatment to decrease mortality. The prognostic value of serum chloride in HF has been the subject of much attention. Mechanistically, the macula densa, a region in the renal juxtaglomerular apparatus, relies on chloride levels to sense salt and volume status. The recent discovery of with-no-lysine (K) (WNK) protein kinase as an intracellular chloride sensor sheds light on the possible reason of diuretic resistance in HF. The action of chloride on WNKs results in the upregulation of the sodium-potassium-chloride cotransporter and sodium-chloride cotransporter receptors, which could lead to increased electrolyte and fluid reabsorption. Genetic studies have revealed that a variant of a voltage-sensitive chloride channel (CLCNKA) gene leads to almost a 50% decrease in current amplitude and function of the renal chloride channel. This variant increases the risk of HF. Several trials exploring the prognostic value of chloride in both acute and chronic HF have shown mostly positive results, some even suggesting a stronger role than sodium. However, so far, interventional trials exploring serum chloride as a therapeutic target have been largely inconclusive. This study is a review of the pathophysiologic effects of hypochloremia in HF, the genetics of chloride channels, and clinical trials that are underway to investigate novel approaches to HF management.

Functional role of amino terminus in ClC-3 chloride channel regulation by phosphorylation and cell volume

2006 ◽  
Vol 187 (1-2) ◽  
pp. 5-19 ◽  
Author(s):  
C. F. Rossow ◽  
D. Duan ◽  
W. J. Hatton ◽  
F. Britton ◽  
J. R. Hume ◽  
...  
Keyword(s):  
Cell Volume ◽  
Chloride Channel ◽  
Functional Role ◽  
Amino Terminus ◽  
Channel Regulation

CFTR chloride channel activation by genistein: the role of serine/threonine protein phosphatases

1996 ◽  
Vol 271 (2) ◽  
pp. C650-C657 ◽  
Author(s):  
W. W. Reenstra ◽  
K. Yurko-Mauro ◽  
A. Dam ◽  
S. Raman ◽  
S. Shorten
Keyword(s):  
Chloride Channel ◽  
Kinase Inhibitor ◽  
Maximal Activity ◽  
Calyculin A ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Nih 3T3 ◽  
Cystic Fibrosis Transmembrane

We have previously shown [B. Illek, H. Fischer, G. F. Santos, J. H. Widdicombe, T. E. Machen, and W. W. Reenstra, Am. J. Physiol. 268 (Cell Physiol. 37): C886-C893, 1995] that genistein, a tyrosine kinase inhibitor, activates the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel in NIH/3T3 cells that have been stably transfected with an expression vector for the CFTR (NIH-CFTR cells). In this study, we present evidence suggesting that both genistein and the serine/threonine protein phosphatase (PPase) inhibitor calyculin A activate the CFTR by inhibiting PPase activity. As measured by 125I efflux, genistein and calyculin A stimulate the CFTR to approximately 50% of the maximal activity with forskolin. Neither agonist increases CFTR activity at saturating forskolin concentrations, but genistein and calyculin A have an additive effect on CFTR activity. Forskolin, but neither genistein nor calyculin A, stimulates protein kinase A(PKA) activity. The PKA inhibitor H-89 inhibits CFTR activation and in vivo phosphorylation by all three agonists. Proteolytic digestion of in vivo phosphorylated CFTR suggests that the CFTR is phosphorylated on the same sites during stimulation with genistein and forskolin but on different sites stimulation with calyculin A. The data suggest that genistein and calyculin A inhibit different PPase activities, allowing CFTR phosphorylation and partial stimulation, by a basal PKA activity.

scholarly journals Dynamic measurement of cytosolic pH and [NO3−] uncovers the role of the vacuolar transporter AtCLCa in cytosolic pH homeostasis

2020 ◽  
Vol 117 (26) ◽  
pp. 15343-15353 ◽  
Author(s):  
Elsa Demes ◽  
Laetitia Besse ◽  
Paloma Cubero-Font ◽  
Béatrice Satiat-Jeunemaitre ◽  
Sébastien Thomine ◽  
...  
Keyword(s):  
Chloride Channel ◽  
Loss Of Function ◽  
Ion Transporters ◽  
Ph Homeostasis ◽  
Cytosolic Ph ◽  
Cellular Processes ◽  
Plasma Membrane Proton Pump ◽  
Cytosolic Acidification

Ion transporters are key players of cellular processes. The mechanistic properties of ion transporters have been well elucidated by biophysical methods. Meanwhile, the understanding of their exact functions in cellular homeostasis is limited by the difficulty of monitoring their activity in vivo. The development of biosensors to track subtle changes in intracellular parameters provides invaluable tools to tackle this challenging issue. AtCLCa (Arabidopsis thalianaChloride Channel a) is a vacuolar NO3−/H+exchanger regulating stomata aperture inA.thaliana. Here, we used a genetically encoded biosensor, ClopHensor, reporting the dynamics of cytosolic anion concentration and pH to monitor the activity of AtCLCa in vivo inArabidopsisguard cells. We first found that ClopHensor is not only a Cl−but also, an NO3−sensor. We were then able to quantify the variations of NO3−and pH in the cytosol. Our data showed that AtCLCa activity modifies cytosolic pH and NO3−. In an AtCLCa loss of function mutant, the cytosolic acidification triggered by extracellular NO3−and the recovery of pH upon treatment with fusicoccin (a fungal toxin that activates the plasma membrane proton pump) are impaired, demonstrating that the transport activity of this vacuolar exchanger has a profound impact on cytosolic homeostasis. This opens a perspective on the function of intracellular transporters of the Chloride Channel (CLC) family in eukaryotes: not only controlling the intraorganelle lumen but also, actively modifying cytosolic conditions.

The Role of the GABAA Receptor/Chloride Channel Complex in Anesthesia

1993 ◽  
Vol 78 (4) ◽  
pp. 757-776 ◽  
Author(s):  
Darrell L. Tanelian ◽  
Peter Kosek ◽  
Istvan Mody ◽  
M. Bruce Maclver
Keyword(s):  
Gabaa Receptor ◽  
Chloride Channel

New Insights into the Role of Intracellular Ca 2+ in the Regulation of the Human Kidney Chloride Channel ClC‐Ka

2020 ◽  
Vol 34 (S1) ◽  
pp. 1-1
Author(s):  
Monica Carmosino ◽  
Andrea Gerbino ◽  
Roberta De Zio ◽  
Serena Milano ◽  
Daniela Russo ◽  
...  
Keyword(s):  
Chloride Channel ◽  
Human Kidney ◽  
Intracellular Ca

scholarly journals The Muscle Chloride Channel ClC-1 Is Not Directly Regulated by Intracellular ATP

2008 ◽  
Vol 131 (2) ◽  
pp. 109-116 ◽  
Author(s):  
Giovanni Zifarelli ◽  
Michael Pusch
Keyword(s):  
Chloride Channel ◽  
Xenopus Oocytes ◽  
Physiological Role ◽  
Patch Clamp Technique ◽  
Intracellular Atp ◽  
Cl Channels ◽  
Nucleotide Regulation ◽  
Inside Out ◽  
Striking Contrast

ClC-1 belongs to the gene family of CLC Cl− channels and Cl−/H+ antiporters. It is the major skeletal muscle chloride channel and is mutated in dominant and recessive myotonia. In addition to the membrane-embedded part, all mammalian CLC proteins possess a large cytoplasmic C-terminal domain that bears two so-called CBS (from cystathionine-β-synthase) domains. Several studies indicate that these domains might be involved in nucleotide binding and regulation. In particular, Bennetts et al. (J. Biol. Chem. 2005. 280:32452–32458) reported that the voltage dependence of hClC-1 expressed in HEK cells is regulated by intracellular ATP and other nucleotides. Moreover, very recently, Bennetts et al. (J. Biol. Chem. 2007. 282:32780–32791) and Tseng et al. (J. Gen. Physiol. 2007. 130:217–221) reported that the ATP effect was enhanced by intracellular acidification. Here, we show that in striking contrast with these findings, human ClC-1, expressed in Xenopus oocytes and studied with the inside-out configuration of the patch-clamp technique, is completely insensitive to intracellular ATP at concentrations up to 10 mM, at neutral pH (pH 7.3) as well as at slightly acidic pH (pH 6.2). These results have implications for a general understanding of nucleotide regulation of CLC proteins and for the physiological role of ClC-1 in muscle excitation.

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