scholarly journals Cloning and Functional Expression of a Plant Voltage-Dependent Chloride Channel

1996 ◽  
Vol 8 (4) ◽  
pp. 701 ◽  
Author(s):  
Claire Lurin ◽  
Danny Geelen ◽  
Helene Barbier-Brygoo ◽  
Jean Guern ◽  
Christophe Maurel
Keyword(s):  
Chloride Channel ◽  
Functional Expression ◽  
Voltage Dependent

scholarly journals Cloning and functional expression of a plant voltage-dependent chloride channel.

1996 ◽  
Vol 8 (4) ◽  
pp. 701-711 ◽  
Author(s):  
C Lurin ◽  
D Geelen ◽  
H Barbier-Brygoo ◽  
J Guern ◽  
C Maurel
Keyword(s):  
Chloride Channel ◽  
Functional Expression ◽  
Voltage Dependent

Association between Hsp90 and the ClC-2 chloride channel upregulates channel function

2006 ◽  
Vol 290 (1) ◽  
pp. C45-C56 ◽  
Author(s):  
Alexandre Hinzpeter ◽  
Joanna Lipecka ◽  
Franck Brouillard ◽  
Maryvonne Baudoin-Legros ◽  
Michal Dadlez ◽  
...  
Keyword(s):  
Chloride Channel ◽  
Fluid Transport ◽  
Cell Swelling ◽  
Dependent Manner ◽  
Patch Clamp Technique ◽  
Mass Spectrometry Identification ◽  
Voltage Dependent ◽  
Channel Expression ◽  
Associated Proteins ◽  
Cellular Stresses

The voltage-dependent ClC-2 chloride channel has been implicated in a variety of physiological functions, including fluid transport across specific epithelia. ClC-2 is activated by hyperpolarization, weakly acidic external pH, intracellular Cl−, and cell swelling. To add more insight into the mechanisms involved in ClC-2 regulation, we searched for associated proteins that may influence ClC-2 activity. With the use of immunoprecipitation of ClC-2 from human embryonic kidney-293 cells stably expressing the channel, followed by electrophoretic separation of coimmunoprecipitated proteins and mass spectrometry identification, Hsp70 and Hsp90 were unmasked as possible ClC-2 interacting partners. Association of Hsp90 with ClC-2 was confirmed in mouse brain. Inhibition of Hsp90 by two specific inhibitors, geldanamycin or radicicol, did not affect total amounts of ClC-2 but did reduce plasma membrane channel abundance. Functional experiments using the whole cell configuration of the patch-clamp technique showed that inhibition of Hsp90 reduced ClC-2 current amplitude and impaired the intracellular Cl− concentration [Cl−]-dependent rightward shift of the fractional conductance. Geldanamycin and radicicol increased both the slow and fast activation time constants in a chloride-dependent manner. Heat shock treatment had the opposite effect. These results indicate that association of Hsp90 with ClC-2 results in greater channel activity due to increased cell surface channel expression, facilitation of channel opening, and enhanced channel sensitivity to intracellular [Cl−]. This association may have important pathophysiological consequences, enabling increased ClC-2 activity in response to cellular stresses such as elevated temperature, ischemia, or oxidative reagents.

scholarly journals KCR1, a Membrane Protein That Facilitates Functional Expression of Non-inactivating K+Currents Associates with Rat EAG Voltage-dependent K+Channels

1998 ◽  
Vol 273 (36) ◽  
pp. 23080-23085 ◽  
Author(s):  
Naoto Hoshi ◽  
Hiroto Takahashi ◽  
Mohammad Shahidullah ◽  
Shigeru Yokoyama ◽  
Haruhiro Higashida
Keyword(s):  
Membrane Protein ◽  
Functional Expression ◽  
K Channels ◽  
Voltage Dependent ◽  
K Currents

Attenuation of endothelin effects by a chloride channel inhibitor, indanyloxyacetic acid

1992 ◽  
Vol 262 (5) ◽  
pp. F799-F806 ◽  
Author(s):  
T. Takenaka ◽  
M. Epstein ◽  
H. Forster ◽  
D. W. Landry ◽  
K. Iijima ◽  
...  
Keyword(s):  
Chloride Channel ◽  
Chloride Channels ◽  
Specific Binding ◽  
Fluorescein Isothiocyanate ◽  
Cytosolic Calcium ◽  
Membrane Depolarization ◽  
Voltage Dependent ◽  
Voltage Dependent Calcium Channels ◽  
Afferent Arterioles ◽  
Subsequent Activation

We have recently proposed that the actions of endothelin (ET) are in part mediated by opening of chloride channels (K. Iijima, L. Lin, A. Nasjletti, and M. S. Goligorsky. Am. J. Physiol. 260 (Cell Physiol. 29: C982-C992, 1991). In the present study the ability of a chloride channel inhibitor, an indanyloxyacetic acid (IAA-94), to block ET-induced effects was examined in cultured vascular smooth muscle cells (VSMC) by spectrofluorometry and direct videomicroscopic visualization of the renal microcirculation in isolated perfused hydronephrotic kidneys (IPHK). A fluorescein isothiocyanate (FITC)-labeled IAA-94 analogue showed specific binding to VSMC. IAA-94 (30 microM) neither affected basal cytosolic calcium concentration ([Ca2+]i) in VSMC nor peak response to ET, but it significantly curtailed sustained elevation of [Ca2+]i (half-time recovery was 147 +/- 23 vs. 248 +/- 33 s in control, P less than 0.05). IAA-94 blunted ET-induced membrane depolarization from 24.5 +/- 3.3 to 8.0 +/- 1.8 mV. In IPHK, ET constricted afferent arterioles (AA) by 29 +/- 2% (18.7 +/- 0.8 to 13.2 +/- 0.6 microns, P less than 0.001). Isradipine reversed this ET-induced vasoconstriction. Pretreatment with IAA-94 did not alter AA diameter, but markedly attenuated ET-induced AA constriction (reduction of AA diameters by only 9 +/- 2%, P less than 0.001). The subsequent addition of isradipine (0.1-1 microM) did not further dilate AA. Our data indicate that IAA-94 markedly attenuates AA vasoconstriction elicited by ET and suggest that ET-induced opening of chloride channels, membrane depolarization, and subsequent activation of voltage-dependent calcium channels contribute to the vasoconstrictor mechanisms of this peptide.

scholarly journals Effect of an N‐terminus deletion on voltage‐dependent gating of the ClC‐2 chloride channel

2002 ◽  
Vol 544 (2) ◽  
pp. 363-372 ◽  
Author(s):  
Diego Varela ◽  
María Isabel Niemeyer ◽  
L. Pablo Cid ◽  
Francisco V. Sepúlveda
Keyword(s):  
Chloride Channel ◽  
N Terminus ◽  
Voltage Dependent

scholarly journals The CFTR Mutation c.3453G > C (D1152H) Confers an Anion Selectivity Defect in Primary Airway Tissue that Can be Rescued by Ivacaftor

2020 ◽  
Vol 10 (2) ◽  
pp. 40 ◽  
Author(s):  
Onofrio Laselva ◽  
Theo J. Moraes ◽  
Gengming He ◽  
Claire Bartlett ◽  
Ida Szàrics ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Chloride Channel ◽  
Functional Expression ◽  
Transmembrane Conductance Regulator ◽  
Wild Type ◽  
Transmembrane Conductance ◽  
Wild Type Level ◽  
Human Nasal Epithelial Cells ◽  
Functional Analyses ◽  
Normal Wild Type

The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene variant, c.3453G > C (D1152H), is associated with mild Cystic Fibrosis (CF) disease, though there is considerable clinical variability ranging from no detectable symptoms to lung disease with early acquisition of Pseudomonas aeruginosa. The approval extension of ivacaftor, the first CFTR modulator drug approved, to include D1152H was based on a positive drug response of defective CFTR-D1152H chloride channel function when expressed in FRT cells. Functional analyses of primary human nasal epithelial cells (HNE) from an individual homozygous for D1152H now revealed that while CFTR-D1152H demonstrated normal, wild-type level chloride conductance, its bicarbonate-selective conductance was impaired. Treatment with ivacaftor increased this bicarbonate-selective conductance. Extensive genetic, protein and functional analysis of the nasal cells of this D1152H/D1152H patient revealed a 90% reduction of CFTR transcripts due to the homozygous presence of the 5T polymorphism in the poly-T tract forming a complex allele with D1152H. Thus, we confirm previous observation in patient-derived tissue that 10% normal CFTR transcripts confer normal, wild-type level chloride channel activity. Together, this study highlights the benefit of patient-derived tissues to study the functional expression and pharmacological modulation of CF-causing mutations, in order to understand pathogenesis and therapeutic responses.

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