External Cl Research Articles

Anoctamin-like protein 1 regulates repolarization in Paramecium behavioral responses.

Paramecium exhibits responsive behavior to environmental changes, moving either closer to or further away from stimuli. Electrophysiological experiments have revealed that these behavioral responses are controlled by membrane potentials. Anoctamin, a Ca2+-activated Cl- channel, is involved in the regulation of membrane potential in mammals. However, it remains uncertain whether Cl- channels like anoctamin regulate Paramecium behavior. Herein, replacement of external Cl- ions with acetate ion and application of Cl- channel blocker niflumic acid (NFA, 0.1 μM) increased spontaneous avoiding reactions (sARs). Hence, we hypothesized that anoctamin is involved in the stabilization of membrane potential fluctuation. Paramecium cells in which the anoctamin-like protein 1 gene was knocked down displayed frequent sARs in the culture medium without external stimulation. Treatment of anoctamin-like protein 1-knockdown cells with the Ca2+ chelator BAPTA or Ca-channel blocker nicardipine reversed the increase in sARs. Electrophysiological experiments revealed extension of membrane depolarization when positive currents were applied to anoctamin-like protein 1-knockdown cells. We concluded that anoctamin-like protein 1 works as a Cl-channel and stabilizes the membrane potential oscillation, reducing sARs.

Pendrin: linking acid base to blood pressure.

Pendrin (SLC26A4) is an anion exchanger from the SLC26 transporter family which is mutated in human patients affected by Pendred syndrome, an autosomal recessive disease characterized by sensoneurinal deafness and hypothyroidism. Pendrin is also expressed in the kidney where it mediates the exchange of internal HCO3- for external Cl- at the apical surface of renal type B and non-A non-B-intercalated cells. Studies using pendrin knockout mice have first revealed that pendrin is essential for renal base excretion. However, subsequent studies have demonstrated that pendrin also controls chloride absorption by the distal nephron and that this mechanism is critical for renal NaCl balance. Furthermore, pendrin has been shown to control vascular volume and ultimately blood pressure. This review summarizes the current knowledge about how pendrin is linking renal acid-base regulation to blood pressure control.

Molecular Cloning, Expression and Transport Activity of SaNPF6.3/SaNRT1.1, a Novel Protein of the Low-Affinity Nitrate Transporter Family from the Euhalophyte Suaeda altissima (L.) Pall.

The SaNPF6.3 gene, a putative ortholog of the dual-affinity nitrate (NO3-) transporter gene AtNPF6.3/AtNRT1.1 from Arabidopsis thaliana, was cloned from the euhalophyte Suaeda altissima. The nitrate transporting activity of SaNPF6.3 was studied by heterologous expression of the gene in the yeast Hansenula (Ogataea) polymorpha mutant strain Δynt1 lacking the original nitrate transporter. Expression of SaNPF6.3 in Δynt1 cells rescued their ability to grow on the selective medium in the presence of nitrate and absorb nitrate from this medium. Confocal laser microscopy of the yeast cells expressing the fused protein GFP-SaNPF6.3 revealed GFP (green fluorescent protein) fluorescence localized predominantly in the cytoplasm and/or vacuoles. Apparently, in the heterologous expression system used, only a relatively small fraction of the GFP-SaNPF6.3 reached the plasma membrane of yeast cells. In S. altissima plants grown in media with either low (0.5 mM) or high (15 mM) NO3-; concentrations, SaNPF6.3 was expressed at various ontogenetic stages in different organs, with the highest expression levels in roots, pointing to an important role of SaNPF6.3 in nitrate uptake. SaNPF6.3 expression was induced in roots of nitrate-deprived plants in response to raising the nitrate concentration in the medium and was suppressed when the plants were transferred from sufficient nitrate to the lower concentration. When NaCl concentration in the nutrient solution was elevated, the SaNPF6.3 transcript abundance in the roots increased at the low nitrate concentration and decreased at the high one. We also determined nitrate and chloride concentrations in the xylem sap excreted by detached S. altissima roots as a function of their concentrations in the root medium. Based on a linear increase in Cl- concentrations in the xylem exudate as the external Cl- concentration increased and the results of SaNPF6.3 expression experiments, we hypothesize that SaNPF6.3 is involved in chloride transport along with nitrate transport in S. altissima plants.

Developing the Key Driver Diagram by Analyzing Home Central Line Caregiver Proficiency Factors.

Caregivers of pediatric oncology and stem cell transplant patients patients with an external CL or removed within 2 weeks were eligible for a survey assessing knowledge, the value of training strategies, and comfort. We mapped responses (n = 79) and acceptability/challenges of introducing a pilot caregiver CL teach-back clinic program onto the capability, opportunity, motivation behavioral (COM-B) model of change to identify drivers of caregiver CL care proficiency. A working group, including caregivers, refined and approved a final driver diagram. Survey: Ninety-four percent of caregivers answered knowledge questions correctly (capability); 95% considered hands-on training helpful (opportunity); 53% were not very comfortable with CL care (motivation). Teach-back: Seventy-nine percent of caregivers were interested in a teach-back as additional training; 38% participated (opportunity); 20% refused participation due to being overwhelmed/not having time (motivation). Thirty-three percent of participants had a CL proficiency assessment (capability). Drivers of home caregiver CL care proficiency included: support for the caregiver's physical capability to perform CL care; enabling the CL care nurse trainer role; facilitating and increasing training opportunities, and engaging caregivers early and continuously to motivate proficiency development appropriately. An approach centered on caregivers as main stakeholders can identify drivers to co-design an intervention for improved home CL care delivery. A standardized process to train and evaluate caregivers with multiple hands-on opportunities might be beneficial.

Binding Mechanism of CSA Cement on Premixed Cl− and Its Governing Parameters

AbstractCalcium sulfoaluminate (CSA) cement showed a good binding capacity on the external Cl− transported into concretes from its surrounding environment. However, it is unclear whether the same b...

Adenylate Cyclase 1 Links Calcium Signaling to CFTR-Dependent Cytosolic Chloride Elevations in Chick Amacrine Cells.

The strength and sign of synapses involving ionotropic GABA and glycine receptors are dependent upon the Cl− gradient. We have shown that nitric oxide (NO) elicits the release of Cl− from internal acidic stores in retinal amacrine cells (ACs); temporarily altering the Cl− gradient and the strength or even sign of incoming GABAergic or glycinergic synapses. The underlying mechanism for this effect of NO requires the cystic fibrosis transmembrane regulator (CFTR) but the link between NO and CFTR activation has not been determined. Here, we test the hypothesis that NO-dependent Ca2+ elevations activate the Ca2+-dependent adenylate cyclase 1 (AdC1) leading to activation of protein kinase A (PKA) whose activity is known to open the CFTR channel. Using the reversal potential of GABA-gated currents to monitor cytosolic Cl−, we established the requirement for Ca2+ elevations. Inhibitors of AdC1 suppressed the NO-dependent increases in cytosolic Cl− whereas inhibitors of other AdC subtypes were ineffective suggesting that AdC1 is involved. Inhibition of PKA also suppressed the action of NO. To address the sufficiency of this pathway in linking NO to elevations in cytosolic Cl−, GABA-gated currents were measured under internal and external zero Cl− conditions to isolate the internal Cl− store. Activators of the cAMP pathway were less effective than NO in producing GABA-gated currents. However, coupling the cAMP pathway activators with the release of Ca2+ from stores produced GABA-gated currents indistinguishable from those stimulated with NO. Together, these results demonstrate that cytosolic Ca2+ links NO to the activation of CFTR and the elevation of cytosolic Cl−.

Targeting Mycobacterium tuberculosis response to environmental cues for the development of effective antitubercular drugs.

Sensing and response to environmental cues, such as pH and chloride (Cl−), is critical in enabling Mycobacterium tuberculosis (Mtb) colonization of its host. Utilizing a fluorescent reporter Mtb strain in a chemical screen, we have identified compounds that dysregulate Mtb response to high Cl− levels, with a subset of the hits also inhibiting Mtb growth in host macrophages. Structure–activity relationship studies on the hit compound “C6,” or 2-(4-((2-(ethylthio)pyrimidin-5-yl)methyl)piperazin-1-yl)benzo[d]oxazole, demonstrated a correlation between compound perturbation of Mtb Cl− response and inhibition of bacterial growth in macrophages. C6 accumulated in both bacterial and host cells, and inhibited Mtb growth in cholesterol media, but not in rich media. Subsequent examination of the Cl− response of Mtb revealed an intriguing link with bacterial growth in cholesterol, with increased transcription of several Cl−-responsive genes in the simultaneous presence of cholesterol and high external Cl− concentration, versus transcript levels observed during exposure to high external Cl− concentration alone. Strikingly, oral administration of C6 was able to inhibit Mtb growth in vivo in a C3HeB/FeJ murine infection model. Our work illustrates how Mtb response to environmental cues can intersect with its metabolism and be exploited in antitubercular drug discovery.

ATP-evoked intracellular Ca2+ transients shape the ionic permeability of human microglia from epileptic temporal cortex

BackgroundIntracellular Ca2+ modulates several microglial activities, such as proliferation, migration, phagocytosis, and inflammatory mediator secretion. Extracellular ATP, the levels of which significantly change during epileptic seizures, activates specific receptors leading to an increase of intracellular free Ca2+ concentration ([Ca2+]i). Here, we aimed to functionally characterize human microglia obtained from cortices of subjects with temporal lobe epilepsy, focusing on the Ca2+-mediated response triggered by purinergic signaling.MethodsFura-2 based fluorescence microscopy was used to measure [Ca2+]i in primary cultures of human microglial cells obtained from surgical specimens. The perforated patch-clamp technique, which preserves the cytoplasmic milieu, was used to measure ATP-evoked Ca2+-dependent whole-cell currents.ResultsIn human microglia extracellular ATP evoked [Ca2+]i increases depend on Ca2+ entry from the extracellular space and on Ca2+ mobilization from intracellular compartments. Extracellular ATP also induced a transient fivefold potentiation of the total transmembrane current, which was completely abolished when [Ca2+]i increases were prevented by removing external Ca2+ and using an intracellular Ca2+ chelator. TRAM-34, a selective KCa3.1 blocker, significantly reduced the ATP-induced current potentiation but did not abolish it. The removal of external Cl− in the presence of TRAM-34 further lowered the ATP-evoked effect. A direct comparison between the ATP-evoked mean current potentiation and mean Ca2+ transient amplitude revealed a linear correlation. Treatment of microglial cells with LPS for 48 h did not prevent the ATP-induced Ca2+ mobilization but completely abolished the ATP-mediated current potentiation. The absence of the Ca2+-evoked K+ current led to a less sustained ATP-evoked Ca2+ entry, as shown by the faster Ca2+ transient kinetics observed in LPS-treated microglia.ConclusionsOur study confirms a functional role for KCa3.1 channels in human microglia, linking ATP-evoked Ca2+ transients to changes in membrane conductance, with an inflammation-dependent mechanism, and suggests that during brain inflammation the KCa3.1-mediated microglial response to purinergic signaling may be reduced.

Chloride and pH Determination on a Wireless, Flexible Electrochemical Sensor Platform

A stamp-sized, flexible, wireless, generic electrochemical sensor platform was demonstrated for use as a potentiometric pH and amperometric Cl− sensor. The platform combines flexible printed circuit technology with screen-printed electrodes, which enables cheap and easy quantification of biorelevant analytes in many different environments. pH sensors with graphene oxide as the recognition element was constructed on a ferrocyanide modified carbon electrode, to maintain a well-defined redox potential even at high alkalinity. A solid-state reference electrode based on a NaCl-doped polyvinyl butyral membrane ensured applicability towards sample matrices of unknown composition by remining unsensitive (±7.1 mV) to external Cl− in the range pCl 0–3. The platform was able to linearly (−26.3 mV pH−1, r2 = 0.99) quantify pH in the range of 2–9 with a maximum inter-sensor standard deviation of 0.43 pH units. Secondly, a Cl− sensor combining three unmodified Ag/AgCl electrodes with squarewave amperometry was designed, simulated and tested. A sensitivity of (−147.7 $\mu \text{A}$ pCl−1, r2 = 0.97) was obtained, with a maximum inter-sensor standard deviation of 0.27 pCl units in the range pCl 0–3.

Mutation of external glutamate residue reveals a new intermediate transport state and anion binding site in a CLC Cl−/H+ antiporter

The CLC family of proteins are involved in a variety of physiological processes to control cellular chloride concentration. Two distinct classes of CLC proteins, Cl- channels and Cl-/H+ antiporters, have been functionally and structurally investigated over the last several decades. Previous studies have suggested that the conformational heterogeneity of the critical glutamate residue, Gluex, could explain the transport cycle of CLC-type Cl-/H+ antiporters. However, the presence of multiple conformations (Up, Middle, and Down) of the Gluex has been suggested from combined structural snapshots of 2 different CLC antiporters: CLC-ec1 from Escherichia coli and cmCLC from a thermophilic red alga, Cyanidioschyzon merolae Thus, we aimed to investigate further the heterogeneity of Gluex-conformations in CLC-ec1, the most deeply studied CLC antiporter, at both functional and structural levels. Here, we show that the crystal structures of the Gluex mutant E148D and wild-type CLC-ec1 with varying anion concentrations suggest a structural intermediate, the "Midlow" conformation. We also found that an extra anion can be located above the external Cl--binding site in the E148D mutant when the anion concentration is high. Moreover, we observed that a carboxylate in solution can occupy either the external or central Cl--binding site in the ungated E148A mutant using an anomalously detectable short carboxylic acid, bromoacetate. These results lend credibility to the idea that the Gluex can take at least 3 distinct conformational states during the transport cycle of a single CLC antiporter.

Novel pendrin inhibitor attenuates airway hyperresponsiveness and mucin expression in experimental murine asthma

Novel pendrin inhibitor attenuates airway hyperresponsiveness and mucin expression in experimental murine asthma

Dissolution of Aramid by Ionization of Byproduct HCl Promoted by Acetate

AbstractPoor solubility of high‐performance polymer has always been a leading bottleneck for its application. Para‐aramid fiber as a typical high‐performance fiber owns significant hydrogen‐bond interaction and chloride salts are generally needed to provide Cl− ions as hydrogen‐bond acceptors for its dissolution. In this paper, Poly‐(benzimidazole‐terephthalamide) (PABI) which complexed with by‐product HCl (PABI‐HCl) during polymerization was fabricated and by‐product HCl was regarded as potential Cl− ions donor. CH3COONa as cosolvent was added in DMAc to dissolve PABI‐HCl. It was confirmed that solubility of PABI‐HCl in DMAc could be improved significantly in existence of CH3COONa. The finding was characterized by conductivity measurement, UV‐Vis spectra, Atomic Absorbance Spectra and Thermogravimetric analysis etc. By‐product HCl as a strong acid was converted into CH3COOH due to existence of CH3COO− in solution. Then it would release Cl− ions and they could interact with secondary amide of aramid to disrupt interaction among macromolecules. Therefore, aramid was dissolved successfully by utilizing by‐product HCl and no external Cl− ions donor was needed.

Ion transport mechanism in ClC-type channel protein under complex electrostatic potential

In order to illustrate the ion transport mechanism of chloride channel (ClC) protein, a type of ClC protein, ClC-ec1, from Escherichia coli is embedded into an explicit membranewater system by using software VMD. Then a parallel molecular dynamics (MD) simulation is employed to equilibrate the ClC-ec1 structure for 27.5 ns at temperature 298.15 K. Based on this equilibrated structure, we compute the channel geometric size variation and electrostatic potential distribution along the channel. Meanwhile, Cl- transport process is simulated using oriented random walk method under variable external potential. The simulation result shows that Cl- transport velocity depends on the width of the narrowest channel region. Mutation of negative glutamate E148 can produce positive potential, which is beneficial for Cl- transport, around external Cl- binding region in the channel. The simulated current-voltage curves about Cl- transporting in ClC-ec1 protein agree with Jayaram’s experimental results.

Ca2+-activated chloride channel activity during Ca2+ alternans in ventricular myocytes

ABSTRACTCardiac alternans, defined beat-to-beat alternations in contraction, action potential (AP) morphology or cytosolic Ca transient (CaT) amplitude, is a high risk indicator for cardiac arrhythmias. We investigated mechanisms of cardiac alternans in single rabbit ventricular myocytes. CaTs were monitored simultaneously with membrane currents or APs recorded with the patch clamp technique. A strong correlation between beat-to-beat alternations of AP morphology and CaT alternans was observed. During CaT alternans application of voltage clamp protocols in form of pre-recorded APs revealed a prominent Ca2+-dependent membrane current consisting of a large outward component coinciding with AP phases 1 and 2, followed by an inward current during AP repolarization. Approximately 85% of the initial outward current was blocked by Cl− channel blocker DIDS or lowering external Cl− concentration identifying it as a Ca2+-activated Cl− current (ICaCC). The data suggest that ICaCC plays a critical role in shaping beat-to-beat alternations in AP morphology during alternans.

Revealing the activation pathway for TMEM16A chloride channels from macroscopic currents and kinetic models.

TMEM16A (ANO1), the pore-forming subunit of calcium-activated chloride channels, regulates several physiological and pathophysiological processes such as smooth muscle contraction, cardiac and neuronal excitability, salivary secretion, tumour growth and cancer progression. Gating of TMEM16A is complex because it involves the interplay between increases in intracellular calcium concentration ([Ca(2+)]i), membrane depolarization, extracellular Cl(-) or permeant anions and intracellular protons. Our goal here was to understand how these variables regulate TMEM16A gating and to explain four observations. (a) TMEM16A is activated by voltage in the absence of intracellular Ca(2+). (b) The Cl(-) conductance is decreased after reducing extracellular Cl(-) concentration ([Cl(-)]o). (c) ICl is regulated by physiological concentrations of [Cl(-)]o. (d) In cells dialyzed with 0.2 μM [Ca(2+)]i, Cl(-) has a bimodal effect: at [Cl(-)]o <30mM TMEM16A current activates with a monoexponential time course, but above 30mM, [Cl(-)]o ICl activation displays fast and slow kinetics. To explain the contribution of Vm, Ca(2+) and Cl(-) to gating, we developed a 12-state Markov chain model. This model explains TMEM16A activation as a sequential, direct, and Vm-dependent binding of two Ca(2+) ions coupled to a Vm-dependent binding of an external Cl(-) ion, with Vm-dependent transitions between states. Our model predicts that extracellular Cl(-) does not alter the apparent Ca(2+) affinity of TMEM16A, which we corroborated experimentally. Rather, extracellular Cl(-) acts by stabilizing the open configuration induced by Ca(2+) and by contributing to the Vm dependence of activation.

Determination of Cl&lt;sup&gt;-&lt;/sup&gt; in Concrete Materials by Ion Chromatography

The determination of chloride ions in concrete materials accurately is far and away crucial, since chloride ions can cause corrosion of steel and concrete cover off. The conventional potential method and silver nitrate titration method usually show features of simple operation and short duration, nevertheless, they are not suitable for accurate analysis for concrete attributing to their low accuracy and detection limit. In this paper, an ion chromatography method was presented to determine chlorine in concrete materials. Concrete samples were pre-processed and then extracted with distilled water. The extraction solutions were purified on a 0.22 μm filter membrane, an On Guard SPE-RP column and a SPE-H column sequentially for eliminating undissolved substance, organisms and metal ions before ion chromatographic analysis. The chromatographic separation was performed on a Dionex ICS-1000 Chromatographic using 25.0 mmol/L KOH solutions as mobile phase at 1.0 mL/min. Results show that the detection limit of the method was 0.004 mg/L. The linear relationship of the external Cl- standard solutions was 0.9994, and the sample analytical RSD was 0.44%.

Evidence for a Revised Ion/Substrate Coupling Stoichiometry of GABA Transporters.

Plasma membrane γ-aminobutyric acid (GABA) transporters (GATs) are electrogenic transport proteins that couple the cotranslocation of Na(+), Cl(-), and GABA across the plasma membrane of neurons and glia. A fundamental property of the transporter that determines its ability to concentrate GABA in cells and, hence, regulate synaptic and extra-synaptic GABA concentrations, is the ion/substrate coupling stoichiometry. Here, we scrutinized the currently accepted 2 Na(+):1 Cl(-):1 GABA stoichiometry because it is inconsistent with the measured net charge translocated per co-substrate (Na(+), Cl(-), and GABA). We expressed GAT1 and GAT3 in Xenopus laevis oocytes and utilized thermodynamic and uptake under voltage-clamp measurements to determine the stoichiometry of the GABA transporters. Voltage-clamped GAT1-expressing oocytes were internally loaded with GABA, and the reversal potential (V rev) of the transporter-mediated current was recorded at different external concentrations of Na(+), Cl(-), or GABA. The shifts in V rev for a tenfold change in the external Na(+), Cl(-), and GABA concentration were 84±4, 30±1, and 29±1mV, respectively. To determine the net charge translocated per Na(+), Cl(-), and GABA, we measured substrate fluxes under voltage clamp in cells expressing GAT1 or GAT3. Charge flux to substrate flux ratios were 0.7±0.1 charge/Na(+), 2.0±0.2 charges/Cl(-), and 2.1±0.1 charges/GABA. Altogether, our results strongly suggest a 3 Na(+):1 Cl(-):1 GABA coupling stoichiometry for the GABA transporters. The revised stoichiometry has important implications for understanding the contribution of GATs to GABAergic signaling in health and disease.

Extracellular Chloride Regulates TMEM16A Gating

The gating mechanism of TMEM16A, an essential subunit of the Ca2+-activated Cl- channel, remains incompletely understood. Gating of TMEM16A channels is complex because elevation of intracellular calcium concentration ([Ca2+]i), strong depolarizations (Vm), and high extracellular Cl or highly permeant anions seem to contribute. In the present work we show that in TMEM16A no gating currents can be detected, however, external Cl ions might play a role in voltage sensing because the kinetics and magnitude of current activation were dependent on [Cl-]e. The onset and offset of Cl- currents produced by 0.5 s depolarisations of cells bathed in 137 mM [Cl-]e followed a mono-exponential behaviour; a subsequent reduction of [Cl-]e to 10 mM diminished the conductance ∼2-fold. These data suggest a single gating process regulated by extracellular Cl-. In contrast, when cells were exposed to 137 mM [Cl-]e the onset and offset currents elicited by 20s depolarisations exhibited fast and slow kinetics. Activation of the slow component resulted in large onset Cl- currents that did not reach steady-state at the end of the 20s pulse. This behaviour was abolished after activating TMEM16A with 5 µM [Ca2+]i or after deleting four residues (448EAVK451) located in the first intracellular loop. Deleting four additional residues (444EEEEEAVK451) resulted in Cl- currents that decayed at the end of the 20 s depolarization. To explain our data we developed a 12-state gating model assuming that TMEM16A is activated by a direct, Vm-dependent binding of two Ca2+ ions. In this model external Cl- increases channel open probability by promoting stable Vm-dependent Ca2+ binding. Our model reproduced the gating behaviour of the TMEM16A currents in response to voltage, Ca2+, and [Cl-]e. Thus, we conclude that external Cl stabilises Ca binding and promotes two gating modes in TMEM16A. Supported by grant 219949 from CONACyT.

Regulation of ClC-3 Cl-/H+ Transport and “Gating” Transients by Chloride Pathway Residues and External Protons

We investigated ClC-3 ion transport properties by employing a “ClC-5/3” plasmid, consisting of the ClC-5 N-terminal (M1-A46) linked to the core ClC-3 protein. This ClC-3 protein is redirected to the plasma membrane of HEK cells. Functionally it exhibits rapidly activated, outwardly rectifying sustained ion currents (ISS) representing coupled Cl-/H+ transport, and prominent “on/off” transient gating charge (Q) movements, as recently described for a ClC-3 mutant (Guzman et al, 2013, ACS Chem Neurosci). Interpreting Q to represent movements of unprotonated (ie, incompletely cycling) “Gluext”/ E224, ClC-3 exhibits low transport efficiency compared to ClC-5 or ClC-4, which exhibit larger ISS and much smaller Q. Replacement of external Cl- with SCN- increases ClC-3 currents by 3-4 fold, and reduces H+ coupling by ∼90%. Removal of a conserved tyrosine (Y630S, V) positioned at the intersection of the Cl-/H+ pathways (Accardi et al, 2006, JMB) greatly increases currents and decreases Q. For Y630S, H+ coupling is reduced by ∼50%; SCN substitution decreases rather than increases current, and eliminates H+ transport. An M568A mutant moderately impacts transport, increasing currents and decreasing Q by <50%. Reduction of external pH (pH 6 or 5) weakly inhibits ClC-3 ISS, but markedly reduces Q, and shifts the Q(V) relationship toward more positive voltages. These results are consistent with external protons inhibiting cycling by neutralization of Gluext. An endogenous Cl- current activated at pH5 (Iacid) has slow activation kinetics and lacks gating transients, is inhibited by 60-120 microM phloretin, and is decreased by ClC-3 expression. Thus, Iacid is readily distinguished from expressed ClC-3 transport. These data indicate that ClC-3 H+ coupling and transport is influenced by anion interaction, and by external protons, as suggested for the bacterial ClCec-1.

Behind the Scenes of CLC Gating: Deriving the Voltage Dependence of Membrane Proteins by Admittance Measurements

Behind the Scenes of CLC Gating: Deriving the Voltage Dependence of Membrane Proteins by Admittance Measurements