A5020262838- Ion channel regulation and function
- Cardiac electrophysiology and arrhythmias
- Neuroscience and Neuropharmacology Research
- Ion Transport and Channel Regulation
- Nicotinic Acetylcholine Receptors Study
- Ion Channels and Receptors
- Neuroscience and Neural Engineering
- Cellular transport and secretion
- Genetic Neurodegenerative Diseases
- Calcium signaling and nucleotide metabolism
- Migraine and Headache Studies
- Erythrocyte Function and Pathophysiology
- Receptor Mechanisms and Signaling
- Neuroscience of respiration and sleep
- RNA regulation and disease
- Electrochemical Analysis and Applications
- Biomedical Research and Pathophysiology
- Bone Metabolism and Diseases
- Pancreatic function and diabetes
- Photoreceptor and optogenetics research
- Trace Elements in Health
- Plant Stress Responses and Tolerance
- Nitric Oxide and Endothelin Effects
- Epilepsy research and treatment
- Chemical Reactions and Isotopes
Czech Academy of Sciences, Institute of Biophysics
2024
National Academies of Sciences, Engineering, and Medicine
2006-2024
Ecosystem (Spain)
2024
Instituto di Biofisica
2015-2024
National Research Council
2009-2024
Institute of Genetics and Biophysics
2003-2023
Leibniz-Forschungsinstitut für Molekulare Pharmakologie
2018
Ludwig-Maximilians-Universität München
2007
Radboud University Nijmegen
2007
Leiden University
2007
The SS2 and adjacent regions of the 4 internal repeats sodium channel II were subjected to single mutations involving, mainly, charged amino acid residues. These mutants, expressed in Xenopus oocytes by microinjection cDNA-derived mRNAs, tested for sensitivity tetrodotoxin saxitoxin single-channel conductance. results obtained show that involving 2 clusters predominantly negatively residues, located at equivalent positions segment repeats, strongly reduce toxin sensitivity, whereas residues...
Epilepsy is caused by an electrical hyperexcitability in the CNS. Because K + channels are critical for establishing and stabilizing resting potential of neurons, a loss could support neuronal hyperexcitability. Indeed, benign familial neonatal convulsions, autosomal dominant epilepsy infancy, mutations KCNQ2 or KCNQ3 channel genes. these contribute to native muscarinic-sensitive current (M current) that regulates excitability numerous types KCNQ (K v 7) activators would be effective...
The skeletal muscle chloride channel CLC-1 and the ubiquitous volume-activated CLC-2 belong to a large gene family whose members often show overlapping expression patterns. are coexpressed in smooth heart. By coexpressing Xenopus oocytes, we now formation of novel CLC-1/CLC-2 heterooligomers that yield time-independent linear currents with → bromide iodide selectivity sequence. Formation heterooligomeric CLC channels increases number possible functions channels.
Autosomal dominant myotonia congenita (Thomsen's disease) is caused by mutations in the muscle chloride channel CIC-1. Several point found affected families (I29OM, R317Q, P480L, and Q552R) dramatically shift gating to positive voltages mutant/WT heterooligomeric channels, when measurable, even more so mutant homooligomers. These channels can no longer contribute repolarization of action potentials, fully explaining why they cause myotonia. Most replacements isoleucine at position 290 toward...
Volume-regulated anion channels (VRACs) play an important role in controlling cell volume by opening upon swelling. Recent work has shown that heteromers of LRRC8A with other LRRC8 members (B, C, D, and E) form the VRAC. Here, we used Xenopus oocytes as a simple system to study proteins. We discovered adding fluorescent proteins C-terminus resulted constitutive channel activity. Using these constructs, reproduced previous findings indicating mediate osmolyte flux subunit-dependent kinetics...
ClC-1 protein channels facilitate rapid passage of chloride ions across cellular membranes, thereby orchestrating skeletal muscle excitability. Malfunction is associated with myotonia congenita, a disease impairing relaxation. Here, we present the cryo-electron microscopy (cryo-EM) structure human ClC-1, uncovering an architecture reminiscent that bovine ClC-K and CLC transporters. The conducting pathway exhibits distinct features, including central glutamate residue ("fast gate") known to...
Single-channel recordings of the currents mediated by muscle Cl− channel, ClC-1, expressed in Xenopus oocytes, provide first direct evidence that this channel has two equidistant open conductance levels like Torpedo ClC-0 prototype. As for case ClC-0, probabilities and dwell times closed conducting states are consistent with presence independently gated pathways ≈ 1.2 pS enabled parallel via a common gate. However, voltage dependence gate is different kinetics much faster than ClC-0....
Mutations in either KCNQ2 or KCNQ3 underlie benign familial neonatal convulsions (BFNC), an inherited epilepsy. The corresponding proteins are co-expressed broad regions of the brain and associate to heteromeric K+ channels. These channels mediate M-type currents that regulate neuronal excitability. We investigated basis for increase seen after co-expressing these subunits Xenopus oocytes. Noise analysis single channel recordings revealed a conductance ≈ 18 pS ≈7 KCNQ3. Different levels...
1. The influence of Cl‐ concentration and pH on gating the skeletal muscle channel, ClC‐1, has been assessed using voltage‐clamp technique Sf‐9 insect cell Xenopus oocyte expression systems. 2. Hyperpolarization induces deactivating inward currents comprising a steady‐state component two exponentially decaying components, which faster is weakly voltage dependent slower strongly dependent. 3. Open probability (Po) kinetics depend external but not internal concentration. 4. A point mutation,...
A distinctive feature of the voltage-dependent chloride channels ClC-0 (the Torpedo electroplaque channel) and ClC-1 major skeletal muscle is that acts as a ligand to its own channel, regulating channel opening so controlling permeation species. We have now studied number foreign anions through using voltage-clamp techniques on Xenopus oocytes Sf9 cells expressing human (hClC-1) or rat (rClC-1) isoforms, respectively. From their effect gating, presented in this paper can be divided into...