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Current Opinion in Neurobiology Jun 1993
Review
Topics: Amino Acid Sequence; Animals; Humans; Ion Channel Gating; Molecular Sequence Data; Potassium Channels
PubMed: 8369623
DOI: 10.1016/0959-4388(93)90119-j -
Proceedings of the National Academy of... Oct 1997An intermediate conductance calcium-activated potassium channel, hIK1, was cloned from human pancreas. The predicted amino acid sequence is related to, but distinct... (Comparative Study)
Comparative Study
An intermediate conductance calcium-activated potassium channel, hIK1, was cloned from human pancreas. The predicted amino acid sequence is related to, but distinct from, the small conductance calcium-activated potassium channel subfamily, which is approximately 50% conserved. hIK1 mRNA was detected in peripheral tissues but not in brain. Expression of hIK1 in Xenopus oocytes gave rise to inwardly rectifying potassium currents, which were activated by submicromolar concentrations of intracellular calcium (K0.5 = 0.3 microM). Although the K0.5 for calcium was similar to that of small conductance calcium-activated potassium channels, the slope factor derived from the Hill equation was significantly reduced (1.7 vs. 3. 5). Single-channel current amplitudes reflected the macroscopic inward rectification and revealed a conductance level of 39 pS in the inward direction. hIK1 currents were reversibly blocked by charybdotoxin (Ki = 2.5 nM) and clotrimazole (Ki = 24.8 nM) but were minimally affected by apamin (100 nM), iberiotoxin (50 nM), or ketoconazole (10 microM). These biophysical and pharmacological properties are consistent with native intermediate conductance calcium-activated potassium channels, including the erythrocyte Gardos channel.
Topics: Amino Acid Sequence; Animals; Brain; Calcium; Conserved Sequence; Female; Humans; Intermediate-Conductance Calcium-Activated Potassium Channels; Large-Conductance Calcium-Activated Potassium Channels; Macromolecular Substances; Membrane Potentials; Molecular Sequence Data; Oocytes; Organ Specificity; Potassium Channels; Potassium Channels, Calcium-Activated; Sequence Alignment; Sequence Homology, Amino Acid; Xenopus laevis
PubMed: 9326665
DOI: 10.1073/pnas.94.21.11651 -
Biochemical and Biophysical Research... Jan 2010Besides their role in the generation of action potentials, voltage-gated potassium channels are implicated in cellular processes ranging from cell division to cell...
Besides their role in the generation of action potentials, voltage-gated potassium channels are implicated in cellular processes ranging from cell division to cell death. The K(+) channel regulator protein (KCNRG), identified as a putative tumor suppressor, reduces K(+) currents through human K(+) channels hKv1.1 and hKv1.4 expressed in Xenopus oocytes. Current attenuation requires the presence of the N-terminal T1 Domain and immunoprecipitation experiments suggest association of KCNRG with the N-terminus of the channel. Our data indicates that KCNRG is an ER-associated protein, which we propose regulates Kv1 family channel proteins by retaining a fraction of channels in endomembranes.
Topics: Action Potentials; Animals; Cell Line; Cell Membrane; Endoplasmic Reticulum; Humans; Immunoprecipitation; Kv1.1 Potassium Channel; Kv1.4 Potassium Channel; Oocytes; Potassium Channels; Protein Structure, Tertiary; Xenopus
PubMed: 19968958
DOI: 10.1016/j.bbrc.2009.11.143 -
Biomolecules Sep 2020Pulmonary arterial hypertension (PAH) is a rare and severe cardiopulmonary disease without curative treatments. PAH is a multifactorial disease that involves genetic... (Review)
Review
Pulmonary arterial hypertension (PAH) is a rare and severe cardiopulmonary disease without curative treatments. PAH is a multifactorial disease that involves genetic predisposition, epigenetic factors, and environmental factors (drugs, toxins, viruses, hypoxia, and inflammation), which contribute to the initiation or development of irreversible remodeling of the pulmonary vessels. The recent identification of loss-of-function mutations in (KCNK3 or TASK-1) and (SUR1), or gain-of-function mutations in (SUR2), as well as polymorphisms in (Kv1.5), which encode two potassium (K) channels and two K channel regulatory subunits, has revived the interest of ion channels in PAH. This review focuses on KCNK3, SUR1, SUR2, and Kv1.5 channels in pulmonary vasculature and discusses their pathophysiological contribution to and therapeutic potential in PAH.
Topics: Animals; Drug Delivery Systems; Humans; Kv1.5 Potassium Channel; Nerve Tissue Proteins; Potassium Channels; Potassium Channels, Inwardly Rectifying; Potassium Channels, Tandem Pore Domain; Pulmonary Arterial Hypertension; Sulfonylurea Receptors
PubMed: 32882918
DOI: 10.3390/biom10091261 -
Current Opinion in Chemical Biology Aug 1999Several important new findings have furthered the development of voltage-gated and calcium-activated potassium channel pharmacology. The molecular constituents of... (Review)
Review
Several important new findings have furthered the development of voltage-gated and calcium-activated potassium channel pharmacology. The molecular constituents of several members of these large ion channel families were identified. Small-molecule modulators of some of these channels were reported, including correolide, the first potent, small-molecule, natural product inhibitor of the Shaker family of voltage-gated potassium channels to be disclosed. The initial crystal structure of a bacterial potassium channel was determined; this work gives a physical basis for understanding the mechanisms of ion selectivity and ion conduction. With the recent molecular characterization of a potassium channel structure and the discovery of new templates for channel modulatory agents, the ability to rationally identify and develop potassium channel agonists and antagonists may become a reality in the near future.
Topics: Amino Acid Sequence; Animals; Calcium; Carbohydrate Sequence; Ion Channel Gating; Molecular Sequence Data; Potassium Channel Blockers; Potassium Channels; Sequence Homology, Amino Acid; Toxins, Biological
PubMed: 10419851
DOI: 10.1016/S1367-5931(99)80066-0 -
Science (New York, N.Y.) Jul 1995Permeation selectivity was studied in two human potassium channels, Kv2.1 and Kv1.5, expressed in a mouse cell line. With normal concentrations of potassium and sodium,...
Permeation selectivity was studied in two human potassium channels, Kv2.1 and Kv1.5, expressed in a mouse cell line. With normal concentrations of potassium and sodium, both channels were highly selective for potassium. On removal of potassium, Kv2.1 displayed a large sodium conductance that was inhibited by low concentrations of potassium. The channel showed a competition mechanism of selectivity similar to that of calcium channels. In contrast, Kv1.5 displayed a negligible sodium conductance on removal of potassium. The observation that structurally similar potassium channels show different abilities to conduct sodium provides a basis for understanding the structural determinants of potassium channel selectivity.
Topics: Animals; Binding, Competitive; Delayed Rectifier Potassium Channels; Humans; L Cells; Membrane Potentials; Mice; Potassium; Potassium Channels; Potassium Channels, Voltage-Gated; Shab Potassium Channels; Sodium
PubMed: 7618108
DOI: 10.1126/science.7618108 -
Heart Rhythm Mar 2020
Topics: ERG1 Potassium Channel; Ethers; Humans; KCNQ1 Potassium Channel; Potassium Channels
PubMed: 31593778
DOI: 10.1016/j.hrthm.2019.10.009 -
Trends in Pharmacological Sciences Dec 1993
Topics: Animals; Binding Sites; Cloning, Molecular; Humans; Potassium Channels; Terminology as Topic
PubMed: 8122320
DOI: 10.1016/0165-6147(93)90182-j -
Nephrology, Dialysis, Transplantation :... Dec 1998
Review
Topics: Animals; Humans; Kidney; Nephrons; Potassium; Potassium Channels; Potassium Channels, Inwardly Rectifying
PubMed: 9870458
DOI: 10.1093/ndt/13.12.3019 -
Current Medicinal Chemistry 2018
Topics: Diuresis; Humans; Hyperglycemia; Potassium Channel Blockers; Potassium Channels; Potassium Channels, Inwardly Rectifying
PubMed: 30014793
DOI: 10.2174/092986732523180704120725