ArticleThe Journal of general physiology2006
Ring of negative charge in BK channels facilitates block by intracellular Mg2+ and polyamines through electrostatics.
Article in The Journal of general physiology, 2006. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 30 papers.
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Who cites it
30 citing papers in PubMed.
- Open-channel block of human TRPV6 by polyamine spermine.Nature communications · 2026Article
- Magnesium Ions as Modulators of Voltage-Gated and Ligand-Gated Ion Channels in Central Neurons.International journal of molecular sciences · 2025Review
- Molecular basis of TRPV3 channel blockade by intracellular polyamines.Communications biology · 2025Article
- Intracellular Spermine Is a Key Player in GSG1L's Regulation of Calcium-Permeable AMPAR Channel Conductance and Recovery from Desensitization.The Journal of neuroscience : the official journal of the Society for Neuroscience · 2025Article
- Effects of Spermine Synthase Deficiency in Mesenchymal Stromal Cells Are Rescued by Upstream Inhibition of Ornithine Decarboxylase.International journal of molecular sciences · 2024Article
- Lysenin Channels as Sensors for Ions and Molecules.Sensors (Basel, Switzerland) · 2020Review
- Polyamine blockade and binding energetics in the MthK potassium channel.The Journal of general physiology · 2020Article
- Polyamine block of MthK potassium channels.The Journal of general physiology · 2020Article
- BK channel density is regulated by endoplasmic reticulum associated degradation and influenced by the SKN-1A/NRF1 transcription factor.PLoS genetics · 2020Article
- Large-conductance CaProceedings of the National Academy of Sciences of the United States of America · 2019Article
- Pore size matters for potassium channel conductance.The Journal of general physiology · 2016Review
- Properties of Slo1 K+ channels with and without the gating ring.Proceedings of the National Academy of Sciences of the United States of America · 2013Article
- Lack of negative slope in I-V plots for BK channels at positive potentials in the absence of intracellular blockers.The Journal of general physiology · 2013Article
- Ca2+ block and flickering both contribute to the negative slope of the IV curve in BK channels.The Journal of general physiology · 2013Article
- Crystal structure of a Ba(2+)-bound gating ring reveals elementary steps in RCK domain activation.Structure (London, England : 1993) · 2012Article
- K⁺ conduction and Mg²⁺ blockade in a shaker Kv-channel single point mutant with an unusually high conductance.Biophysical journal · 2012Article
- Mg(2+) binding to open and closed states can activate BK channels provided that the voltage sensors are elevated.The Journal of general physiology · 2011Article
- Low resistance, large dimension entrance to the inner cavity of BK channels determined by changing side-chain volume.The Journal of general physiology · 2011Article
- Regulation of conductance by the number of fixed positive charges in the intracellular vestibule of the CFTR chloride channel pore.The Journal of general physiology · 2010Article
- Structure and electrostatic property of cytoplasmic domain of ZntB transporter.Protein science : a publication of the Protein Society · 2009Article
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4 authors.
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Abstract
Intracellular Mg2+ and natural polyamines block outward currents in BK channels in a highly voltage-dependent manner. Here we investigate the contribution of the ring of eight negatively charged residues (4 x E321/E324) at the entrance to the inner vestibule of BK channels to this block. Channels with or without (E321N/E324N) the ring of negative charge were expressed in oocytes and unitary currents were recorded from inside-out patches over a range of intracellular Mg2+ and polyamine concentrations. Removing the ring of charge greatly decreased the block, increasing K(B)(ap) (0 mV) for Mg2+ block from 48.3 +/- 3.0 to 143 +/- 8 mM, and for spermine block from 8.0 +/- 1.0 to 721 +/- 9 mM (150 mM symmetrical KCl). Polyamines with fewer amine groups blocked less: putrescine < spermidine < spermine. An equation that combined an empirical Hill function for block together with a Boltzmann function for the voltage dependence of K(B)(ap) described the voltage and concentration dependence of the block for channels with and without the ring of charge. The Hill coefficients for these descriptions were <1 for both Mg2+ and spermine block, and were unchanged by removing the ring of charge. When KCl(i) was increased from 150 mM to 3 M, the ring of charge no longer facilitated block, Mg2+ block was reduced, spermine block became negligible, and the Hill coefficients became approximately 1.0. BK channels in cell-attached oocyte patches displayed inward rectification, which was reduced for channels without the ring of charge. Taken together, these observations suggest that the ring of negative charge facilitates block through a preferential electrostatic attraction of Mg2+ and polyamine over K+. This preferential attraction of multivalent blockers over monovalent K+ would decrease the K+ available at the inner vestibule to carry outward current in the presence of Mg2+ or polyamines, while increasing the concentration of blocker available to enter and block the conduction pathway.
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