ArticleThe Journal of general physiology2002
Spermine block of the strong inward rectifier potassium channel Kir2.1: dual roles of surface charge screening and pore block.
Article in The Journal of general physiology, 2002. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 46 papers.
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Who cites it
46 citing papers in PubMed.
- 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
- Electro-metabolic signaling.The Journal of general physiology · 2024Article
- Pericytes and the Control of Blood Flow in Brain and Heart.Annual review of physiology · 2023Review
- Gating and modulation of an inward-rectifier potassium channel.The Journal of general physiology · 2023Article
- Cardiac potassium inward rectifier Kir2: Review of structure, regulation, pharmacology, and arrhythmogenesis.Heart rhythm · 2021Review
- Cryo-EM structure of SARS-CoV-2 ORF3a in lipid nanodiscs.Nature structural & molecular biology · 2021Article
- Cryo-EM structure of the SARS-CoV-2 3a ion channel in lipid nanodiscs.bioRxiv : the preprint server for biology · 2021Article
- Investigation of the Effects of the Short QT Syndrome D172N Kir2.1 Mutation on Ventricular Action Potential Profile Using Dynamic Clamp.Frontiers in pharmacology · 2021Article
- Kir Channel Molecular Physiology, Pharmacology, and Therapeutic Implications.Handbook of experimental pharmacology · 2021Review
- Polyamines and potassium channels: A 25-year romance.The Journal of biological chemistry · 2018Review
- Kir2 inward rectification-controlled precise and dynamic balances between Kir2 and HCN currents initiate pacemaking activity.FASEB journal : official publication of the Federation of American Societies for Experimental Biology · 2018Article
- Conformational changes at cytoplasmic intersubunit interactions control Kir channel gating.The Journal of biological chemistry · 2017Article
- Flow- and voltage-dependent blocking effect of ethosuximide on the inward rectifier K⁺ (Kir2.1) channel.Pflugers Archiv : European journal of physiology · 2015Article
- Characterization of Staphylococcus aureus responses to spermine stress.Current microbiology · 2014Article
- Multi-ion versus single-ion conduction mechanisms can yield current rectification in biological ion channels.Journal of biological physics · 2014Article
- The bundle crossing region is responsible for the inwardly rectifying internal spermine block of the Kir2.1 channel.Pflugers Archiv : European journal of physiology · 2014Article
- Inward rectifiers and their regulation by endogenous polyamines.Frontiers in physiology · 2014Review
- Multi-ion distributions in the cytoplasmic domain of inward rectifier potassium channels.Biophysical journal · 2012Article
- Revisiting inward rectification: K ions permeate through Kir2.1 channels during high-affinity block by spermidine.The Journal of general physiology · 2012Article
- Functional consequences of Kir2.1/Kir2.2 subunit heteromerization.Pflugers Archiv : European journal of physiology · 2010Article
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3 authors.
Funding
Abstract
Inward rectification in strong inward rectifiers such as Kir2.1 is attributed to voltage-dependent block by intracellular polyamines and Mg(2+). Block by the polyamine spermine has a complex voltage dependence with shallow and steep components and complex concentration dependence. To understand the mechanism, we measured macroscopic Kir2.1 currents in excised inside-out giant patches from Xenopus oocytes expressing Kir2.1, and single channel currents in the inside-out patches from COS7 cells transfected with Kir2.1. We found that as spermine concentration or voltage increased, the shallow voltage-dependent component of spermine block at more negative voltages was caused by progressive reduction in the single channel current amplitude, without a decrease in open probability. We attributed this effect to spermine screening negative surface charges involving E224 and E299 near the inner vestibule of the channel, thereby reducing K ion permeation rate. This idea was further supported by experiments in which increasing ionic strength also decreased Kir2.1 single channel amplitude, and by mutagenesis experiments showing that this component of spermine block decreased when E224 and E299, but not D172, were neutralized. The steep voltage-dependent component of block at more depolarized voltages was attributed to spermine migrating deeper into the pore and causing fast open channel block. A quantitative model incorporating both features showed excellent agreement with the steady-state and kinetic data. In addition, this model accounts for previously described substate behavior induced by a variety of Kir2.1 channel blockers.
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