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Article: Molecular basis of the effect of potassium on heterologously expressed pacemaker (HCN) channels

TitleMolecular basis of the effect of potassium on heterologously expressed pacemaker (HCN) channels
Authors
KeywordsChemicals And Cas Registry Numbers
Issue Date2003
PublisherWiley-Blackwell Publishing Ltd.. The Journal's web site is located at http://www.wiley.com/bw/journal.asp?ref=0022-3751
Citation
Journal Of Physiology, 2003, v. 547 n. 2, p. 349-356 How to Cite?
AbstractHyperpolarization-activated cyclic-nucleotide-gated (HCN) channels modulate the firing rates of neuronal and cardiac pacemaker cells. HCN channels resemble voltage-gated K+ channels structurally, but much less is known about their structure-function correlation. Although modulation of K+ channel gating by external K+ is a well-known phenomenon, such a link has not been established for HCN channels. Here we examined the effects of external permeant (K+, Na+ and Li+) and non-permeant (NMG+) ions on HCN1 and HCN2 gating. Substituting 64 of 96 mM external K+ with Na+, Li+ or NMG+ positively shifted steady-state activation (∼13 mV), and preferentially slowed activation of HCN1. Mutating the pore variant C-terminal to the GYG motif in HCN1, A352, to the analogous conserved Asp in K+ channels or Arg in HCN2 produced a significant hyperpolarizing activation shift (by 5-15 mV), slowed gating kinetics (up to 6-fold), and abolished or attenuated gating responses to external K+. Whereas Na+, Li+ and NMG+ substitutions produced depolarizing activation shifts of HCN2 similar to those of HCN1, deactivation but not activation of HCN2 was exclusively decelerated. We conclude that gating and permeation of HCN channels are coupled, and that modulation of this 'pore-to-gate' coupling by external K+ is isoform-specific.
Persistent Identifierhttp://hdl.handle.net/10722/91543
ISSN
2015 Impact Factor: 4.731
2015 SCImago Journal Rankings: 2.670
PubMed Central ID
ISI Accession Number ID
References

 

DC FieldValueLanguage
dc.contributor.authorAzene, EMen_HK
dc.contributor.authorXue, Ten_HK
dc.contributor.authorLi, RAen_HK
dc.date.accessioned2010-09-17T10:21:06Z-
dc.date.available2010-09-17T10:21:06Z-
dc.date.issued2003en_HK
dc.identifier.citationJournal Of Physiology, 2003, v. 547 n. 2, p. 349-356en_HK
dc.identifier.issn0022-3751en_HK
dc.identifier.urihttp://hdl.handle.net/10722/91543-
dc.description.abstractHyperpolarization-activated cyclic-nucleotide-gated (HCN) channels modulate the firing rates of neuronal and cardiac pacemaker cells. HCN channels resemble voltage-gated K+ channels structurally, but much less is known about their structure-function correlation. Although modulation of K+ channel gating by external K+ is a well-known phenomenon, such a link has not been established for HCN channels. Here we examined the effects of external permeant (K+, Na+ and Li+) and non-permeant (NMG+) ions on HCN1 and HCN2 gating. Substituting 64 of 96 mM external K+ with Na+, Li+ or NMG+ positively shifted steady-state activation (∼13 mV), and preferentially slowed activation of HCN1. Mutating the pore variant C-terminal to the GYG motif in HCN1, A352, to the analogous conserved Asp in K+ channels or Arg in HCN2 produced a significant hyperpolarizing activation shift (by 5-15 mV), slowed gating kinetics (up to 6-fold), and abolished or attenuated gating responses to external K+. Whereas Na+, Li+ and NMG+ substitutions produced depolarizing activation shifts of HCN2 similar to those of HCN1, deactivation but not activation of HCN2 was exclusively decelerated. We conclude that gating and permeation of HCN channels are coupled, and that modulation of this 'pore-to-gate' coupling by external K+ is isoform-specific.en_HK
dc.languageengen_HK
dc.publisherWiley-Blackwell Publishing Ltd.. The Journal's web site is located at http://www.wiley.com/bw/journal.asp?ref=0022-3751en_HK
dc.relation.ispartofJournal of Physiologyen_HK
dc.subjectChemicals And Cas Registry Numbersen_HK
dc.titleMolecular basis of the effect of potassium on heterologously expressed pacemaker (HCN) channelsen_HK
dc.typeArticleen_HK
dc.identifier.emailLi, RA:ronaldli@hkucc.hku.hken_HK
dc.identifier.authorityLi, RA=rp01352en_HK
dc.description.naturelink_to_subscribed_fulltext-
dc.identifier.doi10.1113/jphysiol.2003.039768en_HK
dc.identifier.pmid12562911-
dc.identifier.pmcidPMC2342664-
dc.identifier.scopuseid_2-s2.0-0037336635en_HK
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-0037336635&selection=ref&src=s&origin=recordpageen_HK
dc.identifier.volume547en_HK
dc.identifier.issue2en_HK
dc.identifier.spage349en_HK
dc.identifier.epage356en_HK
dc.identifier.isiWOS:000183570500002-
dc.publisher.placeUnited Kingdomen_HK
dc.identifier.scopusauthoridAzene, EM=6602472909en_HK
dc.identifier.scopusauthoridXue, T=7005064190en_HK
dc.identifier.scopusauthoridLi, RA=7404724466en_HK
dc.identifier.citeulike9713368-

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