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dc.contributor.authorCodding, S.J.
dc.contributor.authorTrudeau, M.C.
dc.date.accessioned2019-08-05T17:00:26Z
dc.date.available2019-08-05T17:00:26Z
dc.date.issued2019
dc.identifier.urihttps://www.scopus.com/inward/record.uri?eid=2-s2.0-85064229479&doi=10.1085%2fjgp.201812129&partnerID=40&md5=2a84723d0ddf3e7a60d44c945c5e4c0b
dc.identifier.urihttp://hdl.handle.net/10713/10180
dc.description.abstractHuman ether-à-go-go–related gene (hERG, KCNH2) voltage-activated potassium channels are critical for cardiac excitability. hERG channels have characteristic slow closing (deactivation), which is auto-regulated by a direct interaction between the N-terminal Per-Arnt-Sim (PAS) domain and the C-terminal cyclic nucleotide binding homology domain (CNBHD). hERG channels are not activated by the binding of extrinsic cyclic nucleotide ligands, but rather bind an “intrinsic ligand” that is composed of residues 860–862 within the CNBHD and mimics a cyclic nucleotide. The intrinsic ligand is located at the PAS–CNBHD interface, but its mechanism of action in hERG is not well understood. Here we use whole-cell patch-clamp electrophysiology and FRET spectroscopy to examine how the intrinsic ligand regulates gating. To carry out this work, we coexpress PAS (a PAS domain fused to cyan fluorescent protein) in trans with hERG “core” channels (channels with a deletion of the PAS domain fused to citrine fluorescent protein). The PAS domain in trans with hERG core channels has slow (regulated) deactivation, like that of WT hERG channels, as well as robust FRET, which indicates there is a direct functional and structural interaction of the PAS domain with the channel core. In contrast, PAS in trans with hERG F860A core channels has intermediate deactivation and intermediate FRET, indicating perturbation of the PAS domain interaction with the CNBHD. Furthermore, PAS in trans with hERG L862A core channels, or PAS in trans with hERG F860G,L862G core channels, has fast (nonregulated) deactivation and no measurable FRET, indicating abolition of the PAS and CNBHD interaction. These results indicate that the intrinsic ligand is necessary for the functional and structural interaction between the PAS domain and the CNBHD, which regulates the characteristic slow deactivation gating in hERG channels.en_US
dc.description.sponsorshipThis work was supported by the National Institutes of Health/National Heart, Lung, and Blood Institute (T32 HL007698-24 to S.J. Codding) and funds from the University of Maryland School of Medicine (to M.C. Trudeau).en_US
dc.description.urihttps://doi.org/10.1085/jgp.201812129en_US
dc.language.isoen-USen_US
dc.publisherRockefeller University Pressen_US
dc.relation.ispartofJournal of General Physiology
dc.subject.meshEther-A-Go-Go Potassium Channels--physiologyen_US
dc.titleThe hERG potassium channel intrinsic ligand regulates N- and C-terminal interactions and channel closureen_US
dc.typearticleen_US
dc.identifier.doi10.1085/jgp.201812129
dc.identifier.pmid30425124


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