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Proc Natl Acad Sci U S A. 2013 Mar 26;110(13):5217-22. doi: 10.1073/pnas.1219611110. Epub 2013 Mar 11.

State-dependent FRET reports calcium- and voltage-dependent gating-ring motions in BK channels.

Author information

1
Research Division, University Hospital of Nuestra Señora de Candelaria, 38010 Tenerife, Spain.

Abstract

Large-conductance voltage- and calcium-dependent potassium channels (BK, "Big K+") are important controllers of cell excitability. In the BK channel, a large C-terminal intracellular region containing a "gating-ring" structure has been proposed to transduce Ca(2+) binding into channel opening. Using patch-clamp fluorometry, we have investigated the calcium and voltage dependence of conformational changes of the gating-ring region of BK channels, while simultaneously monitoring channel conductance. Fluorescence resonance energy transfer (FRET) between fluorescent protein inserts indicates that Ca(2+) binding produces structural changes of the gating ring that are much larger than those predicted by current X-ray crystal structures of isolated gating rings.

PMID:
23479636
PMCID:
PMC3612663
DOI:
10.1073/pnas.1219611110
[Indexed for MEDLINE]
Free PMC Article

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