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

Pablo Miranda, Jorge E. Contreras, Andrew J.R. Plested, Fred J. Sigworth, Miguel Holmgren, Teresa Giraldez

Research output: Contribution to journalArticlepeer-review

38 Scopus citations


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 Ca2+ 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 Ca2+ 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.

Original languageEnglish (US)
Pages (from-to)5217-5222
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number13
StatePublished - Mar 26 2013

All Science Journal Classification (ASJC) codes

  • General


  • Allosteric regulation
  • Fluorescence
  • SLO1 channel


Dive into the research topics of 'State-dependent FRET reports calcium- and voltagedependent gating-ring motions in BK channels'. Together they form a unique fingerprint.

Cite this