An epilepsy/dyskinesia-associated mutation enhances BK channel activation by potentiating Ca2+ sensing.

Published

Journal Article

Ca(2+)-activated BK channels modulate neuronal activities, including spike frequency adaptation and synaptic transmission. Previous studies found that Ca(2+)-binding sites and the activation gate are spatially separated in the channel protein, but the mechanism by which Ca(2+) binding opens the gate over this distance remains unknown. By studying an Asp-to-Gly mutation (D434G) associated with human syndrome of generalized epilepsy and paroxysmal dyskinesia (GEPD), we show that a cytosolic motif immediately following the activation gate S6 helix, known as the AC region, mediates the allosteric coupling between Ca(2+) binding and channel opening. The GEPD mutation inside the AC region increases BK channel activity by enhancing this allosteric coupling. We found that Ca(2+) sensitivity is enhanced by increases in solution viscosity that reduce protein dynamics. The GEPD mutation alters such a response, suggesting that a less flexible AC region may be more effective in coupling Ca(2+) binding to channel opening.

Full Text

Duke Authors

Cited Authors

  • Yang, J; Krishnamoorthy, G; Saxena, A; Zhang, G; Shi, J; Yang, H; Delaloye, K; Sept, D; Cui, J

Published Date

  • June 24, 2010

Published In

Volume / Issue

  • 66 / 6

Start / End Page

  • 871 - 883

PubMed ID

  • 20620873

Pubmed Central ID

  • 20620873

Electronic International Standard Serial Number (EISSN)

  • 1097-4199

Digital Object Identifier (DOI)

  • 10.1016/j.neuron.2010.05.009

Language

  • eng

Conference Location

  • United States