Gating at the selectivity filter in cyclic nucleotide-gated channels

Jorge E. Contreras, Deepa Srikumar, Miguel Holmgren

Research output: Contribution to journalArticle

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By opening and closing the permeation pathway (gating) in response to cGMP binding, cyclic nucleotide-gated (CNG) channels serve key roles in the transduction of visual and olfactory signals. Compiling evidence suggests that the activation gate in CNG channels is not located at the intracellular end of pore, as it has been established for voltage-activated potassium (KV) channels. Here, we show that ion permeation in CNG channels is tightly regulated at the selectivity filter. By scanning the entire selectivity filter using small cysteine reagents, like cadmium and silver, we observed a state-dependent accessibility pattern consistent with gated access at the middle of the selectivity filter, likely at the corresponding position known to regulate structural changes in KcsA channels in response to low concentrations of permeant ions.

Original languageEnglish (US)
Pages (from-to)3310-3314
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number9
Publication statusPublished - Mar 4 2008
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • General


  • Ion channel
  • Signal transduction
  • cGMP

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