Kv7 Channels Can Function Without Constitutive Calmodulin Tethering

PLoS One. 2011;6(9):e25508. doi: 10.1371/journal.pone.0025508. Epub 2011 Sep 28.

Abstract

M-channels are voltage-gated potassium channels composed of Kv7.2-7.5 subunits that serve as important regulators of neuronal excitability. Calmodulin binding is required for Kv7 channel function and mutations in Kv7.2 that disrupt calmodulin binding cause Benign Familial Neonatal Convulsions (BFNC), a dominantly inherited human epilepsy. On the basis that Kv7.2 mutants deficient in calmodulin binding are not functional, calmodulin has been defined as an auxiliary subunit of Kv7 channels. However, we have identified a presumably phosphomimetic mutation S511D that permits calmodulin-independent function. Thus, our data reveal that constitutive tethering of calmodulin is not required for Kv7 channel function.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Calmodulin / metabolism*
  • Cell Membrane / metabolism
  • Gene Expression Regulation
  • HEK293 Cells
  • Humans
  • KCNQ2 Potassium Channel / chemistry
  • KCNQ2 Potassium Channel / genetics
  • KCNQ2 Potassium Channel / metabolism*
  • KCNQ3 Potassium Channel / chemistry
  • KCNQ3 Potassium Channel / genetics
  • KCNQ3 Potassium Channel / metabolism*
  • Molecular Sequence Data
  • Mutation
  • Protein Structure, Secondary
  • Protein Transport

Substances

  • Calmodulin
  • KCNQ2 Potassium Channel
  • KCNQ3 Potassium Channel