Cytoplasmic ATP-sensing domains regulate gating of skeletal muscle ClC-1 chloride channels

Brett Bennetts, Grigori Y. Rychkov, Hooi Ling Ng, Craig J. Morton, David Stapleton, Michael W. Parker, Brett A. Cromer

Research output: Contribution to journalArticlepeer-review

102 Citations (Scopus)

Abstract

ClC proteins are a family of chloride channels and transporters that are found in a wide variety of prokaryotic and eukaryotic cell types. The mammalian voltage-gated chloride channel ClC-1 is important for controlling the electrical excitability of skeletal muscle. Reduced excitability of muscle cells during metabolic stress can protect cells from metabolic exhaustion and is thought to be a major factor in fatigue. Here we identify a novel mechanism linking excitability to metabolic state by showing that ClC-1 channels are modulated by ATP. The high concentration of ATP in resting muscle effectively inhibits ClC-1 activity by shifting the voltage gating to more positive potentials. ADP and AMP had similar effects to ATP, but IMP had no effect, indicating that the inhibition of ClC-1 would only be relieved under anaerobic conditions such as intense muscle activity or ischemia, when depleted ATP accumulates as IMP. The resulting increase in ClC-1 activity under these conditions would reduce muscle excitability, thus contributing to fatigue. We show further that the modulation by ATP is mediated by cystathionine β-synthase-related domains in the cytoplasmic C terminus of ClC-1. This defines a function for these domains as gating-modulatory domains sensitive to intracellular ligands, such as nucleotides, a function that is likely to be conserved in other ClC proteins.

Original languageEnglish
Pages (from-to)32452-32458
Number of pages7
JournalJournal of Biological Chemistry
Volume280
Issue number37
DOIs
Publication statusPublished or Issued - 16 Sep 2005

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this