MEC-2 is recruited to the putative mechanosensory complex in C. elegans touch receptor neurons through its stomatin-like domain

Curr Biol. 2004 Nov 9;14(21):1888-96. doi: 10.1016/j.cub.2004.10.030.


Background: The response to gentle body touch in C. elegans requires a degenerin channel complex containing four proteins (MEC-2, MEC-4, MEC-6, and MEC-10). The central portion of the integral membrane protein MEC-2 contains a stomatin-like region that is highly conserved from bacteria to mammals. The molecular function of this domain in MEC-2, however, is unknown.

Results: Here, we show that MEC-2 colocalizes with the degenerin MEC-4 in regular puncta along touch receptor neuron processes. This punctate localization requires the other channel complex proteins. The stomatin-like region of MEC-2 interacts with the intracellular cytoplasmic portion of MEC-4. Missense mutations in this region that destroy the interaction also disrupt the punctate localization and degenerin-regulating function of MEC-2. Missense mutations outside this region apparently have no effect on the punctate localization but significantly reduce the regulatory effect of MEC-2 on the MEC-4 degenerin channel. A second stomatin-like protein, UNC-24, colocalizes with MEC-2 in vivo and coimmunoprecipitates with MEC-2 and MEC-4 in Xenopus oocytes; unc-24 enhances the touch insensitivity of temperature-sensitive alleles of mec-4 and mec-6.

Conclusion: Two stomatin homologs, MEC-2 and UNC-24, interact with the MEC-4 degenerin through their stomatin-like regions, which act as protein binding domains. At least in the case of MEC-2, this binding allows its nonstomatin domains to regulate channel activity. Stomatin-like regions in other proteins may serve a similar protein binding function.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alleles*
  • Animals
  • Animals, Genetically Modified
  • Blotting, Western
  • Caenorhabditis elegans
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism*
  • Electrophysiology
  • Glutathione Transferase
  • Green Fluorescent Proteins
  • Immunohistochemistry
  • Immunoprecipitation
  • Mechanotransduction, Cellular / physiology*
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mutation, Missense / genetics
  • Protein Structure, Tertiary
  • Sensory Receptor Cells / metabolism*
  • Sensory Receptor Cells / physiology
  • Touch / physiology*


  • Caenorhabditis elegans Proteins
  • MEC-2 protein, C elegans
  • Mec-4 protein, C elegans
  • Membrane Proteins
  • Unc-24 protein, C elegans
  • Green Fluorescent Proteins
  • Glutathione Transferase