Pickpocket is a DEG/ENaC protein required for mechanical nociception in Drosophila larvae

Curr Biol. 2010 Mar 9;20(5):429-34. doi: 10.1016/j.cub.2009.12.057. Epub 2010 Feb 18.


Highly branched class IV multidendritic sensory neurons of the Drosophila larva function as polymodal nociceptors that are necessary for behavioral responses to noxious heat (>39 degrees C) or noxious mechanical (>30 mN) stimuli. However, the molecular mechanisms that allow these cells to detect both heat and force are unknown. Here, we report that the pickpocket (ppk) gene, which encodes a Degenerin/Epithelial Sodium Channel (DEG/ENaC) subunit, is required for mechanical nociception but not thermal nociception in these sensory cells. Larvae mutant for pickpocket show greatly reduced nociception behaviors in response to harsh mechanical stimuli. However, pickpocket mutants display normal behavioral responses to gentle touch. Tissue-specific knockdown of pickpocket in nociceptors phenocopies the mechanical nociception impairment without causing defects in thermal nociception behavior. Finally, optogenetically triggered nociception behavior is unaffected by pickpocket RNAi, which indicates that ppk is not generally required for the excitability of the nociceptors. Interestingly, DEG/ENaCs are known to play a critical role in detecting gentle touch stimuli in Caenorhabditis elegans and have also been implicated in some aspects of harsh touch sensation in mammals. Our results suggest that neurons that detect harsh touch in Drosophila utilize similar mechanosensory molecules.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism*
  • Drosophila melanogaster / genetics
  • Drosophila melanogaster / growth & development
  • Drosophila melanogaster / metabolism*
  • Gene Expression Regulation / physiology
  • Hot Temperature / adverse effects
  • Larva / genetics
  • Larva / metabolism
  • Mechanotransduction, Cellular / physiology
  • Pain Measurement
  • RNA Interference
  • Sensory Receptor Cells / cytology
  • Sensory Receptor Cells / physiology
  • Sodium Channels / genetics
  • Sodium Channels / metabolism*
  • Touch


  • Drosophila Proteins
  • Sodium Channels
  • ppk protein, Drosophila