Hypotonic shocks activate rat TRPV4 in yeast in the absence of polyunsaturated fatty acids

FEBS Lett. 2009 Feb 18;583(4):754-8. doi: 10.1016/j.febslet.2009.01.027. Epub 2009 Jan 25.


Transient-receptor-potential channels (TRPs) underlie the sensing of chemicals, heat, and mechanical force. We expressed the rat TRPV1 and TRPV4 subtypes in yeast and monitored their activities in vivo as Ca(2+) rise using transgenic aequorin. Heat and capsaicin activate TRPV1 but not TRPV4 in yeast. Hypotonic shocks activate TRPV4 but not TRPV1. Osmotic swelling is modeled to activate enzyme(s), producing polyunsaturated fatty acids (PUFAs) to open TRPV4 in mammalian cells. This model relegates mechanosensitivity to the enzyme and not the channel. Yeast has only a single Delta9 fatty-acid monodesaturase and cannot make PUFAs suggesting an alternative mechanism for TRPV4 activation. We discuss possible explanations of this difference.

Publication types

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

MeSH terms

  • Animals
  • Fatty Acids, Unsaturated / genetics*
  • Hypotonic Solutions / pharmacology*
  • Ion Channels / classification*
  • Ion Channels / genetics
  • Ion Channels / metabolism*
  • Rats
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism*
  • TRPV Cation Channels / genetics
  • TRPV Cation Channels / metabolism*


  • Fatty Acids, Unsaturated
  • Hypotonic Solutions
  • Ion Channels
  • TRPV Cation Channels
  • Trpv4 protein, rat