The cyclic GMP-dependent protein kinase EGL-4 regulates olfactory adaptation in C. elegans

Neuron. 2002 Dec 19;36(6):1079-89. doi: 10.1016/s0896-6273(02)01066-8.


Prolonged odor exposure causes a specific, reversible adaptation of olfactory responses. A genetic screen for negative regulators of olfaction uncovered mutations in the cGMP-dependent protein kinase EGL-4 that disrupt olfactory adaptation in C. elegans. G protein-coupled olfactory receptors within the AWC olfactory neuron signal through cGMP and a cGMP-gated channel. The cGMP-dependent kinase functions in AWC neurons during odor exposure to direct adaptation to AWC-sensed odors, suggesting that adaptation is a cell intrinsic process initiated by cGMP. A predicted phosphorylation site on the beta subunit of the cGMP-gated channel is required for adaptation after short odor exposure, suggesting that phosphorylation of signaling molecules generates adaptation at early time points. A predicted nuclear localization signal within EGL-4 is required for adaptation after longer odor exposure, suggesting that nuclear translocation of EGL-4 triggers late forms of adaptation.

Publication types

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

MeSH terms

  • Adaptation, Physiological / genetics*
  • Animals
  • Caenorhabditis elegans / cytology
  • Caenorhabditis elegans / enzymology*
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism*
  • Chemoreceptor Cells / cytology
  • Chemoreceptor Cells / metabolism
  • Chromosome Mapping
  • Cosmids / genetics
  • Cyclic GMP / metabolism
  • Cyclic GMP-Dependent Protein Kinases / deficiency*
  • Cyclic GMP-Dependent Protein Kinases / genetics
  • Cyclic GMP-Dependent Protein Kinases / metabolism*
  • Genetic Testing
  • Ion Channels / genetics
  • Ion Channels / metabolism
  • Molecular Sequence Data
  • Mutation / genetics
  • Nervous System / cytology
  • Nervous System / enzymology*
  • Neurons / cytology
  • Neurons / metabolism
  • Sequence Homology, Amino Acid
  • Sequence Homology, Nucleic Acid
  • Signal Transduction / genetics
  • Smell / genetics*


  • Caenorhabditis elegans Proteins
  • Ion Channels
  • tax-2 protein, C elegans
  • Cyclic GMP-Dependent Protein Kinases
  • EGL-4 protein, C elegans
  • Cyclic GMP