Light-induced recruitment of INAD-signaling complexes to detergent-resistant lipid rafts in Drosophila photoreceptors

Mol Cell Neurosci. 2007 Sep;36(1):36-46. doi: 10.1016/j.mcn.2007.05.006. Epub 2007 Jun 27.


Here, we reveal a novel feature of the dynamic organization of signaling components in Drosophila photoreceptors. We show that the multi-PDZ protein INAD and its target proteins undergo light-induced recruitment to detergent-resistant membrane (DRM) rafts. Reduction of ergosterol, considered to be a key component of lipid rafts in Drosophila, resulted in a loss of INAD-signaling complexes associated with DRM fractions. Genetic analysis demonstrated that translocation of INAD-signaling complexes to DRM rafts requires activation of the entire phototransduction cascade, while constitutive activation of the light-activated channels resulted in recruitment of complexes to DRM rafts in the dark. Mutations affecting INAD and TRP showed that PDZ4 and PDZ5 domains of INAD, as well as the INAD-TRP interaction, are required for translocation of components to DRM rafts. Finally, selective recruitment of phosphorylated, and therefore activatable, eye-PKC to DRM rafts suggests that DRM domains are likely to function in signaling, rather than trafficking.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Detergents / pharmacology*
  • Drosophila
  • Drosophila Proteins / metabolism*
  • Eye Proteins / metabolism*
  • Gene Expression Regulation / physiology
  • Light
  • Membrane Microdomains* / drug effects
  • Membrane Microdomains* / metabolism
  • Membrane Microdomains* / radiation effects
  • Motor Neurons / drug effects
  • Motor Neurons / metabolism
  • Photoreceptor Cells, Invertebrate / cytology*
  • Photoreceptor Cells, Invertebrate / radiation effects
  • Signal Transduction* / drug effects
  • Signal Transduction* / physiology
  • Signal Transduction* / radiation effects


  • Detergents
  • Drosophila Proteins
  • Eye Proteins
  • inaD protein, Drosophila