Light-regulated subcellular translocation of Drosophila TRPL channels induces long-term adaptation and modifies the light-induced current.
Drosophila phototransduction results in the opening of two classes of cation channels, composed of the channel subunits transient receptor potential (TRP), TRP-like (TRPL), and TRPgamma. Here, we report that one of these subunits, TRPL, is translocated back and forth between the signaling membrane and an intracellular compartment by a light-regulated mechanism. A high level of rhabdomeral TRPL, characteristic of dark-raised flies, is functionally manifested in the properties of the light-induced current. These flies are more sensitive than flies with no or reduced TRPL level to dim background lights, and they respond to a wider range of light intensities, which fit them to function better in darkness or dim background illumination. Thus, TRPL translocation represents a novel mechanism to fine tune visual responses.
Bähner
Monika
M
Zoological Institute, Department of Cell- and Neurobiology, University of Karlsruhe, 76128 Karlsruhe, Germany.
Frechter
Shahar
S
Da Silva
Noel
N
Minke
Baruch
B
Paulsen
Reinhard
R
Huber
Armin
A
D000221:Adaptation, Ocular / Q000502:physiology*; D000818:Animals; D002148:Calmodulin-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D003624:Darkness; D004330:Drosophila / Q000235:genetics / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D008027:Light; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D017956:Photoreceptor Cells, Invertebrate / Q000378:metabolism; D021381:Protein Transport / Q000502:physiology; D013347:Subcellular Fractions / Q000378:metabolism; D013995:Time; D050051:Transient Receptor Potential Channels
D002148:Calmodulin-Binding Proteins; D029721:Drosophila Proteins; D008565:Membrane Proteins; D050051:Transient Receptor Potential Channels; C074192:trpl protein, Drosophila