The roles of trp and calcium in regulating photoreceptor function in Drosophila.
Invertebrate photoreceptors use the ubiquitous inositol-lipid signaling pathway for phototransduction. This pathway depends on Ca2+ release from internal stores and on Ca2+ entry via light-activated channels to replenish the loss of Ca2+ in those stores. The Drosophila transient receptor potential (TRP) protein is essential for the high Ca2+ permeability and other biophysical properties of these light-activated channels, which affect both excitation and adaptation in photoreceptor cells. Physiological and heterologous expression studies indicate that TRP is a putative subunit of a surface membrane channel that can be activated by depletion of internal Ca2+ stores. Furthermore, trp is an archetypal member of a multigene family whose products share a structure that is highly conserved throughout evolution, from worms to humans.
Minke
B
B
Department of Physiology, The Hebrew University - Hadassah Medical School, Jerusalem 91120, Israel. minke@md2.huji.ac.il
Selinger
Z
Z
D000221:Adaptation, Ocular / Q000502:physiology; D000818:Animals; D005075:Biological Evolution; D002118:Calcium / Q000502:physiology*; D015220:Calcium Channels; D002413:Cations, Divalent / Q000493:pharmacokinetics; D017124:Conserved Sequence; D004330:Drosophila / Q000502:physiology*; D007473:Ion Channels / Q000235:genetics / Q000378:metabolism / Q000502:physiology* / Q000528:radiation effects; D008027:Light; D009154:Mutation; D010539:Permeability; D017956:Photoreceptor Cells, Invertebrate / Q000502:physiology*; D050052:TRPC Cation Channels
D015220:Calcium Channels; D002413:Cations, Divalent; D007473:Ion Channels; D050052:TRPC Cation Channels; C096351:transient receptor potential cation channel, subfamily C, member 1; D002118:Calcium