Role of Drosophila TRP in inositide-mediated Ca2+ entry.
Inositol lipid signaling relies on an InsP3-induced Ca2+ release from intracellular stores and on extracellular Ca2+ entry, which takes place when the Ca2+ stores become depleted of Ca2+. This interplay between Ca2+ release and Ca2+ entry has been termed capacitative Ca2+ entry and the inward current calcium release activated current (CRAC) to indicate gating of Ca2+ entry by Ca2+-store depletion. The signaling pathway and the gating mechanism of capacitative Ca2+ entry, however, are largely unknown and the molecular participants in this process have not been identified. In this article we review genetic, molecular, and functional studies of wild-type and mutant Drosophila photoreceptors, suggesting that the transient receptor potential mutant (trp) is the first putative capacitative Ca2+ entry mutant. Furthermore, several lines of evidence suggest that the trp gene product TRP is a candidate subunit of the plasma membrane channel that is activated by Ca2+ store depletion.
Minke
B
B
Department of Physiology, Hebrew University, Jerusalem, Israel.
Selinger
Z
Z
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D004330:Drosophila / Q000235:genetics / Q000502:physiology*; D017344:Genes, Insect; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate / Q000494:pharmacology / Q000502:physiology; D008027:Light; D008961:Models, Structural; D010716:Phosphatidylinositols / Q000494:pharmacology / Q000502:physiology*; D010786:Photoreceptor Cells / Q000502:physiology*; D015398:Signal Transduction; D050052:TRPC Cation Channels
D015220:Calcium Channels; D010716:Phosphatidylinositols; D050052:TRPC Cation Channels; C096351:transient receptor potential cation channel, subfamily C, member 1; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium