Inositol 1,4,5-Trisphosphate Receptor and dSTIM Function in<i>Drosophila</i>Insulin-Producing Neurons Regulates Systemic Intracellular Calcium Homeostasis and Flight

Abstract

Calcium (Ca(2+)) signaling is known to regulate the development, maintenance and modulation of activity in neuronal circuits that underlie organismal behavior. In Drosophila, intracellular Ca(2+) signaling by the inositol 1,4,5-trisphosphate receptor and the store-operated channel (dOrai) regulates the formation and function of neuronal circuits that control flight. Here, we show that restoring InsP(3)R activity in insulin-producing neurons of flightless InsP(3)R mutants (itpr) during pupal development can rescue systemic flight ability. Expression of the store operated Ca(2+) entry (SOCE) regulator dSTIM in insulin-producing neurons also suppresses compromised flight ability of InsP(3)R mutants suggesting that SOCE can compensate for impaired InsP(3)R function. Despite restricted expression of wild-type InsP(3)R and dSTIM in insulin-producing neurons, a global restoration of SOCE and store Ca(2+) is observed in primary neuronal cultures from the itpr mutant. These results suggest that restoring InsP(3)R-mediated Ca(2+) release and SOCE in a limited subset of neuromodulatory cells can influence systemic behaviors such as flight by regulating intracellular Ca(2+) homeostasis in a large population of neurons through a non-cell-autonomous mechanism.