Dstac is required for normal circadian activity rhythms in Drosophila

The genetic, molecular and neuronal mechanism underlying circadian activity rhythms is well characterized in the brain of Drosophila. The small ventrolateral neurons (s-LN_Vs) and pigment dispersing factor (PDF) expressed by them are especially important for regulating circadian locomotion. Here we describe a novel gene, Dstac, which is similar to the stac genes found in vertebrates that encode adaptor proteins, which bind and regulate L-type voltage-gated Ca²⁺ channels (CaChs). We show that Dstac is coexpressed with PDF by the s-LN_Vs and regulates circadian activity. Furthermore, the L-type CaCh, Dmca1D, appears to be expressed by the s-LN_Vs. Since vertebrate Stac3 regulates an L-type CaCh we hypothesize that Dstac regulates Dmca1D in s-LN_Vs and circadian activity.