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-LNs) 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 Ca channels (CaChs). We show that Dstac is coexpressed with PDF by the s-LNs and regulates circadian activity. Furthermore, the L-type CaCh, Dmca1D, appears to be expressed by the s-LNs. Since vertebrate Stac3 regulates an L-type CaCh we hypothesize that Dstac regulates Dmca1D in s-LNs and circadian activity.