Department of Neurobiology; Emery Lab; Graduate School of Biomedical Sciences, Neuroscience Program
Animals; Behavior, Animal; Circadian Rhythm; Cryptochromes; DNA Helicases; Drosophila Proteins; Drosophila melanogaster; Gene Expression Regulation; Genes, Insect; *Genetic Testing; Homeodomain Proteins; *Light; Neurons; Protein Processing, Post-Translational; RNA, Double-Stranded
Neuroscience and Neurobiology
Circadian pacemakers are essential to synchronize animal physiology and behavior with the dayrationight cycle. They are self-sustained, but the phase of their oscillations is determined by environmental cues, particularly light intensity and temperature cycles. In Drosophila, light is primarily detected by a dedicated blue-light photoreceptor: CRYPTOCHROME (CRY). Upon light activation, CRY binds to the pacemaker protein TIMELESS (TIM) and triggers its proteasomal degradation, thus resetting the circadian pacemaker. To understand further the CRY input pathway, we conducted a misexpression screen under constant light based on the observation that flies with a disruption in the CRY input pathway remain robustly rhythmic instead of becoming behaviorally arrhythmic. We report the identification of more than 20 potential regulators of CRY-dependent light responses. We demonstrate that one of them, the chromatin-remodeling enzyme KISMET (KIS), is necessary for normal circadian photoresponses, but does not affect the circadian pacemaker. KIS genetically interacts with CRY and functions in PDF-negative circadian neurons, which play an important role in circadian light responses. It also affects daily CRY-dependent TIM oscillations in a peripheral tissue: the eyes. We therefore conclude that KIS is a key transcriptional regulator of genes that function in the CRY signaling cascade, and thus it plays an important role in the synchronization of circadian rhythms with the dayrationight cycle.
Rights and Permissions
Copyright: © 2009 Dubruille et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
DOI of Published Version
PLoS Genet. 2009 Dec;5(12):e1000787. Epub 2009 Dec 24. Link to article on publisher's site
Dubruille, Raphaëlle; Murad, Alejandro D.; Rosbash, Michael; and Emery, Patrick, "A constant light-genetic screen identifies KISMET as a regulator of circadian photoresponses" (2009). Open Access Articles. 2195.