High-Throughput Chemical Screen Identifies a Novel Potent Modulator of Cellular Circadian Rhythms and Reveals CKIα as a Clock Regulatory Kinase

• DOI: 10.1371/journal.pbio.1000559
• Publication Date: 2010-12-14T21:02:29Z
• Authors: Tsuyoshi Hirota; Jae Wook Lee; Warren G. Lewis; Eric E. Zhang; Ghislain Breton; Xianzhong Liu; Michael Garcia; Eric C. Peters; Jean-Pierre Etche...; David Traver; Peter G. Schultz; Steve A. Kay
• Keywords: PER1

The circadian clock underlies daily rhythms of diverse physiological processes, and alterations in function have been linked to numerous pathologies. To apply chemical biology methods modulate dissect the mechanism with new probes, we performed a screen ∼120,000 uncharacterized compounds on human cells containing reporter. analysis identified small molecule that potently lengthens period dose-dependent manner. Subsequent showed compound also lengthened variety from different tissues including mouse suprachiasmatic nucleus, central controlling behavioral rhythms. Based prominent lengthening effect, named longdaysin. Longdaysin was amenable for modification perform affinity chromatography coupled mass spectrometry identify target proteins. Combined siRNA-mediated gene knockdown, protein kinases CKIδ, CKIα, ERK2 as targets longdaysin responsible observed effect period. Although individual knockdown had effects, their combinatorial dramatically similar treatment. We characterized role CKIα found CKIα-mediated phosphorylation stimulated degradation PER1, CKIδ. treatment inhibited PER1 degradation, providing insight into longdaysin-dependent lengthening. Using larval zebrafish, further demonstrated drastically vivo. Taken together, approach not only revealed regulatory kinase but multiple network conferring robustness clock. provides novel possibilities manipulating due its ability simultaneously inhibit several key components this conserved across species.