cullin-3 controls timeless oscillations in the drosophila circadian clockcullin-3果蝇生物钟控制永恒的振荡.pdf

CULLIN-3 Controls TIMELESS Oscillations in the Drosophila Circadian Clock 1,2. 1,2. 1,2 ´ 1,2 1,2 Brigitte Grima , Alexandre Dognon , Annie Lamouroux , Elisabeth Chelot , Franc¸ois Rouyer * ´ ´ 1 Institut de Neurobiologie Alfred Fessard, CNRS UPR3294, Gif-sur-Yvette, France, 2 Departement de Biologie, Universite Paris Sud, Orsay, France Abstract Eukaryotic circadian clocks rely on transcriptional feedback loops. In Drosophila, the PERIOD (PER) and TIMELESS (TIM) proteins accumulate during the night, inhibit the activity of the CLOCK (CLK)/CYCLE (CYC) transcriptional complex, and are degraded in the early morning. The control of PER and TIM oscillations largely depends on post-translational mechanisms. They involve both light-dependent and light-independent pathways that rely on the phosphorylation, ubiquitination, and proteasomal degradation of the clock proteins. SLMB, which is part of a CULLIN-1-based E3 ubiquitin ligase complex, is required for the circadian degradation of phosphorylated PER. We show here that CULLIN-3 (CUL-3) is required for the circadian control of PER and TIM oscillations. Expression of either Cul-3 RNAi or dominant negative forms of CUL-3 in the clock neurons alters locomotor behavior and dampens PER and TIM oscillations in light-dark cycles. In constant conditions, CUL-3 deregulation induces behavioral arrhythmicity and rapidly abolishes TIM cycling, with slower effects on PER. CUL-3 affects TIM accumulation more strongly in the absence of PER and forms protein complexes wi