Sci. STKE, 27 June 2006
CIRCADIAN RHYTHMS Flies and jetlag
Circadian clocks can be reset to a new phase by a brief exposure to light, but the molecular details of this resetting are not clear. In Drosophila, a light-sensitive protein cryptochrome undergoes a conformational change in response to light and binds to a clock component, the protein TIMELESS (TIM). This interaction then triggers TIM degradation, effectively resetting the clock. By screening mutant flies that show reduced sensitivity to this light-induced resetting, Koh et al. identify a gene, termed jetlag, that is necessary for degradation of TIM after the light pulse. JETLAG exists in a complex with TIM and increases its ubiquitination, a tag that marks the protein for degradation. Thus, JETLAG is an F-box protein that targets TIM for ubiquitination and consequent rapid degradation in response to light.
Citation: Flies and jetlag. Sci. STKE 2006, tw217 (2006).
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