Identification of Light-Sensitive Phosphorylation Sites on PERIOD That Regulate the Pace of Circadian Rhythms in Drosophila.
Identification of Light-Sensitive Phosphorylation Sites on PERIOD That Regulate the Pace of Circadian Rhythms in Drosophila.
复制标题
鉴定果蝇中调节昼夜节律节奏的光敏磷酸化位点。
DOI：
10.1128/mcb.00682-15
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发表时间：
2015
影响因子：
5.3
通讯作者：
Edery,Isaac
中科院分区：
文献类型：
--
作者：
Yildirim,Evrim;Chiu,JoannaC;Edery,Isaac
在动物中调节昼夜节律（24 h）时钟的主要成分是PERIOD（PER）蛋白，其是通过复杂的多位点磷酸化程序进行水平和核积累的每日变化的转录调节因子。在本研究中，我们研究了两个磷酸化位点的功能，在Ser 826和Ser 828，位于一个假定的核定位信号（NLS）的果蝇黑腹PER蛋白。这些位点被DOUBLETIME（DBT; CK 1 δ/ε的果蝇同源物）磷酸化，DOUBLETIME是调节PER稳定性和磷酸化的每日变化的关键昼夜节律激酶。突变苍蝇，其中Ser 826/Ser 828磷酸化被阻断，表现出行为节律，周期略长于1小时，并具有改变的温度补偿特性。有趣的是，尽管这些位点的磷酸化不影响PER的稳定性、进入核的时间或转录自抑制，但是Ser 826/Ser 828的磷酸化占据被光快速刺激并被TIMELESS（TIM）阻断，TIMELESS（TIM）是果蝇中主要的光敏时钟成分，也是PER的关键结合伴侣。我们的研究结果确定了核心时钟蛋白的第一个磷酸化位点，这些位点受到光信号的强烈调控，并表明PER蛋白上的一些磷酸化位点可以调节下游行为节律的步伐，而不会改变时钟机制的中心方面。
The main components regulating the pace of circadian (≅24 h) clocks in animals are PERIOD (PER) proteins, transcriptional regulators that undergo daily changes in levels and nuclear accumulation by means of complex multisite phosphorylation programs. In the present study, we investigated the function of two phosphorylation sites, at Ser826 and Ser828, located in a putative nuclear localization signal (NLS) on theDrosophila melanogasterPER protein. These sites are phosphorylated by DOUBLETIME (DBT;Drosophilahomolog of CK1δ/ε), the key circadian kinase regulating the daily changes in PER stability and phosphorylation. Mutant flies in which phosphorylation at Ser826/Ser828 is blocked manifest behavioral rhythms with periods slightly longer than 1 h and with altered temperature compensation properties. Intriguingly, although phosphorylation at these sites does not influence PER stability, timing of nuclear entry, or transcriptional autoinhibition, the phospho-occupancy at Ser826/Ser828 is rapidly stimulated by light and blocked by TIMELESS (TIM), the major photosensitive clock component inDrosophilaand a crucial binding partner of PER. Our findings identify the first phosphorylation sites on core clock proteins that are acutely regulated by photic cues and suggest that some phosphosites on PER proteins can modulate the pace of downstream behavioral rhythms without altering central aspects of the clock mechanism.