Direct association between mouse PERIOD and CKIε is critical for a functioning circadian clock
Direct association between mouse PERIOD and CKIε is critical for a functioning circadian clock
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DOI：
10.1128/mcb.24.2.584-594.2004
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发表时间：
2004-01-01
影响因子：
5.3
通讯作者：
Reppert, SM
中科院分区：
文献类型：
--
作者：
Lee, C;Weaver, DR;Reppert, SM
mPER1 和 mPER2 蛋白在生物钟机制中具有重要作用，而 mPER3 是可消耗的。在这里，我们检查了 mPER3 在小鼠肝脏体内的翻译后调节，并将其与其他 mPER 蛋白进行比较，以确定时钟功能所需的显着特征。与 mPER1 和 mPER2 一样，mPER3 被磷酸化，改变细胞位置，并以时间依赖性方式与其他时钟蛋白相互作用。与 mPer2/3 和 mPer1/3 双突变小鼠的行为数据一致，单独使用 mPER1 或 mPER2 可以维持有节律的翻译后事件。然而，mPER3 无法维持 mPer1/2 双突变小鼠的分子节律。事实上，mPER3 始终存在于细胞质中，并且在 mPer1 缺陷小鼠的肝脏中不被磷酸化，这表明 mPER3 在翻译后水平受到 mPER1 的调节。嵌合蛋白的体外研究表明，mPER3 无法支持生物钟功能，部分原因是缺乏与酪蛋白激酶 Iepsilon (CKIepsilon) 的直接和稳定的相互作用。因此，我们提出 CKIepsilon 结合域不仅对于 mPER 磷酸化至关重要，而且对于生物钟的功能也至关重要。
The mPER1 and mPER2 proteins have important roles in the circadian clock mechanism, whereas mPER3 is expendable. Here we examine the posttranslational regulation of mPER3 in vivo in mouse liver and compare it to the other mPER proteins to define the salient features required for clock function. Like mPER1 and mPER2, mPER3 is phosphorylated, changes cellular location, and interacts with other clock proteins in a time-dependent manner. Consistent with behavioral data from mPer2/3 and mPer1/3 double-mutant mice, either mPER1 or mPER2 alone can sustain rhythmic posttranslational events. However, mPER3 is unable to sustain molecular rhythmicity in mPer1/2 double-mutant mice. Indeed, mPER3 is always cytoplasmic and is not phosphorylated in the livers of mPer1-deficient mice, suggesting that mPER3 is regulated by mPER1 at a posttranslational level. In vitro studies with chimeric proteins suggest that the inability of mPER3 to support circadian clock function results in part from lack of direct and stable interaction with casein kinase Iepsilon (CKIepsilon). We thus propose that the CKIepsilon-binding domain is critical not only for mPER phosphorylation but also for a functioning circadian clock.