Phosphorylation at Thr432 induces structural destabilization of the CII ring in the circadian oscillator KaiC
Phosphorylation at Thr432 induces structural destabilization of the CII ring in the circadian oscillator KaiC
复制标题
Thr432 的磷酸化会导致昼夜节律振荡器 KaiC 中 CII 环的结构不稳定
DOI：
10.1002/1873-3468.12945
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发表时间：
2018
期刊：
影响因子：
3.5
通讯作者：
Terauchi K.
中科院分区：
文献类型：
--
作者：
Oyama K.;Azai C.;Matsuyama J.;Terauchi K.
KaiC是蓝藻生物钟中的中心振荡蛋白。KaiC在ATP存在下与KaiA和KaiB混合，在体外24小时循环中在磷酸化和去磷酸化状态之间自主振荡。KaiC形成C6-对称六聚体，其是分别称为Cl和CII的同源N-末端和C-末端结构域的双环结构。在这里，通过分离的CII结构域蛋白，CIIKaiC的表征，我们表明，KaiC Thr 432的磷酸化使CII环的六聚体状态不稳定为单体状态。结果表明，稳定的六聚体CI环作为一个分子束，以保持CII环，它经历了磷酸化后的动态结构变化。
KaiC is the central oscillator protein in the cyanobacterial circadian clock. KaiC oscillates autonomously between phosphorylated and dephosphorylated states on a 24‐h cyclein vitroby mixing with KaiA and KaiB in the presence of ATP. KaiC forms aC6‐symmetrical hexamer, which is a double ring structure of homologous N‐terminal and C‐terminal domains termed CI and CII, respectively. Here, through the characterization of an isolated CII domain protein, CIIKaiC, we show that phosphorylation of KaiC Thr432 destabilizes the hexameric state of the CII ring to a monomeric state. The results suggest that the stable hexameric CI ring acts as a molecular bundle to hold the CII ring, which undergoes dynamic structural changes upon phosphorylation.