蓝藻生物钟核心振荡器的KaiB-KaiC相互作用机制  

The Mechanism of KaiB-KaiC Interaction of The Cyanobacterial Circadian Oscillator

作　　者：刘松[1] 刘森[1] 

机构地区：[1]三峡大学医学院分子生物学研究所,宜昌443002

出　　处：《生物化学与生物物理进展》2015年第3期220-227,共8页Progress In Biochemistry and Biophysics

基　　金：国家自然科学基金(21103098);北京分子科学国家实验室开放基金;三峡大学科研基金(2011071001;KJ2012B004;KJ2014H015)资助项目~~

摘　　要：蓝藻是已知的具有昼夜节律生物钟调控机制的最简单生物,其生物钟的核心是一个由三个蛋白质(Kai A、Kai B、Kai C)组成的,不依赖于转录翻译水平调控的核心振荡器.研究表明这三个蛋白质仅在体外试管中反应就会表现出周期性磷酸化振荡现象.分子水平研究表明:Kai A加速Kai C的自磷酸化,而Kai B抑制Kai A使Kai C去磷酸化,从而Kai C的磷酸化/去磷酸化形成周期性反复.但是Kai B如何与Kai A,Kai C相互作用,目前还不清楚.本文重点介绍了最近几年来在Kai B-Kai C相互作用机制上的研究进展,并结合我们的一些初步研究,对Kai B-Kai C相互作用的关键问题进行展望,以期为该体系的深入研究提供参考.Cyanobacteria are the simplest organisms with a confirmed circadian clock system. The pacemaker of cyanobacterial circadian clock is made of three proteins, Kai A, KaiB, and KaiC. A major finding on this system is that the circadian oscillation of the pacemaker system is independent of transcriptional/translational controls, and what is more intriguing is that this oscillation can be reconstituted in vitro with only these three proteins, in addition to ATP and an appropriate inorganic buffer. Molecular studies have shown that Kai A promotes the self-phosphorylation of KaiC, whereas KaiB antagonize Kai A＇s role and induce the de-phosphorylation of KaiC.An unsolved question is how KaiB interacts with KaiC exactly, including the binding site of KaiB on KaiC, the oligomerization form of KaiB, and the exact modulating mechanism of KaiB. Here, we reviewed the most recent progress on the KaiB-KaiC interaction mechanism, including our preliminary results on the KaiB-KaiC interaction,and provided a possible molecular mechanism of the molecular oscillator. We hope this review will provide a timely perspective on the study of this model system.

关 键 词：生物振荡器 生物钟 KaiB KAIC 

分 类 号：Q6[生物学—生物物理学] Q7