Dynamic localization of the cyanobacterial circadian clock proteins.
Dynamic localization of the cyanobacterial circadian clock proteins.
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DOI：
10.1016/j.cub.2014.07.036
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发表时间：
2014-08-18
期刊：
影响因子：
9.2
通讯作者：
Golden, Susan S.
中科院分区：
文献类型：
--
作者：
Cohen, Susan E.;Erb, Marcella L.;Selimkhanov, Jangir;Dong, Guogang;Hasty, Jeff;Pogliano, Joe;Golden, Susan S.
蓝藻生物钟系统已被广泛研究，并已很好地阐明了中心振荡器蛋白（KaiA、KaiB和KaiC）的结构、相互作用和生化活性。尽管有如此丰富的信息库，但人们对这些蛋白质在细胞内的分布知之甚少。在这里，我们报告了KaiA和KaiC以时钟依赖的方式定位为细胞单极附近的离散焦点，并且在夜间观察到增强的极性定位。KaiA定位依赖于KaiC；与这一概念一致，KaiA和KaiC彼此共定位，以及与CikA共定位，CikA是先前报道的显示单极定位的关键输入/输出因子。将KaiC定位到极点的分子机制在大肠杆菌（另一种革兰氏阴性杆状细菌）中是保守的，这表明KaiC定位不依赖于其他时钟或蓝藻特异性因素。此外，扩散分布的CikA突变变体的表达导致了KaiC的显著去定位。这项工作表明，蓝藻昼夜节律系统经历了亚细胞组织的昼夜节律编排。我们提出，观察到的时空定位模式代表了一种新的调节层，通过促进蛋白质复合物的形成和使时钟与环境刺激同步，有助于时钟的稳健性。
The cyanobacterial circadian clock system has been extensively studied and the structures, interactions and biochemical activities of the central oscillator proteins (KaiA, KaiB and KaiC) have been well elucidated. Despite this rich repository of information, little is known about the distribution of these proteins within the cell. Here we report that KaiA and KaiC localize as discrete foci near a single pole of cells in a clock-dependent fashion, with enhanced polar localization observed at night. KaiA localization is dependent on KaiC; consistent with this notion, KaiA and KaiC co-localize with each other as well as with CikA, a key input/output factor previously reported to display unipolar localization. The molecular mechanism that localizes KaiC to the poles is conserved in Escherichia coli, another Gram-negative rod shaped bacterium, suggesting that KaiC localization is not dependent on other clock- or cyanobacterial-specific factors. Moreover, expression of CikA mutant variants that distribute diffusely results in the striking de-localization of KaiC. This work shows that the cyanobacterial circadian system undergoes a circadian orchestration of subcellular organization. We propose that the observed spatiotemporal localization pattern represents a novel layer of regulation that contributes to the robustness of the clock by facilitating protein complex formation and synchronizing the clock with environmental stimuli.
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影响因子：
8.8
作者：
Kim Y;Lim J;Yeom M;Kim H;Kim J;Wang L;Kim WY;Somers DE;Nam HG
通讯作者：
Nam HG
影响因子：
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作者：
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DOI：
10.1073/pnas.0604554103
发表时间：
2006-07-18
影响因子：
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作者：
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通讯作者：
Shapiro, Lucy
影响因子：
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作者：
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通讯作者：
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