CSL encodes a leucine-rich-repeat protein implicated in red/violet light signaling to the circadian clock in Chlamydomonas.
CSL encodes a leucine-rich-repeat protein implicated in red/violet light signaling to the circadian clock in Chlamydomonas.
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DOI：
10.1371/journal.pgen.1006645
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发表时间：
2017-03
期刊：
影响因子：
4.5
通讯作者：
Matsuo T
中科院分区：
文献类型：
--
作者：
Kinoshita A;Niwa Y;Onai K;Yamano T;Fukuzawa H;Ishiura M;Matsuo T
绿色衣藻在行为和生理上表现出多种光反应。一种这样的光反应是生物钟，它可以通过外部光信号重置，以将其振荡带入日常环境周期。在以前的报告中，我们提出，光诱导的时钟蛋白ROC 15的降解是一个触发器，以重置衣原体的昼夜节律钟。然而，这一过程的光信号通路仍不清楚。在这里，我们筛选突变体，显示异常ROC 15昼夜节律，包括光诱导的蛋白质降解在黎明时，使用荧光素酶融合报告。在一个突变体中，ROC 15降解和光生物钟的相位重置受损。有趣的是，在红光和紫光下观察到了损伤，而在蓝光下则没有。我们发现，一个未知的基因编码的蛋白类似于RAS信号相关的富含亮氨酸重复序列（LRR）蛋白是负责突变表型。我们的研究结果表明，一个以前未被描述的红/紫光信号通路参与了衣原体生物钟的相位重置。单细胞绿色衣藻是许多生物学研究中的模型系统。虽然这种荧光素的蓝光响应（例如，趋光性）是公知的并且被很好地表征，但是关于对其他波长的响应的理解少得多。生物钟就是这样一种光反应，它可以被从紫色到红色的各种波长的光重置，从而将其振荡带入日常环境周期。在这项研究中，我们确定了一个基因负责红色和紫色光反应的生物钟的正向遗传筛选。我们的研究结果揭示了一个以前未被识别的红/紫光信号通路在绿色藻类。
The green alga Chlamydomonas reinhardtii shows various light responses in behavior and physiology. One such photoresponse is the circadian clock, which can be reset by external light signals to entrain its oscillation to daily environmental cycles. In a previous report, we suggested that a light-induced degradation of the clock protein ROC15 is a trigger to reset the circadian clock in Chlamydomonas. However, light signaling pathways of this process remained unclear. Here, we screened for mutants that show abnormal ROC15 diurnal rhythms, including the light-induced protein degradation at dawn, using a luciferase fusion reporter. In one mutant, ROC15 degradation and phase resetting of the circadian clock by light were impaired. Interestingly, the impairments were observed in response to red and violet light, but not to blue light. We revealed that an uncharacterized gene encoding a protein similar to RAS-signaling-related leucine-rich repeat (LRR) proteins is responsible for the mutant phenotypes. Our results indicate that a previously uncharacterized red/violet light signaling pathway is involved in the phase resetting of circadian clock in Chlamydomonas. The unicellular green alga Chlamydomonas reinhardtii is used as a model system in many biological researches. Although blue light responses of this alga (e.g., phototaxis) are well known and well characterized, far less is understood about responses to other wavelengths. One such photoresponse is the circadian clock, which can be reset by various wavelengths of light, ranging from violet to red, to entrain its oscillation to daily environmental cycles. In this study, we identified a gene responsible for red and violet light responses of the circadian clock by a forward genetic screen. Our results shed light on a previously unrecognized red/violet light signaling pathway in green algae.