Rhythmic transcription in cyanobacteria

地球上的生命依赖于太阳的光和热。地球上最大的生物群之一是蓝藻，它们利用太阳的能量固定二氧化碳，并在光合作用中产生氧气。蓝藻已经进化出了以24小时为周期调节其基因活动的能力。这些周期不仅基于实际的昼夜周期，而且还受到内部昼夜分子时钟的支持，使蓝藻能够预测昼夜的开始。依赖光的和昼夜信息由RNA聚合酶(RNAP)整理并转化为基因表达的节律模式。RNAP是如何破译这一信息的尚不清楚。我们的目标是利用生物信息学、生物化学、蛋白质组学和冷冻-电子显微镜来研究参与基因昼夜节律激活/抑制的RNAP、转录因子和DNA调控元件的结构域。在前期工作中，我们开发了易于操作的体外转录和昼夜节律调控实验系统，并在生化和蛋白质组学数据的支持下获得了蓝藻RNAP复合体的前两个结构。该项目将产生蓝藻的基础知识，蓝藻是全球碳循环的主要贡献者。蓝藻作为碳中和生产者目前越来越受欢迎。我们的研究将为工业菌株的基因和代谢工程提供信息。在未来，将蓝藻生物钟移植到工业微生物中可能成为安排复杂生物合成任务的诱人机制。

Life on Earth depends on light and warmth of the Sun. One of the largest group of organisms on Earth is cyanobacteria who use energy of sun to fix cardon dioxide and produce oxygen during photosynthesis. Cyanobacteria have evolved the ability to regulate activity of their genes in cycles of 24 hours. These cycles are based not only on actual day/night cycles, but also supported by internal circadian molecular clock that allows cyanobacteria to predict the onset of day and night.Light-dependent and circadian- information is collated by RNA polymerase (RNAP) and transformed into rhythmic pattern of gene expression. How this information is deciphered by RNAP is not known. We aim to characterise domains of RNAP, transcription factors and DNA regulatory elements involved in circadian activation/repression of genes by using bioinformatics, biochemistry, proteomics and Cryo-EM microscopy. In preliminary work we developed tractable in vitro experimental system of transcription and circadian regulation, and obtained first two structures of cyanobacterial RNAP complexes, supported by biochemical and proteomics data.This project will generate fundamental knowledge of cyanobacteria, who are the main contributors in global carbon cycle. Cyanobacteria currently gaining popularity as carbon neutral producers. Our research will inform genetic and metabolic engineering of industrial strains. In the future cyanobacterial circadian clock transplanted into industrial microorganisms may serve as attractive mechanism to schedule complex biosynthetic tasks.