Application of an engineered chromatic acclimation sensor for red-light-regulated gene expression in cyanobacteria
Application of an engineered chromatic acclimation sensor for red-light-regulated gene expression in cyanobacteria
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DOI：
10.1016/j.algal.2019.101691
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发表时间：
2019-12-01
影响因子：
5.1
通讯作者：
Sode, Koji
中科院分区：
文献类型：
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作者：
Kobayashi, Shunichi;Nakajima, Mitsuharu;Sode, Koji
开发一种适用于蓝藻的基因调控工具是实现蓝藻生物处理的关键。考虑到从培养物中去除化学诱导物的成本和技术难度，使用化学诱导物来调节基因表达是不实际的。因此，我们专注于蓝细菌衍生的色驯化传感器，绿光传感系统，CcaS/CcaR双组分系统，来自集胞藻属PCC 6803（PCC 6803）作为遗传调控的收费。然而，CcaS对基因表达水平的调控并不严格。我们以前已经开发了一个小型化的CcaS，CcaS#11，这是一个截短的CcaS显示在红光照射下的基因诱导和严格的抑制下，绿光照射在大肠杆菌。在这项研究中，CcaS#11转化蓝藻实现红光调控的基因表达在蓝藻。首先在PCC 6803中尝试了敲除基因组CcaS/CcaR系统以排除干扰后的应用。结果表明，该基因的表达仅在红光照射下被诱导，在绿光照射下被严格抑制。红光调控的基因表达也被应用于海洋蓝藻聚球藻NKBG 15041 c（Synechococcus sp. NKBG 15041 c）。在NKBG 15041 c中，基因表达在红光照射下被诱导，在绿光照射下被严格抑制，与原始CcaS/CcaR双组分系统相比，ON/OFF比率高2倍。因此，利用CcaS#11构建的红光调控基因表达系统具有作为进一步开发蓝藻中严格控制的光调控生物过程的平台技术的巨大潜力。
The development of a versatile tool for the gene regulation in cyanobacteria is critical for the future realization of cyanobacterial bioprocessing. The use of chemical inducers to regulate gene expression are not practical considering their cost and technical difficulty in removing them from culture. Therefore, we have focused on a cyanobacteria-derived chromatic acclimation sensor, the green-light sensing system, CcaS/CcaR two-component system, derived from Synechocystis sp. PCC6803 (PCC6803) as a toll for genetic regulation. However, the regulation of gene expression levels by CcaS is not strict. We have previously developed a miniaturized CcaS, CcaS#11, which is a truncated CcaS showing gene induction under red-light illumination and strict repression under green-light illumination in Escherichia coll. In this study, CcaS#11 was transformed in cyanobacteria to achieve red-light-regulated gene expression in cyanobacteria. The application was first attempted in PCC6803 after knocking out genomic CcaS/CcaR system to exclude interference. The results revealed gene expression was only induced under red-light illumination and strictly repressed under green-light illumination. The red-lightregulated gene expression was also applied for a marine cyanobacteria, Synechococcus sp. NKBG15041c (NKBG15041c). In NKBG15041c, gene expression was induced under red-light illumination and strictly repressed under green-light illumination with a 2-fold higher ON/OFF ratio compared with the original CcaS/CcaR two-component system. Therefore, the constructed red-light-regulated gene expression system using CcaS#11 has a great potential as a platform technology for the further development of light-regulated bioprocesses with strict control in cyanobacteria.