Ma Siya, Luo Siwei, Wu L I, Liang Zhi, Wu Jia-Rui
Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei 230000, China.
J Biosci. 2017 Dec;42(4):565-573. doi: 10.1007/s12038-017-9711-8.
Bacteria live in environments with dynamic changes. To sense and respond to different external stimuli, bacteria make use of various sensor-response circuits, called two-component systems (TCSs). A TCS comprises a histidine protein kinase (HK) sensing environmental stimuli and a response regulator protein (RR) regulating downstream genes. The two components are coupled via a phosphorylation control mechanism. In a recent study, we adopted an optogenetics approach to re-engineer the sensor HKs in as a light-sensing fusion protein. We constructed a light-controllable HK by replacing the original signal-specific sensing domain of HK with the light-sensing domain of Cph1 from , so that HK can be investigated by red light. Here, we extended the study to other 16 HK-RR TCSs and constructed a library of light-responsible HK-Cph1 chimeras. By taking the NarX-NarL system as an example, we demonstrated the light responsiveness of the constructed chimera and investigated the frequency response of the NarXNarL system. The constructed library serves as a toolkit for future TCS study using optogenetics approach.
细菌生活在动态变化的环境中。为了感知并响应不同的外部刺激，细菌利用各种传感-响应回路，即双组分系统（TCSs）。一个双组分系统由感知环境刺激的组氨酸蛋白激酶（HK）和调控下游基因的响应调节蛋白（RR）组成。这两个组分通过磷酸化控制机制相互偶联。在最近的一项研究中，我们采用光遗传学方法对[具体细菌名称]中的传感组氨酸蛋白激酶进行重新设计，使其成为一种光感应融合蛋白。我们通过将组氨酸蛋白激酶原来的信号特异性传感结构域替换为来自[具体细菌名称]的Cph1的光感应结构域，构建了一种光可控的组氨酸蛋白激酶，从而能够用红光对组氨酸蛋白激酶进行研究。在此，我们将研究扩展到其他16个HK-RR双组分系统，并构建了一个光响应性HK-Cph1嵌合体文库。以NarX-NarL系统为例，我们证明了所构建嵌合体的光响应性，并研究了NarX-NarL系统的频率响应。所构建的文库可作为未来使用光遗传学方法进行双组分系统研究的工具包。
