Department of Biochemistry and Molecular Biology, Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637, USA.
J Mol Biol. 2010 Jul 16;400(3):477-86. doi: 10.1016/j.jmb.2010.05.019. Epub 2010 May 13.
Survival of organisms in dynamic environments requires accurate perception and integration of signals. At the molecular level, signal detection is mediated by signal receptor proteins that largely are of modular composition. Sensor modules, such as the widespread Per-ARNT-Sim (PAS) domains, detect signals and, in response, regulate the biological activity of effector modules. Here, we exploit the modularity of signal receptors to design and engineer synthetic receptors that comprise two PAS sensor domains responsive to different signals, and we use these signals to control the activity of a histidine kinase effector. Designed two-input PAS receptors detected oxygen and blue light in a positive cooperative manner. The extent of the response to the signals was dictated by domain topology: the dominant regulatory effect was exerted by the PAS domain proximal to the effector domain. The presence of one sensor domain modulated the signal response function of the other. Sequence and structural data on natural receptors with tandem PAS domains show that these are predominantly linked by short amphipathic alpha-helices. Signals from multiple sensor domains could be integrated and propagated to the effector domain as torques. Our results inform the rational design of receptors that integrate multiple signals to modulate cellular behavior.
生物在动态环境中的生存需要准确感知和整合信号。在分子水平上，信号检测是由信号受体蛋白介导的，这些蛋白主要具有模块化组成。传感器模块，如广泛存在的 Per-ARNT-Sim（PAS）结构域，可检测信号，并响应调节效应器模块的生物学活性。在这里，我们利用信号受体的模块化来设计和构建合成受体，这些受体由两个对不同信号有反应的 PAS 传感器结构域组成，我们使用这些信号来控制组氨酸激酶效应器的活性。设计的双输入 PAS 受体以正协同方式检测氧气和蓝光。对信号的响应程度由结构域拓扑决定：效应域附近的 PAS 结构域发挥主导调节作用。一个传感器结构域的存在调节了另一个传感器结构域的信号响应功能。具有串联 PAS 结构域的天然受体的序列和结构数据表明，这些结构域主要通过短的两亲性α-螺旋连接。多个传感器结构域的信号可以作为扭矩进行整合和传递到效应器结构域。我们的结果为设计能够整合多个信号以调节细胞行为的受体提供了信息。
