Multiscale structural dynamics of membrane protein complexes

膜蛋白复合物的多尺度结构动力学蛋白质是不断运动的，这些动力学对蛋白质的正确折叠和细胞功能至关重要。然而，目前还不完全清楚实时蛋白质动力学如何影响折叠或调节构象变化。最近，我已经证明，细菌多药物外排泵折叠过程中的动态变化可能导致错误的蛋白质拓扑结构，并可能损害细菌产生耐药性的能力。外排泵除了造成耐药性和相关的健康问题外，还在细菌输出各种毒素、与其他细菌交流以及帮助塑造周围生态系统方面发挥着重要作用。我已经证明，蛋白质结构的动态变化很早就开始了，而蛋白质还在核糖体上合成。当一个新的蛋白质被修饰、折叠、靶向和插入到膜上时，这些动力学起着至关重要的作用，但在完全成熟的蛋白质中，动力学也会持续存在。我最近使用实时方法来识别膜蛋白复合物的内在动力学，这种复合物能够实现功能性构象变化，并被细胞底物增强。然而，目前尚不清楚这些动力学是如何在膜蛋白复合物中被控制或调节的。我的研究计划的长期目标是表征膜蛋白复合物的动力学，这些复合物调节生物膜的折叠和组装，以及磷脂双分子层之间的通信。了解外排泵组装和功能的实时动态将有助于深入了解细菌如何对抗生素应激作出反应并产生耐药性，同时也加深了我们对膜蛋白复合物如何在脂质双分子层中折叠、组装和功能的一般认识。因此，我的综合研究计划将使用多药物外排泵作为模型系统来研究膜蛋白复合物，并且，在接下来的五年里，我将专注于两个具体目标：1)了解在正在进行的蛋白质合成过程中外排泵是如何在生物膜中组装的，2)表征驱动和调节抗生素外排的外排泵的结构动力学。通过了解膜蛋白复合物的实时动态，我们可以希望有一天能够提前预测致病突变的影响，或者为针对这些复合物的下一代治疗药物的合理设计提供动力。

Multiscale structural dynamics of membrane protein complexes Proteins are constantly in motion, and these dynamics are critical for proper protein folding and cellular function. However, it is not entirely clear how real-time protein dynamics influence folding or regulate conformational changes. Recently, I have shown that dynamic changes during folding of a bacterial multidrug efflux pump can lead to erroneous protein topology and potentially compromise the capacity of bacteria to develop drug resistance. Efflux pumps, aside from contributing to drug resistance and associated health problems, also play fundamental roles in bacteria exporting various toxins, communicating with other bacteria, and helping to shape the surrounding ecosystem. I have shown that dynamic changes in protein structure start very early, while proteins are still being synthesized on the ribosome. These dynamics play critical roles as a new protein is modified, folded, targeted, and inserted into the membrane, but dynamics persist in fully mature proteins as well. I have recently used real-time methods to identify intrinsic dynamics of membrane protein complexes that enable functional conformational changes and are enhanced by cellular substrates. However, it is still unclear how these dynamics are controlled or regulated within membrane protein complexes. The long-term goal of my research program is to characterize dynamics within membrane protein complexes that regulate folding and assembly in biological membranes as well as communication across the phospholipid bilayer. Understanding the real-time dynamics of efflux pump assembly and function will provide insight into how bacteria respond to antibiotic stress and develop resistance, but also deepen our general knowledge of how membrane protein complexes fold, assemble, and function in a lipid bilayer. Accordingly, my comprehensive research program will study membrane protein complexes using multidrug efflux pumps as model systems, and, in the next five years, I will focus on two specific aims: 1) learn how efflux pumps are assembled in biological membranes during ongoing protein synthesis, and 2) characterize the structural dynamics of efflux pumps that drive and regulate antibiotic efflux. By understanding the real-time dynamics of membrane-protein complexes, we can hope to someday predict the effects of disease-causing mutations in advance, or fuel rational design of next-generation therapeutics targeting these complexes.