Deciphering fundamental biological processes involving protein-nucleic acid interactions at the molecular level

破译涉及分子水平上蛋白质-核酸相互作用的基本生物过程

• 批准号: 10622948
• 负责人: Maria Schumacher
• 金额: $ 26.84万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-01-01 至 2027-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10622948
• 关键词: Address; Anti-Bacterial Agents; Antimicrobial Resistance; Bacteria; Biochemistry; Biological; Biological Process; Cessation of life; Complex; Cryoelectron Microscopy; Cues; DNA; DNA Repair Pathway; Development; Enzymes; Genetic Transcription; Glutamate-Ammonia Ligase; Goals; Gram-Positive Bacteria; Health; Human; Investigation; Life Cycle Stages; Link; Metabolic Pathway; Microbe; Mitochondria; Molecular; Multi-Drug Resistance; Nitrogen; Nucleic Acids; Nutrient availability; Pathogenesis; Pharmaceutical Preparations; Process; Proteins; Protozoa; RNA Editing; Second Messenger Systems; Signal Pathway; Signal Transduction; Source; Streptomyces; Structure; Therapeutic; antimicrobial drug; bacterial resistance; combat; drug resistant microorganism; environmental change; in vivo; interest; microbial; microbial disease; novel; phosphoric diester hydrolase; rational design; therapeutic target

ABSTRACT The central goal of the Schumacher lab is to deduce molecular principles governing fundamental biological processes involving protein-nucleic acid interactions. These investigations focus on processes in microbes and intersect with the lab’s interests in microbial pathogenesis. Indeed, while the main goal is to elucidate biological mechanisms at the atomic level, these studies also provide potential targets for the development of urgently needed antimicrobial agents. Alarmingly, recent estimates suggest that deaths from antimicrobial resistance bacteria may exceed 10 million deaths worldwide by 2050 if steps are not taken to generate new treatments. The specific processes we investigate include transcription, DNA organization and RNA editing. Bacteria must be able to sense and respond to environmental changes for their survival and in some cases, proper development, so our studies on transcription focus on important networks and address how environmental cues are signaled and detected by transcription switches. Streptomyces bacteria represent the main source of antibacterial and other key drugs, which they generate concomitant with development. Thus, understanding their developmental lifecycle has been of significant interest for decades, although it is a mystery what drives this process. Our studies in the last few years have revealed that this developmental switch is controlled by the second messenger, c-di-GMP, functioning through two global transcription regulators, BldD and WhiG. These regulators control the first and second steps in Streptomyces development, respectively, but how c-di-GMP levels are sensed and signaled to these regulators are unknown and is a question we will address in this proposal. Initial studies unveiled a possible link between WhiG and a c-di-GMP phosphodiesterase, possibly indicating colocalization as a mechanism to control the second developmental step, which we will investigate. Studies will also be performed to analyze c-di-GMP levels and identify and characterize additional c-di-GMP modulated developmental regulators. Using a combination of cryo-EM, biochemistry and in vivo studies, we will also dissect the molecular mechanism by which nitrogen levels are sensed in Gram-positive bacteria by the novel Glutamine Synthetase-GlnR signaling pathway whereby the central enzyme for a metabolic pathway (GS) directly transduces nutrient availability to its master transcription regulator (GlnR). Finally, we will elucidate the signal and mechanism behind the first SOS-independent DNA repair pathway in bacteria. Another focus of the lab is the unusual RNA editing process in the mitochondria of kinetoplastid parasitic protozoans called kinetoplastid RNA (kRNA) editing. A recently identified accessory complex, the MRB1 complex, is required for this process. However, the structure and mechanisms of action of this complex are completely unknown. We will obtain structures of this complex and dissect its various molecular functions in editing. These combined studies will elucidate fundamental biological processes at the molecular level, leading to the discovery of potential chemotherapeutic targets against microbial diseases.

抽象的 Schumacher实验室的核心目标是推论基本生物学的分子原理 过程涉及蛋白质核酸相互作用。这些调查的重点是微生物的过程和 与实验室对微生物发病机理的利益相交。确实，主要目标是阐明生物学 原子水平的机制，这些研究还为紧急发展提供了潜在的目标 需要抗菌剂。令人震惊的是，最近的估计表明抗菌素耐药性死亡 如果不采取新的治疗，到2050年，细菌可能会超过全球死亡。 我们研究的特定过程包括转录，DNA组织和RNA编辑。细菌必须 能够感知并应对其生存的环境变化，在某些情况下，适当 开发，因此我们对转录的研究集中在重要的网络上，并解决环境 提示由转录开关签名和检测。链霉菌细菌是主要来源 抗菌和其他关键药物，它们与发育伴随着。那，理解 几十年来，他们的发展生命周期一直引起人们的兴趣，尽管这是一个神秘的驱动力 这个过程。在过去的几年中，我们的研究表明，这种发展开关由 第二使者C-DI-GMP通过两个全局转录调节器BLDD和WHIG运行。这些 监管机构分别控制链霉菌开发的第一和第二步骤，但如何C-DI-GMP 感知并签署了这些调节器的水平是未知的，这是我们将在此解决的问题 提议。初步研究揭示了辉格酶与C-DI-GMP磷酸二酯酶之间的可能联系，可能 表明共定位是控制第二步的一种机制，我们将研究。 还将进行研究以分析C-DI-GMP水平并识别和表征其他C-DI-GMP 调制发育监管机构。结合冷冻EM，生物化学和体内研究，我们将 还剖析了分子机制，通过该机制在革兰氏阳性细菌中被氮水平通过 新型谷氨酰胺合成酶GLNR信号传导途径，该途径为代谢途径的中心酶 （GS）将养分的可用性直接传递到其主转录调节剂（GLNR）。最后，我们会的 阐明细菌中第一个独立于SOS的DNA修复途径背后的信号和机制。 实验室的另一个重点是动力质体寄生的线粒体中的异常RNA编辑过程 原生动物称为动型塑料RNA（KRNA）编辑。最近确定的附件综合体MRB1 复合物是此过程所必需的。但是，该复合物的作用结构和机制是 完全未知。我们将获得该复合物的结构，并在其中剖析其各种分子功能 编辑。这些合并的研究将阐明分子水平的基本生物学过程 发现针对微生物疾病的潜在化学治疗靶标。