Defining mechanisms of diverse CRISPR-Cas complexes

获奖项目概要/摘要 细菌种群，包括那些影响人类健康的细菌，在很大程度上受到 噬菌体噬菌体改变了细菌生态系统的组成， 细菌进化保护细菌免受噬菌体侵害的防御机制很重要 这些宿主-病原体相互作用的调节器。定义这些机制对于 了解细菌组成动力学和致病性。CRISPR-Cas系统 复杂多样的机制，使细菌能够记住感染事件， 在再次感染时保护自己。除了它们在介导细菌中的重要作用外- 噬菌体相互作用，CRISPR-Cas系统已被用于基因组操纵 这些技术极大地促进了生物医学研究，并具有巨大的潜力， 人类疗法我们的研究计划的目标是充分定义的机制， 指导CRISPR介导的CRISPR的多种核酸-蛋白质复合物的特异性 免疫力和CRISPR技术的潜力。我们的计划分为 理解适应过程，在此过程中细菌细胞被免疫， 干扰，在此期间CRISPR-Cas系统中和感染。我们和其他人 最近发现了含有定义不明确的蛋白质的高阶适应复合物 亚单位是有效免疫所必需的。我们的目标是揭示 通过高阶适应复合体实现特异性和精确性， 免疫事件。免疫后，中和感染的Cas效应复合物 在干扰期间必须快速识别病原体，这是一项更具挑战性的任务 当病毒进化并逃避检测时我们的目标是了解Cas效应器如何 即使面对病原体的进化，也能保持有效的免疫力。通过本文的研究 通过该计划，我们将有助于全面了解CRISPR-Cas系统如何影响 细菌种群，并帮助确保基于CRISPR的研究和治疗工具， 安全有效地使用。

PROJECT SUMMARY/ABSTRACT FOR PARENT AWARD Bacterial populations, including those that affect human health, are largely controlled by bacteriophages. Phages change the composition of bacterial ecosystems and strongly influence bacterial evolution. Defense mechanisms that protect bacteria from phages are important regulators of these host-pathogen interactions. Defining these mechanisms is crucial to understanding bacterial compositional dynamics and pathogenicity. CRISPR-Cas systems are sophisticated and diverse mechanisms that allow bacteria to memorize infection events and defend themselves upon reinfection. In addition to their important role in mediating bacteria- phage interactions, CRISPR-Cas systems have been harnessed for genome manipulation technologies that have greatly facilitated biomedical research and have enormous potential for human therapies. The goal of our research program is to fully define the mechanisms and specificities of a variety of nucleic acid-protein complexes that direct CRISPR-mediated immunity and have potential for CRISPR technology. Our program is divided between understanding the process of adaptation, during which a bacterial cell is immunized, and interference, during which the CRISPR-Cas system neutralizes an infection. We and others have recently discovered higher-order adaptation complexes containing poorly defined protein subunits that are essential for effective immunization. Our goal is to uncover the molecular steps that enable specificity and precision by higher-order adaptation complexes, ensuring productive immunization events. Following immunization, Cas effector complexes that neutralize infection during interference must quickly recognize pathogens, a task made even more challenging when phages evolve and evade detection. Our goal is to understand how Cas effectors can maintain effective immunity even in the face of pathogen evolution. Through this research program, we will contribute to the overall understanding of how CRISPR-Cas systems impact bacterial populations and help ensure that CRISPR-based research and therapeutic tools are used safely and effectively.