Defining mechanisms of diverse CRISPR-Cas complexes

项目摘要/摘要 细菌种群，包括那些影响人类健康的细菌，在很大程度上是由 噬菌体。噬菌体改变了细菌生态系统的组成，并强烈影响 细菌进化。保护细菌免受噬菌体侵袭的防御机制很重要 这些寄主-病原体相互作用的调节者。定义这些机制对于 了解细菌的组成动态和致病性。CRISPR-CAS系统是 复杂多样的机制，使细菌能够记住感染事件和 在再次感染时保护自己。除了它们在调节细菌方面的重要作用外- 噬菌体相互作用，CRISPR-Cas系统已被用于基因组操作 极大地促进了生物医学研究并具有巨大潜力的技术 人类疗法。我们研究计划的目标是充分定义机制和 CRISPR介导的多种核酸-蛋白质复合体的特异性 免疫，并具有CRISPR技术的潜力。我们的计划分为两部分 了解适应的过程，在此过程中细菌细胞被免疫，以及 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清的蛋白质的高阶适应复合体 对有效免疫至关重要的亚基。我们的目标是发现分子步骤 通过高阶适应复合体实现特异性和精确度，确保高效 免疫事件。免疫后，Cas效应复合体中和感染 在干扰过程中必须迅速识别病原体，这项任务变得更加具有挑战性 当噬菌体进化并逃避检测时。我们的目标是了解CAS效应器如何 即使面对病原体的进化，也要保持有效的免疫力。通过这项研究 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 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.