Delineation of CRISPR-Cas invader defense pathways in Streptococcus thermophilus

嗜热链球菌 CRISPR-Cas 入侵防御途径的描述

• 批准号: 8371484
• 负责人: MICHAEL P TERNS
• 金额: $ 28.22万
• 依托单位: UNIVERSITY OF GEORGIA
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2016-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8371484
• 关键词: Address; Antibiotic Resistance; Bacteria; Biogenesis; Biological; Cell-Free System; Cleaved cell; Complex; DNA; DNA Sequence; Data; Enzymes; Food; Genome; Goals; Guide RNA; Human; Immune response; Immune system; Infection; Invaded; Laboratories; Lead; Molecular; Nucleic Acids; Pathway interactions; Pharmacologic Substance; Phase; Plasmids; Process; Prokaryotic Cells; Proteins; RNA; RNA Sequences; Reaction; Scientist; Seminal; Site; Small RNA; Streptococcus thermophilus; System; Testing; Transcript; Variant; Viral; Virus; Work; base; combat; endoribonuclease; human BCAR1 protein; human disease; in vivo; insight; interest; pathogen; plasmid DNA; prospective; protein function; reconstitution; research study; response; viral DNA

DESCRIPTION (provided by applicant): CRISPR-Cas systems are recently discovered, RNA-based immune systems that control invasions of viruses and plasmids in prokaryotes. Prokaryotes with CRISPR-Cas systems capture short invader sequences within the CRISPR loci in their genomes, and small RNAs produced from the CRISPR loci (CRISPR (cr)RNAs) are thought to guide Cas proteins to recognize and silence the invading nucleic acids; however, we know very little about how the key steps in the remarkable CRISPR-Cas immune response pathways occur. In this project, we address the molecular basis for the three steps required for CRISPR-Cas defense through the following specific aims: ¿ Determine how CRISPR loci acquire foreign DNA sequences ¿ Determine the mechanisms by which functional CRISPR RNAs are produced ¿ Delineate the mechanisms of invader silencing Specifically, we aim to obtain a molecular understanding of the CRISPR-Cas defense pathways that function in Streptococcus thermophilus. We will identify the essential cellular machinery (proteins and RNAs) and molecular mechanisms involved in each of the three key phases of CRISPR-Cas defense. We hypothesize that Cas proteins function in each of the major steps in the defense pathway, and we will test this and a number of specific related hypotheses in the proposed studies. The experiments will define the CRISPR-Cas pathways used by multitudes of prokaryotes to survive viral attack. The information gained in this study will contribute directly o ongoing efforts aimed at exploiting CRISPR-Cas systems to both strengthen domesticated bacteria (used to produce safe food, pharmaceuticals and biofuels) and weaken human pathogens and limit the spread of antibiotic resistance. PUBLIC HEALTH RELEVANCE: Scientists recently recognized that bacteria depend on a unique immune system to defend themselves against viruses. Our studies will define the major steps and essential factors in this defense pathway. We are very interested in studying this pathway because the discoveries that we make have tremendous potential to be used to protect bacteria that we depend on to make food products, pharmaceuticals, and biofuels, and to combat bacteria that cause human disease and the spread of antibiotic resistance.

描述（由申请人提供）：CRISPR-Cas系统是最近发现的一种基于rna的免疫系统，用于控制原核生物中病毒和质粒的入侵。具有CRISPR-Cas系统的原核生物在其基因组中捕获CRISPR位点内的短入侵序列，并且从CRISPR位点产生的小rna （CRISPR (cr)RNAs）被认为引导Cas蛋白识别并沉默入侵的核酸；然而，我们对CRISPR-Cas免疫反应途径的关键步骤是如何发生的知之甚少。在这个项目中，我们通过以下具体目标来解决CRISPR- cas防御所需的三个步骤的分子基础：确定CRISPR位点如何获得外源DNA序列；确定产生功能性CRISPR rna的机制；描述入侵者沉默的机制。具体来说，我们的目标是获得对嗜热链球菌中起作用的CRISPR- cas防御途径的分子理解。我们将确定参与CRISPR-Cas防御的三个关键阶段的基本细胞机制（蛋白质和rna）和分子机制。我们假设Cas蛋白在防御途径的每个主要步骤中都起作用，我们将在拟议的研究中测试这一点和一些具体的相关假设。这些实验将确定大量原核生物在病毒攻击中生存所使用的CRISPR-Cas途径。在这项研究中获得的信息将直接有助于利用CRISPR-Cas系统增强驯化细菌（用于生产安全食品、药品和生物燃料）、削弱人类病原体和限制抗生素耐药性传播的持续努力。