Peptide Pheromones in Enterococcal Plasmid Maintenance

肠球菌质粒维护中的肽信息素

• 批准号: 7057335
• 负责人: BETTINA A BUTTARO
• 金额: $ 25.72万
• 依托单位: TEMPLE UNIV OF THE COMMONWEALTH
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2008-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7057335
• 关键词: DNA binding protein; Enterococcus; Streptococcus lactis; bacterial genetics; crosslink; drug resistance; electroporation; erythromycin; green fluorescent proteins; high performance liquid chromatography; hormone binding protein; intermolecular interaction; pheromone; plasmids; protein signal sequence; protoplast /spheroplast; replicon; tetracyclines

DESCRIPTION (provided by applicant): Enterococcus faecalis plays a major role in the current antibiotic resistance crisis. It is one of the leading causes of antibiotic-resistant nosocomial infections and, as part of the normal flora of the intestinal tract, also serves as a reservoir of antibiotic resistance genes. Peptide pheromone-induced conjugative plasmid transfer contributes to the spread of these antibiotic resistance genes and of other enterococcal virulence factors. The focus of this research is on the role of peptide signaling in plasmid maintenance, specifically of the tetracycline-resistance plasmid pCF10 in Enterococcus faecalis. The original observations of pheromone signaling in conjugative plasmid biology found that the peptide signal cCF10 produced by plasmid-free recipient cells is used for the induction of conjugative pCF10 transfer. cCF10 is produced at the cell surface and internalized by pCF10-containing donor cells by interaction of the cCF10 receptor with the oligopeptide permease. Once inside the cell cCF10 interacts with intracellular effector molecules to induce conjugation. Recently, we have found a second role, for donor-cell produced cCF10, in maintaining pCF10 in the Enterococcus faecalis cell population. In a donor cell population, cCF10 is also produced and its internalization is required to maintain pCF10 in the apparent absence of conjugation. The maintenance functions occur with a minimum pCF10 replicon construct that is unable to be conjugatively transferred, suggesting the role of cCF10 in pCF10 maintenance is distinct from its role in conjugative transfer. The main goal of the research proposed in this application is to gain a basic understanding of how cCF10 is affecting pCF10 maintenance. (1) Does cCF10 act as a pheromone in maintenance of pCF10? (2) Are the oligopeptide permease and the cCF10 receptor PrgZ required for efficient transport of cCF10 (produced extracellularly)? (3) What are the basic features of the pCF1 0 replicon? (4) What are the intracellular effector molecules responsible for cCF10-dependent pCF10 maintenance? This will lay the groundwork for future experiments to determine how the same peptide can be used for plasmid maintenance without inducing detectable levels of conjugation.

描述（由申请方提供）：粪肠球菌在当前的抗生素耐药性危机中起着重要作用。它是抗生素耐药医院感染的主要原因之一，作为肠道正常植物群的一部分，也是抗生素耐药基因的储存库。肽信息素诱导的接合质粒转移有助于这些抗生素抗性基因和其他肠球菌毒力因子的传播。本研究的重点是肽信号在质粒维持中的作用，特别是粪肠球菌中的四环素抗性质粒pCF10。在接合质粒生物学中对信息素信号传导的最初观察发现，由无质粒受体细胞产生的肽信号cCF10用于诱导接合pCF10转移。cCF 10在细胞表面产生，并通过cCF 10受体与寡肽通透酶的相互作用被含pCF 10的供体细胞内化。一旦进入细胞内，cCF10与细胞内效应分子相互作用以诱导缀合。最近，我们发现了供体细胞产生的cCF10在维持粪肠球菌细胞群中的pCF10中的第二个作用。在供体细胞群中，也产生cCF10，并且需要其内化以在明显不存在缀合的情况下维持pCF10。维持功能发生在最小的pCF10复制子构建体中，其不能被接合转移，这表明cCF10在pCF10维持中的作用不同于其在接合转移中的作用。 本申请中提出的研究的主要目标是基本了解cCF10如何影响pCF10的维持。(1)cCF10在pCF10的维持中是否充当信息素？(2)寡肽通透酶和cCF10受体PrgZ是否是cCF10（细胞外产生）有效转运所必需的？(3)pCF10复制子的基本特征是什么？(4)什么是负责cCF10依赖性pCF10维持的细胞内效应分子？这将为将来的实验奠定基础，以确定如何使用相同的肽进行质粒维持，而不诱导可检测水平的接合。