Investigating SloR virulence gene metalloregulation in S. mutans.

研究变形链球菌的 SloR 毒力基因金属调节。

• 批准号: 8294393
• 负责人: Grace A. Spatafora
• 金额: $ 26.23万
• 依托单位: MIDDLEBURY COLLEGE
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-15 至 2014-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8294393
• 关键词: Address; Adherence; Adult; American; Amino Acids; Applications Grants; Attenuated; Binding; Biochemical; Biological Assay; Biological Process; Child; Circular Dichroism; Communicable Diseases; Competence; Consensus; Coupled; DNA; DNA Binding; DNA Footprint; DNA Sequence; Dental; Dental Plaque; Dental caries; Developed Countries; Developing Countries; Development; Diffusion; Disease; Distal; Drug Design; Elements; Energy Metabolism; Environment; Fluorescence Anisotropy; Gene Activation; Gene Expression; Gene Expression Regulation; Genes; Genetic; Genome; Goals; Grant; Homeostasis; Homologous Gene; Human; Ion Transport; Ions; Iron; Journals; Laboratories; Manganese; Manuscripts; Mediating; Mediator of activation protein; Metals; Microbial Biofilms; Mission; Modeling; Molecular; Molecular Profiling; Molecular Sieve Chromatography; Monitor; National Institute of Dental and Craniofacial Research; Nucleotides; Oral cavity; Oral health; Outcome; Oxidative Stress; Pathogenesis; Peer Review; Physiological; Prevalence; Prevention strategy; Primary Dentition; Process; Property; Proteins; Publishing; Qualifying; Rattus; Reporter Genes; Reporting; Repression; Research; Severities; Solutions; Streptococcus mutans; Structure; Temperature; Therapeutic Agents; Thermodynamics; Time; United States; United States National Institutes of Health; Variant; Virulence; Virulence Factors; Water fluoridation; World Health Organization; abstracting; base; carbohydrate transport; combat; cost; design; gene repression; improved; in vivo; metalloregulatory protein; mutant; novel strategies; novel therapeutics; pathogen; pathogenic bacteria; permanent tooth; progenitor; programs; promoter; public health relevance; research study; response; stress tolerance; treatment strategy; uptake; vapor

DESCRIPTION (provided by applicant): Streptococcus mutans-induced caries formation continues to be a major problem in developed and developing nations which, according to the World Health Organization, impacts 60-90% of children world-wide (128). Despite widespread water fluoridation and the implementation of educational programs aimed at improving oral health in the United States, recent reports reveal no significant improvement in the prevalence or severity of dental caries in the primary dentition (64, 120). Moreover, approximately 90% of adult Americans have dental caries in their permanent teeth, contributing to the nation's estimated costs for dental treatment that exceeded $70 billion in 2002 (44). Since the survival and virulence of S. mutans is directly related to the availability and transport of essential metal ions in the plaque environment, particularly iron and manganese, metal ion uptake mechanisms represent attractive targets for drug design aimed at combating cavities. In the present grant application, we profess a novel approach to alleviating tooth decay that is centered on investigating global virulence gene regulation by the S. mutans SloR metalloregulatory protein. During the previous grant term, we confirmed SloR-dependent repression of S. mutans metal ion transport genes and virulence factors when sustainable levels of manganese are achieved (such as during a mealtime), and loss of this repression when metal ions become limiting (such as between meals). These observations led us to hypothesize that enhanced SloR repression at physiological manganese concentrations will attenuate S. mutans virulence gene expression and impede the process of cariogenesis. This application sets out to address this hypothesis by elucidating the structural basis for SloR activation and DNA binding in S. mutans using molecular and biochemical approaches. Crystallographic analysis of the wild-type and mutant SloR protein coupled with DNA footprinting and DNA bending experiments will elucidate the details of the SloR:DNA interaction, and in vivo experiments will validate SloR-mediated virulence gene regulation and its relationship with cariogenic outcome. Taken together, these studies can facilitate the design of new therapeutic agents that target SloR activity so that caries may be controlled or eliminated. PUBLIC HEALTH RELEVANCE: This application proposes to investigate the details of SloR-mediated virulence gene regulation in an important human pathogen, Streptococcus mutans. To this end, we will characterize the binding of a SloR metalloregulatory protein to specific conserved DNA sequences in the S. mutans genome that can facilitate the process of cavities formation. The mechanisms which promote gene activation and repression by SloR will be explored and the cariogenic potential of SloR mutant variants investigated in a germfree rat model so that ultimately SloR can be targeted for drug design to alleviate S. mutans-induced disease. The proposed research fits the mission of the NIH/NIDCR because it can promote the development of improved caries treatment and prevention strategies, and so curtail a most ubiquitous infectious disease that continues to compromise millions of human lives.

描述（由申请人提供）：变形链球菌诱导的龋齿形成仍然是发达国家和发展中国家的一个主要问题，根据世界卫生组织的数据，全世界60-90%的儿童受到影响（128）。尽管在美国广泛使用氟化水和实施旨在改善口腔健康的教育计划，但最近的报告显示，乳牙列龋齿的患病率或严重程度没有显著改善（64，120）。此外，大约90%的美国成年人的恒牙有龋齿，导致2002年全国牙科治疗的估计费用超过700亿美元（44）。由于S.变形杆菌与斑块环境中必需金属离子（特别是铁和锰）的可用性和转运直接相关，金属离子摄取机制代表了旨在对抗蛀牙的药物设计的有吸引力的目标。在目前的拨款申请中，我们提出了一种新的方法来减轻蛀牙，该方法的核心是研究由沙门氏菌引起的全球毒性基因调控。变形杆菌SloR金属调节蛋白。在上一个资助期，我们证实了SloR依赖的S.当达到可持续的锰水平时（例如在用餐时间），变异体金属离子转运基因和毒力因子，以及当金属离子变得有限时（例如在两餐之间），这种抑制作用丧失。这些观察结果使我们假设，在生理锰浓度下增强的SloR阻遏将减弱S。变形杆菌毒力基因的表达，并阻碍龋的过程。本申请通过阐明SloR激活和S.利用分子和生物化学方法研究变异株。结合DNA足迹和DNA弯曲实验对野生型和突变型SloR蛋白进行晶体学分析，将阐明SloR：DNA相互作用的细节，体内实验将验证SloR介导的毒力基因调控及其与致龋结果的关系。总之，这些研究可以促进靶向SloR活性的新治疗剂的设计，从而可以控制或消除龋齿。 公共卫生相关性：本申请旨在研究SloR介导的人类重要病原体变形链球菌毒力基因调控的细节。为此，我们将描述SloR金属调节蛋白与S.变异体基因组，可以促进空腔形成的过程。将探索SloR促进基因激活和抑制的机制，并在无菌大鼠模型中研究SloR突变变体的致龋潜力，以便最终SloR可以作为药物设计的靶点，以缓解S。突变引起的疾病这项拟议的研究符合NIH/NIDCR的使命，因为它可以促进改进龋齿治疗和预防策略的发展，从而减少一种继续危害数百万人生命的最普遍的传染病。