Determination of structure-function relationships and role in virulence of a MerR-type regulator that mediates zinc tolerance in Streptococcus mutans

确定介导变形链球菌锌耐受性的 MerR 型调节因子的结构-功能关系及其毒力作用

• 批准号: 10749982
• 负责人: Alexandra Peterson
• 金额: $ 4.29万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-16 至 2025-08-15
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10749982
• 关键词: ATP phosphohydrolase; Acceleration; Amino Acids; Animals; Bacteria; Binding; Cadmium; Calculi; Caries prevention; Caring; Cells; Characteristics; Chronic; Chronic Disease; Cobalt; Collaborations; Communicable Diseases; Complement; Computing Methodologies; Copper; Crystallography; Dental Enamel; Dental Plaque; Dental caries; Development; Disease; Drug Targeting; Educational workshop; Environment; Etiology; Floods; Functional disorder; Future; Genes; Genetic Transcription; Gingivitis; Glucans; Goals; Growth; Halitosis; Healthcare; Homeostasis; Immune system; In Vitro; Infection; Infective endocarditis; Invaded; Iron; Knowledge; Lactic acid; Learning; Lesion; Life; Literature; Mammalian Cell; Manganese; Mediating; Medicine; Metalloproteins; Metals; Methodology; Microbial Biofilms; Micronutrients; Modeling; Mutagenesis; Mutation; Names; Nutritional Immunity; Oral; Oral cavity; Oral health; Organism; Parents; Pharmaceutical Chemistry; Play; Poisoning; Polymers; Positioning Attribute; Predisposition; Prevention; Process; Property; Proteins; Rattus; Research; Role; Series; Starvation; Streptococcus; Streptococcus mutans; Stress; Structure; Structure-Activity Relationship; Sucrose; Surface; System; Testing; Time; Tooth structure; Toxic effect; Trace metal; Training; Transcriptional Regulation; Treatment Cost; Virulence; Work; Writing; Zinc; anticaries; antimicrobial; combat; comparative efficacy; coping; cost; demineralization; design; druggable target; experimental study; extracellular; immunoregulation; improved; in vivo; individualized medicine; inhibitor; insight; microbial; microbiota; novel therapeutics; oral bacteria; oral biofilm; pathogen; prevent; programs; protein function; response; skills; small molecule inhibitor; student mentoring; tooth surface; toxic metal

Abstract Dental caries is the most prevalent chronic infectious disease, with an estimated treatment cost of ~$70 billion/year. While a multifactorial disease, Streptococcus mutans is recognized as a keystone caries pathogen because of its capacity to modulate the oral biofilm in a way that promotes the establishment of a highly acidogenic (cariogenic) microbiota. The trace metals iron, manganese, and zinc (Zn) play structural, catalytic, and regulatory roles in proteins and so are essential to all forms of life. Conversely, these same metals are toxic when in excess such that the ability to maintain metal homeostasis is a critical aspect of host-pathogen interactions. The toxicity of Zn derives from its top position in the Irving-Williams series of metal stability, which allows Zn to avidly bind to non-cognate metalloproteins rendering them nonfunctional. Because it has both antimicrobial and immunomodulatory properties and relatively low toxicity to mammalian cells, Zn has been used for decades in medicine, including incorporation into oral health products for the treatment of gingivitis, halitosis, and prevention of calculus formation. Recently, it was discovered that S. mutans is intrinsically and substantially more tolerant to toxic levels of Zn than all other streptococci and that this high tolerance is mediated by a unique P-type ATPase exporter that has been named ZccE. Expression of zccE is controlled by a unique MerR-type regulator, ZccR for zccE regulator, that strongly activates zccE transcription in response to high Zn stress. Because both ZccE and ZccR are unique to S. mutans, the Lemos lab proposes that both can be targeted for the development of a Zn-based therapy tailored against S. mutans. While other projects in the Lemos lab are exploring the antimicrobial potential of ZccE, the specific aims of this application center around the ZccR regulator. The goals of this application are to determine the structure-function relationships of ZccR and explore its potential as an antimicrobial target. To accomplish these goals, the PI will (i) use crystallography and computational-based approaches to determine the structure of ZccR and identify its critical functional residues, and (ii) utilize the rat model to determine the contribution of ZccR to oral biofilm colonization and caries development alone or in combination with topical Zn treatment. Knowledge gained from this study will facilitate the structure-guided design of small molecule inhibitors for ZccR and reveal the potential of targeting mechanisms of Zn homeostasis to combat S. mutans infections, with the long-term objective of developing novel therapies for the prevention of dental caries and treatment of systemic S. mutans infections (i.e., infective endocarditis). This work will be conducted in a highly supportive and collaborative research environment with Aim 1 establishing a collaboration between the Lemos and McKenna labs. Moreover, the comprehensive training plan provided will accelerate the PI's academic and scientific growth through participation in formal course work and workshops, opportunities to learn new methodologies, mentoring students, establishing new collaborations, and improving scientific writing and presentation skills.

抽象的 龋齿是最普遍的慢性传染病，估计治疗费用约为70美元 十亿/年。虽然多因素疾病，但链球菌突变被认为是基石龋齿病原体 由于其能力以促进高度建立的方式调节口腔生物膜 酸性（致癌）微生物群。痕量金属铁，锰和锌（Zn）的结构，催化， 以及在蛋白质中的调节作用，因此对于各种形式的生命都是必不可少的。相反，这些相同的金属是 当过量时，有毒能力保持金属稳态是宿主 - 病原体的关键方面 互动。 Zn的毒性来自其在欧文 - 威廉姆斯系列的金属稳定性中的最高位置， 允许Zn与非物质的非认知金属蛋白保持无功能。因为这两个 抗菌和免疫调节特性以及对哺乳动物细胞的毒性相对较低，Zn一直以来 数十年来用于医学，包括纳入口腔健康产品以治疗牙龈炎， 口腔症和预防结石形成。最近，发现S. mutans本质上是 与所有其他链球菌相比 由名为ZCCE的唯一P型ATPase出口商介导的。 ZCCE的表达受 独特的MERR类型调节剂，用于ZCCE调节器的ZCCR，强烈激活ZCCE转录，以响应于 高Zn应力。因为ZCCE和ZCCR都是S. mutans独有的 针对开发针对S. utans量身定制的基于Zn的疗法。而其他项目 LEMOS实验室正在探索ZCCE的抗菌潜力，该应用程序的具体目的围绕 ZCCR调节器。该应用程序的目标是确定ZCCR的结构功能关系 并探索其作为抗菌靶标的潜力。为了实现这些目标，PI将（i）使用 晶体学和基于计算的方法来确定ZCCR的结构并确定其关键 功能残基，（ii）利用大鼠模型来确定ZCCR对口服生物膜的贡献 单独或与局部Zn治疗结合定殖和龋齿发育。从中获得的知识 这项研究将促进针对ZCCR的小分子抑制剂的结构引导设计，并揭示 Zn稳态的靶向机制对作战链球菌感染的潜力，长期 开发用于预防龋齿和全身性链球菌治疗的新型疗法的目的 感染（即感染性心内膜炎）。这项工作将以高度支持和协作的方式进行 AIM 1的研究环境建立了Lemos和McKenna Labs之间的合作。 此外，提供的全面培训计划将加速PI的学术和科学成长 通过参加正式的课程工作和研讨会，学习新方法的机会， 指导学生，建立新的合作以及提高科学写作和演讲技巧。