Coordinate Regulation of Salmonella Virulence and Antimicrobial Resistance by MarR Transcription Factors

MarR 转录因子协调调节沙门氏菌毒力和抗菌素耐药性

• 批准号: 10624306
• 负责人: Ferric C Fang
• 金额: $ 49.47万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10624306
• 关键词: Affinity; Antibiotic Resistance; Antibiotics; Antimicrobial Resistance; Bacteria; Bacterial Infections; Binding Sites; Data; Disease; Drug Efflux; Drug resistance; Evolution; Family; Genes; Genetic; Genetic Transcription; Health; Human; In Vitro; Ligands; Link; Metabolic; Metabolism; Metabolite Interaction; Methods; Mutation; Operon; Phenocopy; Phenotype; Prevention; Proteins; Regulation; Regulon; Repression; Salmonella; Salmonella infections; Salmonella typhimurium; Signal Transduction; Transcription Repressor; Virulence; bacterial metabolism; carboxylate; carboxylation; comparative; efflux pump; enteric pathogen; in vivo; insight; metabolomics; new therapeutic target; response; transcription factor; virulence gene

SUMMARY. MarR (Multiple antibiotic resistance Repressor) proteins comprise an ancient family of transcription factors that are widely conserved in bacteria. In the enteric pathogen Salmonella Typhimurium, MarR is a negative regulator of the AcrAB-TolC drug efflux pump, while another MarR transcription factor called SlyA is a counter-silencer required for the expression of horizontally-acquired virulence genes. We have recently shown that despite its divergent function, SlyA shares with MarR the ability to undergo allosteric modulation by aromatic carboxylate molecules and can influence the mar phenotype by repressing the marRAB operon. Inactivation of TolC, an essential component of the AcrAB and other RND-family efflux pumps, phenocopies a slyA mutation, reducing the expression of Salmonella virulence genes. This suggests that efflux regulates the levels of an endogenous metabolite that interacts with SlyA, which in turn controls MarR expression, completing a regulatory circuit that coordinately links antimicrobial resistance, virulence, and bacterial metabolism. This proposal investigates the hypothesis that Salmonella antimicrobial resistance and virulence are coordinately regulated in response to metabolic signals by the MarR and SlyA transcription factors through the following specific aims: (1) Identification of endogenous ligand(s) that modulate MarR/SlyA activity. Preliminary data indicate that SlyA-interacting ligand(s) are aromatic carboxylates. Specific endogenous ligands will be identified by genetic and metabolomic methods and characterized with regard to affinity and allosteric inhibition. (2) Functional characterization of MarR-SlyA-TolC regulatory interactions in Salmonella antimicrobial resistance and virulence. The contribution of the MarR-SlyA regulatory network to Salmonella phenotypic antimicrobial resistance and virulence will be assessed in vitro and in vivo. (3) Comparative analysis of the MarR and SlyA regulons. MarR/SlyA-regulated genes and binding sites will be comprehensively identified to determine the regulatory requirements for repression and counter-silencing, respectively, and to elucidate the mechanisms of transcriptional network evolution. These studies will provide important insights into a central regulatory network linking bacterial virulence, drug resistance, and metabolism, which can lead to the identification of new therapeutic targets for the prevention or treatment of bacterial infections.

概括。 MARR（多种抗生素抗性阻遏物）蛋白质包括一个古老的转录家族 在细菌中广泛保守的因素。在肠病腹膜鼠伤寒中，Marr是一个 Acrab-Tolc药物外泵的负调节剂，而另一个称为Slya的MARR转录因子是一个 表达水平获得的毒力基因所需的反沉降。我们最近显示了 尽管功能不同，但Slya与Marr共享了通过芳香族的变构调制的能力 羧酸盐分子，可以通过抑制Marrab操纵子来影响MAR表型。失活 TOLC是ACRAB和其他RND家庭外排泵的重要组成部分，表件是Slya突变， 减少沙门氏菌毒力基因的表达。这表明外排调节 与Slya相互作用的内源代谢产物，进而控制MARR表达，完成调节 可以协同连接抗菌耐药性，毒力和细菌代谢的电路。 该提议调查了以下假设：沙门氏菌抗菌素的耐药性和毒力是 MARR和SLYA转录因子对代谢信号的响应进行了协调调节 通过以下特定目的： （1）鉴定调节marr/slya活性的内源配体。初步数据表明 Slya相互作用的配体是芳族羧酸盐。特定的内源配体将通过遗传来识别 和代谢组方法，并在亲和力和变构抑制方面进行了特征。 （2）沙门氏菌抗菌剂中Marr-Slya-TOLC调节相互作用的功能表征 抗性和毒力。 Marr-Slya调节网络对沙门氏菌表型的贡献 将在体外和体内评估抗菌素的耐药性和毒力。 （3）MARR和SLYA规范的比较分析。 MARR/SLYA调节的基因和结合位点将 全面确定以确定压制和反沉降的监管要求， 分别阐明转录网络演化的机制。 这些研究将为中央调节网络提供重要的见解，该网络将细菌毒力，药物联系起来 抗药性和代谢，这可以导致鉴定预防或 细菌感染的治疗。