Phosphate homeostasis and uptake in Staphylococcus aureus

金黄色葡萄球菌的磷酸盐稳态和摄取

• 批准号: 10092944
• 负责人: Thomas Everett Kehl-Fie
• 金额: $ 18.42万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-02-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10092944
• 关键词: Acids; Animal Model; Antibiotic Resistance; Antibiotic Therapy; Antibiotics; Bacillus subtilis; Bacteria; Bacterial Infections; Cell Wall; Cell physiology; Centers for Disease Control and Prevention (U.S.); Daptomycin; Defect; Development; Disease; Environment; Escherichia coli; Genus staphylococcus; Goals; Growth; Health; Homeostasis; Homologous Gene; Human; Infection; Inorganic Phosphate Transporter; Investigation; Lead; Life; Link; Modeling; Molecular; Mutagenesis; Nutrient; Organism; Phenotype; Physiological Processes; Process; Proteins; Regulation; Regulon; Resistance; Series; Staphylococcus aureus; System; Teichoic Acids; Tertiary Protein Structure; Testing; Time; Variant; Virulence; burden of illness; drug resistant pathogen; emerging antibiotic resistance; experimental study; genetic regulatory protein; innovation; inorganic phosphate; insight; lipoteichoic acid; mutant; novel strategies; novel therapeutics; overexpression; pathogen; response; transcriptome sequencing; transposon sequencing; uptake

Project Summary / Abstract Phosphate is an essential nutrient that contributes to all aspects of cellular physiology. Despite its essentiality, phosphate can also be toxic, thus regulation of phosphate uptake and homeostasis is critical for all forms of life. This is exemplified by the observation that disrupting these processes reduces the virulence of many enterobacterial pathogens. Staphylococcus aureus is a devastating pathogen that is a serious threat to human health due to the continued emergence of antibiotic resistance. Surprisingly, neither phosphate uptake nor homeostasis have been systematically studied in S. aureus. This is despite the fact that phosphate homeostasis in S. aureus is linked to changes in daptomycin resistance. Phosphate homeostasis has been most comprehensively studied in Escherichia coli where it is controlled by a two-component system known as PhoBR (PhoPR in S. aureus). In E. coli, the activity of PhoBR is controlled by the PstSCAB phosphate transporter and the PhoU accessory protein. Loss of either PstSCAB or PhoU in E. coli and other bacteria results in constitutive activation of PhoBR. Preliminary investigations have revealed that S. aureus possesses three phosphate transporters, PstSCAB, PitA, and NptA, that expand the environments where S. aureus can obtain phosphate and contribute to infection. In S. aureus, both PstSCAB and NptA, but not PitA, are dependent on PhoPR for expression. Further differing from E. coli, S. aureus possesses three PhoU homologs, one associated with each transporter. Surprisingly, loss of either PstSCAB or the canonical PhoU homolog does not result in constitutive activation of PhoPR in S. aureus. These and other observations demonstrate that phosphate homeostasis in S. aureus differs from established models. Loss of PhoPR or PstSCAB and NptA reduces the ability of S. aureus to cause infection. Intriguingly, the phoPR and pstSCABnptA mutants do not phenocopy each other. The phoPR mutant has a reduced ability to grow in phosphate-limited environments and cause infection relative to the transporter double mutant. These observations indicate that PhoPR regulates additional unknown transporter-independent factors that enable S. aureus to survive phosphate limitation and cause disease. Together, these observations lead to the hypothesis that an expanded repertoire of regulatory proteins controls phosphate homeostasis in S. aureus and that disruption of this regulatory network reduces staphylococcal virulence. The two Aims of this proposal will test this hypothesis and elucidate the factors controlled by PhoPR that enable S. aureus to cause infection. Aim I will determine the contribution of PhoPR to S. aureus phosphate homeostasis and virulence. Aim II will evaluate the contribution of the three PhoU homologs possessed by S. aureus to controlling phosphate homeostasis.

项目概要/摘要 磷酸盐是一种必需营养素，有助于细胞生理学的各个方面。尽管其重要性， 磷酸盐也可能有毒，因此调节磷酸盐的吸收和体内平衡对于所有生命形式都至关重要。 观察到破坏这些过程可以降低许多病毒的毒力就证明了这一点。 肠细菌病原体。金黄色葡萄球菌是一种破坏性病原体，对人类造成严重威胁 由于抗生素耐药性不断出现，健康状况受到影响。令人惊讶的是，磷酸盐吸收和 金黄色葡萄球菌的体内平衡已得到系统研究。尽管事实上磷酸盐稳态 金黄色葡萄球菌中的细菌与达托霉素耐药性的变化有关。磷酸盐稳态最 在大肠杆菌中进行了全面研究，该大肠杆菌由称为 PhoBR 的双组分系统控制 （金黄色葡萄球菌中的 PhoPR）。在大肠杆菌中，PhoBR 的活性由 PstSCAB 磷酸盐转运蛋白控制，并且 PhoU 辅助蛋白。大肠杆菌和其他细菌中 PstSCAB 或 PhoU 的丢失会导致组成型 PhoBR 的激活。初步调查显示，金黄色葡萄球菌具有三种磷酸盐 转运蛋白 PstSCAB、PitA 和 NptA，扩大金黄色葡萄球菌获取磷酸盐的环境 并助长感染。在金黄色葡萄球菌中，PstSCAB 和 NptA（但不包括 PitA）都依赖于 PhoPR 表达。与大肠杆菌进一步不同的是，金黄色葡萄球菌拥有三种 PhoU 同源物，每一种都与 运输者。令人惊讶的是，PstSCAB 或典型 PhoU 同系物的丢失不会导致组成型 金黄色葡萄球菌中 PhoPR 的激活。这些和其他观察结果表明，S. 中的磷酸盐稳态。 金黄色葡萄球菌与已建立的模型不同。 PhoPR 或 PstSCAB 和 NptA 的缺失会降低金黄色葡萄球菌的能力 以引起感染。有趣的是，phoPR 和pstSCABnptA 突变体并不相互表型复制。这 相对于磷酸盐限制的环境，phoPR 突变体的生长能力和引起感染的能力降低 转运蛋白双突变体。这些观察结果表明 PhoPR 调节额外的未知 使金黄色葡萄球菌能够在磷酸盐限制下生存并引起疾病的独立于转运蛋白的因素。 总之，这些观察结果得出这样的假设：调节蛋白的扩展库控制 金黄色葡萄球菌中的磷酸盐稳态，并且该调节网络的破坏会减少葡萄球菌 毒力。该提案的两个目标将检验这一假设并阐明 PhoPR 控制的因素 使金黄色葡萄球菌能够引起感染。目标 I 将确定 PhoPR 对金黄色葡萄球菌磷酸盐的贡献 稳态和毒力。 Aim II 将评估 S. 拥有的三个 PhoU 同系物的贡献。 金黄色葡萄球菌控制磷酸盐稳态。