Serine/threonine kinase signaling in beta-lactam resistance of Staphylococcus aureus

金黄色葡萄球菌 β-内酰胺耐药中的丝氨酸/苏氨酸激酶信号传导

• 批准号: 10582130
• 负责人: Som Chatterjee
• 金额: $ 75.55万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 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 2027-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10582130
• 关键词: Affinity; Amino Acids; Antibiotic Resistance; Antibiotics; Attenuated; Bacteria; Bacterial Genes; Binding; Biochemical; Cell Wall; Cell division; Cell physiology; Communities; Cytosol; Data; Drug resistance; Ensure; Expenditure; FLT3 gene; Genes; Goals; Hospitals; Infection; Integral Membrane Protein; Knowledge; Mediating; Mediator; Membrane; Metalloproteases; Methicillin Resistance; Molecular Genetics; Mutation; Pathway interactions; Penicillin-Binding Proteins; Pharmaceutical Preparations; Phenotype; Phosphoric Monoester Hydrolases; Phosphorylation; Play; Predisposition; Protein Dephosphorylation; Protein-Serine-Threonine Kinases; Proteins; Proteolysis; Proteomics; Quality Control; Regulation; Regulatory Pathway; Repression; Resistance; Resources; Role; Serine; Serine/Threonine Phosphorylation; Signal Pathway; Signal Transduction; Site; Staphylococcus aureus; Staphylococcus aureus infection; System; Therapeutic; Threonine; Transcription Repressor; Transcriptional Activation; Treatment Efficacy; Zinc; bacterial resistance; beta-Lactam Resistance; beta-Lactams; derepression; drug sensitivity; genetic approach; genetic regulatory protein; genome sequencing; improved; inducible gene expression; inhibitor; kinase inhibitor; loss of function; methicillin resistant Staphylococcus aureus; mutant; novel; novel therapeutic intervention; overexpression; resistant strain; sensor

Project Abstract: We have identified novel roles of the eukaryotic-like serine/threonine kinase (eSTK) signaling pathway in mediating broad-spectrum β-lactam resistance in methicillin-resistant Staphylococcus aureus (MRSA). Broad-spectrum β-lactam resistance, which renders most β-lactam drugs therapeutically ineffective, is classically mediated through mecA, the gene that encodes penicillin-binding protein 2a. Broad-spectrum resistance to β-lactams in S. aureus also occurs through non-classical mediators not directly related to mecA. The role played by the non-classical mediators in β-lactam resistance is only superficially understood. Both Stk1 and Stp1 (effectors of eSTK signaling; a serine/threonine kinase and phosphatase), mediate β-lactam sensitivity by loss of function or overexpression respectively, whereas functional Stk1 and non-functional Stp1 favor drug resistance. Our results show that eSTK modulates β-lactam resistance via pathways controlling mecA expression and through unknown non-classical mediators independently regulated by Stk1 and Stp1. mecA expression in community MRSA strains (and many hospital strains as well) is regulated by the BlaR1- BlaI regulatory pathway. Expression of mecA is normally suppressed by the transcriptional repressor, BlaI. Presence of β-lactam drugs is sensed by BlaR1, an integral membrane protein. Subsequently, BlaR1 undergoes a site-specific auto-proteolysis releasing its intracellular zinc metalloprotease (ZnMP) domain into the bacterial cytosol. The released ZnMP degrades BlaI to de-repress mecA expression, leading to drug resistance. Our data show that eSTK mediated phosphorylation of BlaR1 is important for efficient mecA induction. Through passaging studies, we have identified compensatory mechanisms that enable the bacteria to overcome drug sensitivity due to Stk1 loss of function or Stp1 overexpression, mentioned above. Genome sequencing studies carried out to decipher the basis of resistance in passaged strains indicated involvement of pathways that are unrelated to mecA. Three aims are proposed: a) to decipher the mechanism through which eSTK controls mecA expression, b) to identify eSTK mediators that confer non-classical β-lactam resistance, and c) to investigate the compensatory basis of resistance among resistant passaged strains. Our study will help determine the mechanism/s through which Stk1 and Stp1 control β-lactam resistance and could help to identify novel and improved treatment options for S. aureus infections.

项目摘要： 我们已经确定了类真核丝氨酸/苏氨酸激酶（eSTK）信号通路在 介导耐甲氧西林金黄色葡萄球菌 (MRSA) 的广谱 β-内酰胺耐药性。 广谱β-内酰胺耐药性导致大多数β-内酰胺药物治疗无效， 经典地通过编码青霉素结合蛋白 2a 的基因 mecA 介导。 金黄色葡萄球菌对 β-内酰胺的耐药性也通过与 mecA 不直接相关的非经典介质发生。 非经典介质在 β-内酰胺耐药中所起的作用仅被肤浅地了解。 和 Stp1（eSTK 信号传导的效应子；丝氨酸/苏氨酸激酶和磷酸酶），介导 β-内酰胺敏感性 分别由功能丧失或过度表达引起，而功能性 Stk1 和非功能性 Stp1 有利于药物 我们的结果表明，eSTK 通过控制 mecA 的途径调节 β-内酰胺耐药性。 表达并通过 Stk1 和 Stp1 独立调节的未知非经典介质。 社区 MRSA 菌株（以及许多医院菌株）中的 mecA 表达受 BlaR1- 调节 BlaI 调控途径。mecA 的表达通常受到转录抑制子 BlaI 的抑制。 BlaR1（一种整合膜蛋白）可感知 β-内酰胺药物的存在，随后，BlaR1 会发生变化。 位点特异性自动蛋白水解将其细胞内锌金属蛋白酶 (ZnMP) 结构域释放到细菌中 释放的 ZnMP 会降解 BlaI 以解除 mecA 表达的抑制，从而导致耐药性。 表明 eSTK 介导的 BlaR1 磷酸化对于有效的 mecA 诱导很重要。 通过研究，我们已经确定了使细菌能够 克服上述因 Stk1 功能丧失或 Stp1 基因组过度表达而导致的药物敏感性。 为破译传代菌株的耐药性基础而进行的测序研究表明， 与 mecA 无关的途径。 提出了三个目标：a) 破译 eSTK 控制 mecA 表达的机制，b) 识别赋予非经典 β-内酰胺耐药性的 eSTK 介质，以及 c) 研究补偿性 抗性传代菌株中抗性的基础。 我们的研究将有助于确定 Stk1 和 Stp1 控制 β-内酰胺耐药性的机制以及 可能有助于确定金黄色葡萄球菌感染的新颖和改进的治疗方案。