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： 我们已经确定了真核生物样丝氨酸/苏氨酸激酶（ESTK）信号通路的新作用 介导耐甲氧西林金黄色葡萄球菌（MRSA）中的广谱β-内酰胺抗性。 广谱β-内酰胺抗性使大多数β-内酰胺药的热无效，是 通过MECA进行古典介导，MECA是编码青霉素结合蛋白2a的基因。广谱 金黄色葡萄球菌中对β-内酰胺的耐药性也通过与MECA直接相关的非经典介体发生。 非经典介体在β-内酰胺抗性中所起的作用仅是超级理解的。两个stk1 和STP1（ESTK信号的效应子；丝氨酸/苏氨酸激酶和磷酸酶），介导β-内酰胺敏感性 分别通过功能或过表达的损失，而功能性STK1和非功能性STP1有利药物 反抗。我们的结果表明，ESTK通过控制MECA的途径调节β-内酰胺 表达，通过不明的非古典介体，由STK1和STP1独立调节。 MECA在社区MRSA菌株中的表达（以及许多医院菌株）受Blar1-的调节 Blai监管途径。通常被转录复制品Blai抑制MECA的表达。 β-内酰胺药物的存在通过BLAR1（一种积分膜蛋白）感测。随后，Blar1经历 特定于位点的自身蛋白解会释放其细胞内锌金属蛋白酶（ZnMP）结构域中 细胞质。释放的ZnMP将Blai降低至抑制MECA表达，从而导致耐药性。我们的数据 表明ESTK介导的BLAR1磷酸化对于有效的MECA诱导很重要。 通过通过研究，我们确定了使细菌能够达到的补偿机制 在上面提到的功能或STP1过表达的STK1丧失或STP1过表达引起的药物敏感性。基因组 进行的测序研究是为破译传送菌株抗性的基础的基础表明 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） 确定会议的ESTK介体会议非古典β-内酰胺抗性，以及c）研究代偿性 抗性转移菌株中抗性的基础。 我们的研究将有助于确定STK1和STP1控制β-内酰胺的耐药性和 可以帮助确定金黄色葡萄球菌感染的新颖和改进的治疗选择。