PENICILLIN INTERACTIVE PROTEINS OF STAPHYLOCOCCUS AUREUS

金黄色葡萄球菌的青霉素相互作用蛋白

• 批准号: 6349926
• 负责人: Henry F HENRY CHAMBERS
• 金额: $ 31.23万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-02-01 至 2004-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6349926
• 关键词: DNA binding protein; Staphylococcus aureus; Staphylococcus infection; bacteria infection mechanism; bacterial genetics; bacterial proteins; beta lactamase; biological signal transduction; cell cycle; enzyme activity; enzyme induction /repression; gene deletion mutation; gene expression; immunoelectron microscopy; metalloendopeptidases; methicillin; multidrug resistance; northern blottings; penicillins; protein localization; protein protein interaction; protein structure function; regulatory gene; sequence tagged sites; zymogens

Methicillin-resistant strains of Staphylococcus aureus are a major clinical problem. They are multiple drug resistant, but ineffectiveness of penicillins and beta-lactam antibiotics is the real problem, as these are drug of choice to treat staphylococcal infections. The objective of this research is to further knowledge of mechanisms of methicillin resistance. Resistance is determined by several proteins that interact with penicillin. The interactions among these proteins are critical, but poorly understood. Knowledge of these interrelationships may lead to new drug discovery and new and more effective approaches to therapy./ Resistance is mainly due to production a novel low affinity penicillin bind protein, PBP 2a, a well wall synthetic enzyme. PBP 2a seems to substitute for all other PBPs. mecA, the gene encoding PBP 2a, is regulated by the same regulatory genes that control production of inducible beta-lactamase. Another type of penicillin interactive protein, a penicillin sensory signal transducer BlaR1, signals the cell to express PBP 2a and beta-lactamase, which together mediate all beta-lactam resistance in staphylococci. BlaR1 appears to be a PBP fused to an intracellular Zn++ metalloprotease, and as such may represent a completely new type of transmembrane signaling system. There are three aims. Aim1. To determine the intracellular pathway by which penicillin binding to BlaR1 signals induction of beta- lactamase and PBP 2a. The effect of specific mutations in BlaR1 on signaling will be determined to prove whether or not Blar1 is a metalloprotease. Putative consensus motifs of this superfamily of proteins will be targeted. The relationship between BlaR1 activation and proteolysis of BlaI, the repressor of the beta-lactamase regulon, will be defined. Aim 2. To identify PBPs, structural determinants, and other elements that interfere with PBP 2a mediated resistance. Effects of PBP deletion and mutations on PBP 2a mediated resistance will test whether PBP 2a can substitute for other PBPs and where essential functions reside within the molecule. The curious phenomenon of negative selection for expression of PBP 2a that we observed in mec naive cells also will be examined. Aim 3. To determine when during the cell cycle PBPs are expressed and where they are localized. An electron microscopic method for immunolocalization of specific myc-targeted PBPs in the cell will be developed. To augment information about where PBPs localize, when they are expressed during the cell cycle will be determined by Northern blotting.

金黄色葡萄球菌的耐甲氧西林菌株是主要的临床问题。它们具有多种耐药性，但是青霉素和β-内酰胺抗生素的无效性是真正的问题，因为这些是治疗葡萄球菌感染的选择。这项研究的目的是进一步了解甲氧西林耐药机制。抗性由几种与青霉素相互作用的蛋白质确定。这些蛋白质之间的相互作用至关重要，但理解不足。对这些相互关系的了解可能会导致新药物发现和新的，更有效的治疗方法。/耐药性主要是由于生产新型的低亲和力青霉素结合蛋白PBP 2A，PBP 2A，井壁合成酶。 PBP 2A似乎代替了所有其他PBP。 MECA是编码PBP 2a的基因，受控制可诱导β-内酰胺酶产生的相同调节基因。青霉素感觉信号传感器blar1的另一种类型的青霉素相互作用蛋白向细胞表达PBP 2a和β-内酰胺酶，它们共同介导葡萄球菌中的所有β-内酰胺耐药性。 BLAR1似乎是融合到细胞内Zn ++金属蛋白酶的PBP，因此可能代表了一种全新的跨膜信号传导系统。有三个目标。 AIM1。为了确定青霉素与β-乳酰胺酶和PBP 2A的BLAR1信号诱导的细胞内途径。将确定BLAR1中特定突变对信号传导的影响，以证明Blar1是否是金属蛋白酶。该超家族蛋白质的假定共识基序将成为目标。将定义BLAR1激活与蛋白水解（BLAI）的蛋白水解（β-内酰胺酶调节剂的阻遏物）之间的关系。目的2。确定干扰PBP 2A介导的抗性的PBP，结构决定因素和其他元素。 PBP缺失和突变对PBP 2A介导的电阻的影响将测试PBP 2A是否可以代替其他PBP，并且在分子中存在基本功能。我们在MEC幼稚细胞中观察到的PBP 2a表达的负选择的奇怪现象也将被检查。目标3。确定在细胞周期何时表达何时表达何时何处。将开发一种用于细胞中特定MYC靶向PBP的免疫定位的电子显微镜方法。为了增加有关PBP在何处定位的信息，将在细胞周期中表达时，将通过北印迹确定。