Mycoplasma pneumoniae Gliding Motility

肺炎支原体滑行运动

• 批准号: 8134723
• 负责人: GRANT J JENSEN
• 金额: $ 3.58万
• 依托单位: UNIVERSITY OF GEORGIA
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2013-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8134723
• 关键词: Accounting; Address; Asthma; Bacterial Adhesins; Biochemical; Cell Wall; Cell model; Cell surface; Cells; Child; Chronic; Cilia; Communities; Complex; Cytoskeletal Proteins; Cytoskeleton; Defect; Development; Distal; Electrons; Epithelial Cells; Epithelium; Event; Exhibits; Failure; Foundations; Frequencies; Genes; Growth; Homologous Gene; Human; Image Analysis; In Vitro; Infection; Lateral; Left; Link; Location; Lung; Lung diseases; Mechanics; Membrane Proteins; Modeling; Motion; Motor; Movement; Mucins; Mucous body substance; Mycoplasma; Mycoplasma pneumoniae; Organelles; Pathogenesis; Penetration; Phenotype; Phosphoproteins; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphotransferases; Pneumonia; Productivity; Prokaryotic Cells; Protein Kinase; Protein phosphatase; Proteins; Recurrence; Resistance; Respiratory Mucosa; Respiratory System; Respiratory tract structure; Role; Schools; Structure; Surface; Tail; Testing; Time; Work; Workplace; airway surface liquid; base; bronchial epithelium; cell behavior; cell motility; cellular imaging; digital imaging; in vivo; mutant; neuronal cell body; p65; ranpirnase; surface coating; synaptotagmin I; young adult

DESCRIPTION (provided by applicant): Mycoplasma pneumoniae is the leading cause of pneumonia in older children and young adults and accounts for 20% of all community-acquired pneumonia. This cell wall-less prokaryote moves by gliding motility, which we contend facilitates colonization of the conducting airways of the respiratory tract. Gliding motility is poorly understood, and no homologs of known motility genes, gliding or otherwise, are found in M. pneumoniae. In the current project period we identified a diverse set of gliding- associated genes, demonstrated conclusively that the terminal organelle alone is the gliding motor, defined the requirement and function of several terminal organelle components in gliding, and generated direct evidence that gliding is required for colonization of mucosal epithelium. The studies proposed here build upon that foundation to define further the role of gliding in pathogenesis and explore the mechanical basis for gliding, encompassing three specific aims. Aim 1 addresses the gliding mechanism, focusing on gliding-associated proteins P65, P41 and P24. The terminal organelle detaches from the cell body with the loss of P41 but retains gliding function. Insertions in the P65 gene result in the dragging of surface adhesin P30 from the terminal organelle to the trailing end, where it detaches to leave a trail behind the gliding cell. In the absence of P41, P24 foci appear to move along the long axis of the cell. In the next project period we will apply biochemical and cell imaging approaches including electron cryotomography to explore further the roles of P24, P41, P65, and other selected proteins in gliding. In Aim 2 we will analyze in detail certain gliding mutants exhibiting a distinctive lawn-like growth as a result of disruption of the genes for the only annotated M. pneumoniae protein phosphatase and cognate ser/thr protein kinase. We will confirm cause and effect for these mutants and explore the impact of loss of protine kinase or phosphatase function on the phosphorylation of terminal organelle proteins HMW1 and HMW2. We will also examine cell behavior of these mutants in detail by microcinematography to establish how lawn-like growth is achieved. In Aim 3 we will use a differentiated normal human bronchial epithelium model and wild-type and gliding-defective mycoplasmas to explore how gliding motility specifically contributes to resistance of mucociliary defenses in the colonization of conducting airways. Mycoplasma pneumoniae is the leading cause of pneumonia in older children and young adults and accounts for 20% of all community-acquired pneumonia. Most infections result in respiratory disease that is chronic and protracted, impacting attendance at school and productivity in the workplace, and permanent lung damage can result. In addition, a growing body of evidence supports a significant, contributing role for M. pneumoniae in onset and recurrence of asthma. The studies proposed here will elucidate the mechanism and role of gliding motility in the colonization of the conducting airways.

描述（由申请人提供）：支原体肺炎是年龄较大的儿童和年轻人肺炎的主要原因，占所有社区获得性肺炎的20％。这种无细胞壁原核生物通过滑行运动来移动，我们认为，这有助于促进呼吸道导电道的定殖。滑行运动知之甚少，在肺炎支原体中没有发现已知运动基因或其他方式的同源物。在当前的项目期间，我们确定了各种滑行相关的基因，最终证明了单独的末端细胞器是滑行运动，它定义了滑行中几个末端细胞器成分的需求和功能，并且生成的直接证据表明滑行是粘膜上皮定植所必需的。这里提出的研究以该基础为基础，以进一步定义滑行在发病机理中的作用，并探索滑行的机械基础，包括三个特定目标。 AIM 1解决了滑行机制，重点是滑行相关蛋白p65，p41和p24。末端细胞器随着P41的损失而从细胞体脱离，但保留了滑行功能。在p65基因中的插入导致将表面粘附素P30从末端细胞器拖到后端，在那里它脱离，在滑翔单元后留下一条小径。在没有p41的情况下，p24灶似乎沿细胞的长轴移动。在下一个项目期间，我们将采用包括电子冷冻学（电子冷冻理学）在内的生化和细胞成像方法，以进一步探索P24，p41，p65和其他选定的蛋白质在滑行中的作用。在AIM 2中，我们将详细分析某些表现出独特的草坪样生长的滑行突变体，这是由于唯一带注释的肺炎支原体蛋白磷酸酶和同源性SER/THR蛋白激酶的基因破坏而导致的。我们将确认这些突变体的原因和作用，并探讨保护性激酶或磷酸酶功能丧失对末端细胞器蛋白HMW1和HMW2磷酸化的影响。我们还将通过微观刻板学详细检查这些突变体的细胞行为，以确定如何实现草坪样生长。在AIM 3中，我们将使用差异化的正常人支气管上皮模型以及野生型和滑行缺陷的支原体来探讨滑行运动在导电呼吸道定植中如何特别有助于粘膜防御能力的抵抗力。支原体肺炎是年龄较大的儿童和年轻人肺炎的主要原因，占所有社区获得性肺炎的20％。大多数感染会导致呼吸道疾病慢性和持久，从而影响学校的出勤和工作场所的生产力，并且会导致永久性的肺部损害。此外，越来越多的证据支持了肺炎支原体在哮喘的发作和复发中的重要作用。此处提出的研究将阐明滑行运动在导电道的定植中的机制和作用。