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(申请人提供)：肺炎支原体是导致大龄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%。这种无细胞壁的原核生物通过滑动运动运动，我们认为这有助于呼吸道传导呼吸道的定植。人们对滑行运动知之甚少，在肺炎支原体中也没有发现已知的滑行或其他运动基因的同源基因。在本项目期间，我们鉴定了一组不同的滑动相关基因，最终证明了末端细胞器本身就是滑动运动，定义了滑动过程中几种末端细胞器组件的需求和功能，并产生了滑动对粘膜上皮定植所需的直接证据。在此提出的研究建立在此基础上，以进一步确定滑行在发病机制中的作用，并探索滑行的力学基础，包括三个特定的目标。目的1探讨滑行机制，重点研究滑行相关蛋白P65、P41和P24。末端细胞器脱离细胞体，失去P41，但仍保留滑行功能。P65基因的插入导致表面粘附素P30从末端细胞器拖到末端，在那里它分离，在滑动细胞后面留下一条痕迹。在没有P41的情况下，P24焦点似乎沿着细胞的长轴移动。在下一个项目期间，我们将应用生化和细胞成像方法，包括电子冷冻断层扫描，进一步探索P24、P41、P65和其他选定的蛋白质在滑行中的作用。在目标2中，我们将详细分析某些滑行突变体，这些突变体表现出独特的草坪样生长，这是由于唯一注释的肺炎支原体蛋白磷酸酶和同源丝氨酸/苏氨酸蛋白激酶的基因中断所致。我们将确定这些突变的因果关系，并探索蛋白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。我们还将通过显微摄影技术详细检查这些突变体的细胞行为，以确定草坪样生长是如何实现的。在目标3中，我们将使用一个分化的正常人支气管上皮模型和野生型和滑行缺陷支原体来探索在传导呼吸道定植过程中，滑行运动如何特异性地对粘液纤毛防御系统的抵抗起作用。肺炎支原体是大龄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%。大多数感染会导致慢性和旷日持久的呼吸道疾病，影响学校出勤率和工作场所的生产力，并可能导致永久性肺损伤。此外，越来越多的证据支持肺炎支原体在哮喘的发病和复发中起着重要的作用。本文提出的研究将阐明滑行运动在导气管定植中的机制和作用。