Mycoplasma pneumoniae Gliding Motility

描述（由申请人提供）：肺炎支原体是年龄较大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移动，我们认为这有助于呼吸道传导气道的定植。对滑行运动的了解很少，在M中没有发现已知运动基因的同源物，滑行或其他。肺炎。在本项目期间，我们鉴定了一组不同的滑行相关基因，最终证明了末端细胞器单独是滑行马达，定义了滑行中几种末端细胞器组分的要求和功能，并产生了滑行是粘膜上皮定植所需的直接证据。在此基础上，本文提出的研究进一步定义了滑动在发病机制中的作用，并探讨了滑动的力学基础，包括三个具体目标。目的1研究了细胞的滑动机制，重点研究了滑动相关蛋白P65、P41和P24。终末细胞器随着P41的缺失而与细胞体分离，但仍保持滑动功能。P65基因的插入导致表面粘附素P30从末端细胞器拖到尾端，在那里它分离，在滑动细胞后面留下痕迹。在缺乏P41的情况下，P24灶似乎沿细胞的长轴沿着移动。在下一个项目期间，我们将应用生物化学和细胞成像方法，包括电子冷冻断层扫描，以进一步探索P24，P41，P65和其他选定的蛋白质在滑翔中的作用。在目标2中，我们将详细分析某些滑动突变体，其表现出独特的草坪状生长，这是唯一注释的M的基因被破坏的结果。肺炎杆菌蛋白磷酸酶和同源Ser/Thr蛋白激酶。我们将确认这些突变体的因果关系，并探讨蛋白激酶或磷酸酶功能丧失对末端细胞器蛋白HMW 1和HMW 2磷酸化的影响。我们还将通过显微摄影详细研究这些突变体的细胞行为，以确定如何实现草坪状生长。在目标3中，我们将使用分化的正常人支气管上皮模型和野生型和滑行缺陷型支原体，以探讨滑行运动如何特别有助于阻力的粘液纤毛防御的殖民化进行气道。肺炎支原体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%。大多数感染会导致慢性和持久的呼吸道疾病，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部损伤。此外，越来越多的证据支持M.肺炎在哮喘发作和复发中的作用。本文的研究将阐明滑翔运动在气道定植中的机制和作用。

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.