Pheromone Signaling in Pneumocystis Carinii

卡氏肺孢子虫中的信息素信号转导

• 批准号: 6450166
• 负责人: CHARLES FRANCIS THOMAS
• 金额: $ 32.51万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-01 至 2005-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6450166
• 关键词: Pneumocystis carinii; antibody; biological signal transduction; cell cycle; cell cycle proteins; cell growth regulation; cell proliferation; complementary DNA; enzyme activity; enzyme inhibitors; flow cytometry; fungal genetics; gene expression; immunoelectron microscopy; immunoprecipitation; light microscopy; meiosis; messenger RNA; mitogen activated protein kinase; pheromone; polymerase chain reaction; pulsed field gel electrophoresis; tissue /cell culture; western blottings

DESCRIPTION (provided by applicant): Pneumocystis carinii is an opportunistic fungal pathogen which causes severe pneumonia in patients with impaired immunity such as patients with AIDS. The life cycle of P. carinii is poorly understood. In fungi related to P. carinii, nutrient deprivation and dessication are the major stimuli for the release of pheromone mating factors which activate a mitogen-activated protein kinase (MAPK), resulting in mitotic cell cycle arrest, conjugation and meiosis, and increased pathogenicity. MAPK is the essential molecule in the pheromone-induced signal transduction cascade which controls these events. As an essential molecule regulating an organism's life cycle, MAPK activity is highly regulated. Dual phosphorylations are requiring for activation, and variable MAPK activity and expression are restricted to certain life cycle forms. Our initial studies indicate that P. carinii possesses a MAPK which is closely related to fungal pheromone-induced MAPKs. We hypothesize that the pheromone-induced mitogen-activated protein kinase (MAPK) signal transduction cascade regulates cellular differentiation and proliferation of P. carinii organisms. As an essential component in the life cycle of fungi, investigation of the P. carinii MAPK will result in an enhanced understanding of the P. carinii life cycle, pathogenicity, and lead to development of novel therapeutic agents to treat P. carinii pneumonia. To evaluate these hypotheses, we will undertake several parallel investigations. MAPK activity and expression in separated life cycle forms will be accessed to determine whether P. carinii MAPK is differentially regulated over the P. carinii life cycle. We will identify and characterize the P. carinii pheromone receptors and separate P. carinii mating types by FACS. We will access whether nutrient deprivation, hypoxia, or temperature changes results in mitotic cell cycle arrest leading to meiosis and formation of the cyst, and whether inhibitors of the MAPK cascade block these effects. We will also investigate if isolated mating types undergo haploid mitosis or if mixing of mating types is essential for meiosis and formation of the cyst. Through these investigations, we hope to gain important insights into the life cycle regulation and pathogenicity ofP. carinii.

描述（由申请人提供）： 卡氏肺孢子虫是一种机会性病原体 真菌病原体，导致受损患者出现严重肺炎 免疫力，例如艾滋病患者。 P. carinii 的生命周期很差 明白了。在与 P. carinii 相关的真菌中，营养缺乏和 干燥是释放信息素交配因子的主要刺激因素 它激活丝裂原激活蛋白激酶（MAPK），导致有丝分裂 细胞周期停滞、接合和减数分裂以及致病性增加。 MAPK 是信息素诱导的信号转导级联中的重要分子 它控制这些事件。作为调节生物体的重要分子 在生命周期中，MAPK 活性受到高度调控。双磷酸化是 需要激活，并且可变 MAPK 活性和表达是 仅限于某些生命周期形式。我们的初步研究表明 P. carinii 拥有与真菌信息素诱导密切相关的 MAPK MAPK。我们假设信息素诱导的有丝分裂原激活蛋白 激酶 (MAPK) 信号转导级联调节细胞分化 和 P. carinii 生物体的增殖。作为一个重要的组成部分 真菌的生命周期，对 P. carinii MAPK 的研究将导致 增强对 P. carinii 生命周期、致病性的了解，并导致 开发治疗卡氏疟原虫肺炎的新型治疗剂。到 评估这些假设，我们将进行几项平行调查。 分离的生命周期形式中的 MAPK 活动和表达将被访问 确定 P. carinii MAPK 是否受到与 P. carinii 不同的调控。 卡里尼生命周期。我们将识别并表征 P. carinii 信息素 受体并通过 FACS 分离 P. carinii 交配类型。我们将访问是否 营养缺乏、缺氧或温度变化导致细胞有丝分裂 周期停滞导致减数分裂和囊肿形成，以及是否 MAPK 级联抑制剂可阻断这些效应。我们还将调查是否 孤立的交配类型经历单倍体有丝分裂，或者如果交配类型的混合是 对于减数分裂和囊肿的形成至关重要。通过这些调查， 我们希望获得对生命周期监管的重要见解 P的致病性。卡里尼。