Coxiella secreted proteins mediating inter-organelle membrane contact sites

柯克斯体分泌的蛋白质介导细胞器间膜接触位点

• 批准号: 10575434
• 负责人: STACEY D GILK
• 金额: $ 23.03万
• 依托单位: UNIVERSITY OF NEBRASKA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-11-04 至 2024-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10575434
• 关键词: Acute; Address; Antibiotic Therapy; Antibiotics; Bacteria; Bacterial Infections; Bacterial Proteins; Binding; Binding Proteins; Bioinformatics; Biological Assay; Cell physiology; Cells; Cessation of life; Cholesterol; Cholesterol Homeostasis; Chronic; Complement; Coxiella; Coxiella burnetii; Data; Development; Disease Outbreaks; Ectopic Expression; Endocarditis; Endoplasmic Reticulum; Etiology; Eukaryotic Cell; Family; Family member; Fatigue; Fluorescence; Funding; Future; Genetic Complementation Test; Growth; Health; Homeostasis; Human; Immune response; Individual; Infection; Lipids; Location; Macrophage; Maintenance; Measures; Mediating; Membrane; Modeling; Molecular; Molecular Structure; Molecular Target; Netherlands; Organelles; Pathogenesis; Patient Noncompliance; Phagolysosome; Play; Protein Family; Protein Secretion; Proteins; Publishing; Q Fever; Regimen; Research; Role; Site; Symptoms; System; Testing; Therapeutic Intervention; Vacuole; Virulence Factors; chronic infection; experimental study; flu; insight; lipid metabolism; member; mutant; novel; pathogen; therapeutic target; yeast two hybrid system

PROJECT SUMMARY/ABSTRACT Coxiella burnetii is an obligate intracellular bacterium and the etiological agent of Q fever. Inside the host cell, the bacterium survives in a phagolysosome-like vacuole called the Coxiella Containing Vacuole (CCV). Coxiella is uniquely sensitive to host cholesterol levels, where elevated cholesterol, especially in the CCV and endolysosomal system, leads to bacterial death. While Coxiella directly regulates host cholesterol homeostasis through effector proteins secreted by the Coxiella Type 4B Secretory System (T4BSS), the T4BSS effector proteins responsible for manipulating host cell cholesterol have not yet been identified. Using a bioinformatic approach, we identified a new family of Coxiella T4BSS effector proteins which contain a eukaryotic FFAT motif. In eukaryotic cells, FFAT proteins bind to the VAP protein family on the endoplasmic reticulum (ER) and mediate membrane contact sites (MCS) between cell organelles and ER. These inter-organelle MCS play a critical role in regulating lipid homeostasis. The proposed experiments will test our hypothesis that Coxiella FFAT-containing T4BSS effector proteins mediate MCS between the ER and other host organelles in order to manipulate host cholesterol metabolism. Aim 1 will establish which members of the Coxiella FFAT protein family bind to VAP proteins, and determine where these proteins localize in the host cell. Aim 2 will test whether these proteins are essential for Coxiella infection, as well as whether they function in modulating host cholesterol. Completion of these studies will not only reveal a new strategy utilized by Coxiella to modulate host lipid metabolism, but significantly add to our knowledge on how pathogen-secreted proteins manipulate the host cell.

项目摘要/摘要 Coxiella burnetii是一种强制性细胞内细菌，也是Q发烧的病因。在主机单元中， 该细菌在一种称为含胶液（CCV）的吞噬体样液泡中生存。考克斯 对宿主胆固醇水平敏感，胆固醇升高，尤其是在CCV和 内溶性系统，导致细菌死亡。而Coxiella直接调节宿主胆固醇稳态 通过Coxiella型4B分泌系统（T4BS）分泌的效应蛋白，T4BSS效应器 尚未确定负责操纵宿主细胞胆固醇的蛋白质。使用生物信息学 方法是，我们确定了一个新的Coxiella T4BSS效应子蛋白，其中包含真核FFAT基序。 在真核细胞中，FFAT蛋白与内质网（ER）上的VAP蛋白家族结合并介导 细胞细胞器和ER之间的膜接触位点（MCS）。这些轨道间MCS起着关键作用 在调节脂质稳态方面。提出的实验将检验我们的假设，即含卷FFAT的coxiella T4BSS效应蛋白介导ER和其他宿主细胞器之间的MC，以操纵宿主 胆固醇代谢。 AIM 1将确定Coxiella FFAT蛋白家族的哪些成员与VAP结合 蛋白质，并确定这些蛋白质位于宿主细胞中的位置。 AIM 2将测试这些蛋白是否是 对于考克斯菌感染所必需的，以及它们是否在调节宿主胆固醇中起作用。完成 这些研究不仅会揭示Coxiella使用的新策略来调节宿主脂质代谢，而且还可以 显着增加了我们关于病原体分泌蛋白如何操纵宿主细胞的知识。