Choline phosphotransferase-dependent phospholipid synthesis in Treponema

密螺旋体中胆碱磷酸转移酶依赖性磷脂合成

• 批准号: 7509591
• 负责人: J CHRISTOPHER FENNO
• 金额: $ 26.6万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-06-17 至 2010-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7509591
• 关键词: 1,2-diacylglycerol; Address; Anabolism; Antibiotic Resistance; Area; Cellular Structures; Choline; Chronic; Communicable Diseases; Cytidine Diphosphate Choline; DNA; Development; Diglycerides; Elements; Environment; Enzymes; Ethanolamines; Eukaryota; Eukaryotic Cell; Event; Facility Construction Funding Category; Future; Genes; Genetic; Genome; Glycoconjugates; Homologous Gene; Horizontal Gene Transfer; Human; Hybrids; Knowledge; Laboratories; Lecithin; Life Style; Membrane; Membrane Biology; Microbe; Mitochondrial Carnitine Palmitoyltransferase Pathway; Order Spirochaetales; Organism; Pathway interactions; Phosphatidylethanolamine; Phospholipids; Phosphorylcholine; Phosphotransferase Gene; Phosphotransferases; Positioning Attribute; Process; Public Health; Range; Regulation; Role; Saccharomyces cerevisiae; Testing; Therapeutic Agents; Tissues; Treponema; Treponema denticola; Treponema pallidum; Up-Regulation; Virulence; base; ethanolamine; insight; mutant; novel; novel therapeutics; pathogen; phosphatidylethanolamine; uptake

DESCRIPTION (provided by applicant): The unique CDP-choline pathway for phosphatidylcholine (PtdCho) biosynthesis present in spirochetes of the genus Treponema is likely both a consequence of and a contributor to the commensal/pathogenic lifestyles of these organisms, reflecting their coevolution with eukaryotic hosts. We hypothesize that the final enzyme step in T. denticola PtdCho synthesis (1,2- diacylglycerol choline phosphotransferase [CPT]) is encoded by TDE0021, a gene of apparent eukaryotic origin. In many eukaryotes, this enzyme also has 1,2-diacylglycerol ethanolamine phosphotransferase (EPT) activity required for phosphatidylethanolamine (PtdEtn) synthesis. In T. denticola, PtdEtn (synthesized by an as-yet unidentified pathway) is upregulated when the first step in PtdCho synthesis is blocked. We hypothesize that T. denticola TDE0021 encodes CPT activity and may also have EPT activity, thus making it the key enzyme in phospholipid synthesis and an attractive target for development of specific anti-Treponema agents against a range of mucosal and venereal treponematoses. This application addresses the following areas: Aim 1: To characterize the CPT activity of T. denticola required for synthesis of PtdCho. We will determine if T. denticola TDE0021 encodes CPT activity by (A) construction and characterization of an isogenic TDE0021 mutant and (B) complementation of a Saccharomyces cerevisiae CPT/EPT mutant with T. denticola TDE0021 DNA. Aim 2: To characterize synthesis and expression of PtdEtn in T. denticola. We will (A) identify and characterize the T. denticola PtdEtn synthesis pathway, and (B) characterize the mechanism(s) responsible for increased levels of PtdEtn in a defined PtdCho-deficient T. denticola mutant. Upon completion of the two Aims of this project, we will have made significant progress toward understanding the genetic components and mechanisms of the unique phospholipid synthesis pathway in the genus Treponema, which includes both mucosal and venereal pathogens. The knowledge gained will significantly enhance understanding of spirochete membrane biology, will provide a basis for continued studies of the role of the phospholipid environment on microbe-host interactions, and may provide the basis for development of novel therapeutic agents. PUBLIC HEALTH RELEVANCE: This project will characterize genetic components and mechanisms comprising the unique phospholipid synthesis pathways in the genus Treponema, which includes both mucosal and venereal pathogens. This will contribute to understanding of the role of the membrane phospholipid environment on microbe-host interactions, and may provide a basis for development of novel therapeutic agents.

描述(由申请人提供)：在密螺旋体属螺旋体中存在的磷脂酰胆碱(PtdCho)生物合成的独特CDP-胆碱途径可能既是这些生物共生/致病生活方式的结果，也是其贡献者，反映了它们与真核宿主的共同进化。我们推测，齿状毛滴虫合成PtdCho的最后一步(1，2-二甘油胆碱磷酸转移酶[CPT])是由TDE0021编码的，TDE0021是一个明显起源于真核细胞的基因。在许多真核生物中，该酶还具有合成磷脂酰乙醇胺(PtdEtn)所需的1，2-二酰甘油乙醇胺磷酸转移酶(EPT)活性。在齿纹夜蛾中，当PtdCho合成的第一步被阻断时，PtdEtn(通过一种未知的途径合成)被上调。我们推测TDE0021编码CPT活性，也可能具有EPT活性，从而使其成为磷脂合成的关键酶和开发针对一系列粘膜和性病螺旋体的特异性抗密螺旋体药物的有吸引力的靶点。本申请涉及以下方面：目的1：鉴定合成PtdCho所需的齿状毛滴虫的CPT活性。我们将通过(A)构建和鉴定等基因TDE0021突变体和(B)将酿酒酵母CPT/EPT突变体与TDE0021 DNA互补来确定TDE0021是否编码CPT活性。目的：研究PtdEtn的合成及其在齿纹夜蛾中的表达。我们将(A)鉴定和表征齿纹夜蛾PtdEtn的合成途径，以及(B)表征在已定义的PtdCho缺乏的齿纹夜蛾突变体中导致PtdEtn水平升高的机制(S)。随着这个项目的两个目标的完成，我们将在了解密螺旋体独特的磷脂合成途径的遗传成分和机制方面取得重大进展，包括粘膜病原体和性病原体。所获得的知识将显著提高对螺旋体膜生物学的了解，将为继续研究磷脂环境对微生物-宿主相互作用的作用提供基础，并可能为开发新型治疗药物提供基础。与公共卫生相关：该项目将描述密螺旋体中独特的磷脂合成途径的遗传成分和机制，其中包括粘膜病原体和性病病原体。这将有助于理解膜磷脂环境在微生物-宿主相互作用中的作用，并可能为开发新型治疗药物提供基础。