Chromatin-based regulation of multidrug resistance genes

基于染色质的多药耐药基因调控

• 批准号: 7140423
• 负责人: Karl W. Henry
• 金额: $ 14.65万
• 依托单位: DREXEL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7140423
• 关键词: Candida; Saccharomyces cerevisiae; antifungal agents; chromatin; chromatin immunoprecipitation; enzyme activity; fungal genetics; gene expression; gene mutation; genetic promoter element; genetic regulatory element; genetic screening; genetic strain; histones; multidrug resistance; pharmacogenetics

DESCRIPTION (provided by applicant): The development of drug resistance often results in treatment failure in a variety of infectious organisms and this is of particular importance in pathogenic fungi where increased expression of multidrug efflux pumps is observed in drug-resistant clinical isolates. The baker's yeast Saccharomyces cerevisiae has served as an excellent model system for the study of both antifungal resistance and chromatin-based gene regulation. In this proposal, I will bring together these two areas of research to test the hypothesis that histone modifications play an important role in the regulation of genes that are involved in multidrug resistance (MDR). I propose to do this by using strains where either the major activation-correlated histone modification sites are mutated or have deletions in the histone modifying enzymes; I will test for changes in susceptibility to a variety of inhibitors and for defects in the expression of genes that encode for important multidrug efflux proteins. Using a novel genetic screening method that we have developed, I will attempt to identify positive and negative regulators of the gene encoding the Pdr5 drug efflux pump and confirm these interactions with the promoter by chromatin immunoprecipitation. Lastly, I will delete genes that encode histone modifying enzymes in the opportunistic pathogen Candida glabrata to determine if these regulatory systems also control drug susceptibility and MDR gene expression. The data that are generated from this initial research proposal may prove useful for understanding the control of MDR genes and reveal novel drug targets for antifungal therapy. These mechanisms can then be studied directly using medically important opportunistic fungi such as other Candida species and Aspergillus species in future proposals.

描述（由申请人提供）：耐药性的发展通常会导致多种感染性生物体的治疗失败，这对于病原性真菌尤其重要，因为在耐药性临床分离株中观察到多药外排泵的表达增加。面包酵母酿酒酵母已成为抗真菌耐药性和基于染色质的基因调控研究的优秀模型系统。在本提案中，我将把这两个领域的研究结合起来，检验组蛋白修饰在涉及多药耐药性 (MDR) 的基因调控中发挥重要作用的假设。我建议通过使用主要激活相关组蛋白修饰位点突变或组蛋白修饰酶缺失的菌株来实现这一点；我将测试对各种抑制剂的敏感性变化以及编码重要多药外排蛋白的基因表达缺陷。使用我们开发的新型遗传筛选方法，我将尝试识别编码 Pdr5 药物外排泵的基因的正向和负向调节因子，并通过染色质免疫沉淀证实这些与启动子的相互作用。最后，我将删除机会性病原体光滑念珠菌中编码组蛋白修饰酶的基因，以确定这些调节系统是否也控制药物敏感性和 MDR 基因表达。这项初步研究提案产生的数据可能有助于理解 MDR 基因的控制，并揭示抗真菌治疗的新药物靶点。在未来的提案中，可以使用医学上重要的机会性真菌（例如其他念珠菌属物种和曲霉属物种）直接研究这些机制。