Pathogenic Yeast Stress Signaling Networks

致病性酵母应激信号网络

• 批准号: 9058118
• 负责人: Jason Malcolm Rauceo
• 金额: $ 11.77万
• 依托单位: JOHN JAY COLLEGE OF CRIMINAL JUSTICE
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2019-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9058118
• 关键词: Adhesions; Anabolism; Antifungal Agents; Area; Binding; Biology; Biomedical Research; Candida albicans; Candidiasis; Carbohydrates; Caspofungin; Catheters; Cations; Cell Wall; Cells; Cerebrospinal Fluid; Chronically Ill; Computer Simulation; DNA; DNA Sequence; Data; Development; Disseminated candidiasis; Drug usage; Environment; Eye; Funding; Gene Expression Regulation; Gene Targeting; Genes; Genetic; Genetic Epistasis; Genetic Screening; Genomics; Goals; Health; Hispanic-serving Institution; Human; Infection; Infectious Agent; Kidney; Microbial Biofilms; Molecular Genetics; Mutation; Osmotic Shocks; Pathogenesis; Patients; Physicians; Physiological; Play; Population; Process; Research; Role; Signal Pathway; Signal Transduction; Sodium Chloride; Stress; Students; Testing; Time; Urine; Virulence; Work; Yeasts; base; biological adaptation to stress; candidemia; carbohydrate metabolism; cell growth; cell type; college; combinatorial; cost effective; dimorphism; environmental change; gene discovery; genetic approach; genomic data; inhibitor/antagonist; innovation; insight; interest; mortality; novel; pathogen; promoter; prospective; resistance mechanism; response; therapeutic target; transcription factor; urinary

DESCRIPTION (provided by applicant): Candida albicans is the most common fungal pathogen in humans and the third most common nosocomial infectious agent. Signaling pathways control processes critical for adaptation, survival, and pathogenesis. Our long-term research goal is to understand the roles of signaling pathways in C. albicans survival in response to environmental stress and antifungal drugs. We discovered that transcription factor Sko1 plays a novel role as a major regulator of the cell wall damage response caused by the antifungal drug caspofungin. In addition, we found a conserved role of Sko1 as a regulator of the osmotic stress response. Our objective in this proposal is to identify and functionally characterize the Sko1 transcriptional network underlying the response to successive hyperosmotic stress and caspofungin-induced cell wall damage. Our transcriptional profiling studies uncovered the genetic network underlying Sko1-dependent osmotic stress signaling and caspofungin-induced signaling; however, the direct gene targets remain unknown. Moreover, numerous Sko1-dependent genes have not been functionally characterized. Our central hypothesis is that Sko1 binding to the DNA promoter sequences ATAGCAAT(C/T)A and G(A/T)GATGAGATG confers caspofungin tolerance when cells are pre-exposed to hyperosmotic environments, and Sko1-dependent genes involved in carbohydrate and cation transport are required for adaptive cell growth. This hypothesis is based on three observations. First, our in silico findings show that the aforementioned DNA sequences were enriched in Sko1-dependent genes. Second, strains containing mutations to several Sko1-dependent genes including the carbohydrate transporter HGT6 are hypersensitive to caspofungin. Third, C. albicans wild-type cells pre- treated with sodium chloride have increased tolerance to caspofungin. We propose the following specific aims to test our central hypothesis: 1) To determine the promoter sequences required for Sko1 gene regulation and 2) To determine the role of carbohydrate and cation transporters in the osmotic and cell wall damage stress responses. We will utilize a genomics and high-throughput molecular genetics approach that is cost-effective and time-saving. Caspofungin has limited activity against C. albicans infections in hyperosmotic environments such as the kidneys and urine, the cerebrospinal fluid, and the eyes. Hence, this proposal is innovative in the identification of an adaptive mechanism to successive stress. Moreover, it will provide a framework of genetic targets that can propel development of novel antifungal agents that can be used synergistically with caspofungin. John Jay College (CUNY) is the largest Hispanic-serving institution in the northeastern U.S. and funding of this proposal will expand biomedical research to a student population that currently lacks opportunities in this critical area.

描述（由申请人提供）：白色念珠菌是人类最常见的真菌病原体，也是第三大最常见的医院感染原。信号通路控制对适应、生存和发病机制至关重要的过程。我们的长期研究目标是了解信号通路在白色念珠菌响应环境压力和抗真菌药物的生存中的作用。我们发现转录因子 Sko1 作为抗真菌药物卡泊芬净引起的细胞壁损伤反应的主要调节因子发挥着新的作用。此外，我们发现 Sko1 作为渗透应激反应调节剂的保守作用。我们在本提案中的目标是识别和功能表征 Sko1 转录网络，该网络是对连续高渗应激和卡泊芬净诱导的细胞壁损伤反应的基础。我们的转录谱研究揭示了 Sko1 依赖性渗透应激信号传导和卡泊芬净诱导的信号传导背后的遗传网络；然而，直接的基因目标仍然未知。此外，许多 Sko1 依赖性基因尚未得到功能表征。我们的中心假设是，当细胞预先暴露于高渗环境时，Sko1 与 DNA 启动子序列 ATAGCAAT(C/T)A 和 G(A/T)GATGAGATG 的结合赋予卡泊芬净耐受性，并且 Sko1 依赖性基因参与碳水化合物和阳离子适应性细胞生长需要运输。该假设基于三个观察。首先，我们的计算机研究结果表明，上述 DNA 序列富含 Sko1 依赖性基因。其次，含有多个 Sko1 依赖性基因（包括碳水化合物转运蛋白 HGT6）突变的菌株对卡泊芬净过敏。第三，用氯化钠预处理的白色念珠菌野生型细胞对卡泊芬净的耐受性增加。我们提出以下具体目标来检验我们的中心假设：1）确定 Sko1 基因调控所需的启动子序列；2）确定碳水化合物和阳离子转运蛋白在渗透压和细胞壁损伤应激反应中的作用。我们将利用经济高效且节省时间的基因组学和高通量分子遗传学方法。卡泊芬净在高渗环境（例如肾脏和尿液、脑脊液和眼睛）中对抗白色念珠菌感染的活性有限。因此，该提议在识别连续应激的适应性机制方面具有创新性。此外，它将提供一个遗传靶标框架，可以推动可与卡泊芬净协同使用的新型抗真菌药物的开发。约翰·杰伊学院 (CUNY) 是美国东北部最大的拉美裔服务机构，该提案的资助将把生物医学研究扩展到目前在这一关键领域缺乏机会的学生群体。