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（由申请方提供）：白色念珠菌是人类最常见的真菌病原体，也是第三常见的医院感染因子。信号通路控制着对适应、生存和发病至关重要的过程。我们的长期研究目标是了解信号通路在C。白念珠菌生存的环境压力和抗真菌药物的反应。我们发现，转录因子Sko 1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，我们发现了一个保守的作用Sko 1作为一个调节器的渗透胁迫反应。我们的目标是在这个建议是确定和功能特征的Sko 1转录网络的响应连续高渗胁迫和卡泊芬净诱导的细胞壁损伤。我们的转录谱研究揭示了Sko 1依赖的渗透胁迫信号和卡泊芬净诱导的信号的遗传网络，然而，直接的基因靶点仍然未知。此外，许多Sko 1依赖性基因的功能尚未得到表征。我们的中心假设是，当细胞预先暴露于高渗环境时，Sko 1与DNA启动子序列ATAGCAAT（C/T）A和G（A/T）GATGAGATG结合赋予卡泊芬净耐受性，并且参与碳水化合物和阳离子转运的Sko 1依赖性基因是适应性细胞生长所必需的。这一假设基于三个观察。首先，我们的计算机研究结果表明，上述DNA序列富含Sko 1依赖性基因。第二，含有几个Sko 1依赖性基因（包括碳水化合物转运蛋白HGT 6）突变的菌株对卡泊芬净过敏。第三，C.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验证我们的中心假设：1）确定Sko 1基因调控所需的启动子序列和2）确定碳水化合物和阳离子转运蛋白在渗透和细胞壁损伤应激反应中的作用。我们将利用基因组学和高通量分子遗传学方法，这是成本效益和节省时间。卡泊芬净对C.高渗环境中的白色念珠菌感染，如肾脏和尿液、脑脊液和眼睛。因此，该提议在识别连续压力的适应机制方面具有创新性。此外，它将提供一个遗传靶点的框架，可以推动新的抗真菌药物的开发，这些药物可以与卡泊芬净协同使用。约翰·杰伊学院（纽约市立大学）是美国东北部最大的西班牙裔服务机构，该提案的资助将扩大生物医学研究，目前在这一关键领域缺乏机会的学生群体。