Probing organismal proteostasis through the response to intracellular infection

通过对细胞内感染的反应探索机体蛋白质稳态

• 批准号: 9353488
• 负责人: Emily R Troemel
• 金额: $ 38.75万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-30 至 2017-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9353488
• 关键词: Aging; Alzheimer' s Disease; Amyotrophic Lateral Sclerosis; Animals; Binding; Biochemical; Boxing; Budgets; CUL1 gene; Caenorhabditis elegans; Caring; Cells; Complex; Cullin Proteins; Data; Defect; Degenerative Disorder; Degradation Pathway; Disease; F Box Domain; Gene Expression; Genes; Genetic; Genetic Epistasis; Genetic Screening; Genetic Transcription; Glutamine; Goals; Growth; Health; Healthcare; Healthcare Systems; Homeostasis; Human; Huntington Disease; Immune response; Infection; Intestines; Lead; Ligase; Maintenance; Mediating; Methods; Microbe; Microsporidia; Molecular; Monitor; Nematoda; Neurodegenerative Disorders; Outcome; Parkinson Disease; Pathway interactions; Patient Care; Patients; Proteasome Inhibition; Proteins; Proteomics; RNA Interference; RNA Viruses; Research; Resistance; Role; Signal Pathway; Source; Stress; Structure; Testing; Tissues; Ubiquitination; Up-Regulation; Virus; age related; base; coping; improved; innovation; insight; mutant; novel; novel strategies; novel therapeutics; pathogen; polyglutamine; pressure; protein aggregate; protein misfolding; response; stressor; transcriptome sequencing; ubiquitin ligase; ubiquitin-protein ligase

 DESCRIPTION (provided by applicant): Maintenance of protein homeostasis, or proteostasis, is critical for health. Proteostasis is perturbed in several aging-related diseases including neurodegenerative diseases like Alzheimer's, Parkinson's, and Huntington's diseases. Caring for patients with these diseases is consuming an increasing fraction of our health care budget. Strikingly, care for Alzheimer's patients alone is responsible for $226 billion in spending per year, and no treatments are available. Thus, new approaches are needed. One such approach involves leveraging the host/pathogen response to infection with intracellular microbes. Our long-term goal is to dissect the mechanisms by which host cells upregulate proteostasis pathways to cope with the increased burden of intracellular infection and replication. Closing this gap in our understanding will provide new insights about proteostasis, and could provide novel treatments for neurodegenerative diseases. Our central hypothesis is that hosts can sense the effects of intracellular infection and increase proteostasis capacity to cope with this increased burden. The objective here is to determine the mechanisms by which the nematode C. elegans upregulates ubiquitin ligase components in response to infection by a natural intracellular microbe that belongs to the microsporidia phylum. Microsporidia commonly infect all animals including humans, and can replicate to very high levels without causing overt effects on the host, likely due to host compensatory mechanisms. Our recent findings indicate that C. elegans upregulates ubiquitin ligase components in response to diverse intracellular infections including microsporidia and virus (Bakowski et al 2014). In unpublished data we have isolated mutants defective in an F-box-related gene (fbxr-1) that constitutively express these ubiquitin ligase components. fbxr-1 mutants have increased pathogen resistance, as well as greatly enhanced thermotolerance and reduced levels of aggregated proteins, indicating improved proteostasis capacity. We hypothesize that C. elegans increases transcription of Skp-Cullin-F-box (SCF) ubiquitin ligase components in order to target misfolded proteins for ubiquitination and destruction, increasing tolerance of proteotoxic insults. In Specific Aim 1 we will determine where the Cullin, as well as its upstream negative regulator FBXR-1 act to regulate thermotolerance. We also will perform structure/function analysis on the Cullin to test the hypothesis that it is part of a multi-subunit SCF ubiquitin ligase component. In Specific Aim 2 we will identify these other SCF ligase components using genetic and biochemical approaches. In Specific Aim 3 we will identify new components of the FBXR-1/Cullin pathway using RNAseq analysis, genetic epistasis, and a forward genetic screen. In Specific Aim 4 we will determine where and when FBXR-1 regulates levels of protein aggregates. This approach is innovative because it leverages the host response to obligate intracellular infection to understand how proteostasis can be improved. The proposed research is significant because it could lead to new treatments for diseases of compromised proteostasis, such as Alzheimer's disease.

 描述（由适用提供）：维持蛋白质稳态或蛋白质的维持对健康至关重要。在几种与衰老有关的疾病中，包括神经退行性疾病，如阿尔茨海默氏症，帕金森氏症和亨廷顿的疾病，都受到蛋白质的干扰。照顾这些疾病的患者正在消耗越来越多的医疗保健预算。令人惊讶的是，仅对阿尔茨海默氏症患者的护理负责每年支出2260亿美元，并且没有治疗。那是需要新的方法。一种这样的方法涉及利用细胞内微生物感染的宿主/病原体反应。我们的长期目标是剖析宿主细胞上调蛋白质的途径以应对细胞内感染和复制增加的机制。关闭这个 我们的理解差距将提供有关蛋白质症的新见解，并可以为神经退行性疾病提供新的治疗方法。我们的中心假设是，宿主可以感觉到细胞内感染的影响并增加蛋白质的能力以应对这种增加的伯嫩。这里的目的是确定线虫C.秀丽隐杆线虫上调泛素连接酶成分的机制，以响应属于微孢子虫的天然细胞内微生物感染。微孢子虫通常感染了包括人类在内的所有动物，并且可以复制至非常高的水平，而不会对宿主产生明显的影响，这可能是由于宿主补偿机制所致。我们最近的发现表明，秀丽隐杆线虫在响应于包括微孢子虫和病毒在内的潜水细胞内感染的响应中上调泛素连接酶成分（Bakowski等，2014）。在未发表的数据中，我们在与F-box相关的基因（FBXR-1）中有缺陷的分离突变体，该基因（FBXR-1）组成性地表达了这些泛素连接酶成分。 FBXR-1突变体具有增强的病原体耐药性，并且大大增强了耐热性和骨料蛋白水平降低，表明蛋白质量的能力提高。我们假设秀丽隐杆线虫增加了SKP库蛋白 - F-box（SCF）泛素连接酶成分的转录，以靶向错误折叠的蛋白质以用于泛素化和破坏。我们还将对Cullin进行结构/功能分析，以测试它是多支亚基SCF泛素连接酶成分的一部分的假设。在特定目标2中，我们将使用遗传和生化方法鉴定这些其他SCF连接酶成分。特定目标3我们将使用RNASEQ分析，遗传性遗传和正向遗传筛选来确定FBXR-1/Cullin途径的新组件。在特定目标4中，我们将确定FBXR-1调节蛋白质聚集体的水平。这种方法具有创新性，因为它利用宿主对义务细胞内感染的反应，以了解如何改善蛋白质的抑制作用。拟议的研究之所以重要，是因为它可能导致对受损蛋白质症（例如阿尔茨海默氏病）疾病的新治疗方法。