Small molecule inhibitors of a Candida albicans histone modifying enzyme

白色念珠菌组蛋白修饰酶的小分子抑制剂

基本信息

批准号：
8204934
负责人：
Jessica Ramos Lopes da Rosa-Spiegler
金额：
$ 1.64万
依托单位：
UNIV OF MASSACHUSETTS MED SCH WORCESTER
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-01-20 至 2012-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8204934
关键词：
Acetylation Acquired Immunodeficiency Syndrome Antibodies Antifungal Agents Biochemical Biological Assay Candida Candida albicans Candidiasis Cells Chemicals Development Enzymatic Biochemistry Enzyme-Linked Immunosorbent Assay Enzymes Eukaryota Eukaryotic Cell Family Funding Gene Expression Genes Genetic Transcription Genome Stability Goals Growth Health Histone Acetylation Histone H3 Histones Homologous Gene Human Immunocompromised Host In Vitro Individual Infection Laboratories Laboratory Research Lysine Mammalian Cell Massachusetts Measures Microbial Genetics Modeling Mus Mutagens Mycoses Pathogenesis Pathogenicity Pathology Patients Phagosomes Physiological Predisposition Proteins Protocols documentation Reactive Oxygen Species Recombinants Research Resistance Role Saccharomyces cerevisiae Saccharomycetales Screening procedure Stress Systemic infection Testing Therapeutic Therapeutic Intervention Tissues Toxic effect Training Universities Virulence Virulence Factors Yeasts base combat fungus high throughput screening histone acetyltransferase histone modification in vivo inhibitor/antagonist killings macrophage medical schools microbial mortality mutant novel novel therapeutic intervention pathogen pre-doctoral research study response small molecule small molecule libraries

项目摘要

DESCRIPTION (provided by applicant): Candida albicans is a widespread human fungal pathogen that causes high rates of mortality during systemic infections, and is particularly dangerous for immunocompromised AIDS patients. Because fungi such as C. albicans are eukaryotes, development of antifungal therapeutics that is non-toxic to humans is often challenging. Recently, RU109 was identified as the enzyme that catalyzes acetylation of histone H3 lysine 56 in the budding yeast, Saccharomyces cerevisiae. Mutants lacking Rtt109 are viable, but is slow growing and extremely sensitive to genotoxic agents. Notably, no close homologs of RTT109 genes are found outside of fungal species, and Rtt109 proteins do not contain signature residues found in the other families of histone acetyltransferase (HAT) enzymes. Therefore, we hypothesize that we can identify small molecules that inhibit Rtt109 function without substantial effect on other HAT enzymes. Furthermore, as Rtt109 homologs are restricted to fungi, they represent promising targets for small molecule therapeutic intervention with minimal toxicity for mammalian hosts. In this revised proposal, I aim to elucidate the role of Rtt109 in pathogenesis by C. albicans and to discover Rtt109 inhibitory compounds that are efficient in vivo. I have confirmed the functional conservation of the C. albicans Rtt109 enzyme, because it is essential for H3K56 acetylation and for resistance to genotoxic agents. I will test whether C. albicans rtt109-/- mutants display increased sensitivity to macrophages in vitro and whether they are pathogenic in the established murine candidiasis model. Second, I will screen a library of small molecules for inhibition of histone acetylation by Rtt109 in vitro. To do this, we have developed a high-throughput assay which will allow quantitative assessment of histone acetylation by purified, recombinant Rtt109, detected with an anti-H3K56-acetyl antibody. Finally, I will begin to characterize candidate compounds that are non-toxic to mammalian cells for their effects on histone modification in Candida, and on pathogenesis in mice. PUBLIC HEALTH RELEVANCE: Candida albicans is a pathogenic fungus that is particularly dangerous to immunocompromised individuals, including AIDS patients. Recently, a new enzyme was discovered that is important for normal growth of fungi. I propose to study how this enzyme contributes to growth and virulence of Candida albicans. I will also identify compounds that inhibit this enzyme, with the goal of developing new therapeutic approaches to combat fungal infections.

描述（由申请人提供）：白色念珠菌是一种广泛存在的人类真菌病原体，在全身感染期间导致高死亡率，对于免疫功能低下的艾滋病患者尤其危险。由于白色念珠菌等真菌是真核生物，因此开发对人类无毒的抗真菌疗法通常具有挑战性。最近，RU109 被鉴定为在芽殖酵母（酿酒酵母）中催化组蛋白 H3 赖氨酸 56 乙酰化的酶。缺乏 Rtt109 的突变体是可行的，但生长缓慢并且对基因毒性剂极其敏感。值得注意的是，在真菌物种之外没有发现 RTT109 基因的密切同源物，并且 Rtt109 蛋白不包含在其他组蛋白乙酰转移酶 (HAT) 家族中发现的特征残基。因此，我们假设我们可以鉴定出抑制 Rtt109 功能的小分子，而不会对其他 HAT 酶产生实质性影响。此外，由于 Rtt109 同源物仅限于真菌，因此它们代表了小分子治疗干预的有希望的目标，并且对哺乳动物宿主的毒性最小。在这个修订后的提案中，我的目标是阐明 Rtt109 在白色念珠菌发病机制中的作用，并发现在体内有效的 Rtt109 抑制化合物。我已经证实了白色念珠菌 Rtt109 酶的功能保守性，因为它对于 H3K56 乙酰化和对基因毒性剂的抵抗力至关重要。我将测试白色念珠菌 rtt109-/- 突变体是否在体外表现出对巨噬细胞的敏感性增加，以及它们在已建立的鼠念珠菌病模型中是否具有致病性。其次，我将在体外筛选 Rtt109 抑制组蛋白乙酰化的小分子文库。为此，我们开发了一种高通量测定法，可以通过纯化的重组 Rtt109 定量评估组蛋白乙酰化，并使用抗 H3K56-乙酰基抗体进行检测。最后，我将开始表征对哺乳动物细胞无毒的候选化合物，因为它们对念珠菌的组蛋白修饰和小鼠的发病机制有影响。公共卫生相关性：白色念珠菌是一种致病真菌，对免疫功能低下的个体（包括艾滋病患者）尤其危险。最近，发现了一种对真菌正常生长很重要的新酶。我建议研究这种酶如何促进白色念珠菌的生长和毒力。我还将鉴定抑制这种酶的化合物，目标是开发新的治疗方法来对抗真菌感染。