Role of histone modifying enzymes in regulating alternate active versus silent gene expression in plants

组蛋白修饰酶在调节植物中活性与沉默基因交替表达中的作用

基本信息

批准号：
1913165
负责人：
Vitaly Citovsky
金额：
$ 72万
依托单位：
SUNY at Stony Brook
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-08-01 至 2024-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1913165&HistoricalAwards=false
关键词：
Role histone modifying enzymes regulating

项目摘要

This project addresses a poorly studied, yet fundamental, question of how enzymes that chemically modify chromosome-associated proteins can elicit opposing effects on gene expression, i.e., activating or silencing the gene. A combination of genetic and genomic approaches will be applied in the model plant, Arabidopsis thaliana, to test the idea that these alternate outcomes arise from coordinating the action of distinct enzymes. The research is integrated into educational activities including: research experiences for undergraduate students from two predominantly undergraduate and minority-serving institutions--Hunter College and Lehman College--in New York City; training for high school teachers through a series of seminars and summer workshops offered through Stony Brook's Center for Science and Mathematics Education; and mentoring of a postdoctoral researcher for an independent career in academia, industry, or the Federal government. Post-translational histone modifications are central to gene regulation in all eukaryotic organisms, determining the active or inactive state of the chromatin. These modifications are dynamic, effected by writers and erasers, i.e., histone modifying enzymes that add or remove specific functional groups. Moreover, one histone modification often promotes generation of another, a process termed histone crosstalk, that shapes the histone modification landscape and its transcriptional outcomes. In plants, one major class of important, yet poorly characterized, erasers are histone deubiquitinases, implicated in diverse aspects of the plant life cycle. The study focuses on histone deubiquitinase OTLD1, which is known to deubiquitylate histone H2B, associate with the chromatin mainly by binding to histone H3, and directly interact with another histone modifying enzyme, the histone lysine demethylase KDM1C. OTLD1 is found at the promoter regions of target genes and, fascinatingly, OTLD1 can both repress and activate its direct targets. These findings identify a gap in our understanding: how does deubiquitylation of the same type of histone by the same histone deubiquitinase elicit two opposing effects on transcription of the direct target genes and what is the biological significance of this ability? This question will be addressed by two specific aims: (i) define how association of OTLD1 and KDM1C with different histones variants affects the resulting histone modifications and transcriptional regulation of the target genes, and (ii) discover whether KDM1C and/or OTLD1 are down-regulated via the ubiquitin/proteasome system and study the effects of this regulation on OTLD1/KDM1C-mediated histone modifications and their transcriptional outcomes. The results are expected to advance understanding of new junction in chromatin-level processes leading to transcriptional repression or activation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目解决了一个研究良好但基本的问题，即化学修改染色体相关蛋白的酶如何引起对基因表达的相反作用，即激活或沉默基因。模型植物Thaliana将应用遗传和基因组方法的结合，以测试这些替代结果是由协调不同酶的作用而产生的。这项研究纳入了教育活动，包括：来自两个主要是本科生和少数族裔服务机构的本科生的研究经验 - 猎人学院和雷曼学院 - 纽约市；通过斯托尼·布鲁克（Stony Brook）科学与数学教育中心提供的一系列研讨会和夏季研讨会，对高中教师的培训；并指导学术界，工业或联邦政府独立职业的博士后研究员。翻译后组蛋白的修饰对于所有真核生物中的基因调节都是至关重要的，确定了染色质的活性或不活性状态。这些修饰是动态的，由作家和橡皮擦，即组蛋白修改添加或删除特定功能组的酶的组蛋白。此外，一种组蛋白的修饰通常会促进另一个组蛋白的产生，这是一种称为组蛋白串扰的过程，该过程塑造了组蛋白修饰景观及其转录结果。在植物中，一类重要但特征较差的主要类别是组蛋白去泛素酶，涉及植物生命周期的各个方面。该研究的重点是组蛋白去泛素酶OTLD1，该酶otld1已知是去泛素化组蛋白H2b的，它主要通过与组蛋白H3结合，并与另一种组蛋白修饰酶，组蛋白赖氨酸赖氨酸脱甲基酶KDM1C与染色质相关。 OTLD1在靶基因的启动子区域中发现，并且令人着迷的是，OTLD1既可以抑制和激活其直接靶标。这些发现在我们的理解中确定了差距：相同的组蛋白去泛素酶对相同类型的组蛋白的去泛素化如何引起对直接靶基因转录的两种相反影响？这种能力的生物学意义是什么？ This question will be addressed by two specific aims: (i) define how association of OTLD1 and KDM1C with different histones variants affects the resulting histone modifications and transcriptional regulation of the target genes, and (ii) discover whether KDM1C and/or OTLD1 are down-regulated via the ubiquitin/proteasome system and study the effects of this regulation on OTLD1/KDM1C-mediated histone修改及其转录结果。预计结果将在染色质级过程中提高对新连接的理解，从而导致转录抑制或激活。该奖项反映了NSF的法定任务，并且使用基金会的知识分子优点和更广泛的影响评估标准，认为值得通过评估值得支持。