Regulation of chromatin and genome stability by the H4K20 methyltransferase SMYD5

H4K20 甲基转移酶 SMYD5 对染色质和基因组稳定性的调节

• 批准号: 9238605
• 负责人: Benjamin L Kidder
• 金额: $ 24.53万
• 依托单位: WAYNE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-03-10 至 2019-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9238605
• 关键词: Academia; Address; Advisory Committees; Angelman Syndrome; Bioinformatics; Biological; Cancer Biology; Cell Differentiation process; Cell physiology; Cells; ChIP-seq; Chromatin; Chromatin Structure; Chromosome Condensation; Chromosome abnormality; Communication; Computational Biology; Computer Analysis; DNA; DNA Sequence; DNA Transposable Elements; DNA sequencing; DNase I hypersensitive sites sequencing; Data Analyses; Defense Mechanisms; Deposition; Development; Development Plans; Educational process of instructing; Elements; Epigenetic Process; Exhibits; Experimental Designs; Facioscapulohumeral Muscular Dystrophy; Friedreich Ataxia; Gene Expression; Gene Expression Profile; Gene Expression Regulation; Genes; Genetic Transcription; Genome; Genome Stability; Goals; Heterochromatin; Histone H4; Histones; Human; In Vitro; K-Series Research Career Programs; Karyotype determination procedure; Knockout Mice; Laboratories; Lysine; Maintenance; Malignant Neoplasms; Mass Spectrum Analysis; Mediating; Mentored Clinical Scientist Development Award (K08); Mentors; Mentorship; Methods; Methylation; Methyltransferase; Mus; Mutant Strains Mice; National Heart, Lung, and Blood Institute; Patients; Phase; Phenotype; Physical condensation; Play; Positioning Attribute; Postdoctoral Fellow; Prader-Willi Syndrome; Proteins; RNA; RNA immunoprecipitation sequencing; Recruitment Activity; Regulation; Repetitive Sequence; Repression; Research; Research Personnel; Research Proposals; Research Training; Role; Scientist; Students; Technology; Testing; Training; Training Programs; Transcript; Tumor Suppressor Proteins; United States National Institutes of Health; Untranslated RNA; Western Blotting; Work; cancer cell; career; cell transformation; cohesin; embryonic stem cell; epigenetic regulation; experience; experimental study; gene repression; genome integrity; histone methyltransferase; human disease; in vivo; insight; meetings; metaplastic cell transformation; nervous system disorder; next generation sequencing; novel; pluripotency; prevent; self-renewal; skill acquisition; skills; student training; survival outcome; symposium; transcriptome sequencing; tumor; tumorigenesis; whole genome

 DESCRIPTION (provided by applicant): The candidate is currently a Research Fellow in the laboratory of Dr. Keji Zhao at NHLBI. The proposal describes a research and training program that will support the goal of transitioning the proposed research to an independent laboratory. The Career Development Award will provide a platform for continued training at NIH/NHLBI in support of the projects described in this proposal. Specific activities that will be supported include the formation of an Advisory Committee consisting of several scientists who have extensive scientific experience in fields related to work proposed in this application. These advisors also have significant experience in mentoring postdocs, of which many have obtained independent investigator positions in academia. This panel will be helpful in guiding my training and career goals. The mentored phase of the Career Development Plan will consist of continued training in bioinformatics and computational analysis, which is essential for application of next-generation sequencing technologies (e.g. RNA- Seq, ChIP-Seq), experimental training in genome integrity and cancer biology at the NIH to support the aims presented in this application, and development of mentorship skills through training of students. Specific mentoring activities during the Intramural phase will include training and mentoring a postbaccalaureate student in the scientific method including teaching hypothesis formation, experimental design, data analysis, and interpretation, as well as communication skills through public presentation of results. I will also work directly with a bioinformatics postdoc in Dr. Zhaos lab to develop skills in addressing biological questions through the use of computational biology. The intramural phase of this proposal will allow continued development of skills required to become a successful investigator such as communication skills, including presentation of results obtained from experiments proposed in the Research Plan at local and national conferences and meetings on topics related to the work described in this proposal. The goal of the research proposal is to investigate the role of SMYD5, a histone H4 lysine 20 histone methyltransferase, in regulating heterochromatin formation and genome stability in ES cells and during development. Dysregulation of heterochromatin leads to several human diseases including cancer and neurological disorders such as Friedreich's ataxia, Angelman syndrome, and Prader-Willi syndrome, and facioscapulohumeral muscular dystrophy. Heterochromatin plays a critical role in gene expression during development and differentiation, and is also involved in maintaining genome integrity by stabilizing repetitive DNA sequences throughout the genome. H4K20 methylation marks have been implicated in having diverse cellular functions including the formation of heterochromatin, gene regulation and repression of transcription, chromosome condensation, and genome stability. I recently discovered that SMYD5 is a novel mammalian H4K20 methyltransferase that deposits H4K20me3 marks at LTR/LINE repetitive DNA elements. Loss of SMYD5 results in decreased levels of heterochromatin constituents and causes chromosome aberrations and cellular transformation during in vitro ES cell differentiation. The expression signature of SMYD5-depleted transformed cells is correlated with a number of human cancers and can predict patient survival outcome. Despite these preliminary findings, our understanding about the role of SMYD5 in regulating heterochromatin formation and maintenance, and genome stability, is very limited. The experiments described in this proposal will clarify the role of SMYD5 in promoting chromatin compaction and controlling genome stability in ES cells and during development. I hypothesize that SMYD5 promotes chromatin compaction by regulating H4K20me3 levels and by recruiting heterochromatin proteins. I propose to define the role for SMYD5 in regulating heterochromatin formation by evaluating the chromatin accessibility of SMYD5 depleted ES cells and by investigating interactions between SMYD5 and heterochromatin proteins and long non-coding RNAs (lncRNAs) (Aim 1). I also hypothesize that SMYD5 acts as a tumor suppressor by regulating genome stability. I propose to cross SMYD5 knockout mice (generated for this project) with Suv420h2 deficient mice (another H4K20me3 methyltransferase) to further reduce H4K20me3 levels, and to evaluate tumor formation and chromosomal aberrations in cells from mutant mice (Aim 2). I also hypothesize that SMYD5 regulates gene expression in ES cells by silencing LTR elements nearby known genes, by interacting with transcriptional regulators, and by regulating a novel bivalent chromatin structure marked by co-occupancy of activating (H3K4me3) and repressing (H4K20me3) histone marks (Aim 3). Altogether, these studies will provide greater insight into the epigenetic role of a novel histone methyltransferase, SMYD5, in regulating heterochromatin formation and genome stability in ES cells and during differentiation.

 描述（由申请人提供）：候选人目前是NHLBI的Keji Zhao博士实验室的研究员。该提案描述了一项研究和培训计划，该计划将支持将拟议研究转移到独立实验室的目标。职业发展奖将为NIH/NHLBI提供一个继续培训的平台，以支持本提案中描述的项目。将得到支持的具体活动包括成立一个咨询委员会，由在与本申请所提议的工作有关的领域具有广泛科学经验的若干科学家组成。这些顾问在指导博士后方面也有丰富的经验，其中许多人在学术界获得了独立调查员的职位。这个小组将有助于指导我的培训和职业目标。职业发展计划的指导阶段将包括生物信息学和计算分析方面的持续培训，这对于下一代测序技术（例如RNA-Seq，ChIP-Seq）的应用至关重要，在NIH进行基因组完整性和癌症生物学方面的实验培训，以支持本申请中提出的目标，并通过培训学生发展指导技能。在校内阶段的具体指导活动将包括培训和指导一个学士后的学生在科学方法，包括教学假设的形成，实验设计，数据分析和解释，以及通过结果的公开演示的沟通技巧。我还将直接与赵博士实验室的生物信息学博士后合作，通过使用计算生物学来发展解决生物学问题的技能。本提案的内部阶段将允许继续发展成为成功的研究者所需的技能，如沟通技能，包括在地方和国家会议上介绍研究计划中提出的实验结果，以及与本提案所述工作相关的主题。该研究提案的目标是研究SMYD 5（一种组蛋白H4赖氨酸20组蛋白甲基转移酶）在ES细胞和发育过程中调节异染色质形成和基因组稳定性的作用。异染色质的失调导致几种人类疾病，包括癌症和神经障碍，如弗里德赖希共济失调、安格尔曼综合征和普拉德-威利综合征，以及面肩肱型肌营养不良。异染色质在发育和分化期间的基因表达中起关键作用，并且还通过稳定整个基因组中的重复DNA序列来参与维持基因组完整性。H4 K20甲基化标记涉及具有多种细胞功能，包括异染色质的形成、基因调控和转录抑制、染色体浓缩和基因组稳定性。我最近发现SMYD 5是一种新的哺乳动物H4 K20甲基转移酶，在LTR/LINE重复DNA元件上沉积H4 K20 me 3标记。SMYD 5的缺失导致异染色质成分水平降低，并在体外ES细胞分化期间引起染色体畸变和细胞转化。SMYD 5耗尽的转化细胞的表达特征与许多人类癌症相关，并且可以预测患者的生存结果。尽管有这些初步的发现，我们对SMYD 5在调节异染色质形成和维持以及基因组稳定性中的作用的理解非常有限。本提案中描述的实验将阐明SMYD 5在ES细胞和发育过程中促进染色质致密化和控制基因组稳定性的作用。我推测SMYD 5通过调节H4 K20 me 3水平和募集异染色质蛋白来促进染色质致密化。我建议通过评估SMYD 5缺失ES细胞的染色质可及性以及通过研究SMYD 5与异染色质蛋白和长链非编码RNA（lncRNA）之间的相互作用来确定SMYD 5在调节异染色质形成中的作用（目的1）。我还假设SMYD 5通过调节基因组稳定性作为肿瘤抑制因子。我建议将SMYD 5敲除小鼠（为本项目生成）与Suv 420 h2缺陷小鼠（另一种H4 K20 me 3甲基转移酶）杂交，以进一步降低H4 K20 me 3水平，并评估突变小鼠细胞中的肿瘤形成和染色体畸变（目的2）。我还假设SMYD 5通过沉默已知基因附近的LTR元件，通过与转录调节因子相互作用，以及通过调节由激活（H3 K4 me 3）和抑制（H4 K20 me 3）组蛋白标记（Aim 3）共同占据标记的新型二价染色质结构来调节ES细胞中的基因表达。总之，这些研究将提供更深入的了解一种新的组蛋白甲基转移酶，SMYD 5，在调节异染色质的形成和基因组稳定性在ES细胞和分化过程中的表观遗传作用。