Distinct Modes of Gene Regulation by KDM5

KDM5 的不同基因调控模式

基本信息

批准号：
8994293
负责人：
Julie Secombe
金额：
$ 32.15万
依托单位：
ALBERT EINSTEIN COLLEGE OF MEDICINE, INC
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-01-15 至 2019-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8994293
关键词：
Accounting Affect Alleles Animal Model Animals Behavioral Binding Breast Bypass C-terminal Candidate Disease Gene Cell physiology Chromatin Chromatin Remodeling Factor Clinical Pathology Cognitive Cognitive deficits Colorectal Colorectal Cancer DNA Data Defect Deletion Mutation Development Disease Drosophila genus Drug resistance Family Gene Activation Gene Expression Gene Expression Regulation Gene Targeting Generations Genes Genetic Models Genetic Transcription Genomics Goals Histone Acetylation Histone H3 Human In Vitro Intellectual functioning disability KDM5B gene Knowledge Lead Learning Lysine Malignant Neoplasms Mammalian Cell Mediating Memory Missense Mutation Mutation Nucleosomes Oncogenic Organism Oxidative Stress Pathology Pathway interactions Patients Pattern Phenotype Point Mutation Positioning Attribute Process Protein Family Proteins Public Health Recruitment Activity Regulation Regulator Genes Research Role Tertiary Protein Structure Testing Time Transgenes X-linked intellectual disability Zinc Fingers base cell growth clinically significant fly histone demethylase human disease innovation loss of function mutation malignant breast neoplasm melanoma member mutant novel novel therapeutics overexpression paralogous gene promoter protein protein interaction public health relevance resistance gene therapy development transcription factor tumorigenic

项目摘要

DESCRIPTION (provided by applicant): KDM5 family transcriptional regulators are increasingly recognized as critical players at the interface of development and human disease. Mammalian cells encode four KDM5 paralogs (KDM5A-D), three of which are clinically significant: KDM5A or KDM5B are overexpressed in a number of cancers including breast, colorectal and melanoma, and mutations in KDM5C account for ~3% of X-linked intellectual disability patients. A lack of basic knowledge regarding the mechanisms of KDM5 action has hindered the development of therapies to treat these diseases. The long-term goal of these studies is therefore to dissect the gene- regulatory functions of KDM5 proteins using Drosophila, since the presence of a single KDM5 protein in this organism bypasses the issue of functional redundancy in mammalian cells. Previous data showed that KDM5 proteins can repress transcription via their histone demethylase activity and can activate gene expression by altering histone acetylation. In this proposal, new data demonstrate for the first time that KDM5 also influences gene expression by altering the recruitment of transcription factors to their target promoters. Specifically, KDM5 recruits the oncogenic transcription factor Myc to cell growth gene promoters, and this requires the chromatin-binding PHD motif of KDM5. KDM5 also recruits Foxo to oxidative stress resistance gene promoters, however this occurs in a PHD-independent manner. Based on these data, the first hypothesis of this proposal is that KDM5 affects transcription factor recruitment by more than one mechanism, and that this involves distinct domains of KDM5. Preliminary data also show that the expression of KDM5-Foxo co- regulated targets is reduced in a fly strain harboring an allele associated with severe intellectual disability in humans (kdm5L854F). Because the remaining 12 missense mutations in KDM5C associated with intellectual disability also occur in evolutionarily conserved residues, the second hypothesis is that the corresponding mutations in fly KDM5 will show transcriptional defects. These hypotheses will be tested by pursuing three specific aims: 1) Determine the mechanism by which KDM5 recruits Myc to cell growth genes; 2) Define the mechanism by which KDM5 recruits Foxo to oxidative stress target genes; and 3) Determine the transcriptional and phenotypic defects of kdm5 alleles analogous to human intellectual disability-associated mutations. These analyses are significant because defining how KDM5 functions in context-dependent manner will lead to new strategies for treating malignancies and cognitive phenotypes caused by dysregulation of KDM5 family proteins in humans. The proposal is innovative because it deviates from the current focus on the enzymatic function of lysine demethylase (KDM) proteins by describing two new mechanisms of gene activation by KDM5 that are independent of its enzymatic activity. An additional innovation is the analyses of kdm5 missense alleles in flies that are analogous to mutations found in patients with intellectual disability as a means to dissect the gene- regulatory functions of KDM5.

描述（由申请人提供）： KDM5 家族转录调节因子越来越被认为是发育和人类疾病之间的关键参与者。哺乳动物细胞编码四种 KDM5 旁系同源物 (KDM5A-D)，其中三种具有临床意义：KDM5A 或 KDM5B 在包括乳腺癌、结直肠癌和黑色素瘤在内的多种癌症中过度表达，KDM5C 突变约占 X 连锁智力的 3%。残疾患者。由于缺乏有关 KDM5 作用机制的基础知识，阻碍了治疗这些疾病的疗法的开发。因此，这些研究的长期目标是利用果蝇剖析 KDM5 蛋白的基因调控功能，因为该生物体中单个 KDM5 蛋白的存在绕过了哺乳动物细胞中功能冗余的问题。先前的数据表明，KDM5 蛋白可以通过其组蛋白去甲基化酶活性抑制转录，并可以通过改变组蛋白乙酰化来激活基因表达。在该提案中，新数据首次证明 KDM5 还通过改变转录因子向其目标启动子的募集来影响基因表达。具体来说，KDM5 将致癌转录因子 Myc 招募到细胞生长基因启动子中，这需要 KDM5 的染色质结合 PHD 基序。 KDM5 还将 Foxo 招募到氧化应激抗性基因启动子中，然而这是以不依赖于 PHD 的方式发生的。基于这些数据，该提议的第一个假设是 KDM5 通过多种机制影响转录因子招募，并且这涉及 KDM5 的不同域。初步数据还表明，在含有与人类严重智力障碍相关的等位基因（kdm5L854F）的果蝇品系中，KDM5-Foxo 共同调节靶点的表达降低。由于 KDM5C 中与智力障碍相关的其余 12 个错义突变也发生在进化上保守的残基中，因此第二个假设是果蝇 KDM5 中的相应突变将表现出转录缺陷。这些假设将通过追求三个具体目标来检验：1）确定 KDM5 将 Myc 招募到细胞生长基因的机制； 2）明确KDM5招募Foxo至氧化应激靶基因的机制； 3) 确定 kdm5 等位基因的转录和表型缺陷，类似于人类智力障碍相关突变。这些分析意义重大，因为定义 KDM5 如何以上下文相关的方式发挥作用将导致治疗人类 KDM5 家族蛋白失调引起的恶性肿瘤和认知表型的新策略。该提案具有创新性，因为它通过描述 KDM5 独立于其酶活性的两种新的基因激活机制，偏离了目前对赖氨酸脱甲基酶 (KDM) 蛋白酶功能的关注。另一项创新是对果蝇中 kdm5 错义等位基因的分析，类似于在智力障碍患者中发现的突变，作为剖析 KDM5 基因调控功能的手段。