Coordinate gene expression via nucleosome remodeling and chromosomal looping

通过核小体重塑和染色体环协调基因表达

基本信息

批准号：
8692551
负责人：
Schahram Akbarian
金额：
$ 38.16万
依托单位：
UNIVERSITY OF CALIFORNIA-IRVINE
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-07-01 至 2017-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8692551
关键词：
ATP Hydrolysis ATP phosphohydrolase Acetylation Adult Affect Animals Area Attention Autistic Disorder Behavior Biological Assay ChIP-seq Chromatin Chromatin Loop Chromatin Structure Chromosomes Chronic Cocaine Complex DNA DNA Methylation DNA Modification Process Data Development Disease Distal Dominant-Negative Mutation Epigenetic Process Event FarGo Gene Expression Gene Expression Regulation Genes Genetic Enhancer Element Genomic DNA Human In Vitro Intellectual functioning disability Investigation Knock-out Malignant Neoplasms Memory Memory impairment Mental Retardation Molecular Conformation Molecular Profiling Mus Mutant Strains Mice Mutate Mutation NURF Nervous system structure Neuroglia Neurons Neurosciences Nucleosomes Phase Physiology Play Positioning Attribute Regulation Research Proposals Role Seminal Services Structure Substance Use Disorder Synapses Syndrome Techniques Testing Time Transcriptional Silencer Elements Transgenic Organisms Viral Work cocaine use cognitive function drug seeking behavior exome sequencing flexibility histone modification innovation long term memory memory process next generation sequencing precursor cell preference promoter protein complex public health relevance tool transcriptome sequencing virus genetics yeast genetics

项目摘要

DESCRIPTION (provided by applicant): In this proposal, we examine for the first time an epigenetic mechanism called nucleosome remodeling and how it regulates coordinate gene expression required for cocaine-induced memory formation. The nucleosome is the repeating unit of chromatin and fundamental to the compaction of genomic DNA. Nucleosome remodeling complexes modify chromatin structure and regulate expression by repositioning nucleosomes at the promoters of genes. Recent human exome sequencing studies have identified subunits of the polymorphic BAF complexes (mammalian SWI/SNF nucleosome remodeling complex) that are frequently mutated in sporadic mental retardation and sporadic autism. Moreover, de novo mutations in various subunits of neuron-specific Brg1- associated factor (nBAF) nucleosome remodeling complex have been implicated in Coffin-Siris and Nicolaides-Baraitser syndromes, both of which are associated with intellectual disability. Together, these studies suggest that nBAF function is necessary for normal cognitive function. Although an important topic in other fields (e.g. yeast genetics and cancer), nucleosome remodeling has received little attention in neuroscience. However, a major discovery was the identification of the first neuron-specific BAF complex, which was subsequently found to regulate gene expression required for the conversion of precursor cells into terminally differentiated neurons. Importantly, the nBAF complex has a subunit, BAF53b, which participates in making nBAF neuron- specific. This subunit is both neuron and nBAF complex specific, making it an ideal target for investigating the potential contributions of nBAF to synaptic physiology and behavior. Building on this point, we propose to test the hypothesis that BAF53b, after playing a key role in neuronal fate decisions during development, continues to regulate gene expression and does so in a manner critical to adult memory processes as well as cocaine-induced memory formation. We propose three specific aims to test this hypothesis. In Specific Aim 1, we will use genetically modified mice to examine the role of BAF53b in long-term memory. In Specific Aim 2, we will use next generation sequencing, RNA seq, and chromosomal conformation capture 3C to determine what gene expression profiles are being regulated by BAF53b and chromatin looping during memory consolidation. In Specific Aim 3, we will determine how cocaine regulates coordinate gene expression via BAF53b-dependent nucleosome remodeling and chromatin looping during cocaine-induced memory formation. Together, the work under these specific aims will elucidate the contributions of BAF53b and the nBAF complex in general, to memory processes, and more specifically to cocaine-induced memory formation as a precursor event to persistent drug-seeking behavior.

描述（由申请人提供）：在本提案中，我们首次研究了一种称为核小体重塑的表观遗传机制，以及它如何调节可卡因诱导的记忆形成所需的协调基因表达。核小体是染色质的重复单位，是基因组 DNA 压缩的基础。核小体重塑复合物通过在基因启动子处重新定位核小体来改变染色质结构并调节表达。最近的人类外显子组测序研究已经确定了多态性 BAF 复合物（哺乳动物 SWI/SNF 核小体重塑复合物）的亚基，这些亚基在散发性智力低下和散发性自闭症中经常发生突变。此外，神经元特异性 Brg1 相关因子 (nBAF) 核小体重塑复合物的各个亚基的从头突变与 Coffin-Siris 和 Nicolaides-Baraitser 综合征有关，这两种综合征都与智力障碍有关。总之，这些研究表明 nBAF 功能对于正常认知功能是必需的。尽管核小体重塑在其他领域（例如酵母遗传学和癌症）是一个重要的话题，但在神经科学中却很少受到关注。然而，一项重大发现是第一个神经元特异性 BAF 复合物的鉴定，随后发现该复合物可以调节前体细胞转化为终末分化神经元所需的基因表达。重要的是，nBAF 复合体有一个亚基 BAF53b，它参与使 nBAF 神经元特异性。该亚基是神经元和 nBAF 复合体特异性的，使其成为研究 nBAF 对突触生理学和行为的潜在贡献的理想目标。基于这一点，我们建议检验以下假设：BAF53b 在发育过程中的神经元命运决定中发挥关键作用后，继续调节基因表达，并以对成人记忆过程以及可卡因诱导的记忆形成至关重要的方式进行调节。我们提出了三个具体目标来检验这一假设。在具体目标 1 中，我们将使用转基因小鼠来检查 BAF53b 在长期记忆中的作用。在具体目标 2 中，我们将使用下一代测序、RNA seq 和染色体构象捕获 3C 来确定哪些基因表达谱在记忆巩固过程中受到 BAF53b 和染色质循环的调节。在具体目标 3 中，我们将确定可卡因如何在可卡因诱导的记忆形成过程中通过 BAF53b 依赖性核小体重塑和染色质循环来调节协调基因表达。这些具体目标下的工作将共同阐明 BAF53b 和 nBAF 复合物对记忆过程的总体贡献，更具体地说，对可卡因诱导的记忆形成作为持续性药物寻求行为的前兆事件的贡献。