权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Genetic and Molecular Studies of Drosophila Chromatin Remodeling Factors

果蝇染色质重塑因子的遗传和分子研究

基本信息

批准号：
7320281
负责人：
JOHN W. TAMKUN
金额：
$ 29.81万
依托单位：
UNIVERSITY OF CALIFORNIA SANTA CRUZ
依托单位国家：
美国
项目类别：
财政年份：
1993
资助国家：
美国
起止时间：
1993-08-01 至 2009-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7320281
关键词：
ASCL1 gene ATP phosphohydrolase Address Affect Animal Model Binding Biological Models Biological Response Modifiers Catalytic Domain Chromatin Chromatin Remodeling Factor Chromatin Structure Chromosome Structures Chromosomes Complex DNA Defect Development Disease Disruption Dominant-Negative Mutation Drosophila genus Drosophila melanogaster Engineering Enzymes Eukaryota Eukaryotic Cell Family Gene Expression Genes Genetic Genetic Screening Genetic Transcription Goals Higher Order Chromatin Structure Histone H1 Histone H1(s)Histones Homeobox Genes Human ISWI Laboratories Learning Light Maintenance Malignant Neoplasms Maps Methylation Modification Molecular Molecular Genetics Mutation Nucleosomes Organism Play Process Proteins RNA Interference RNA Polymerase II Regulation Repression Research Rhabdoid Tumor Role SWI2/SNF2 Site Structure TXN gene Tail Testing Transcriptional Activation brahma chromatin remodeling gene repression genetic regulatory protein histone methyltransferase human disease in vivo leukemia loss of function malignant breast neoplasm member mutant novel transcription factor

项目摘要

Nucleosomes and other components of chromatin act as potent repressers of eukaryotic transcription by blocking the access of transcription factors and other regulatory proteins to DNA. Chromatin repression is regulated via two general mechanisms: ATP-dependent chromatin remodeling and the covalent modification of nucleosomal histones. The disruption of these processes leads to a variety of human diseases, including cancer. In spite of tremendous progress toward determining the mechanism of action of chromatin- remodeling factors and histone-modifying enzymes, much remains to be learned about their roles in eukaryotic transcription and human disease. Recent studies have suggested that chromatin-remodeling factors can regulate higher-order chromatin structure, but their role in this process remains poorly understood. To address these important issues, our laboratory uses Drosophila melanogaster as a model system to study three different chromatin-remodeling factors: BRM, KIS-L and ISWI. We recently found that BRM and KIS-L play global roles in transcription by RNA Polymerase II. To determine the precise roles of BRM and KIS-L in transcription, we will characterize defects resulting from their loss of function and map the regions of active genes with which they interact in vivo. We will also examine whether the site-specific methylation of histone tails affects the ability of BRM or KIS-L to interact with their chromatin substrates. Unlike BRM and KIS-L, ISWI plays a global role in chromatin compaction and transcriptional repression, possibly by promoting the association of the linker histone H1 with chromatin. To test this hypothesis, we will characterize defects in chromosome structure resulting from the loss of ISWIfunction and investigate the consequences of reducing histone H1 function using RNAi and engineered dominant-negative mutations. To identify other factors involved in the regulation of higher-order chromatin structure, we will screen for mutations that cause chromosome defects similar to those observed in ISWI mutants. By simultaneously studying three different chromatin-remodeling factors in a single organism, we will gain a much better understanding of their roles in transcription and other processes. Counterparts of Drosophila chromatin-remodeling factors - including BRM,KIS-L and ISWI - are present in humans, where they play highly conserved roles in gene expression and development. Mutations in these factors are associated with a variety of cancers, including rhabdoid tumors, breast cancer, and leukemias. Our studies of chromatin-remodeling factors in a genetic model organism should therefore shed light on the molecular mechanisms underlying these human cancers and other diseases.

核小体和染色质的其他组分作为真核生物转录的有效阻遏物，阻断转录因子和其他调节蛋白进入DNA。染色质阻遏是通过两种一般机制调节：ATP依赖的染色质重塑和共价修饰核小体组蛋白这些过程的中断导致各种人类疾病，包括癌尽管在确定染色质的作用机制方面取得了巨大进展，重塑因子和组蛋白修饰酶，还有很多关于他们的作用，真核生物转录和人类疾病。最近的研究表明，染色质重塑因子可以调节高级染色质结构，但它们在这一过程中的作用仍然很差明白为了解决这些重要问题，我们的实验室使用果蝇作为模型系统研究三种不同的染色质重塑因子：BRM，KIS-L和ISWI。我们最近发现， BRM和KIS-L通过RNA聚合酶II在转录中发挥全局作用。为了确定 BRM和KIS-L在转录中的作用，我们将描述其功能丧失所导致的缺陷，并绘制其基因组图谱。与它们在体内相互作用的活性基因区域。我们亦会研究个别地盘的组蛋白尾部的甲基化影响BRM或KIS-L与其染色质底物相互作用的能力。与BRM和KIS-L不同，ISWI在染色质致密化和转录抑制中发挥全局作用，可能通过促进连接体组蛋白H1与染色质的结合。为了验证这个假设，我们将表征ISWI功能丧失导致的染色体结构缺陷，并研究使用RNAi和工程显性负突变降低组蛋白H1功能的后果。到确定其他参与调控高阶染色质结构的因素，我们将筛选这些突变导致与ISWI突变体中观察到的类似的染色体缺陷。通过同时研究三种不同的染色质重塑因子在一个单一的有机体，我们将获得更好的理解它们在转录和其他过程中的作用。果蝇染色质重塑因子的对应物-包括BRM，KIS-L和ISWI -存在于在人类中，它们在基因表达和发育中发挥高度保守的作用。这些基因突变这些因子与包括横纹肌样瘤、乳腺癌和白血病在内的多种癌症有关。因此，我们在遗传模式生物中对染色质重塑因子的研究应该有助于阐明这些人类癌症和其他疾病背后的分子机制。