Structural and Functional Analysis of the Chd1 Chromatin Remodeler

Chd1 染色质重塑剂的结构和功能分析

• 批准号: 9544975
• 负责人: GREGORY DEAN BOWMAN
• 金额: $ 38.74万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-01 至 2021-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9544975
• 关键词: 2-Aminopurine; ATP phosphohydrolase; ATPase Domain; Architecture; Back; Behavior; Bypass; CHD1 gene; Cell physiology; Chromatin; Chromatin Loop; Communication; Complex; Coupled; Crystallization; DNA; DNA Binding; DNA Binding Domain; DNA Polymerase II; DNA Repair; DNA Sequence; DNA Structure; DNA biosynthesis; DNA-Directed RNA Polymerase; Dissociation; Enzymes; Family; Fluorescence; Genes; Genetic Transcription; Genome; Growth and Development function; Health; Histones; Human; ISWI; Link; Maintenance; Malignant Neoplasms; Measures; Modeling; Molecular Conformation; Monitor; Motor; Movement; Mutagenesis; Mutation; Nature; Normal Cell; Nucleosomes; Outcome; Play; Positioning Attribute; Process; Regulation; Resistance; Role; Single-Stranded DNA; Site; Slide; Sodium Chloride; Stem cells; Structure; Surface; Testing; Work; cancer type; cell growth; chromatin remodeling; crosslink; developmental disease; dimer; experimental study; follow-up; helicase; human disease; insight; melting; physical process; pluripotency; response; sensory mechanism; single-molecule FRET; transcription factor; translocase

ABSTRACT Chromatin remodelers are ATP-dependent DNA translocases that catalyze disassembly, reassembly, and repositioning of nucleosomes throughout eukaryotic genomes. As evidenced from multiple types of cancer and developmental disorders associated with remodeler inactivation, chromatin remodeling is essential for normal growth and development. Remodeling requires transient and controlled disruption of histone-DNA interactions, with different families of remodelers possessing unique domains thought to assist or regulate action of a conserved ATPase motor. Our crystal structure of the Chd1 chromatin remodeler provided the first view of ATPase motor regulation, showing how a DNA-binding surface of the ATPase motor was blocked by adjacent chromodomains. As seen from work with the ISWI remodeler family, the auto-inhibitory nature of the Chd1 chromodomains has proven to be a common strategy for regulating ATPase action on the nucleosome. However, it remains unclear how such domain-domain interactions enable remodelers to sense and respond to particular nucleosome substrates, or achieve unique remodeling outcomes. Here we follow up our recent discoveries of Chd1 architecture on the nucleosome, where the Chd1 DNA-binding domain was found to directly communicate with the chromo-ATPase across the gyres of the nucleosome. We propose to test the hypothesis that inter-domain interactions of Chd1 are responsible for sensing DNA outside the nucleosome and that domains work together to achieve particular remodeling outcomes. In addition to remodeler regulation, the mechanism by which chromatin remodelers reposition nucleosomes along DNA is also poorly understood. Intriguing single molecule FRET experiments with the ISWI remodeler have revealed step-like and discontinuous movements DNA, suggesting that DNA behaves as a spring on the nucleosome. We will test this idea and further investigate DNA interactions needed for high processive steps that we also observe for Chd1. Together, these studies will provide new mechanistic insights into how chromatin remodelers manipulate the structure of the nucleosome and use domain-domain communication to regulate remodeler action. !

抽象的 染色质重塑剂是ATP依赖性的DNA易位酶，可催化拆卸，重新组装和 整个真核基因组的核小体重新定位。从多种类型的癌症和 与重塑灭活相关的发育障碍，染色质重塑对于正常 增长与发展。重塑需要瞬时和受控的组蛋白-DNA相互作用， 有不同的重塑家族拥有独特的领域，以协助或规范行动 保守的ATPase电机。我们的CHD1染色质重塑剂的晶体结构提供了第一视图 ATPase Motor调节，显示ATPase电动机的DNA结合表面如何被相邻阻断 染色体。从与ISWI改建家族的工作中可以看出，CHD1的自动抑制性质 事实证明，染色体是调节ATPase对核小体作用的常见策略。 但是，目前尚不清楚这种域域的相互作用如何使改建器能够感知和回应 特定的核小体底物或实现独特的重塑结果。在这里，我们跟进了我们最近的 在核小体上发现CHD1结构的发现，发现CHD1 DNA结合结构域是 直接与核小体回旋中的铬酸染色体通信。我们建议测试 假设CHD1的域间相互作用负责在核小体外传感DNA 该领域共同努力，以实现特定的重塑结果。 除了重塑器调节外，染色质重塑蛋白重新定位核小体的机制 沿着DNA的理解也很差。 ISWI重塑器的有趣的单分子FRET实验 已经揭示了阶梯状和不连续的运动DNA，表明DNA在 核小体。我们将测试这个想法，并进一步研究高处理步骤所需的DNA相互作用 我们也观察到CHD1。这些研究将共同​​提供有关如何 染色质重塑器操纵核小体的结构，并使用结构域通信与 调节重塑作用。 呢