Characterization of Type B Histone Acetyltransferases

B 型组蛋白乙酰转移酶的表征

• 批准号: 6636629
• 负责人: MARK R PARTHUN
• 金额: $ 24.49万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-01 至 2006-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6636629
• 关键词: DNA repair; Saccharomyces cerevisiae; acetylation; acyltransferase; chromatin; cytoplasm; enzyme reconstitution; fungal genetics; fungal proteins; gene induction /repression; genetic recombination; genetic regulation; histones; intermolecular interaction; microarray technology; molecular assembly /self assembly; nucleic acid structure; protein purification; protein structure function; reporter genes; ribosomal DNA; site directed mutagenesis; telomere

DESCRIPTION (Verbatim from the applicant's abstract): Chromatin is the nucleoprotein structure that enables chromosomal DNA to be condensed and packaged in eukaryotic nuclei. The primary protein components of chromatin are the core histones (H2A, H2B, H3, and H4). Chromatin structure plays an active role in the regulation of many cellular processes that involve accessing chromosomal DNA, such as transcription, DNA replication, recombination and DNA repair. As the regulation of many aspects of normal cell growth requires the tight control of these processes, it is important to understand how they are influenced by, and interact with, chromatin structure. Much of the regulatory potential of the core histones resides small, positively charged domains called the NH2-terminal tails. The core histone NH2-terminal tails are subject to a wide range of post-translational modifications, of which acetylation is the most extensively characterized. The acetylation of histones, which appears to be a fundamental mechanism by which cells regulate chromatin structure, occurs on lysine residues, negating their positive charge. The acetylation state of the histones is governed by the interplay of enzymes that add acetyl groups (histone acetyltransf erases) and enzymes that remove them (histone deacetylases). Histone acetyltransferases can be divided into two classes based on substrate specificity and cellular localization. Type A histone acetyltransferases are nuclear enzymes that acetylate histones in a chromatin context. Type B histone acetyltransferases acetylate free histones and can be found in the cytoplasm. While type A histone acetyltransferases, such asGcn5p, have been conclusively linked to the regulation of gene expression, little is known about the function of type B histone acetyltransferases. However, using the yeast type B histone acetyltransferase Hat1 p as a model, we have recently obtained evidence that these enzymes are involved in silent chromatin structure and DNA damage repair. The primary goal of our research is to extend these results, using a combination of molecular genetics and biochemistry, to define the in vivo role of type B histone acetyltransferases. This goal will be pursued through three specific aims. The first is to determine the mechanism(s) through which Hat1p affects the silent chromatin structure found near yeast telomeres. The second is to characterize the involvement of Hat1p and chromatin structure the repair of DNA double strand breaks. Third, we will isolate and characterize novel type B histone acetyltransferases.

描述（逐字病申请人的摘要）：染色质是 使染色体DNA凝结并包装在真核核中的核蛋白结构。染色质的主要蛋白质成分是 核心组蛋白（H2A，H2B，H3和H4）。染色质结构发挥活性 在涉及访问的许多蜂窝过程的调节中的作用 染色体DNA，例如转录，DNA复制，重组和DNA 维修。由于对正常细胞生长的许多方面的调节需要 严格控制这些过程，重要的是要了解它们的状态 受染色质结构并与染色质结构相互作用。大部分监管 核心组蛋白的潜力驻留着较小的，带正电荷的域称为 NH2末端尾巴。核心组蛋白NH2末端尾部受到 广泛的翻译后修饰，其中乙酰化是 最广泛的特征。组蛋白的乙酰化似乎 是细胞调节染色质结构的基本机制 关于赖氨酸残留物，否定其阳性电荷。乙酰化状态 组蛋白受添加乙酰基的酶相互作用的控制 （组蛋白乙酰transf擦除）和去除它们的酶（组蛋白 脱乙酰基酶）。组蛋白乙酰转移酶可以分为两个基于两个类别 关于底物特异性和细胞定位。键入A组蛋白 乙酰转移酶是乙酰酸组蛋白中乙酰化组蛋白的核酶 语境。 B型组蛋白乙酰基转移酶乙酰酸酯无组蛋白，可以是 在细胞质中发现。而A型组蛋白乙酰转移酶（例如ASGCN5P） 已经与基因表达的调节结束了联系，几乎没有 知道B型组蛋白乙酰转移酶的功能。但是，使用 B组型酵母型乙酰转移酶HAT1 P作为模型，我们最近有 获得了这些酶参与静音染色质结构的证据 和DNA损伤修复。我们研究的主要目标是扩展这些 结果，结合了分子遗传学和生物化学来定义 B型组蛋白乙酰转移酶的体内作用。这个目标将是 通过三个特定目标追求。首先是确定机制 HAT1P会影响酵母附近发现的无声染色质结构 端粒。第二个是表征HAT1P和染色质的参与 构造DNA双链断裂的修复。第三，我们将孤立和 表征新型B型组蛋白乙酰转移酶。