Functional Analysis of the SIR2/HST Deacetylases

描述(申请人提供)：转录调控机制有 对正常生长控制和发育至关重要。近年来，Key 转录元件已被认为是由染色质介导的 修饰，通常通过大分子络合物结合 用基本的转录机制修饰酶。一种主要形式的 染色质修饰是组蛋白乙酰化。扰乱受监管的 染色质乙酰化和去乙酰化与 丧失正常的新陈代谢、生长控制和癌症的发展。 对Sir2/HST基因家族编码染色质乙酰化的认识 改变活性将这些基因置于更核心的调控 用于基因组控制的电路。 Sir2/HST基因家族可能是最保守的家族 调节染色质和基因表达，包括古生代成员， 真细菌，并在所有真核生物中进行了检查。在理解方面的进展 Sir2p及其同系物的作用机制来源于最近的研究 发现这些蛋白质具有固有的NAD依赖的蛋白脱乙酰酶 (NAD-DAC)活动。这一活动提供了对染色质和 然而，染色体控制也引发了一些问题，答案是 对于理解生物功能，特异性， 以及对这类新定义的酶的调节。要解决的实验 这些问题是本文研究的基础。 我们研究的长期目标是了解体内的调节， SJR2/HST家族NAD-DAC的靶向性和特异性。这个目标将是 通过三个具体目标来实现： 1.确定Sir2和HST蛋白的酶活性。 2.通过以下步骤建立大分子络合物的分子定义 酶在其中起作用。 3.评价NAD-DAC复合体及其功能意义 基因组靶向。 这些目标将通过结合分子遗传、 细胞生物学和生化方法将随着新兴技术的出现而扩展 微阵列技术。

DESCRIPTION (provided by applicant): Transcriptional regulatory mechanisms are critical for normal growth control and development. In recent years, key elements of transcription have been recognized to be mediated by chromatin modification, often through large macromolecular complexes which combine modifying enzymes with the basic transcriptional machinery. One major form of chromatin modification is histone acetylation. Disruption of regulated chromatin acetylation and deacetylation has been increasingly correlated with loss of normal metabolism, growth control, and development of cancer. Recognition that the SIR2/HST gene family encodes a chromatin acetylation modifying activity places these genes even more centrally in regulatory circuits for genomic control. The SIR2/HST family of genes is perhaps the most broadly conserved family regulating chromatin and gene expression and includes members in the Archaea, the eubacteria, and in all eukaryotes examined. Progress toward understanding the mechanism of function of Sir2p and its homologues came from the recent discovery that these proteins have intrinsic NAD-dependent protein deacetylase (NAD-DAC) activity. This activity provides important insight into chromatin and chromosomal control, however, it also raises a number of questions, the answers to which are critical for understanding the biological function, specificity, and regulation of this newly defined class of enzymes. Experiments to address these questions are the foundation for the proposed research. The long-term goal of our research is to understand the in vivo regulation, targeting and specificity of the SJR2/HST family of NAD-DACs. This goal will be approached through three specific aims: 1. To define the enzymatic activity of Sir2 and the Hst proteins. 2. To establish a molecular definition of the macromolecular complexes through which the enzymes act. 3. To evaluate the functional significance of the NAD-DAC complexes and their genomic targeting. These aims will be accomplished through a combination of molecular genetic, cell biological and biochemical approaches that will be extended with emerging microarray technologies.