The function of a single-component chromatin remodeling protein Fun30 in vivo

描述(由申请人提供)：依赖于ATP的染色质重塑是核事件的关键调控成分，如DNA复制、修复、重组和转录。这些事件的错误调控会导致基因表达紊乱，DNA损伤反应失败，以及随后的基因组不稳定，所有这些都是人类癌症的主要原因。我研究的长期目标是了解染色质重塑如何调节这些事件，以及这种调节如何在癌细胞中改变。我们已经在酵母中鉴定出一种单组分染色质重塑因子，以前被命名为Fun30。酵母FUN30的缺失使细胞对DNA损伤剂敏感。FUN30或其人类同源物的过度表达与导致基因组不稳定有关。生化研究表明，Fun30具有依赖于ATP的核小体滑动活性。然而，对Fun30在体内的染色质重塑功能知之甚少。我们推测，Fun30依赖于ATP的染色质重塑调节了核小体在体内的定位。以酿酒酵母为模型系统，结合最新技术，我们提出：1)通过对依赖于Fun30的核小体定位变化的全染色体定位来确定Fun30的染色质重塑功能。2)利用高密度ChlP芯片对Fun30进行全基因组定位定位，确定Fun30的生物学靶点。3)Fun30靶基因的功能分析。这些研究的成功完成将提供第一次全基因组范围内由ATP依赖的染色质重塑调节的核小体定位的检查。它还将深入了解Fun30介导的染色质重塑对转录和其他核事件的功能意义。

DESCRIPTION (provided by applicant): ATP-dependent chromatin remodeling is a key regulatory component of nuclear events, such as DNA replication, repair, recombination and transcription. Misregulation of these events can lead to disordered gene expression, failed DNA damage response and subsequent genome instability, all of which are major causes of human cancer. The long-term objective of my research is to understand how chromatin remodeling regulates these events and how this regulation may be altered in cancer cells. We have identified a single-component chromatin remodeling factor previously designated as Fun30 in yeast. Deletion of yeast FUN30 renders cells sensitive to DNA damaging agents. Overexpression of FUN30 or its human homolog has been implicated in causing genome instability. Biochemical studies show that Fun30 exhibits an ATP-dependent nucleosome sliding activity. However, little is known about the chromatin remodeling function of Fun30 in vivo. We hypothesize that the ATP dependent chromatin remodeling by Fun30 regulates nucleosome positioning in vivo. Using the yeast Saccharomyces cerevisiae as model system and the state-of-the-art techniques, we propose to: 1) Determine the chromatin remodeling function of Fun30 by chromosome-wide mapping of changes in Fun30 dependent nucleosome positioning. 2) Determine the biological targets of Fun30 by genome-wide mapping of Fun30 localization using high density ChlP-chip. 3) Functional analysis of Fun30 at its target genes. The successful completion of these studies will provide the first genome-wide examination of nucleosome positioning regulated by ATP-dependent chromatin remodeling. It will also provide insight into the functional significance of Fun30 mediated chromatin remodeling for transcription and other nuclear events.