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

描述（由申请人提供）：atp依赖性染色质重塑是DNA复制、修复、重组和转录等核事件的关键调控成分。这些事件的错误调控可导致基因表达紊乱，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。我们已经在酵母中发现了一种单组分染色质重塑因子，先前被指定为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表达与引起基因组不稳定有关。生化研究表明，Fun30具有atp依赖性核小体滑动活性。然而，关于Fun30在体内的染色质重塑功能知之甚少。我们假设由Fun30介导的ATP依赖性染色质重塑调节了体内核小体的定位。以酿酒酵母为模型系统，利用最新的技术，我们提出：1)通过对Fun30依赖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基因进行全基因组定位，确定Fun30的生物学靶点。3) Fun30在靶基因上的功能分析。这些研究的成功完成将为atp依赖性染色质重塑调节的核小体定位提供第一个全基因组检查。这也将有助于深入了解Fun30介导的染色质重塑在转录和其他核事件中的功能意义。

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.