Role of Multimerization in H3.3/H4 deposition by the HIRA complex

项目摘要 这个项目的目标是表征，与分子细节，多聚化的作用， HIRA组蛋白伴侣复合物在将组蛋白H3.3/H4沉积到DNA上中起作用。为了适应 大约两米的DNA进入一个十微米的细胞核，组蛋白被用作支架 蛋白质将线性遗传物质浓缩成染色质的高级结构。后生 调节机制对于确保染色质景观得到良好维护以允许 为了使某些基因表达易于被激活或失活以调节细胞命运和细胞周期， 稳定HIRA组蛋白分子伴侣复合物负责将组蛋白H3.3/H4递送到 在活跃的基因转录区域中的新生DNA，因此与染色质变化有关 在发育、维持终末分化的细胞类型和衰老过程中。的 我提出的策略将首先提供对相互作用的分子基础的理解， HIRA和CABIN 1的C末端三聚化结构域，然后将探测这些结构域的相关性。 通过研究突变体对组蛋白沉积过程的影响， 使用核小体组装试验和在细胞中通过研究突变体对细胞的影响， 复杂的定位和组蛋白沉积在拥挤的核景观。拟议 这项研究将加深我们对一种普遍存在的表观遗传机制的理解， 健康人体细胞的染色质环境。

Project Summary The goal of this project is to characterize, with molecular detail, the role that multimerization of the HIRA histone chaperone complex plays in depositing histone H3.3/H4 onto DNA. In order to fit roughly two meters worth of DNA into a ten-micron cell nucleus, histones are used as scaffolding proteins to condense linear genetic material into the higher order structures of chromatin. Epigenetic regulatory machinery is essential to ensure that the chromatin landscape is well maintained to allow for certain gene expressions to be readily activated or inactivated to regulate both cell fate and cell stability. The HIRA histone chaperone complex is responsible for delivering histone H3.3/H4 onto nascent DNA in areas of active gene transcription and is therefore implicated in chromatin changes during development, in maintenance of terminally differentiated cell types, and in aging. The strategies I propose will first provide understanding of the molecular basis of the interaction between the C-terminal trimerization domain of HIRA and CABIN1 and then will probe the relevance of these interactions in vitro by investigating the effect that mutants have on the histone deposition process using a nucleosome assembly assay and in cells by investigating the effect that mutants have on complex localization and histone deposition within the crowded nuclear landscape. The proposed study will deepen our understanding of a ubiquitous epigenetic mechanism essential for regulating the chromatin environment of healthy human cells.