Functional elucidation of BRCA1-containing complexes

描述(申请人提供)：本实验室致力于研究含有BRCA1的核多蛋白复合体的功能。我们使用生化方法分离了两个不同的含有BRCA1的配合物，分别称为BRCC和BRCA1-BACH1，并对其进行了功能表征。虽然这两个复合体共享一个共同的核心亚单位(BRCA1、BARD1、BRCA2)，但每个复合体都包含区分它们的独特亚基。BRCC包含两个新的亚基BRCC45和一个类似信号体的亚基BRCC36，而第二个复合体包含DNA解旋酶BACH1。虽然已经发现BRCA1在细胞的S期表现出明显的核模式，但含有BRCA1的复合体在细胞周期中多肽组成和生化功能的动态变化还没有得到深入的研究。这项建议旨在深入了解这两种复合体在体外和体内的生物学功能。我们假设这两个含有BRCA1的复合体在DNA复制应激反应中发挥作用。这三个目标旨在提供包含BRCA1的络合物的全面物理和功能表征。目的1将评估BACH1、BRCC36和BRCC45在细胞周期的不同阶段和DNA复制应激反应后与BRCA1的物理和功能联系。目的2详细分析了BRCC和BACH1-BRCA1这两个复合体对复制应激的反应和对常见脆性位点稳定性的调节。目的3分析BRCC和BACH1-BRCA1复合体对晚期复制DNA和异染色质结构的调节作用。

DESCRIPTION (provided by applicant): Our laboratory is focused on the function of nuclear multiprotein complexes containing BRCA1. We have used biochemical methods to isolate and functionally characterize two distinct BRCA1-containing complexes termed BRCC and BRCA1-BACH1. Although both complexes share a common core subunits (BRCA1, BARD1, BRCA2), each contain unique subunits that distinguish them apart. While BRCC contains two novel subunits BRCC45 and a signalosome-like subunit, BRCC36, the second complex contains the DNA helicase, BACH1. Although BRCA1 has been shown to display a distinct nuclear pattern during the S phase of the cell, the dynamic changes in the polypeptide composition and biochemical function of BRCA1-containing complexes during the cell cycle have not been thoroughly studied. This proposal is aimed at gaining insight into the biological function of these two complexes in vitro and in vivo. We hypothesize that the two BRCA1-containing complexes play roles in the DNA replication stress response. The three Aims are designed to provide a thorough physical and functional characterization of BRCA1-containing complexes. Aim 1 will assess the physical and functional association of BACH1, BRCC36 and BRCC45 with BRCA1 at different stages of the cell cycle and following DNA replication stress response. Aim 2 describes a detailed functional analysis of the two complexes, BRCC and BACH1-BRCA1 in responsiveness to replication stress and in regulation of common fragile site stability. Aim 3 extends the work to analysis of the effect of BRCC and BACH1-BRCA1 complexes on regulation of late replicating DNA and heterochromatin structure.