GENETIC/BIOCHEM STUDIES OF CHROMATIN REMODELING FACTORS

染色质重塑因子的遗传/生物化学研究

• 批准号: 2396064
• 负责人: JOHN W. TAMKUN
• 金额: $ 16.65万
• 依托单位: UNIVERSITY OF CALIFORNIA SANTA CRUZ
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-08-01 至 2001-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2396064
• 关键词: Drosophilidae; SDS polyacrylamide gel electrophoresis; alleles; binding proteins; chromatin; developmental genetics; fluorescence microscopy; gel filtration chromatography; gene expression; gene interaction; gene mutation; homeobox genes; human tissue; in situ hybridization; invertebrate embryology; loss of heterozygosity; molecular cloning; protein biosynthesis; protein sequence; protein structure function; receptor expression; tissue /cell culture; transcription factor

Nucleosomal histones and other components of chromatin can act as potent inhibitors of transcription by blocking the accessibility of both regulatory proteins and the general transcription machinery to DNA. Recent genetic and biochemical studies have identified a family of ATPases that counteract the repressive effects of chromatin. These chromatin remodeling factors are the catalytic subunits of huge heterometric complexes (including the yeast SWI/SNF, Drosophila BRM and human BRG1/HBRM complexes) that play highly conserved roles in eukaryotic cells. We are interested in the role of chromatin remodeling factors in Drosophila development, where alterations in chromatin structure are critical for the control of cell fate. This proposal is focused on two highly related Drosophila genes, brahma (brm) and imitation-SWI(ISWI). brm and ISWI encode the catalytic subunits of distinct chromatin remodeling complexes: the BRM complex and the nucleosome-remodeling fctor (NURF). brm plays an important role in the control of cell fate, but the biological function of ISWI is unknown. The proposed research is designed to elucidate the roles of brm and ISWI in animal development and clarify their mechanism of action in vivo. To gain an understanding of the mechanism of action of the BRM, we will identify the proteins with which it interacts in vivo. This will be accomplished by identifying the subunits of the BRM complex and screening for enhancers and suppressors of a dominant-negative brm mutation. To determine if brm and ISWI play similar roles in development, we will characterize the phenotype of loss-of-function and dominant-negative ISWI mutations. It has been proposed that BRM and ISWI may facilitate the binding of regulatory proteins to DNA by altering local chromatin structure. We will test this model by examining whether mutations in brm or ISWI affect the association of Polycomb and trithorax group proteins with polytene chromosomes. Recent studies have suggested that human proteins related to BRM are involved in development, viral integration, cell cycle control and cancer. The ability to conduct genetic studies of chromatin remodeling factors in Drosophila thus represents an excellent opportunity to increase our understanding of their roles in transcription, development and disease.

核小体组蛋白和染色质的其他组分可以充当 有效的转录抑制剂，通过阻断两者的可及性， 调节蛋白和一般的转录机制到DNA。 最近的遗传和生物化学研究已经确定了一个家庭， 抵消染色质抑制作用的ATP酶。 这些 染色质重塑因子是一种催化亚单位， 异规复合物（包括酵母SWI/SNF、果蝇BRM 和人BRG 1/HBRM复合物），其在以下方面发挥高度保守的作用： 真核细胞 我们感兴趣的是染色质重塑的作用 果蝇发育中的因素，其中染色质的改变 结构对于控制细胞命运至关重要。 这项建议是 主要集中在两个高度相关的果蝇基因，brahma（brm）和 模拟SWI（ISWI）。 brm和ISWI分别编码 不同的染色质重塑复合物：BRM复合物和 核小体重塑因子（Nucleosome-remodeling factor，CNTF）。 BRM在以下方面发挥着重要作用： 控制细胞命运，但ISWI的生物学功能尚不清楚。 这项研究旨在阐明BRM和 ISWI在动物发育中的作用，并阐明其作用机制， vivo. 为了了解BRM的作用机制， 我们将鉴定出它在体内与之相互作用的蛋白质。 这将 通过鉴定BRM复合物的亚基来实现， 显性阴性BRM的增强子和抑制子的筛选 突变 为了确定BRM和ISWI在以下方面是否扮演类似的角色， 发展，我们将表征功能丧失的表型， 显性阴性ISWI突变。 有人提出，BRM和 ISWI可能通过改变DNA的结构，促进调节蛋白与DNA的结合。 局部染色质结构。 我们将通过检查是否 brm或ISWI的突变影响Polycomb和 多线染色体的三胸组蛋白质。 最近的研究 已经表明与BRM相关的人类蛋白质参与了 发育、病毒整合、细胞周期控制和癌症。 的能力 进行果蝇染色质重塑因子的遗传研究 这是一个极好的机会来增进我们对 它们在转录、发育和疾病中的作用。