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: 2749947
• 负责人: JOHN W. TAMKUN
• 金额: $ 16.07万
• 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/2749947
• 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成分可以充当 通过阻断两者的可及性来有效抑制转录 调节蛋白和 DNA 的一般转录机制。 最近的遗传和生化研究发现了一个家族 抵消染色质抑制作用的 ATP 酶。 这些 染色质重塑因子是巨大的催化亚基 异源复合体（包括酵母 SWI/SNF、果蝇 BRM 和人类 BRG1/HBRM 复合物）在 真核细胞。 我们对染色质重塑的作用感兴趣 果蝇发育的因素，其中染色质的改变 结构对于控制细胞命运至关重要。 这个提议是 重点关注两个高度相关的果蝇基因：brahma (brm) 和 仿-SWI(ISWI)。 brm 和 ISWI 编码催化亚基 不同的染色质重塑复合物：BRM 复合物和 核小体重塑因子（NURF）。 brm在其中发挥着重要作用 控制细胞命运，但 ISWI 的生物学功能尚不清楚。 拟议的研究旨在阐明 brm 和 ISWI在动物发育中的作用并阐明其作用机制 体内。 为了了解 BRM 的作用机制， 我们将鉴定在体内与其相互作用的蛋白质。 这将 通过识别 BRM 复合体的亚基来完成 筛选显性失活brm的增强子和抑制子 突变。 确定 brm 和 ISWI 是否在 发育，我们将表征功能丧失和 显性失活 ISWI 突变。 有人建议 BRM 和 ISWI 可能通过改变调节蛋白与 DNA 的结合来促进 局部染色质结构。 我们将通过检查是否 brm 或 ISWI 突变影响 Polycomb 和 具有多线染色体的三胸组蛋白。 最近的研究 已经表明与 BRM 相关的人类蛋白质参与 发育、病毒整合、细胞周期控制和癌症。 能力 进行果蝇染色质重塑因子的遗传学研究 因此这是一个增进我们理解的绝佳机会 它们在转录、发育和疾病中的作用。