Developmental Functions of SNR1 and the BRM Chromatin Remodeling Complex in Drosophila

在大多数活细胞中，染色体由高度浓缩的DNA和碱性蛋白质形成，碱性蛋白质的功能是将染色体压缩成一种称为染色质的结构。这项研究的重点是了解染色质结构在正常发育中起着至关重要的作用。特别是，这项工作集中在一个高度保守的蛋白质组，形成一个复合物，其主要功能是通过对染色质结构的直接影响来调节基因表达。这种复合物利用能量改变染色体DNA和组蛋白（细胞中包裹DNA的碱性蛋白质）之间的接触，以允许基因表达的特定变化。这种能量驱动的过程被称为“染色质重塑”。当这种复合物的成分缺失或突变时，细胞失去了正确控制其命运和生长的能力，导致适当的身体模式和不受调节的细胞增殖的各种缺陷。该项目利用分子遗传学和生物化学检测来探索发育过程中激素信号与染色质重塑之间的重要联系。激素信号引导组织的发育以采取某些命运。使用经典和“反向”（在研究中的基因中产生特定突变）遗传学和基于细胞培养的研究，激素受体选择它们将调节的基因以及它们如何与染色质重塑复合物合作以响应激素信号的存在而打开或关闭基因的机制正在被定义。基因间的相互作用正在研究中，这些基因对激素信号传导很重要，而这些基因有助于将这些信号传递给适当的细胞靶点。在这一过程中重要的基因也在培养的细胞中被选择性沉默，在那里可以直接解决染色质重塑复合物如何帮助确定某些基因是否会被激活或抑制。该项目利用果蝇（果蝇）Brahma（Brm）染色质重塑复合体的分子，遗传和生物化学分析。研究工作主要集中在一个最高度保守和至关重要的组成部分，称为SNR 1。该亚基在果蝇和人类中对于协调或靶向复合物与各种转录因子和细胞周期调节蛋白之间的特异性蛋白质相互作用至关重要。 这些研究的更广泛的科学影响是：（1）在系统生物学的基本概念，包括分子遗传学，生物化学和生物信息学/结构生物学的研究生和本科生的教学和培训;和（2）更好地理解一个大的和极其重要的染色质重塑复合物的亚基之间的功能关系。该项目还为正常发育过程中染色质重塑的生物学意义提供了新的见解，包括细胞生长的依赖性基因调控和控制。

In most living cells, chromosomes are formed from highly condensed DNA and basic proteins that function to compact the chromosomes into a structure called chromatin. This research is focused on understanding the multitude of critically important roles chromatin structure plays in normal development. In particular, the work focuses on a highly conserved group of proteins that form a complex whose main function is to regulate gene expression through direct effects on chromatin structure. This complex uses energy to alter the contacts between chromosomal DNA and histones (basic proteins that wrap DNA in the cell) to allow for specific changes in gene expression. This energy driven process is called 'chromatin remodeling'. When components of this complex are missing or mutated, cells lose the ability to properly control their fates and growth, leading to a variety of defects in proper body patterning and unregulated cellular proliferation. This project utilizes molecular genetics and biochemical assays to explore important connections between hormone signaling and chromatin remodeling during development. Hormone signaling directs the development of tissues to adopt certain fates. Using both classical and 'reverse' (making specific mutations in the genes under study) genetics and cell-culture based studies, the mechanisms are being defined by which hormone receptors select the genes they will regulate and how they cooperate with chromatin remodeling complexes to either turn genes on or off in response to the presence of hormone signals. Genetic interactions are being examined between genes important for hormone signaling and the genes that help convey those signals to the proper cellular targets. The genes important in this process are also being selectively silenced in cultured cells where it is possible to directly address how the chromatin remodeling complexes help to determine whether certain genes will be activated or repressed. The project utilizes molecular, genetic and biochemical analyses of the Drosophila melanogaster (fruitfly) Brahma (Brm) chromatin remodeling complex. Research efforts are primarily focused on one of the most highly conserved and critically important components, known as SNR1. This subunit is crucial in both flies and humans for coordinating or targeting specific protein interactions between the complex and a variety of transcription factors and cell cycle regulatory proteins. The broader scientific impacts of these studies are: (1) teaching and training of graduate and undergraduate students in fundamental concepts of systems biology, including molecular genetics, biochemistry, and bioinformatics/structural biology; and (2) a better understanding of the functional relationships among subunits of a large and extremely important chromatin remodeling complex. This project also provides new insights into the biological significance of chromatin remodeling in normal developmental processes, including hormone-dependent gene regulation and control of cell growth.