Functions, mechanisms, and therapeutic potential of chromatin looping

染色质环化的功能、机制和治疗潜力

基本信息

批准号：
8714048
负责人：
Gerd A Blobel
金额：
$ 52.05万
依托单位：
CHILDREN'S HOSP OF PHILADELPHIA
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-08-05 至 2018-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8714048
关键词：
Accounting Address Adult Area Basic Science Biological Models Biology Cell Nucleus Cells Chromatin Chromatin Fiber Chromatin Loop Clinical Complex DNA Binding DNA-Directed RNA Polymerase Development Developmental Gene Dimerization Disease model Elements Embryo Engraftment Enhancers Erythroid Cells Fetal Hemoglobin GATA1 gene Gene Activation Gene Expression Gene Expression Profile Gene Expression Regulation Genes Genetic Transcription Genome Genomics Globin Growth Hemoglobinopathies Higher Order Chromatin Structure Human Interphase Left Locus Control Region Mediating Mus Nature Nuclear Play Positron-Emission Tomography Proteins Regulatory Element Research Research Design Role Sickle Cell Anemia Specificity Staging Stem cells Structure System Technology Testing Therapeutic Time Transcriptional Regulation Transplantation Work Zinc Fingers cell type design erythroid Kruppel-like factor fetal globin genome-wide improved in vivo mammalian genome mouse model novel novel strategies promoter public health relevance research study stem three dimensional structure

项目摘要

DESCRIPTION (provided by applicant): The eukaryotic genome is non-randomly organized in the interphase nucleus. Critical control elements can physically contact each other to form chromatin loops. Looped configurations of the chromatin fiber have been described at numerous gene loci, however, the mechanism by which these structures are established and their functional relationship with gene expression have remained unclear. The transcription co-factor Ldb1 is critical for establishing looped chromatin interactions at the murine ¿-globin locus. Specifically, we showed that tethering Ldb1 to the locus via artificial zinc finger proteins in immature erythroid cells is sufficient to promote a looped interaction between the ¿-globin enhancer and promoter and potently activate transcription. This suggested for the first time that chromatin looping causally underlies gene expression and raised the possibility that forced chromatin looping might be employed to effectively manipulate gene expression. This proposal builds on these findings by investigating in Specific Aim 1 the mechanisms of Ldb1 function and its broad role in genome organization. In Specific Aim 2 we will further develop the approach of forced chromatin looping to enhance and broaden its usefulness. In Specific Aim 3 we will examine forced chromatin looping as an approach to developmentally reprogram the murine and human ¿-globin locus. In Specific Aim 4 proof-of-concept studies will examine whether reactivation of fetal hemoglobin via chromatin looping can ameliorate sickle cell anemia in a humanized mouse model. To our knowledge, the manipulation of higher order chromatin structure for the purpose of regulating gene expression is unique and novel in its design. The juxtaposition of complex regulatory elements promises more dramatic changes in gene activation when compared to conventional approaches, and might also be exploited to repress gene transcription for exploratory or therapeutic purposes.

描述（应用程序提供）：真核基因组在相间核us中组织非随机组织。关键的控制元素可以物理接触以形成染色质环。染色质纤维的循环构型已在许多基因基因座上进行了描述，但是，建立这些结构的机制以及它们与基因表达的功能关系尚不清楚。转录辅助因子LDB1对于在鼠处建立环状染色质相互作用至关重要。这首次表明，染色质循环意外地是基因表达的基础，并提出了可能采用强迫染色质环的可能性来有效操纵基因表达的可能性。该建议是基于这些发现的基于这些发现的基于特定目的1的核心功能机制及其在基因组组织中的广泛作用的基础。在特定目标2中，我们将进一步开发强制染色质循环以增强和扩大其实用性的方法。在特定的目标3中，我们将研究强制染色质循环，作为一种可以开发重新编程鼠和人类 - 珠蛋白基因座的方法。在特定目标中4概念验证研究将检查通过染色质循环对胎儿血红蛋白的重新激活是否可以在人源性小鼠模型中改善镰状细胞贫血。据我们所知，为调节基因表达的目的操纵高阶染色质结构在其设计中是独特而新颖的。与常规方法相比，复杂调节元件的并置有望在基因激活中更具巨大的变化，并且也可能被利用以反映基因转录的探索性或治疗目的。