Molecular basis of transvection

横传的分子基础

• 批准号: 7131893
• 负责人: Mariano Labrador-San Jose
• 金额: $ 21.54万
• 依托单位: UNIVERSITY OF TENNESSEE KNOXVILLE
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7131893
• 关键词: Drosophilidae; alleles; bioassay; chromatin; computer simulation; fluorescence microscopy; gel mobility shift assay; gene expression; genetic enhancer element; genetic recombination; genetic regulation; genetic transcription; genetically modified animals; intermolecular interaction; molecular dynamics; nucleic acid repetitive sequence; polymerase chain reaction; transcription factor; transfection

DESCRIPTION (provided by applicant): Our laboratory is interested in understanding the mechanisms presiding enhancer-promoter interactions and the role of insulators in gene expression regulation. The goal of this proposal is to explore the molecular mechanisms underlying the phenomenon of transvection. Interaction of enhancers with promoters is a critical step in the orchestrated process leading to time and tissue specific regulation of gene expression. Enhancers can specifically activate promoters even at distances longer than 100 kb. Remarkably, enhancers can also trans-activate promoters located in homologue chromosomes, a phenomenon known as transvection. Transvection depends on somatic pairing between chromosomes, wherein the expression of one gene is influenced by regulatory signals emerging from its corresponding allele on the homologue chromosome. Transvection has been very well characterized at the genetic level in Drosophila, but numerous examples reported from multiple organisms including yeasts, plants and mammals, suggest that trans-activation (i.e. transvection) is a conserved eukaryotic regulatory feature. We propose that insulators are the molecular vehicles by which enhancers can communicate with promoters located in separate chromosomes. The following two aims are designed to test this hypothesis. A: assess the ability of gypsy insulators to mediate transvection using transgenic assays. Cell and molecular biology assays as well as mutational analysis will asses the involvement of insulators in experimentally controlled transvection settings. B: assess whether there is a general role of endogenous insulators in transvection. We will map and characterize specific endogenous insulators with a predicted role in transvection using computer analysis, fluorescence microscopy, gel shift assays and transgenic assays. Genetic analysis will also assess the role that insulator proteins play in previously reported transvection phenomena. These studies might have an immediate repercussion in the general understanding of the regulatory processes involved in somatic and germ-line development. Both, transvection as well as genome insulators may be involved in the control of transcription of numerous genes and therefore have a broad impact in the biology of human diseases, including cancer. Understanding how enhancers interact with promoters and the role of insulators in this process may provide new avenues to approach the study of genetic diseases.

描述（由申请人提供）：我们的实验室有兴趣了解主导增强子-启动子相互作用的机制和绝缘子在基因表达调控中的作用。这个提议的目的是探索transvection现象背后的分子机制。增强子与启动子的相互作用是导致基因表达的时间和组织特异性调节的协调过程中的关键步骤。增强子可以特异性地激活启动子，甚至在超过100 kb的距离。值得注意的是，增强子也可以反式激活位于同源染色体中的启动子，这种现象称为transvection。转染依赖于染色体之间的体细胞配对，其中一个基因的表达受到来自同源染色体上其相应等位基因的调控信号的影响。在果蝇的基因水平上已经很好地表征了Transvection，但是从包括酵母、植物和哺乳动物在内的多种生物体报道的许多实例表明，trans-activation（即transvection）是保守的真核调控特征。我们认为绝缘子是增强子与位于不同染色体上的启动子进行通讯的分子载体。以下两个目标旨在检验这一假设。A：使用转基因测定评估吉普赛绝缘子介导转染的能力。细胞和分子生物学分析以及突变分析将评估绝缘子在实验控制的transvection设置中的参与。B：评估内源性绝缘子在转染中是否具有一般作用。我们将利用计算机分析、荧光显微镜、凝胶位移测定和转基因测定来绘制和表征特定的内源性绝缘子，并预测其在转染中的作用。遗传分析也将评估绝缘子蛋白在以前报道的transvection现象中所起的作用。这些研究可能会立即在体细胞和生殖系发育的调控过程的一般理解的影响。转染和基因组绝缘子都可能参与控制许多基因的转录，因此在人类疾病（包括癌症）的生物学中具有广泛的影响。了解增强子如何与启动子相互作用，以及绝缘子在这一过程中的作用，可能会为遗传疾病的研究提供新的途径。