Regulation of gene silencing by an imprinted non-coding RNA

描述（由申请人提供）：基因调控是一个复杂的过程，协调基因激活和基因沉默的精确时间和位置。基因组印记是一种特殊的机制，基因显示沉默的一个亲本等位基因。人类染色体11p15.5上的印记区域及其在小鼠中的同源结构域由一簇基因组成，这些基因在父本染色体上被反义非编码RNA Kcnq 1 ot 1沉默。很少有人知道的等位基因特异性沉默的分子机制和非编码RNA在调节这一过程中的作用。本研究将首先利用转基因RNA干扰技术来检测Kcnq 1 ot 1在该位点建立印迹中的作用。在第二个和第三个目标，我们将研究的表观遗传过程，使一些基因逃脱沉默，应用生物信息学，生物化学和体内方法的组合，以确定在这个域中的调节元件，物理相互作用，并创建转录活性域散布与沉默区域。确定建立和维持印记的分子机制将促进我们对人类生长缺陷和疾病的理解。 公共卫生相关性：印记Kcnq 1结构域中的基因与贝克威-维德曼综合征有关，该综合征导致产前过度生长和癌症易感性。印记的丧失与几种人类肿瘤有关。这项提案将提供一个更彻底的了解等位基因特异性基因沉默的调控机制，并将深入了解这些机制如何在人类疾病中出错。

DESCRIPTION (provided by applicant): Gene regulation is a complex process that orchestrates the precise timing and location of both gene activation and gene silencing. Genomic imprinting is a specialized mechanism whereby a gene displays silencing of one parental allele. The imprinted region on human chromosome 11p15.5 and its homologous domain in the mouse consists of a cluster of genes that are silenced on the paternal chromosome by an antisense non-coding RNA, Kcnq1ot1. Very little is known of the molecular mechanisms involved in allele-specific silencing and the role of the non-coding RNAs in modulating this process. This proposal will first exploit transgenic RNA interference technology to test the role of Kcnq1ot1 in establishing imprinting at this locus. In the second and third aims, we will study the epigenetic processes that allow some genes to escape silencing, applying a combination of bioinformatic, biochemical and in vivo approaches to identify regulatory elements in this domain that interact physically and create transcriptionally active domains interspersed with the silenced regions. Identifying the molecular mechanisms underlying the establishment and maintenance of imprinting will advance our understanding of human growth defects and disease. PUBLIC HEALTH RELEVANCE: Genes in the imprinted Kcnq1 domain are involved in Beckwith-Wiedemann syndrome, which causes prenatal overgrowth and predisposition to cancer. Loss of imprinting has been implicated in several human neoplasias. This proposal will provide a more thorough understanding of the regulatory mechanisms deployed in allele-specific gene silencing and will give insight into how these mechanisms can go awry in human disease.