Epigenetic activation of the human growth hormone gene

人类生长激素基因的表观遗传激活

• 批准号: 7100336
• 负责人: YUGONG HO
• 金额: $ 10.44万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7100336
• 关键词: chromatin; epigenetics; functional /structural genomics; gene expression; gene interaction; genetic promoter element; genetic regulatory element; genetic transcription; genetically modified animals; laboratory mouse; nuclear transport; pituitary gland; polymerase chain reaction; somatotropin; transfection

DESCRIPTION (provided by applicant): The overall goal of this K01 award is to extend the scientific training and capabilities of the candidate and prepare him for an independent research career. This will be accomplished in the context of a detailed study of human growth hormone gene (hGH) expression. Prior studies from this laboratory have identified a tissue-specific locus control region (hGH LCR) that regulates the human growth hormone (hGH) gene cluster. The components of the hGH LCR are located quite far (15-32 kb) 5' to the target hGH-N gene promoter. Thus a central question in this model system is how the implied long-range gene activation between the hGH LCR and hGH-N promoter is mediated. During the current K01 mentored training period, the candidate has discovered that the hGH LCR is itself actively transcribed by Pol II and that the regions that are transcribed are also modified by specific and distinct patterns of histone alterations. The candidate's goal in the current proposal is to determine how these epigenetic alterations in LCR structure contribute to higher-order chromatin interactions that eventuate in hGH gene activation. The Hypothesis of the proposal is that the hGH LCR acts by recruitment and spreading of epigenetic modifiers. These modifications facilitate direct interactions within the LCR and between the LCR and the remote hGH-N promoter and they mediate relocation of the hGH locus to specific, transcriptionally-active sub-regions of the somatotrope nucleus. Aim I is to define the long-range interactions between the hGH LCR and hGH-N gene in somatotrope chromatin. This aim will address direct interactions within the LCR and between the LCR and the hGH-N promoter by applying Chromatin Conformation Capture (3C) analysis. The chromatin to be studied will be isolated from pituitaries and control tissues of mouse lines carrying informative transgenes. Aim II will establish functional relationships between hGH LCR activities and sub-nuclear localization of the hGH locus in somatotrope nuclei using high definition microscopic technology. A new collaboration will provide the candidate with additional training in the technology necessary to successfully implement this second aim. These studies address fundamental mechanisms of gene control and contribute to a foundation of knowledge necessary for understanding normal and pathological states of pituitary hormone expression. Such understanding establishes a basis for advances in diagnosis and treatment of endocrine disorders.

描述（由申请人提供）： 该K 01奖项的总体目标是扩展候选人的科学培训和能力，并为他的独立研究生涯做好准备。这将在详细研究人生长激素基因（hGH）表达的背景下完成。该实验室先前的研究已经确定了一个组织特异性基因座控制区（hGH LCR），可调节人生长激素（hGH）基因簇。hGH LCR的组分位于距靶hGH-N基因启动子相当远的5'端（15-32 kb）。因此，该模型系统中的一个中心问题是如何介导hGH LCR和hGH-N启动子之间隐含的长距离基因激活。在当前的K 01指导培训期间，候选人发现hGH LCR本身由Pol II主动转录，并且转录的区域也被组蛋白改变的特定和独特模式修饰。候选人在当前提案中的目标是确定LCR结构中的这些表观遗传改变如何有助于最终导致hGH基因激活的高阶染色质相互作用。该提案的假设是hGH LCR通过表观遗传修饰剂的募集和扩散起作用。这些修饰促进LCR内以及LCR与远程hGH-N启动子之间的直接相互作用，并且它们介导hGH基因座重新定位到生长激素细胞核的特定转录活性亚区。目的研究生长激素LCR与生长激素N基因在体细胞染色质中的长程相互作用。这一目标将通过应用染色质构象捕获（3C）分析来解决LCR内以及LCR与hGH-N启动子之间的直接相互作用。待研究的染色质将从携带信息性转基因的小鼠品系的垂体和对照组织中分离。目的二利用高清晰度显微镜技术建立生长激素LCR活性与生长激素基因座在生长激素细胞核亚核定位之间的函数关系。新的合作将为候选人提供成功实现第二个目标所需的技术方面的额外培训。这些研究涉及基因控制的基本机制，并有助于了解垂体激素表达的正常和病理状态所需的知识基础。这种认识为内分泌疾病的诊断和治疗进展奠定了基础。