Characterizing the Mechanisms of Transcription Regulation of RGMc/Hemojuvelin

RGMc/血幼素转录调控机制的表征

• 批准号: 8073469
• 负责人: Christopher John Severyn
• 金额: $ 4.55万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8073469
• 关键词: Adolescent; Affect; Anemia; Binding Sites; Biological Assay; Chromatin; Chromatin Remodeling Factor; Complex; Cues; DNA-Protein Interaction; Data; Development; Disease; Drug or chemical Tissue Distribution; Duodenum; Foundations; Gene Expression Regulation; Genes; Genetic Transcription; Goals; Hemochromatosis; Histocompatibility Testing; Homeostasis; Individual; Iron; Iron Metabolism Disorders; Iron Overload; Kinetics; Liver; Metabolic; Molecular; Mus; Muscle; Muscle Cells; Mutagenesis; Mutation; Pathway interactions; Physical condensation; Physiological; Positioning Attribute; Public Health; Regulation; Research; Role; Series; Striated Muscles; Tissue-Specific Gene Expression; Tissues; Transcriptional Regulation; Work; absorption; cell type; gene discovery; hepcidin; histone modification; in vivo; insight; iron metabolism; member; novel; peptide hormone; research study; response; restriction enzyme; transcription factor; uptake

SPACE PROVIDED. Iron-related metabolic and hematologic disorders affect millions of individuals worldwide. Repulsive guidance molecule c (RGMc), or Hemojuvelin (HJV), is a recently discovered gene shown to be critical for iron regulation. Mutations in RGMc/HJV cause the severe systemic iron overload disorder, juvenile hemochromatosis. The molecular mechanisms responsible for the regulation of RGMc under physiological and pathological conditions are unknown. In addition, understanding the regulation of RGMc expression has been complicated by its unique tissue distribution. To date there are no other genes whose expression is restricted to striated muscle and liver, placing RGMc in a unique position in that understanding its regulatory mechanisms will provide insight into systemic iron regulation and tissue-specific gene expression. The primary focus of this application will be to define the mechanisms responsible for the tissue-specific expression of RGMc. I hypothesize that the RGMc locus goes from a 'closed' to an 'open' chromatin state in differentiating muscle cells, and is 'open' in the liver. In order to define the molecular mechanisms that regulate the expression of RGMc, I propose a series of experiments with the following specific aims: (1) To determine the transcriptional regulatory mechanisms of RGMc in muscle. (2) To define the mechanisms of regulation of RGMc gene transcription in the liver. Regulatory mechanisms will be characterized using DNA- protein interactions and functional mutagenesis studies to define transcription factor binding sites in each type of tissue, restriction enzyme accessibility assays to query the state of chromatin condensation under different conditions of RGMc expression, and ChiP to determine the kinetics of histone modifications associated with repressed and active gene transcription, as well as the in vivo analysis of transcriptional machinery (including chromatin-remodeling complexes) at the RGMc locus in tissues that express RGMc. The long range goals are to understand the mechanisms of tissue-specific regulation of RGMc/HJV in response to developmental or physiological cues and how this expression influences iron metabolism in normal and diseased states. This proposal will focus on the expression of RGMc in two developmentally and physiologically distinct tissues, and establish a foundation for regulation of the gene with the long term goal of understanding tissue-specific response of RGMc expression and its role in systemic iron homeostasis. This work is of particular importance to public health in that it is becoming increasingly apparent that disorders of iron metaboilsm show different tissue-specific responses during iron overload or anemia; treatment will require novel insight into the molecular mechanisms of tissue-specific expression.

空间 假如。 与铁相关的代谢和血液学疾病会影响全球数百万个个体。丑恶 引导分子C（RGMC）或Hemojuvelin（HJV）是最近发现的基因，证明对 铁调节。 RGMC/HJV中的突变导致严重的全身铁超载障碍，少年 血色素沉着病。在生理下调节RGMC的分子机制 病理条件尚不清楚。此外，了解RGMC表达的调节具有 由于其独特的组织分布而变得复杂。迄今为止，没有其他基因表达 仅限于条纹的肌肉和肝脏，将RGMC置于其理解调节的独特位置 机制将提供有关系统性铁调节和组织特异性基因表达的见解。这 该应用的主要重点是定义负责组织特异性的机制 RGMC的表达。我假设RGMC基因座从“封闭”到“开放”染色质状态 区分肌肉细胞，并在肝脏中“开放”。为了定义分子机制 调节RGMC的表达，我提出了一系列具有以下特定目的的实验：（1）至 确定肌肉中RGMC的转录调节机制。 （2）定义机制 调节肝脏中RGMC基因转录。使用DNA-将对调节机制进行表征 蛋白质相互作用和功能性诱变研究，以定义每个转录因子结合位点 组织类型，限制酶可访问性测定，以查询染色质凝结状态 RGMC表达的不同条件和芯片以确定组蛋白修饰的动力学 与受压抑和活性基因转录以及转录的体内分析相关 在表达RGMC的组织中的RGMC基因座处的机械（包括染色质复制复合物）。 远距离目标是了解RGMC/HJV组织特异性调节的机制 对发育或生理提示的反应以及这种表达如何影响铁代谢 正常和患病状态。该提案将重点介绍RGMC在两个发展上的表达， 生理上不同的组织，并建立了具有长期目标的基因调节的基础 了解RGMC表达及其在系统性铁稳态中的作用的组织特异性反应。 这项工作对公共卫生而言尤为重要，因为它变得越来越明显 铁超石油的疾病在铁超负荷或贫血期间显示出不同的组织特异性反应。 治疗将需要对组织特异性表达的分子机制进行新的了解。