Characterizing the Mechanisms of Transcription Regulation of RGMc/Hemojuvelin

空间 但前提是。 与铁有关的代谢和血液疾病影响着全世界数百万人。令人厌恶的 引导分子c(RGMc)或血凝素(HJV)是最近发现的一种基因，被证明对 铁一般的监管。RGMc/HJV突变导致严重的全身性铁超载障碍 血色沉着症。生理条件下RGMc调控的分子机制 病理情况尚不清楚。此外，了解RGMc表达的调节 因其独特的组织分布而变得复杂。到目前为止，还没有其他基因表达 仅限于横纹肌和肝脏，使RGMc处于独特的地位，因为它的调节 这些机制将提供对全身铁调节和组织特异性基因表达的洞察。这个 本申请的主要焦点将是定义负责组织特异性 RGMc的表达。我假设RGMc基因座在染色体中从“关闭”状态变为“开放”状态 分化的肌肉细胞，在肝脏中是“开放的”。为了定义分子机制， 为了调控RGMc的表达，我提出了一系列实验，具体目的如下：(1) 确定RGMc在肌肉中的转录调控机制。(2)界定 肝脏中RGMc基因转录的调控。调控机制将使用DNA- 蛋白质相互作用和功能突变研究以确定各自的转录因子结合部位 组织类型，限制性内切酶可及性分析，以询问染色质凝集状态 不同条件下RGMc的表达，并用芯片测定组蛋白修饰的动力学 与抑制和活跃的基因转录相关，以及体内转录分析 在表达RGMc的组织中，RGMc基因座的机械(包括染色质重塑复合体)。 长期目标是了解RGMc/HJV的组织特异性调控机制。 对发育或生理提示的反应以及这种表达如何影响铁的代谢 正常状态和患病状态。这项建议将集中在RGMc在两个发育和 生理上不同的组织，并为长期目标的基因调控奠定基础 了解RGMc表达的组织特异性反应及其在全身铁稳态中的作用。 这项工作对公共卫生特别重要，因为越来越明显的是 铁代谢紊乱在铁超载或贫血时表现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有新的见解。

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.