Characterizing the Mechanisms of Transcription Regulation of RGMc/Hemojuvelin

空间 提供了 铁相关的代谢和血液疾病影响着全世界数百万人。排斥 引导分子c（RGMc），或Hemojuvelin（HJV），是最近发现的基因，其显示对于 铁规RGMc/HJV突变导致严重的全身性铁过载障碍，青少年 血色病在生理条件下负责调节RGMc的分子机制 病理状况尚不清楚。此外，了解RGMc表达的调控， 由于其独特的组织分布而变得复杂。到目前为止，没有其他基因的表达是 仅限于横纹肌和肝脏，将RGMc置于理解其调节的独特位置， 机制将提供深入了解系统性铁调节和组织特异性基因表达。的 本申请的主要重点将是定义负责组织特异性 RGMc的表达。我假设RGMc基因座从一个"封闭"到一个"开放"的染色质状态， 分化的肌肉细胞，并在肝脏中“开放”。为了确定 为了调控RGMc的表达，我提出了一系列实验，具体目的如下：（1） 确定肌肉中RGMc的转录调控机制。(2)为了定义 调节RGMc基因在肝脏中的转录。调控机制将使用DNA进行表征- 蛋白质相互作用和功能诱变研究，以确定转录因子结合位点， 组织类型，限制性酶可及性测定，以查询染色质浓缩的状态， RGMc表达的不同条件，和ChiP以确定组蛋白修饰的动力学 与抑制和活性基因转录相关，以及转录的体内分析 在表达RGMc的组织中，在RGMc基因座处的染色质重塑复合物（包括染色质重塑复合物）。 长期的目标是了解RGMc/HJV的组织特异性调节机制， 以及这种表达如何影响铁代谢， 正常和疾病状态。该提案将集中于RGMc在两个发育和发育过程中的表达。 生理上不同的组织，并建立一个长期目标的基因调控的基础 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， 铁代谢障碍在铁过载或贫血期间显示不同的组织特异性反应; 治疗需要对组织特异性表达的分子机制有新的认识。

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.