Iron-sensitive RNA regulation during erythropoiesis

项目总结 正常的红细胞生成需要干细胞和蛋白质合成基因表达和蛋白质合成的协调变化 祖细胞分化并积累维持生命所需的惊人数量的含铁血红蛋白 在人类身上。贫血--循环中的红细胞不足--最常见的原因是缺铁 仍然是世界上最常见的营养缺乏症之一。除产生血红蛋白外，铁在 红细胞生成过程中的其他细胞过程，如基因表达和RNA加工能力较差 明白了。RNA加工事件是由RNA结合蛋白(如聚C结合蛋白)介导的 (PCBP)。PCBP2通过选择性剪接驱动红系的基因转录调控红系的生成 差异化计划。令人惊讶的是，PCBP还被发现具有细胞内铁伴侣的功能， 提出了铁结合是独立于RNA结合还是与RNA结合同时发生的问题。考虑到 铁水平密切调节红细胞分化，我们试图调查PCBP活性是否 在红细胞发育过程中受铁的调节。具体地说，我们假设铁调节 PCBP与靶RNA的亲和力或特异性导致对RED重要的RNA剪接变化 血细胞分化。我们将通过以下方式解决这一假设：1)确定铁对PCBP-RNA的影响 使用无偏高通量体外试验的相互作用，II)评估铁对PCBP调节的影响 细胞中的RNA剪接事件，以及III)决定全球基因表达和原发地区的RNA剪接变化 缺铁和不缺铁的人和鼠样本。从这些实验中，我们将发现铁- 决定红细胞生成的敏感的RNA剪接程序。

PROJECT SUMMARY Proper erythropoiesis requires coordinated changes in gene expression and protein synthesis for stem and progenitor cells to differentiate and amass the striking amount of iron-laden hemoglobin required to sustain life in humans. Anemia—insufficient circulating erythrocytes—is most frequently caused by iron deficiency which remains one the most common nutritional deficit in the world. Beyond hemoglobin production, the role of iron in other cellular processes during erythropoiesis, such as gene expression and RNA processing is poorly understood. RNA processing events are mediated by RNA binding proteins, such as the poly C binding proteins (PCBPs). PCBP2 regulates erythropoiesis via alternative splicing of gene transcripts that drive erythroid differentiation programs. Surprisingly, PCBPs were also discovered to function as intracellular iron chaperones, raising the question of whether iron-binding occurs independently of or in concert with RNA-binding. Given that iron levels intimately modulate red blood cell differentiation, we sought to investigate whether PCBP activity is modulated by iron in the context of red cell development. Specifically, we hypothesize that iron modulates the affinity or specificity of PCBPs towards target RNAs causing changes in RNA splicing that are important for red blood cell differentiation. We will address this hypothesis by i) determining the effect of iron on PCBP-RNA interactions using unbiased high throughput in vitro assays, ii) evaluating the effect of iron on PCBP-regulated RNA splicing events in cells, and iii) determine global gene expression and RNA splicing changes in primary human and mouse samples with and without iron deficiency. From these experiments we will uncover iron- sensitive RNA splicing programs that dictate erythropoiesis.