NOVEL IRON/HEMIN RESPONSIVE GENES IN HEMATOPOIESIS

铁是一种关键的营养元素，对许多种类的 重要的生物过程，包括细胞生长和分化， 电子转移反应，以及氧的传输、活化和 解毒。此外，最近越来越多的关注集中在角色上 铁在调节基因表达中的作用。铁对基因表达的调控 存在于细菌、植物、酵母和包括人类在内的哺乳动物中。这 铁的功能可能为进一步理解铁提供基础。 细胞增殖和分化的要求。尽管铁- 有反应的转录后基因调控已经被很好地描述了， 铁对转录调控的研究较少。我们的 实验室最近描述了一种新的铁依赖系统 转录调控。至少两个真核基因，蛋白激酶 C-β和酒石酸抗性酸性磷酸酶/子宫铁蛋白 在以铁形式存在的Fe(III)存在下转录活性 转铁蛋白(FeTf)，而两者都在转录水平上被抑制 在外源氯化血红素(铁原卟啉IX)存在的情况下。现在是时候了 建议在这些观察的基础上确定更多的基因 其表达受铁或氯化血红素的调节，并研究其作用 造血细胞中铁/氯化血红素调控基因的产物 增殖分化。以下是具体目标 建议：(1)研究hTRAP和hPKC-β基因的作用， 原型铁/氯化血红素反应基因，在造血中；(2)测试 其他具有候选氯化血红素调控的哺乳动物基因的可能性 基序也可能受铁和氯化血红素的调控；(3)通过聚合酶链式反应进行鉴定 差异杂交筛选)和/或差异显示PCR (DDRT-PCR)激活或抑制的新的造血细胞基因 通过铁或氯化血红素并确定它们在造血细胞中的作用 诱导分化；(4)将目的3中鉴定的克隆基因在 细菌表达系统，并检测纯化的效果， 重组蛋白对造血细胞分化的影响。鉴定 在转录水平上受铁和铁蛋白调控的一组基因 氯化血红素和阐明这些基因的可能功能 造血术将为扩大对铁的理解提供基础 以及相关化合物在细胞内稳态中的作用，应该会开辟新的途径 在铁的研究中进行调查。

Iron is a critical nutritional element essential for a great variety of important biological processes including cell growth and differentiation, electron transfer reactions, and oxygen transport, activation, and detoxification. Also, increasing recent attention has focused on the role of iron in regulating gene expression. Iron regulation of gene expression occurs in bacteria, plants, yeast, and mammals including humans. This function of iron may provide a basis for further understanding the iron requirements of cell proliferation and differentiation. Although iron- responsive post-transcriptional gene regulation has been well described, transcriptional regulation by iron has been less well studied. Our laboratory has recently delineated a novel iron-dependent system of transcriptional regulation. At least two eukaryotic genes, protein kinase C-beta and tartrate resistant acid phosphatase/uteroferrin, are transcriptionally active in the presence of Fe (III) presented as ferric transferrin (FeTF), whereas both are inhibited at the transcriptional level in the presence of exogenous hemin (ferric protoporphyrin IX). It is now proposed to build upon these observations to identify additional genes whose expression is regulated by iron or hemin and to examine the roles of the products of iron/hemin regulated genes in hematopoietic cell proliferation and differentiation. The following specific aims are proposed: (1) to study the roles of the hTRAP and hPKC-beta genes, prototype iron/hemin responsive genes, in hematopoiesis; (2) to test the possibility that other mammalian genes with candidate hemin regulatory motifs may also be regulated by iron and hemin; (3) to identify by PCR differential hybridization screening )PDHS) and/or differential display PCR (DDRT-PCR) new hematopoietic cell genes which are activated or suppressed by iron or hemin and to determine their roles in hematopoietic cell differentiation; (4) to express the cloned genes identified in Aim 3 in a bacterial expression system and to examine effects of the purified, recombinant proteins on hematopoietic cell differentiation. Identification of a group of genes regulated at the transcriptional level by iron and hemin and elucidation of the possible functions of these genes in hematopoiesis will provide a basis for an expanded understanding of iron and related compounds in cellular homeostasis and should open new avenues for investigation in iron research.