SCL GENE AND HEMATOPOIETIC DEVELOPMENT

这项拟议的研究将调查TIMP的表达和功能 SCL基因在造血发育过程中的蛋白产物 在老鼠身上。这个基因最初是在一个断裂点发现的 人类T细胞白血病的染色体易位，是 转录因子家族，其成员被认为是 分化的调节器。这些实验的结果应该是 提供对造血基本机制的洞察。自.以来 最常见的是通过染色体重排来激活这个基因。 急性T细胞白血病的遗传损害，这些研究也应该 有助于我们理解白血病的发生。第一个具体 这项工作的目的是刻画 小鼠SCL基因在造血细胞中的表达。美国人的蛋白质产品 小鼠SCL基因将在造血细胞系和 小鼠组织进行放射免疫沉淀和Western印迹分析。 SCL蛋白的亚细胞定位将由以下因素决定 COS细胞和稳定表达细胞系的瞬时表达 单独的蛋白质。第二个具体目标是描述 小鼠SCL基因的转录和翻译产物 在造血发育过程中。将研究SCL mRNA的表达 通过核糖核酸酶保护、原位杂交和聚合酶链 免疫细胞化学方法检测细胞增殖反应及SCL蛋白的表达 分期的小鼠胚胎。转录和翻译产品 也将在体外模型中表征该基因的特征 利用胚胎干细胞(ES细胞)进行造血发育 类胚体。第三个具体目标是定义 SCL蛋白在造血发育中的作用这件事将被调查 在功能获得和功能丧失的ES细胞突变体中 经历分化。第四个具体目标是确定 SCL蛋白作为转录调节因子的能力 在造血发育过程中。SCL蛋白的能力 激活人工目标和生理目标，如果识别的话 要下定决心。某些SCL蛋白可能具有 不同的转录能力，并作为转录 将对拮抗者进行调查。细胞目标将被识别 使用基于SCL诱导的分离的功能策略 启动子，以及不同SCL亚型激活这些 发起人将被定义。

The proposed research will investigate the expression and functions of the protein products of the SCL gene during hematopoietic development in the mouse. This gene was first identified at the breakpoint of a chromosomal translocation in human T-cell leukemia and is a member of a family of transcription factors whose members are recognized to be regulators of differentiation. The results of these experiments should provide insight into basic mechanisms of hematopoiesis. Since activation of this gene by chromosomal rearrangement is the most common genetic lesion in acute T-cell leukemia, these studies should also contribute to our understanding of leukemogenesis. The first specific aim of this work is to characterize the translational products of the murine SCL gene in hematopoietic cells. The protein products of the murine SCL gene will be characterized in hematopoietic cell lines and mouse tissues by radioimmunoprecipitation and Western blot analysis. Subcellular localization of SCL proteins will be determined by transient expression in COS cells and in cell lines stably expressing individual proteins. The second specific aim is to characterize the transcriptional and translational products of the murine SCL gene during hematopoietic development. SCL mRNA expression will be studied with RNase protection, in situ hybridization, and the polymerase chain reaction (PCR) and SCL protein expression by immunocytochemistry in staged mouse embryos. The transcriptional and translational products of the gene will also be characterized in an in vitro model of hematopoietic development using embryonic stem (ES) cell-derived embryoid bodies. The third specific aim is to define the actions of SCL proteins in hematopoietic development. This will be investigated in gain of function and loss of function mutants of ES cells made to undergo differentiation. The fourth specific aim is to determine the ability of SCL proteins to function as transcriptional regulators during hematopoietic development. The ability of SCL proteins to transactivate artificial and, if identified, physiologic targets will be determined. The possibility that certain SCL proteins may have different transcriptional potencies and act as transcriptional antagonists will be investigated. Cellular targets will be identified using a functional strategy based on the isolation of SCL-inducible promoters, and the ability of different SCL isoforms to activate such promoters will be defined.