STK-1--A HUMAN HEMATOPOIETIC GROWTH FACTOR RECEPTOR

我们对这一项目的长期目标是获得了解 参与调节人的生命的控制机制 淋巴造血干细胞(LHSC)和祖细胞。这是一个 重要的研究领域，因为它可能对临床产生影响 能够操纵这一过程。我们已经采取了这样的方法 受体酪氨酸激酶可能在调节 细胞数量或这些细胞的发育。这一前提是基于 关于它们在造血和血液系统中的作用的累积证据 非造血细胞。 我们成功地克隆了人受体酪氨酸的cdna。 STK-1，与c-fms和c-kit关系最密切，两者都是 参与造血的生长因子受体。STK-1是 从一群人的骨髓细胞中克隆出来的 富含LHSC和祖细胞。初步研究表明， STK-1的表达仅限于骨骼的这一“年轻”部分 骨髓。该受体的小鼠同源基因最近被克隆并被 表现为具有类似的受限表达模式。感受器 因此令人感兴趣，因为它可能提供潜在的见解 我们进入了对造血的控制。 我们已经提出了一系列实验，大多数试剂 已经作为我们初步工作的结果提供了。我们会 仔细观察STK-1在人骨髓中的表达 通过RT-PCR来确定STK-1可能在哪些细胞中发挥作用。 测试的级分将包括一些纯度最高的LHSC， 为我们提供受体是否在这些细胞上表达的指示 细胞。针对受体的抗体将使我们能够确认这些结果 通过流式细胞仪分析，可以进一步纯化这些细胞。 我们将研究STK-1基因编码的调节。我们会 首先完成包含该基因的区域的克隆。我们会 搜索赋予表达的顺式作用序列 报告基因分析。因此，可以洞察到对 其他基因的表达也同样局限于年轻的造血细胞 细胞。 我们将分析STK-1信号转导途径 地点。我们已经了解了信号转导的靶点 并希望发现一些新的蛋白质，如 井。 最后，我们将测试该受体参与 恶性肿瘤或其他涉及造血系统的疾病过程。 STK-1在几种白血病细胞系中表达的发现可能 表明它以某种方式参与其中。RNA和DNA样本来自 患有这些疾病的患者将接受过度表达或 受体的表达发生了变化。

Our long-term objectives for this project are to obtain an understanding of the control mechanisms involved in regulating human lymphohematopoietic stem (LHSC) and progenitor cells. This is an important area of research because of the potential clinical impact of being able to manipulate this process. We have taken the approach that receptor tyrosine kinases are likely to be important in regulating the cell numbers or the development of these cells. This premise is based on the accumulated evidence of their role in both hematopoietic and nonhematopoietic cells. We have successfully cloned the cDNA for a human receptor tyrosine kinase, STK-1, that is most closely related to c-fms and c-kit, both growth factor receptors that are involved in hematopoiesis. STK-1 was cloned from a population of human bone marrow cells that are greatly enriched for LHSC and progenitor cells. Initial studies indicate that the expression of STK-1 is restricted to this "young" fraction of bone marrow. The mouse homolog of this receptor was cloned recently and was shown to have similarly restricted pattern of expression. The receptor is therefore of interest because of the potential insights it may give us into the control of hematopoiesis. We have proposed a series of experiments for which most of the reagents are already available as an outcome of our preliminary work. We will carefully examine the expression of STK-1 in subfractionated human marrow by RT-PCR to determine in which cells STK-1 is likely to play a role. The fractions tested will include some of the most highly purified LHSC, to give us an indication of whether the receptor is expressed on these cells. Antibodies to the receptor will allow us to confirm these results by FACS analysis and may enable the further purification of these cells. We will investigate the regulation of the gene coding for STK-1. We will first complete the cloning of the region containing the gene. We will search for cis-acting sequences that confer expression by use of a reporter gene assay. Thus insight may be gained into the control of other genes with expression similarly restricted to "young" hematopoietic cells. We will analyze the pathway by which STK-1 signal transduction takes place. We will look at the targets of signal transduction already identified for other receptors and hope to find some novel proteins as well. Lastly, we will test the hypothesis that this receptor is involved in malignancy or other disease processes involving the hematopoietic system. The finding that STK-1 is expressed in several leukemic cell lines may be an indication that it is somehow involved. RNA and DNA samples from patients afflicted with these diseases will be tested over-expression or altered expression of the receptor.