ABI-1 GENE PRODUCT IN SIGNAL TRANSDUCTION & TRANSFORMATION BY VABL & BCR-ABL

这项研究描述了实验，以确定功能的Abi-1 （Abelson interactor-1）蛋白在肿瘤转化中的作用 Abelson癌蛋白v-Abl和BCR-ABL。 细胞质酪氨酸激酶; v-Abl是由细胞质酪氨酸激酶表达的活化形式。 Abelson小鼠白血病病毒，导致小鼠前B淋巴瘤， BCR-ABL是一种不太有效的版本，负责慢性髓细胞性白血病。 白血病（CML），有时是急性淋巴细胞白血病（ALL）， 人类Abi-1最初是用酵母双杂交技术鉴定的， 系统作为一种新的SH 3蛋白，结合到富含脯氨酸的C末端 v-Abl的尾部并抑制其转化活性。遗传和 将进行生化实验以确定哪个信号 转导途径由Abi-1蛋白控制或抑制 或被阿比-1蛋白抑制。表达高水平的 将检测野生型或突变型Abi-1的激活， 下游靶基因（c-myc，DHFR）;用于激活下游 靶基因（c-myc，DHFR）：用于激活已知的PDGF途径（Ras， PLCg，PI 3 K）;用于刺激细胞周期调节蛋白;以及用于 磷酸化和激活Jak/Stat和Crkl蛋白。人类 将测试来自CML患者的肿瘤样品以确定 Abi-1蛋白，以及与BCR-ABL结合的部分。 ABL将产生转化活性。酵母双杂交 系统将用于分离与一个伴侣结合但不与另一个伴侣结合的突变体。 携带相关突变的病毒， 在细胞系和小鼠中测试转化活性。这些 实验应该有助于确定哪些不同的途径 是致癌转化所必需的。这些 实验可以提供关于诱导的重要信息， 人类CML和ALL的疾病进展。

This study describes experiments to determine the functions of the Abi-l (Abelson interactor-1) protein in oncogenic transformation by the Abelson oncoproteins v-Abl and BCR-ABL. The Abelson gene encodes a cytoplasmic tyrosine kinase; v-Abl is an activated form expressed by the Abelson murine leukemia virus, causing a pre-B lymphoma in mice, which BCR-ABL is a less potent version responsible for chronic myelogenous leukemia (CML) and, sometimes, acute lymphocytic leukemia (ALL) in humans. Abi-l was originally identified using the yeast two-hybrid system as a novel SH3 protein that binds to the proline-rich C terminal tail of v-Abl and suppresses its transforming activity. Genetic and biochemical experiments will be performed to determine which signal transduction pathways are controlled or inhibited by the Abi-1 protein or inhibited by the Abi-1 proteins. Cell lines expressing high levels of either the wild-type or mutant Abi-1 will be examined for activation of downstream target genes (c-myc, DHFR); for activation of downstream target genes (c-myc, DHFR): for activation of known PDGF pathways (Ras, PLCg, PI3K); for stimulation of cell cycle regulatory proteins; and for phosphorylation and activation of Jak/Stat and Crkl proteins. Human tumor samples from CML patients will be tested to determine the level of Abi-1 protein, and the fraction bound to BCR-ABL. Finally, mutants of v- Abl will be generated that transforming activity. The yeast two-hybrid system will be used to isolate mutants that bind to one partner but not to others, and viruses carrying the relevant mutations will then be tested for transforming activity in cell lines and mice. These experiments should help identify which of the various pathways emanating from the Abl kinase are required for oncogenic transformation. These experiments may provide important information about the induction and progression of disease in human CML and ALL.