LINOLEIC ACID METABOLITES WITH PROTEIN TYROSINE KINASES & PHOSPATASES

具有蛋白质酪氨酸激酶的亚油酸代谢物

• 批准号: 2574396
• 负责人: T ELING
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF ENVIRONMENTAL HEALTH SCIENCES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/2574396
• 关键词: DNA replication; biological signal transduction; chemical association; enzyme activity; epidermal growth factor; fatty acid metabolism; gene expression; gene mutation; growth factor receptors; hamsters; linoleate; molecular cloning; phosphorylation; prostaglandins; protein tyrosine kinase; protein tyrosine phosphatase; receptor binding; tissue /cell culture; tumor suppressor genes

The focus of this project is to examine the mechanism(s) by which prostaglandins and linoleic acid metabolites potentiate the EGF mitogenic signal in fibroblast cell lines. In our previous work with Syrian hamster embryo (SHE) cells, we found that linoleate products stimulate EGF- dependent DNA synthesis in normal cells, but do not enhance the mitogenic response in variant SHE cells that had lost tumor suppressor gene function. One plausible interpretation of these results is that the tumor suppressor (-) cell line lacks the responsive element in the EGF signal transduction pathway which interacts with linoleate compounds. These results suggest that linoleate products may act at control points where tumor suppressor genes interact with EGF-mitogenic signals, in particular, the protein tyrosine phosphorylation pathway. We have recently examined in more detail the expression of signaling proteins and the extent of their tyrosine phosphorylation of the EGF signaling pathway in the two SHE cell variants. One minor differences in protein levels was observed with the exception that higher level of eps8 was observed in the supB' variant. The SH-2 containing tyrosine phosphatase PTP-1-D binds to the phosphorylated EGFR in the supB+ as expected but does not bind to the phosphorylated EGFR in the supB' cells. Incubation of human purified PTP-1-D with SHE cells does result in the bind of the EGFR of both variants. This and other data point to a mutation or defect in the PTP-1-D present in the supB' cells. Furthermore, the activity of the PTP-1-D is greater in the supB+ variant compared to the supB' cell. We are in the process of cloning the PTP-1-D and the EGFR receptor from the SHE cells. We are also deterring if the 13(S)-HpODE alters either the activity or the association of the PTP-1-D with the EGFR.

该项目的重点是研究以下机制： 前列腺素和亚油酸代谢物增强 EGF 促有丝分裂 成纤维细胞系中的信号。在我们之前与叙利亚仓鼠的合作中 胚胎（SHE）细胞，我们发现亚油酸酯产品刺激 EGF- 正常细胞中依赖 DNA 合成，但不增强有丝分裂 失去抑癌基因的变异 SHE 细胞的反应 功能。 对这些结果的一种合理解释是 肿瘤抑制 (-) 细胞系缺乏 EGF 中的反应元件 与亚油酸酯化合物相互作用的信号转导途径。 这些结果表明亚油酸酯产品可能在控制点起作用 肿瘤抑制基因与 EGF 促有丝分裂信号相互作用， 特别是蛋白质酪氨酸磷酸化途径。 我们最近更详细地研究了信号传导的表达 蛋白质及其 EGF 酪氨酸磷酸化程度 两种 SHE 细胞变体中的信号通路。 一处细微差别 观察到蛋白质水平的变化，但较高水平的 在supB'变体中观察到eps8。 含有酪氨酸的SH-2 磷酸酶 PTP-1-D 与 suB+ 中的磷酸化 EGFR 结合 预期的，但不与supB'细胞中的磷酸化EGFR结合。 将人纯化的 PTP-1-D 与 SHE 细胞一起孵育确实会导致 两种变体的 EGFR 结合。 该数据和其他数据表明 存在于supB'细胞中的PTP-1-D的突变或缺陷。 此外，supB+ 变体中 PTP-1-D 的活性更高 与supB'细胞相比。 我们正在克隆 PTP-1-D 以及来自SHE细胞的EGFR受体。 我们也正在阻止如果 13(S)-HpODE 改变 PTP-1-D 的活性或关联 与EGFR。