INTERACTIONS OF HEAVY METAL IONS WITH THE HUMAN GENOME

描述：（改编自研究者摘要）这是一个 继续申请一项有关微量金属影响的长期项目 离子对人类细胞基因表达的影响。 在上一阶段，我们开始 研究有毒金属离子对信号转导途径的影响 用于基因表达、细胞增殖和 生存 发现肿瘤促进剂亚砷酸盐（As+3）是一种有效的 两个丝裂原活化蛋白激酶（MAPK）级联的激活剂， 刺激转录因子AP-1的活性。 As+3的这种效应是 由于双特异性蛋白磷酸酶JNK的抑制， 磷酸酶，其正常功能是使MAPKs、JNK和p38保持在一定的水平。 低活动状态。 由于AP-1活性的诱导与 在肿瘤促进中，JNK磷酸酶可能是一个重要的介导因子， As+3致癌作用。 它还可能参与As+3诱导的炎症反应 疾病 为了研究JNK磷酸酶的生理作用，我们将 使用生物化学的组合来表征和分子鉴定它， 和分子生物学方法。 显性阴性突变体将 转染到培养的细胞系中以抑制内源性JNK磷酸酶 活性，从而评估其在细胞生理学中的功能。 我们还将 检测JNK缺陷小鼠品系和细胞系的易感性 或JNK磷酸酶对As+3诱导的致癌作用和毒性的影响。 As+3和 其他微量金属也被认为是通过非特异性诱导作用 氧化应激。 因此，我们开始研究 转录因子NF-κ B，这被认为是一个主要的传感器， 氧化应激 我们最近纯化并克隆了一个关键成分， 导致NF-κ B活化的蛋白激酶途径， NF-κ B抑制剂的磷酸化和最终降解， IKB。 我们现在建议研究氧化剂 导致该IKB激酶（IKK）活化。 由于NF-κ B在 炎症，了解氧化剂对IKK活性的调节， 如臭氧，将提供氧化剂引起的炎症的分子基础 疾病

DESCRIPTION: (Adapted from the Investigator's Abstract) This is a continuation application for a long-term project on effects of trace metal ions on gene expression in human cells. During the last period, we began to investigate the effects of toxic metal ions on signal transduction pathways used for global regulation of gene expression, cell proliferation and survival. The tumor promoter arsenite (As+3) was found to be a potent activator of two mitogen activated protein kinase (MAPK) cascades that stimulate the activity of transcription factor AP-1. This effect of As+3 is due to inhibition of a dual-specificity protein phosphatase, JNK phosphatase, whose normal function is to keep the MAPKs, JNK and p38 in a low activity state. As induction of AP-1 activity is closely linked to tumor promotion, the JNK phosphatase is probably an important mediator of As+3 cocarcinogenesis. It may also be involved in As+3 induced inflammatory disease. To examine the physiological role of the JNK phosphatase we will characterize and molecularly identify it using a combination of biochemical and molecular biological approaches. Dominant-negative mutants will be transfected into cultured cell lines to inhibit endogenous JNK phosphatase activity and thus assess its function in cell physiology. We will also examine the susceptibility of mouse strains and cell lines deficient in JNK or JNK phosphatase to As+3 induced cocarcinogenesis and toxicity. As+3 and other trace metals were also proposed to act through non-specific induction of oxidant stress. We therefore started to investigate the regulation of transcription factor NF-KB, which was proposed to be a major sensor of oxidant stress. We recently purified and cloned a key component in the pathway leading to NF-KB activation, the protein kinase responsible for phosphorylation and eventual degradation of the inhibitors of NF-KB, the IKBs. We now propose to study the molecular mechanism by which oxidants lead to activation of this IKB kinase (IKK). As NF-KB plays a key role in inflammation, understanding the regulation of IKK activity by oxidants, such as ozone, will provide a molecular basis for oxidant induced inflammatory disease.