SIGNAL TRANSDUCTION MECHANISMS AND LEAD TOXICITY

描述：(改编自《调查者摘要》)铅中毒 被确定为影响环境健康的最重要的危害 美国的儿童，但这种毒性的机制是 未知。多项研究证实，蛋白激酶C(PKC)是 对Pb2+非常敏感，从而表明该激酶在 在Pb2+介导的毒性中起关键作用。以前在这一领域的工作， 然而，一直集中在Pb2+对酶分析中PKC的影响和 关于它的细胞定位。研究还没有解决这些影响 Pb2+对培养细胞中PKC活性或蛋白质磷酸化的影响 活着。为了研究这个问题，我们将对红细胞进行检查，因为 它们是Pb2+的靶标，被PKC磷酸化的蛋白质已经被 它们在活体研究中比其他方法更容易获得 纸巾。这项研究的第一个长期目标是确定 Pb2+通过以下途径促进红细胞膜蛋白的磷酸化 激活PKC。这将在目标1中通过一个最终的 沙门氏菌细胞膜磷蛋白的免疫学和生化分析 体外暴露于Pb2+的人红细胞。此外， 激活机制将通过检查物理机制来阐明 发生在Pb2+和PKC之间的相互作用。第二个长期目标是 确定体内暴露于Pb2+是否会增加红细胞膜 蛋白质磷酸化。为此，从内部获得的信息 AIM 2将使用体外系统来研究蛋白质的磷酸化 分离Pb2+染毒大鼠红细胞。最终，一种蛋白质是 Pb2+升高的大鼠体内的磷酸化可能提供一个生物标志物 来监测Pb2+。

DESCRIPTION: (Adapted from the Investigator's Abstract) Lead toxicity has been identified as the most important environmental health hazard affecting children in the United States, but the mechanism for this toxicity is unknown. Several studies have established that protein kinase C (PKC) is exquisitely sensitive to Pb2+, thereby suggesting that this kinase plays a pivotal role in Pb2+-mediated toxicity. Previous work in this area, however, has focused on the effects of Pb2+ on PKC in enzymatic assays and on its cellular localization. Studies have not addressed the effects of Pb2+ on PKC activity or on protein phosphorylation in cultured cells or in vivo. In order to study this problem, erythrocytes will be examined because they are a target for Pb2+, proteins phosphorylated by PKC have been described, and they are more accessible in studies in vivo than other tissues. The first long term goal of this study is to determine whether Pb2+ stimulates phosphorylation of erythrocyte membrane proteins by activating PKC. This will be accomplished in Aim 1 by a definitive immunological and biochemical analysis of membrane phosphoproteins from human erythrocytes that were exposed in vitro to Pb2+. In addition, the mechanism of activation will be elucidated by examining the physical interaction that occurs between Pb2+ and PKC. The second long term goal is to determine whether exposure to Pb2+ in vivo increases erythrocyte membrane protein phosphorylation. For this purpose, information gained from the in vitro system will be used in Aim 2 to study protein phosphorylation in erythrocytes isolated from Pb2+-exposed rats. Ultimately, a protein that is phosphorylated in rats with elevated levels of Pb2+ may provide a biomarker to monitor Pb2+.