SIGNAL TRANSDUCTION MECHANISMS AND LEAD TOXICITY

描述：（改编自研究者摘要）铅毒性 已被确定为最重要的环境健康危害， 在美国的儿童，但这种毒性的机制是 未知 几项研究已经确定蛋白激酶C（PKC）是一种重要的蛋白激酶。 对Pb2+非常敏感，从而表明这种激酶在 在Pb2+介导的毒性中起关键作用。 以前在这方面的工作， 然而，在酶法测定中， 在细胞定位上。 研究还没有解决的影响， Pb2+对PKC活性或蛋白磷酸化的影响 vivo. 为了研究这个问题，将检查红细胞，因为 它们是Pb2+的靶点，被PKC磷酸化的蛋白质已经被发现， 描述，并且它们在体内研究中比其他方法更容易获得。 组织中 这项研究的第一个长期目标是确定是否 Pb~（2+）刺激红细胞膜蛋白磷酸化 激活PKC。 这将在目标1中通过一个明确的 膜磷蛋白免疫学和生物化学分析 体外暴露于Pb2+的人红细胞。 此外该 激活机制将通过检查物理 Pb2+与PKC之间的相互作用。 第二个长期目标是 为了确定体内暴露于Pb2+是否会增加红细胞膜 蛋白质磷酸化 为此目的， 体外系统将用于目的2研究蛋白质磷酸化， 从铅暴露的大鼠中分离的红细胞。 最终，一种蛋白质， 磷酸化的大鼠与升高水平的Pb2+可能提供一个生物标志物 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+.