INFLUENCE OF ENTHALNOL ON MITOCHONDRIAL PROTEIN IMPORT

在这些研究中提出的假设是，乙醇 消耗损害前体蛋白质运输到 线粒体，因此影响线粒体功能， 组装件. 建议的实验将寻求确定1）如果 乙醇和乙醛可以直接影响 肝线粒体输入和处理特定前体 蛋白质和2）如果长期乙醇管理影响进口 和加工活性。 的 提出的方法是使用体外 翻译/线粒体输入测定，其中放射性 蛋白质将首先在体外合成使用兔的裂解物， 用大鼠肝脏RNA编程的网织红细胞。 的放射性标记 然后将翻译产物与离体大鼠肝脏孵育， 线粒体和蛋白质的输入和加工 尤其是线粒体谷氨酸酶 脱氢酶（GDH），将被测量。 后一种测定将 测定较高分子量前体GDH的量 转化为成熟的低分子量形式的 酶 这些实验旨在确定 线粒体输入是否因乙醇消耗而受损 以及这是否有助于乙醇诱导的 线粒体结构和功能的异常， 他人 酒精引起的正常线粒体损伤 功能可能有助于酒精性肝的发病机制 疾病，因为许多其他需要能量的细胞活动， 依赖于正常的线粒体能量产生。 如果 线粒体输入显示被乙醇和/或 乙醛在拟议的实验中，它将是一个 第一次直接证明了一种机制， 乙醇消费如何显著改变结构， 这个细胞器的功能。

The hypothesis proposed in these investigations is that ethanol consumption impairs the transport of precursor proteins into the mitochondrion, and therefore affects mitochondrial function and assembly. The experiments proposed will seek to determine 1) if ethanol and acetaldehyde can directly affect the ability of hepatic mitochondria to import and process a specific precursor protein and 2) if chronic ethanol administration affects the import and processing activity of isolated liver mitochondria. The methodology proposed is the use of an in vitro translation/mitochondrial import assay in which radioactive proteins will first be synthesized in vitro using lysates of rabbit reticulocytes programmed with rat liver RNA. The radiolabelled translation products will then be incubated with isolated rat liver mitochondria and, the import and processing of proteins in general and, in particular, of the mitochondrial enzyme glutamate dehydrogenase (GDH), will be measured. The latter assay will determine the amount of higher molecular weight precursor GDH that is converted to the mature, lower molecular weight form of the enzyme. These experiments specifically seek to determine whether mitochondrial import is impaired by ethanol consumption and whether this may contribute to the ethanol-induced abnormalities in mitochondrial structure and function reported by others. Alcohol-induced impairment of normal mitochondrial function may contribute to the pathogenesis of alcoholic liver disease since many other energy-requiring cellular activities are dependent on normal mitochondrial energy generation. If mitochondrial import is shown to be altered by ethanol and/or acetaldehyde in the proposed experiments, it will be one of the first direct demonstrations of a mechanism which may explain how ethanol consumption can significantly alter the structure and function of this organelle.