INFLUENCE OF ENTHALNOL ON MITOCHONDRIAL PROTEIN IMPORT

在这些研究中提出的假设是乙醇 消耗会损害前体蛋白的运输。 线粒体，并因此影响线粒体的功能和 集合。提议的实验将寻求确定1)是否 乙醇和乙醛可直接影响提取能力。 肝脏线粒体输入和加工特定的前体 蛋白质和2)如果长期使用乙醇影响进口 以及分离的肝脏线粒体的加工活性。这个 所提出的方法是使用体外 翻译/线粒体进口检测中的放射性 蛋白质将首先在体外用兔的裂解物合成 用大鼠肝脏RNA编程的网织红细胞。有放射性标记的 翻译产品随后将与分离的大鼠肝脏孵化。 线粒体和蛋白质的一般进口和加工 尤其是线粒体谷氨酸酶 脱氢酶(GDH)，将进行测定。后一种化验方法将 测定高相对分子质量前驱体GDH量 它被转化为成熟的、较低分子量的 这种酶。这些实验明确地试图确定 线粒体输入是否因酒精摄入而受损 以及这是否可能有助于乙醇诱导的 报告的线粒体结构和功能异常 其他。酒精对正常线粒体的损伤作用 功能可能参与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 线粒体输入可被乙醇和/或 在提议的乙醛实验中，它将是 首次直接演示一种机制，该机制可以解释 乙醇消费如何显著改变结构和 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.