FUNCTIONAL STUDIES OF CYTOSOLIC ANTIOXIDANT PROTEINS

描述：空气中的生命是可能的，因为 生物体中的氧气通常是缓慢的。此外，氧化 对健康细胞成分的损害通常通过以下方法来预防或修复 存在于细胞中的抗氧化剂、替代或修复系统 维持和恢复氧化还原平衡的目的。我们的方法是 研究超氧化物、过氧化氢、金属离子和小分子的作用 酵母中的分子抗氧化剂。酿酒酵母 是一种简单的真核生物，其广泛的遗传学和分子生物学 是存在的。来自高等生物体的许多基因已被证明可以替代 在功能上，他们的酵母类似物，以及更多，现在预计整个 酵母基因组已经测序，可以使用了。当生长在一种 非发酵碳源，酵母细胞以一种方式代谢氧气 类似于人类细胞，以及用于预防、修复和 氧化损伤的细胞成分的替换也是相似的。酵母菌 因此是研究氧化还原平衡的一个很好的系统 维持在健康的真核细胞中。这些研究有望引领 为了更好地理解真核生物中的氧化还原平衡和 “氧化应激”在导致人类衰老、细胞死亡、 和疾病。我们将确定超氧化物的主要自然来源和 酵母菌中的过氧化氢，并测定其浓度和 细胞内的小分子抗氧化剂(还原和氧化)。这些 方法将应用于野生型菌株和各种突变株 抗氧化系统和/或氧气代谢一直处于 修改；结果将用于解释观察到的 这些突变菌株。自然产生的过氧化氢传感器 参与基因表达调控的水平将被研究。 将测定铜、锌、锰和钙金属离子的水平。 在野生型和突变型菌株中各种抗氧化剂的水平 系统已经被修改。添加或耗尽金属离子的影响 关于抗氧化剂和促氧化剂过程的性质和比率以及 将在野生型和突变型中检查氧化还原平衡的维持 压力也很大。不同的金属离子扮演的角色也将是 在酵母模型系统中进行检查，旨在研究与 衰老、细胞死亡和疾病。

DESCRIPTION: Life in air is possible because uncatalyzed reactions of dioxygen in living organisms are usually slow. In addition, oxidative damage to components of healthy cells is frequently prevented or repaired by antioxidant, replacement, or repair systems that exist in the cells for the purpose of maintaining and restoring redox balance. Our approach is to study the roles of superoxide, hydrogen peroxide, metal ions, and small molecule antioxidants in the yeast S. cerevisiae. The yeast S. cerevisiae is a simple eucaryote for which extensive genetics and molecular biology exist. Many genes from higher organism have been shown to substitute functionally for their yeast analogs, and more are expected now the entire yeast genome has been sequenced and is available. When grown on a non-fermentable carbon source, yeast cells metabolize dioxygen in a fashion similar to human cells, and the cellular systems for prevention, repair, and replacement of oxidatively damaged cell components are also similar. Yeast is thus an excellent system in which to study how redox balance is maintained in healthy eucaryotic cells. These studies are expected to lead to a better understanding of redox balance in eucaryotic organisms and the role of "oxidative stress" in processes leading to human aging, cell death, and disease. We will determine the major natural sources of superoxide and hydrogen peroxide in yeast and measure their concentrations and those of small molecule antioxidants (reduced and oxidized) within the cells. These methods will be applied to the wild type strains and to a variety of mutant strains in which antioxidant systems and/or dioxygen metabolism have been modified; the results will be used to interpret the phenotypes observed for these mutant strains. Naturally occurring sensors of hydrogen peroxide levels that are involved in regulation of gene expression will be studied. Levels of copper, zinc, manganese, and calcium metal ions will be determined in wild type and mutant strains in which levels of various antioxidant systems have been modified. Effects of addition or depletion of metal ions on the nature and rates of antioxidant and pro-oxidant processes and the maintenance of redox balance will be examined in the wild type and mutant strains as well. The roles played by the different metal ions will also be examined in yeast model systems designed to investigate processes related to aging, cell death and disease.