Laboratory of Molecular Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan.
Biochem Biophys Res Commun. 2011 Aug 5;411(3):580-5. doi: 10.1016/j.bbrc.2011.06.189. Epub 2011 Jul 6.
Gpx2, one of three glutathione peroxidase homologs (Gpx1, Gpx2, and Gpx3) in Saccharomyces cerevisiae, is an atypical 2-Cys peroxiredoxin that prefers to use thioredoxin as a reducing agent in vitro. Despite Gpx2 being an antioxidant, no obvious phenotype of gpx2Δ mutant cells in terms of oxidative stress has yet been found. To gain a clue as to Gpx2's physiological function in vivo, here we identify its intracellular distribution. Gpx2 was found to exist in the cytoplasm and mitochondria. In mitochondria, Gpx2 was associated with the outer membrane of the cytoplasmic-side, as well as the inner membrane of the matrix-side. The redox state of the mitochondrial Gpx2 was regulated by Trx1 and Trx2 (cytoplasmic thioredoxin), and by Trx3 (mitochondrial matrix thioredoxin). In addition, we found that the disruption of GPX2 reduced the sporulation efficiency of diploid cells.
Gpx2 是酿酒酵母中三种谷胱甘肽过氧化物酶同源物（Gpx1、Gpx2 和 Gpx3）之一，是一种非典型的 2-Cys 过氧化物酶，在体外更倾向于使用硫氧还蛋白作为还原剂。尽管 Gpx2 是一种抗氧化剂，但尚未发现 gpx2Δ 突变细胞在氧化应激方面有明显的表型。为了了解 Gpx2 在体内的生理功能，我们在这里确定了它的细胞内分布。发现 Gpx2 存在于细胞质和线粒体中。在线粒体中，Gpx2 与细胞质侧的外膜以及基质侧的内膜相关联。线粒体 Gpx2 的氧化还原状态受 Trx1 和 Trx2（细胞质硫氧还蛋白）以及 Trx3（线粒体基质硫氧还蛋白）的调节。此外，我们发现破坏 GPX2 会降低二倍体细胞的产孢效率。
