Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
Redox Rep. 2023 Dec;28(1):2168635. doi: 10.1080/13510002.2023.2168635.
Methionine sulfoxide reductases are found in all aerobic organisms. They function in antioxidant defense, cellular regulation by reversible oxidation of methionine in proteins, and in protein structure. However, very few binding partners or substrates of the reductases have been identified.
We implemented a proximity labeling method, TurboID, to covalently link mitochondrial methionine sulfoxide reductase A (MSRA) to its binding partners in HEK293 cells. Proteomic analyses were performed to identify putative binding partners.
We show that human Ndufaf2, also called mimitin, is a binding partner of MSRA as well as all 3 MSRBs. We found that both methionine residues in Ndufaf2 were susceptible to oxidation by hydrogen peroxide and that the methionine sulfoxide reductases can reduce these methionine sulfoxide residues back to methionine.
Methionine sulfoxide reductases can reduce methionine sulfoxide back to methionine in Ndufaf2. In addition to a repair function, it also creates a mechanism that could regulate cellular processes by modulation of methionine oxidation in Ndufaf2.
甲硫氨酸亚砜还原酶存在于所有需氧生物中。它们在抗氧化防御、蛋白质中蛋氨酸的可逆氧化的细胞调节以及蛋白质结构中发挥作用。然而，仅鉴定出极少数还原酶的结合伴侣或底物。
我们实施了一种邻近标记方法 TurboID，以使线粒体甲硫氨酸亚砜还原酶 A (MSRA)与 HEK293 细胞中的其结合伴侣发生共价连接。进行蛋白质组学分析以鉴定潜在的结合伴侣。
我们表明人 Ndufaf2，也称为 mimitin，是 MSRA 以及所有 3 种 MSRBs 的结合伴侣。我们发现 Ndufaf2 中的两个蛋氨酸残基都易受过氧化氢的氧化，并且甲硫氨酸亚砜还原酶可以将这些蛋氨酸亚砜残基还原回蛋氨酸。
甲硫氨酸亚砜还原酶可以将 Ndufaf2 中的蛋氨酸亚砜还原为蛋氨酸。除了修复功能外，它还通过调节 Ndufaf2 中的蛋氨酸氧化来创建一种可以调节细胞过程的机制。
