Institute of Biology, College of Natural Sciences, University of Rzeszow, 35-959 Rzeszow, Poland.
Department of Plant Biology and Biotechnology, Faculty of Biotechnology and Horticulture, University of Agriculture in Krakow, 31-425 Krakow, Poland.
Int J Mol Sci. 2024 Aug 27;25(17):9296. doi: 10.3390/ijms25179296.
Redox homeostasis is the balance between oxidation and reduction reactions. Its maintenance depends on glutathione, including its reduced and oxidized form, GSH/GSSG, which is the main intracellular redox buffer, but also on the nicotinamide adenine dinucleotide phosphate, including its reduced and oxidized form, NADPH/NADP. Under conditions that enable yeast cells to undergo fermentative metabolism, the main source of NADPH is the pentose phosphate pathway. The lack of enzymes responsible for the production of NADPH has a significant impact on yeast cells. However, cells may compensate in different ways for impairments in NADPH synthesis, and the choice of compensation strategy has several consequences for cell functioning. The present study of this issue was based on isogenic mutants: Δ, Δ, Δ, and the wild strain, as well as a comprehensive panel of molecular analyses such as the level of gene expression, protein content, and enzyme activity. The obtained results indicate that yeast cells compensate for the lack of enzymes responsible for the production of cytosolic NADPH by changing the content of selected proteins and/or their enzymatic activity. In turn, the cellular strategy used to compensate for them may affect cellular efficiency, and thus, the ability to grow or sensitivity to environmental acidification.
氧化还原平衡是氧化和还原反应之间的平衡。其维持取决于谷胱甘肽，包括其还原和氧化形式 GSH/GSSG，它是主要的细胞内氧化还原缓冲剂，但也取决于烟酰胺腺嘌呤二核苷酸磷酸，包括其还原和氧化形式 NADPH/NADP。在允许酵母细胞进行发酵代谢的条件下，NADPH 的主要来源是戊糖磷酸途径。缺乏产生 NADPH 的酶对酵母细胞有重大影响。然而，细胞可能会以不同的方式补偿 NADPH 合成的损伤，而补偿策略的选择对细胞功能有几个后果。本研究基于同基因突变体：Δ、Δ、Δ 和野生型菌株，以及综合的分子分析，如基因表达水平、蛋白质含量和酶活性。获得的结果表明，酵母细胞通过改变选定蛋白质的含量和/或其酶活性来补偿负责产生细胞质 NADPH 的酶的缺乏。反过来，细胞用来补偿它们的策略可能会影响细胞效率，从而影响生长能力或对环境酸化的敏感性。
