Pákozdi Klaudia, Antal Károly, Pázmándi Kitti, Miskei Márton, Szabó Zsuzsa, Pócsi István, Emri Tamás
Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary.
Doctoral School of Nutrition and Food Sciences, University of Debrecen, H-4032 Debrecen, Hungary.
J Fungi (Basel). 2024 Nov 27;10(12):823. doi: 10.3390/jof10120823.
The importance of manganese superoxide dismutase (Mn-SOD), an evolutionarily ancient metalloenzyme that maintains the integrity and function of mitochondria, was studied in oxidative stress-treated cultures. Deletion of the Mn-SOD gene () increased both the menadione sodium bisulfite (MSB)-elicited oxidative stress and the deferiprone (DFP)-induced iron limitation stress sensitivity of the strain. Moreover, DFP treatment enhanced the MSB sensitivity of both the gene deletion mutant and the reference strain. The lack of SodB also increased the susceptibility of conidia to killing by human macrophages. Concurring with the stress sensitivity data, RNS sequencing data also demonstrated that the deletion of largely altered the MSB-induced oxidative stress response. The difference between the oxidative stress responses of the two strains manifested mainly in the intensity of the response. Importantly, upregulation of "Ribosome protein", "Iron uptake", and "Fe-S cluster assembly" genes, alterations in the transcription of "Fe-S cluster protein" genes, and downregulation of "Heme binding protein" genes under MSB stress were characteristic only for the Δ gene deletion mutant. We assume that the elevated superoxide level generated by MSB treatment may have destroyed Fe-S cluster proteins of mitochondria in the absence of SodB. This intensified the resynthesis of Fe-S cluster proteins, which was accompanied with enhanced translation and iron acquisition, leading to increased DFP sensitivity.
锰超氧化物歧化酶（Mn-SOD）是一种在进化上古老的金属酶，可维持线粒体的完整性和功能。本文研究了其在氧化应激处理的培养物中的重要性。Mn-SOD基因（）的缺失增加了甲萘醌亚硫酸氢钠（MSB）引发的氧化应激以及去铁酮（DFP）诱导的铁限制应激对该菌株的敏感性。此外，DFP处理增强了基因缺失突变体和参考菌株对MSB的敏感性。SodB的缺失还增加了分生孢子对人巨噬细胞杀伤的敏感性。与应激敏感性数据一致，RNS测序数据也表明，的缺失在很大程度上改变了MSB诱导的氧化应激反应。两种菌株氧化应激反应的差异主要体现在反应强度上。重要的是，在MSB应激下，“核糖体蛋白”、“铁摄取”和“铁硫簇组装”基因的上调、“铁硫簇蛋白”基因转录的改变以及“血红素结合蛋白”基因的下调仅为Δ基因缺失突变体所特有。我们推测，在没有SodB的情况下，MSB处理产生的超氧化物水平升高可能破坏了线粒体的铁硫簇蛋白。这加剧了铁硫簇蛋白的重新合成，同时伴随着翻译和铁摄取增强，导致DFP敏感性增加。
