The iron-sulfur protein subunit of succinate dehydrogenase is critical in driving mitochondrial reactive oxygen species generation in Apostichopus japonicus.
The iron-sulfur protein subunit of succinate dehydrogenase is critical in driving mitochondrial reactive oxygen species generation in Apostichopus japonicus.
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DOI：
10.1016/j.fsi.2020.04.060
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发表时间：
2020-05
影响因子：
4.7
通讯作者：
Lianlian Sun;Fangyuan Zhou;Y. Shao;Zhimeng Lv;Chenghua Li
中科院分区：
文献类型：
--
作者：
Lianlian Sun;Fangyuan Zhou;Y. Shao;Zhimeng Lv;Chenghua Li
Succinate dehydrogenase (SDH) is a mitochondrial enzyme with the unique ability to participate in both the tricarboxylic acid cycle and the electron transport chain to produce reactive oxygen species (ROS). The B subunit of SDH is required for succinate oxidation, which is critical for pro-inflammatory response. In this study, we cloned the iron–sulfur protein subunit of SDH from Apostichopus japonicus (denoted asAjSDHB) via RACE technology and explored its role in the immune system as a response to pathogen infection. The full-length cDNA ofAjSDHBwas 1442 bp with a complete open reading frame of 858 bp encoding 286 amino acids. Simple modular architecture research tool analysis revealed thatAjSDHBcontained two conserved domains, including a 2Fe–2S iron–sulfur cluster binding domain and a 4Fe–4S dicluster domain, without a signal peptide. Multiple sequence alignment demonstrated thatAjSDHBshared a high degree of structural conservation and sequence identities with other counterparts from invertebrates and vertebrates. Phylogenetic analysis supported the finding thatAjSDHBis a new member of the SDHB protein subfamily. Tissue distribution analysis revealed thatAjSDHBwas expressed in all examined tissues and particularly highly expressed in the muscles.AjSDHBtranscripts were markedly induced in coelomocytes both by Vibrio splendidus challengein vivoand lipopolysaccharide exposurein vitro. Function analysis showed that siRNA-mediatedAjSDHBknockdown could substantially reduce the mitochondrial membrane potential (ΔΨm) and further decrease mitochondrial ROS production inA. japonicuscoelomocytes. By contrast,AjSDHBoverexpression considerably increased ΔΨm and mitochondrial ROS production ofA. japonicuscoelomocytes. These results supported the idea that AjSDHB is involved in the innate immunity ofA. japonicusthrough its participation in mitochondrial ROS generation.
