Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, 210046, China.
Insect Sci. 2022 Feb;29(1):215-229. doi: 10.1111/1744-7917.12930. Epub 2021 May 28.
The sigma glutathione S-transferases (GSTSs) are a class of cytosolic glutathione S transferases (GSTs) that play important roles in antioxidant defense in insects, but the mechanisms by which GSTSs contribute to antioxidant activity remain unclear. Here, we isolated a GSTS (GSTS6) from Tribolium castaneum and explored its function. Homology and phylogenetic analysis revealed that TcGSTS6 shared high identity with other evolutionarily conserved GSTSs. The recombinant TcGSTS6 protein had strong activity toward cumene hydroperoxide and 4-hydroxynonenal but low activity toward the universal substrate 1-chloro-2,4-dinitrobenzene. Exposure to various types of oxidative stress, including heat, cold, UV and pathogenic microbes, significantly induced TcGSTs6 expression, which indicates that it is involved in antioxidant defense. Knockdown TcGSTs6 by using RNA interference (RNAi) caused reduced antioxidant capacity, which was accomplished by cooperating with other antioxidant genes. Moreover, treatment with various insecticides such as phoxim, lambda-cyhalothrin, dichlorvos and carbofuran revealed that TcGSTS6 plays an important role in insecticide detoxification. The RNAi results showed that TcGSTS6 is essential for embryogenesis in T. castaneum. Our study elucidates the mechanism by which a GSTS contributes to antioxidant activity and enhances our understanding of the functional diversity of GSTSs in insects.
sigma 谷胱甘肽 S-转移酶（GSTs）是一类细胞溶质谷胱甘肽 S-转移酶（GSTs），在昆虫的抗氧化防御中发挥重要作用，但 GSTs 如何有助于抗氧化活性的机制尚不清楚。在这里，我们从赤拟谷盗中分离出一种 GSTS（GSTS6），并探索了其功能。同源性和系统发育分析表明，TcGSTS6 与其他进化上保守的 GSTS 具有高度同源性。重组 TcGSTS6 蛋白对 cumene hydroperoxide 和 4-hydroxynonenal 具有很强的活性，但对通用底物 1-氯-2,4-二硝基苯的活性较低。暴露于各种类型的氧化应激，包括热、冷、紫外线和致病微生物，显著诱导 TcGSTs6 的表达，这表明它参与了抗氧化防御。使用 RNA 干扰（RNAi）敲低 TcGSTs6 会导致抗氧化能力降低，这是通过与其他抗氧化基因合作实现的。此外，用各种杀虫剂如 phoxim、lambda-cyhalothrin、敌敌畏和carbofuran 处理表明，TcGSTS6 在杀虫剂解毒中起重要作用。RNAi 结果表明，TcGSTS6 是赤拟谷盗胚胎发生所必需的。我们的研究阐明了 GSTS 如何有助于抗氧化活性的机制，并增强了我们对昆虫中 GSTS 功能多样性的理解。
