State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, PR China.
Gene. 2013 Sep 15;527(1):33-41. doi: 10.1016/j.gene.2013.05.062. Epub 2013 Jun 7.
Thioredoxins (Trxs) are a family of small, highly conserved and ubiquitous proteins that are involved in protecting organisms against toxic reactive oxygen species (ROS). In this study, a typical thioredoxin 2 gene was isolated from Apis cerana cerana, AccTrx2. The full-length cDNA sequence of AccTrx2 was composed of 407 bp containing a 318 bp open reading frame (ORF) that encodes a predicted protein of 105 amino acids, 11.974 kDa and an isoelectric point of 4.45. Expression profile of AccTrx2 as determined by a quantitative real-time PCR (qRT-PCR) analysis was higher in brain than in other tissues, with its highest transcript occurring on the 15day post-emergence adult and upregulated by such abiotic stresses as 4 °C, 16 °C, 25 °C, H2O2, cyhalothrin, acaricide, paraquat, phoxime and mercury (HgCl2) treatments. However, AccTrx2 was slightly repressed when exposed to 42 °C treatment. Characterisation of the recombinant protein showed that the purified AccTrx2 had insulin disulfide reductase activity and could protect DNA from ROS damage. These results indicate that AccTrx2 functions as an antioxidant that plays an important role in response to oxidative stress.
硫氧还蛋白（Trxs）是一类小型、高度保守且普遍存在的蛋白质，参与保护生物免受有毒活性氧（ROS）的侵害。在本研究中，从中华蜜蜂中分离到了一个典型的硫氧还蛋白 2 基因，命名为 AccTrx2。AccTrx2 的全长 cDNA 序列由 407bp 组成，包含一个 318bp 的开放阅读框（ORF），编码一个预测的 105 个氨基酸的蛋白质，分子量为 11.974kDa，等电点为 4.45。通过定量实时 PCR（qRT-PCR）分析确定的 AccTrx2 表达谱在脑中的表达高于其他组织，其转录本在出房后 15 天的成虫中最高，并受到 4°C、16°C、25°C、H2O2、氯氰菊酯、杀螨剂、百草枯、肟和汞（HgCl2）等非生物胁迫的上调。然而，当暴露于 42°C 处理时，AccTrx2 略有抑制。重组蛋白的特性表明，纯化的 AccTrx2 具有胰岛素二硫键还原酶活性，可以保护 DNA 免受 ROS 损伤。这些结果表明，AccTrx2 作为一种抗氧化剂发挥作用，在应对氧化应激中起着重要作用。
