Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province, 63243, Republic of Korea.
Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province, 63243, Republic of Korea; Marine Science Institute, Jeju National University, Jeju Self-Governing Province, 63333, Republic of Korea.
Fish Shellfish Immunol. 2021 Feb;109:62-70. doi: 10.1016/j.fsi.2020.12.010. Epub 2020 Dec 19.
Glutathione S-transferases (GSTs) are important enzymes involved in phase II detoxification and function by conjugating with the thiol group of glutathione. In this study, we isolated an omega class GST from the big-belly seahorse (Hippocampus abdominalis; HaGSTO1) to study the putative xenobiotic responses and defense ability against viral and bacterial infections in this animal. The isolated HaGSTO1 gene, with a cording sequence of 720 bp, encodes a peptide of 239 amino acids. The predicted molecular mass and theoretical isoelectric point of HaGSTO1 was 27.47 kDa and 8.13, respectively. In-silico analysis of HaGSTO1 revealed a characteristic N-terminal thioredoxin-like domain and a C-terminal domain. Unlike other GSTs, the C-terminal of HaGSTO1 reached up to the N-terminal, and the N-terminal functional group was cysteine rather than tyrosine or serine, as observed in other GSTs. Phylogenetic analysis showed the evolutionary proximity of HaGSTO1 with other identified vertebrate and invertebrate GST orthologs. For the first time, we demonstrated the viral defense capability of HaGSTO1 against viral hemorrhagic septicemia virus (VHSV) infection. All six nucleoproteins of VHSV were significantly downregulated in HaGSTO1-overexpressing FHM cells at 24 h after infection compared with those in the control. Moreover, arsenic toxicity was significantly reduced in HaGSTO1-overexpressing FHM cells, and cell viability increased. Real-time polymerase chain reaction analysis showed that HaGSTO1 transcripts were highly expressed in the pouch and gill when compared with those in other tissues. Blood HaGSTO1 transcripts were significantly upregulated after Edwardsiella tarda, Streptococcus iniae, lipopolysaccharide, and polyinosinic:polycytidylic acid challenge experiments. Collectively, these findings suggest the involvement of HaGSTO1 in the host defense mechanism of seahorses.
谷胱甘肽 S-转移酶（GSTs）是参与 II 相解毒的重要酶，通过与谷胱甘肽的巯基结合发挥作用。本研究从大腹海马（Hippocampus abdominalis；HaGSTO1）中分离出一种ω类 GST，以研究该动物对异生物质的反应和防御病毒及细菌感染的能力。分离出的 HaGSTO1 基因，其编码序列为 720bp，编码 239 个氨基酸的肽。HaGSTO1 的预测分子质量和理论等电点分别为 27.47kDa 和 8.13。HaGSTO1 的计算机分析显示了一个特征性的 N 端硫氧还蛋白样结构域和 C 端结构域。与其他 GST 不同，HaGSTO1 的 C 端延伸到 N 端，而 N 端的功能基团是半胱氨酸而不是酪氨酸或丝氨酸，这与其他 GST 观察到的情况不同。系统进化分析表明，HaGSTO1 与其他已鉴定的脊椎动物和无脊椎动物 GST 同源物具有进化上的亲缘关系。我们首次证明了 HaGSTO1 对病毒性出血性败血症病毒（VHSV）感染的病毒防御能力。与对照组相比，感染后 24 小时，HaGSTO1 过表达的 FHM 细胞中所有 6 种核蛋白的表达均显著下调。此外，砷毒性在 HaGSTO1 过表达的 FHM 细胞中显著降低，细胞活力增加。实时聚合酶链反应分析显示，与其他组织相比，HaGSTO1 在袋和鳃中的转录本表达水平较高。在爱德华氏菌、链球菌、脂多糖和多聚肌苷酸：多聚胞苷酸刺激实验后，血液 HaGSTO1 转录本显著上调。综上所述，这些发现表明 HaGSTO1 参与了海马的宿主防御机制。
