Marine Biotechnology Division, Central Marine Fisheries Research Institute, P.B. No 1603, Ernakulam North P.O., Kochi 682018, Kerala, India.
Fish Shellfish Immunol. 2013 Mar;34(3):946-50. doi: 10.1016/j.fsi.2012.12.024. Epub 2013 Jan 12.
Because of its capacity to rapidly convert superoxide to hydrogen peroxide, superoxide dismutase (SOD) is crucial in both intracellular signalling and regulation of oxidative stress. In this paper we report the cloning of a Cu/Zn SOD (designated as pfSOD) from the pearl oyster (Pinctada fucata) using rapid amplification of cDNA ends (RACE) PCR. The full-length cDNA of this Cu/Zn SOD contains an open reading frame (ORF) of 471 bp coding for 156 amino acids. No signal peptide was identified at the N-terminal amino acid sequence of Cu/Zn SOD indicating that this pfSOD encodes a cytoplasmic Cu/Zn SOD. This is supported by the presence of conserved amino acids required for binding copper and zinc. Semi-quantitative analysis in adult tissues showed that the pfSOD mRNA was abundantly expressed in haemocytes and gill and scarcely expressed in other tissues tested. After challenge with lipopolysaccharide (LPS), expression of pfSOD mRNA in haemocytes was increased, reaching the highest level at 8 h, then dropping to basal levels at 36 h. These results suggest that Cu/Zn SOD might be used as a bioindicator of the aquatic environmental pollution and cellular stress in pearl oyster.
由于超氧化物歧化酶（SOD）能够迅速将超氧化物转化为过氧化氢，因此它在细胞内信号转导和氧化应激调节中至关重要。本文采用快速扩增 cDNA 末端（RACE）PCR 技术，从珍珠贝（Pinctada fucata）中克隆得到一种 Cu/Zn SOD（命名为 pfSOD）。Cu/Zn SOD 的全长 cDNA 含有 471bp 的开放阅读框（ORF），编码 156 个氨基酸。Cu/Zn SOD 的 N 末端氨基酸序列没有发现信号肽，表明该 pfSOD 编码一种细胞质 Cu/Zn SOD。这一点得到了结合铜和锌所需保守氨基酸存在的支持。在成年组织中的半定量分析表明，pfSOD mRNA 在血细胞和鳃中大量表达，在其他测试组织中几乎不表达。用脂多糖（LPS）处理后，血细胞中 pfSOD mRNA 的表达增加，在 8 小时达到最高水平，然后在 36 小时降至基础水平。这些结果表明，Cu/Zn SOD 可作为珍珠贝水环境污染和细胞应激的生物标志物。
