CuZnSOD and MnSOD from freshwater planarian Dugesia japonica: cDNA cloning, mRNA expression and enzyme activity in response to environmental pollutants.
CuZnSOD and MnSOD from freshwater planarian Dugesia japonica: cDNA cloning, mRNA expression and enzyme activity in response to environmental pollutants.
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DOI：
10.1016/j.aquatox.2018.12.013
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发表时间：
2019-03
影响因子：
4.5
通讯作者：
He-Cai Zhang;Kexue Ma;Yu-Juan Yang;Changying Shi;Guangwen Chen;Dezeng Liu
中科院分区：
文献类型：
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作者：
He-Cai Zhang;Kexue Ma;Yu-Juan Yang;Changying Shi;Guangwen Chen;Dezeng Liu
超氧化物歧化酶（SOD）是一种重要的抗氧化酶，它通过催化超氧化物歧化为过氧化氢和氧气，保护需氧生物免受氧化损伤。SOD已被克隆在一些物种和它们的动态表达或酶活性响应环境胁迫进行了研究。本研究首次克隆了淡水三角洲三角洲涡虫（Dugesia japonica）两种SOD的全长cDNA（分别命名为DjCuZnSOD和DjMnSOD）。DjCuZnSOD全长cDNA由661个核苷酸组成，编码186个氨基酸，而DjMnSOD全长cDNA为765 bp，编码226个氨基酸。序列分析和多重比对结果表明，DjCuZnSOD具有两个CuZnSOD家族特征基序和一个N端信号肽，表明其为胞外分泌蛋白。DjMnSOD具有MnSOD家族特征序列，预计位于线粒体中，具有线粒体靶向序列。基于代表物种的CuZnSOD和MnSOD同源物的系统发育分析进一步证实了DjCuZnSOD是一种胞外CuZnSOD，而DjMnSOD是一种胞内MnSOD。为研究其对环境污染物的潜在作用，以草甘膦和溴化1-癸基-3-甲基咪唑（[C10 mim]Br）为暴露源，测定了DjCuZnSOD和DjMnSOD的mRNA表达水平和总SOD活性。结果表明，与DjMnSOD相比，DjCuZnSOD对环境污染物的响应表现出更敏感的表达谱，并且DjCuZnSOD对两种污染物的响应中总SOD活性与DjMnSOD表达水平的相关性更大，表明CuZnSOD的mRNA表达在水环境污染监测中可能比MnSOD更敏感，CuZnSOD在消除污染中可能比MnSOD更重要。污染物引起的超氧阴离子。
As an important antioxidant enzyme, the superoxide dismutase (SOD) can protect aerobic organisms from oxidative damage through catalyzing the dismutation of superoxide into hydrogen peroxide and oxygen. TheSODshave been cloned in some species and their dynamic expression or enzymatic activity in response to environmental stressors were investigated. In the current study, the full-length cDNA of twoSODsfrom freshwater planarianDugesia japonicawere firstly cloned (named asDjCuZnSODandDjMnSOD, respectively). The complete cDNA ofDjCuZnSODconsists of 661 nucleotides encoding 186 amino acids while the 765 bpDjMnSODencodes a polypeptide of 226 residues. Sequence analysis and multiple alignment showed that DjCuZnSOD possesses two CuZnSOD family signature motifs and an N-terminal signal peptide suggesting it is an extracellular secretory protein. DjMnSOD possesses the MnSOD family signature sequence and is predicted to be located in mitochondrion with a mitochondrial targeting sequence. Phylogenetic analysis based on CuZnSOD and MnSOD orthologs from representative species further verified thatDjCuZnSODis an extracellularCuZnSODwhileDjMnSODis a mitochondrialMnSOD. For the purpose of studying their potential role against environmental pollutants,D.japonicawere exposed to glyphosate or 1-decyl-3-methylimidazolium bromide ([C10mim]Br), and the mRNA expression levels ofDjCuZnSODandDjMnSODalong with total SOD activity were measured. The results showed thatDjCuZnSODexhibited more sensitive expression profiles in response to environmental pollutants in contrast withDjMnSOD, and the total SOD activity in response to both pollutants was more related to the expression level ofDjCuZnSODthan toDjMnSOD, indicating that the mRNA expression ofCuZnSODwould be a more sensitive biomarker thanMnSODin monitoring the pollution of aquatic environment and CuZnSOD might play more important role than MnSOD in eliminating superoxide anions caused by pollutants inD.japonica.