Zhao D X, Chen L Q, Qin J G, Qin C J, Zhang H, Wu P, Li E C
Department of Biology, East China Normal University, Shanghai, China.
Department of Biology, East China Normal University, Shanghai, China
Genet Mol Res. 2014 Nov 11;13(4):9429-42. doi: 10.4238/2014.November.11.8.
A cytosolic manganese superoxide dismutase gene (Es-cMnSOD) was cloned from the Chinese mitten crab Eriocheir sinensis, using reverse transcription-polymerase chain reaction and the rapid amplification of cDNA ends. The open reading frame of Es-cMnSOD is 867 bp in length and encodes a 288-amino acid protein without a signal peptide. The calculated molecular mass of the translated protein of Es-cMnSOD is 31.43 kDa, with an estimated isoelectric point of 6.30. The deduced amino acid sequence of Es-cMnSOD has similarities of 90, 89, 84, 87, and 81% to those of white shrimp Litopenaeus vannamei MnSOD, black tiger shrimp Penaeus monodon MnSOD, giant freshwater prawn Macrobrachium rosenbergii MnSOD, blue crab Callinectes sapidus MnSOD, and red swamp crayfish Procambarus clarkii MnSOD, respectively. Es-cMnSOD contains a manganese superoxide dismutase domain (DVWEHAYY) and 4 conserved amino acids responsible for binding manganese. Es-cMnSOD was expressed in the hemocytes, eyestalk, muscle, intestine, gill, and hepatopancreas. Es-cMnSOD transcripts in hemocytes of E. sinensis increased at 1.5 and 48 h after injection of Aeromonas hydrophila, indicating that the induction of the SOD system response occurred within a short period of time. This study suggests that MnSOD may play a critical role in crab immunity, allowing efficient activation of an early innate immune response in the crab.
利用逆转录聚合酶链反应和cDNA末端快速扩增技术，从中华绒螯蟹中克隆出一种胞质锰超氧化物歧化酶基因（Es-cMnSOD）。Es-cMnSOD的开放阅读框长度为867 bp，编码一个不含信号肽的288个氨基酸的蛋白质。Es-cMnSOD翻译蛋白的计算分子量为31.43 kDa，估计等电点为6.30。Es-cMnSOD推导的氨基酸序列与凡纳滨对虾Litopenaeus vannamei MnSOD、斑节对虾Penaeus monodon MnSOD、罗氏沼虾Macrobrachium rosenbergii MnSOD、青蟹Callinectes sapidus MnSOD和克氏原螯虾Procambarus clarkii MnSOD的氨基酸序列相似性分别为90%、89%、84%、87%和81%。Es-cMnSOD包含一个锰超氧化物歧化酶结构域（DVWEHAYY）和4个负责结合锰的保守氨基酸。Es-cMnSOD在血细胞、眼柄、肌肉、肠道、鳃和肝胰腺中表达。注射嗜水气单胞菌后1.5小时和48小时，中华绒螯蟹血细胞中Es-cMnSOD转录本增加，表明SOD系统反应在短时间内被诱导。本研究表明，MnSOD可能在蟹的免疫中起关键作用，使蟹的早期先天免疫反应能够有效激活。
