Key Laboratory of Marine Biotechnology of Guangdong Province, Shantou University, Shantou, 515063, China; Mariculture Research Center for Subtropical Shellfish & Algae of Guangdong Province, Shantou, 515063, China; STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou, 515063, China.
Key Laboratory of Marine Biotechnology of Guangdong Province, Shantou University, Shantou, 515063, China; Mariculture Research Center for Subtropical Shellfish & Algae of Guangdong Province, Shantou, 515063, China; STU-UMT Joint Shellfish Research Laboratory, Shantou University, Shantou, 515063, China.
Fish Shellfish Immunol. 2019 May;88:9-16. doi: 10.1016/j.fsi.2019.02.051. Epub 2019 Feb 27.
As a major intracellular iron storage protein, ferritin plays important roles in iron homeostasis and innate immunity. In this study, two novel ferritin subunits from noble scallop Chlamys nobilis (CnFer1 and CnFer2) were identified and analyzed. The open reading frame of CnFer1 and CnFer2 was 522 and 519bp long, encoding 173 and 172 amino acids, respectively. Both ferritins contained a putative iron-binding region signature (IBRS). Analysis of putative conserved domains showed the two CnFer genes contained three key domains of ferritin subunits, a ferroxidase diiron center (E25, Y32, E59, E60, H63, E105, and Q139), an iron ion channel (H116, D129, E132) and a ferrihydrite nucleation center (D58, E59, and E62) that present in M type subunits. A putative iron response element (IRE) was observed at both CnFer genes in the 5' UTR. Phylogenetic analysis result suggested that the two genes are cytoplasmic ferritins and have the closest evolution relationship with ferritins from Mizuhopecten yessoensis. The two ferritin genes were wildly expressed in examined tissues and the highest level was found in gill. After V. parahaemolyticus challenged, both CnFer genes were significantly up-regulated suggesting that they are important proteins involved in host immune defense. Moreover, under bacterial challenge, the expression levels of both two genes in Golden scallops (rich in carotenoids) were significantly higher than that in Brown scallops (less in carotenoids) which suggesting that carotenoids enhance the immunity in scallops to defense against the bacterial stress.
作为一种主要的细胞内铁储存蛋白，铁蛋白在铁稳态和先天免疫中发挥重要作用。在这项研究中，从高贵扇贝 Chlamys nobilis 中鉴定并分析了两种新型铁蛋白亚基（CnFer1 和 CnFer2）。CnFer1 和 CnFer2 的开放阅读框分别为 522 和 519bp，分别编码 173 和 172 个氨基酸。这两种铁蛋白都含有一个假定的铁结合区域特征（IBRS）。假定保守结构域分析表明，这两个 CnFer 基因包含铁蛋白亚基的三个关键结构域，即亚铁氧化酶双铁中心（E25、Y32、E59、E60、H63、E105 和 Q139）、铁离子通道（H116、D129、E132）和 ferrihydrite 成核中心（D58、E59 和 E62），这些结构域存在于 M 型亚基中。在两个 CnFer 基因的 5'UTR 中都观察到了一个假定的铁反应元件（IRE）。系统发育分析结果表明，这两个基因是细胞质铁蛋白，与 Mizuhopecten yessoensis 的铁蛋白具有最密切的进化关系。这两个铁蛋白基因在检测到的组织中广泛表达，在鳃中表达水平最高。在副溶血弧菌攻毒后，两个 CnFer 基因均显著上调，表明它们是参与宿主免疫防御的重要蛋白。此外，在细菌攻毒下，富含类胡萝卜素的金扇贝中这两个基因的表达水平均显著高于类胡萝卜素含量较低的棕扇贝，这表明类胡萝卜素增强了扇贝的免疫力，以抵御细菌应激。
