Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
Fish Shellfish Immunol. 2014 Mar;37(1):53-9. doi: 10.1016/j.fsi.2014.01.008. Epub 2014 Jan 13.
As an important iron storage protein, ferritin plays a crucial role in the iron-withholding defense system. In this study, two secreted ferritin subunits (PyFerS1 and PyFerS2) were identified from the Yesso scallop, Patinopecten yessoensis. The complete DNA sequences of the two ferritins are 7101 and 5359 bp, consisting of seven and five exons, respectively. The full-length cDNAs of PyFerS1 and PyFerS2 are 960 and 956 bp in length, encoding 228 and 220 amino acids, respectively. They have typical ferritin structures, with four long α-helices, one short α-helix and an L-loop. Signal peptides were found at the N-terminus of both ferritins, and phylogenetic analysis showed that they both clustered with secreted mollusc ferritins. PyFerS1 possesses all seven conserved residues of the ferroxidase center, whereas PyFerS2 only has two. Real-time PCR analysis indicated high expression level of PyFerS2 in the D-shaped larvae, and PyFerS1 in both D-shaped larvae and fertilized eggs. In adult scallops, PyFerS1 was only detected in the hepatopancreas, whereas PyFerS2 was detected in both hepatopancreas and mantle. After the scallops were challenged by iron ion or bacteria Vibrio anguillarum, the expression of both PyFerS1 and PyFerS2 was significantly elevated, suggesting they may play a role in scallop innate immune defense. For the first time, secreted ferritins were cloned and comprehensively characterized in bivalve molluscs. It will assist in better understanding of the role of secreted ferritins in bivalve innate immunity.
作为一种重要的铁储存蛋白，铁蛋白在铁保持防御系统中起着至关重要的作用。本研究从虾夷扇贝（Patinopecten yessoensis）中鉴定出两种分泌型铁蛋白亚基（PyFerS1 和 PyFerS2）。这两种铁蛋白的完整 DNA 序列分别为 7101bp 和 5359bp，由七个和五个外显子组成。PyFerS1 和 PyFerS2 的全长 cDNA 分别为 960bp 和 956bp，分别编码 228 个和 220 个氨基酸。它们具有典型的铁蛋白结构，有四个长α-螺旋、一个短α-螺旋和一个 L 环。在两种铁蛋白的 N 端都发现了信号肽，系统发育分析表明它们都与分泌型软体动物铁蛋白聚类。PyFerS1 具有铁氧化酶中心的七个保守残基，而 PyFerS2 只有两个。实时 PCR 分析表明，PyFerS2 在 D 形幼虫中的表达水平较高，而 PyFerS1 在 D 形幼虫和受精卵中均有表达。在成年扇贝中，仅在肝胰腺中检测到 PyFerS1，而在肝胰腺和套膜中均检测到 PyFerS2。当扇贝受到铁离子或细菌鳗弧菌的刺激时，PyFerS1 和 PyFerS2 的表达均显著上调，表明它们可能在扇贝先天免疫防御中发挥作用。本研究首次在双壳贝类中克隆并全面表征了分泌型铁蛋白。这将有助于更好地理解分泌型铁蛋白在双壳类动物先天免疫中的作用。
