title: Identification of two secreted ferritin subunits involved in immune defense of Yesso scallop Patinopecten yessoensis.
abstract: 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.
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
authors.forename: Yueyue
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
authors.forename: Xiaoteng
authors.initials: X
authors.lastname: Fu
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
authors.forename: Ru
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
authors.forename: Jiajun
authors.initials: J
authors.lastname: Zou
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
authors.forename: Shi
authors.initials: S
authors.lastname: Wang
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Hu
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China. Electronic address: lingling80@ouc.edu.cn.
authors.forename: Lingling
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
authors.forename: Zhenmin
authors.initials: Z
authors.lastname: Bao
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001483:Base Sequence; D002681:China; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D005293:Ferritins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D040461:Gene Components; D007113:Immunity, Innate / Q000235:genetics* / Q000276:immunology; D008969:Molecular Sequence Data; D049897:Pectinidae / Q000235:genetics* / Q000276:immunology; D010802:Phylogeny; D011487:Protein Conformation; D021122:Protein Subunits / Q000235:genetics / Q000276:immunology; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
chemical_list: D017931:DNA Primers; D021122:Protein Subunits; D005293:Ferritins
keywords: Innate immunity; Iron-withholding strategy; Patinopecten yessoensis; Secreted ferritin