title: Four crustins involved in antibacterial responses in Marsupenaeus japonicus.
abstract: Crustins are a family of cationic, cysteine-rich antimicrobial peptides with a whey acidic protein (WAP) domain in the C-terminal. They have diverse functions in antimicrobial immune responses. Four groups of crustins (crustins I, II, III, and IV) have been identified in crustaceans, but type I crustins have not been reported in penaeid shrimp until now. In this study, we identified four crustins in kuruma shrimp Marsupenaeus japonicus, and named them MjCrus I-2, 3, 4 and 5. These four crustins belong to type I crustins, which contain a signal peptide, cysteine-rich region at the N-terminus, and WAP domain at the C-terminus. Tissue distribution demonstrated that MjCrus I-2, 3 and 5 had high expression levels in hemocytes, gills and stomach. whereas MjCrus I-4 was distributed in all tissues detected. MjCrus I-2 to 5 showed different expression patterns in different tissues after Gram-positive bacterial (Staphylococcus aureus), Gram-negative bacterial (Vibrio anguillarum), and white spot syndrome virus (WSSV) challenge. The expression of MjCrus I-2 to 5 was upregulated by bacterial or WSSV challenge. The three crustins were recombinantly expressed in Escherichia coli, and the purified proteins showed few antimicrobial activities. Three MjCrus Is could bind to different bacteria. MjCrus I-2 and 3 showed different inhibitory abilities to secreted bacterial proteases. MjCrus I-4 could not inhibit bacterial proteases. After knockdown of MjCrus I-3, the bacterial scavenging ability to V. anguillarum was impaired. These results suggested that type I crustins played an important role in the innate immunity of shrimp.
authors.affiliation: Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China.
authors.forename: Hai-Shan
authors.initials: HS
authors.lastname: Jiang
authors.affiliation: Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China.
authors.forename: Wen-Ming
authors.initials: WM
authors.lastname: Jia
authors.affiliation: Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China.
authors.forename: Xiao-Fan
authors.initials: XF
authors.lastname: Zhao
authors.affiliation: Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Jinan, Shandong 250100, China. Electronic address: jxwang@sdu.edu.cn.
authors.forename: Jin-Xing
authors.initials: JX
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000998:Antiviral Agents / Q000494:pharmacology*; D060829:Arthropod Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D008969:Molecular Sequence Data; D009928:Organ Specificity; D033561:Penaeidae / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology / Q000821:virology; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013211:Staphylococcus aureus / Q000502:physiology; D014733:Vibrio / Q000502:physiology; D046848:White spot syndrome virus 1 / Q000502:physiology
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D000998:Antiviral Agents; D060829:Arthropod Proteins; D018076:DNA, Complementary; D012333:RNA, Messenger
keywords: Antibacterial peptide; Crustin; Innate immunity; Marsupenaeus japonicus