title: Role of transglutaminase in immune defense against bacterial pathogens via regulation of antimicrobial peptides.
abstract: Transglutaminase (TGase) is critical for blood coagulation, a conserved immunological defense mechanism among invertebrates. Here, a 3248-bp (full-length) TGase cDNA in Eriocheir sinensis (EsTGase) was cloned, with a 2274-bp open reading frame (ORF) encoding a 757 amino acid protein containing two transglut domains, one TGase/protease-like homolog domain and a KGD (Lys-Gly-Asp) motif. Phylogenetic analysis demonstrated that EsTGase appeared earlier in evolution compared with TGases of other crustaceans and mammals. EsTGase mRNA was mainly detected in hemocytes and up-regulated post-challenge with bacteria (Vibrio parahaemolyticus and Staphylococcus aureus), suggesting an immune function for this gene. Moreover, the EsTGase activity in hemocytes challenged with V. parahaemolyticus and S. aureus was decreased significantly. RNA interference of EsTGase down-regulated expression of immune-related genes CrusEs2, EsLecG and Es-DWD1 with or without bacteria stimulation in vitro. Furthermore, absence of EsTGase led to higher bacterial counts in the hemocyte culture medium. Thus, EsTGase is an important component of the crab immune response and is involved in the regulation of certain immune-related genes, particularly those encoding anti-microbial peptides.
authors.affiliation: Laboratory of Invertebrate Immunological Defense & Reproductive Biology, School of Life Science, East China Normal University, Shanghai, China.
authors.forename: You-Ting
authors.initials: YT
authors.lastname: Zhu
authors.affiliation: Laboratory of Invertebrate Immunological Defense & Reproductive Biology, School of Life Science, East China Normal University, Shanghai, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.affiliation: Laboratory of Invertebrate Immunological Defense & Reproductive Biology, School of Life Science, East China Normal University, Shanghai, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Laboratory of Invertebrate Immunological Defense & Reproductive Biology, School of Life Science, East China Normal University, Shanghai, China.
authors.forename: Xue-Jie
authors.initials: XJ
authors.lastname: Li
authors.affiliation: Laboratory of Invertebrate Immunological Defense & Reproductive Biology, School of Life Science, East China Normal University, Shanghai, China. Electronic address: Liweiwei85@gmail.com.
authors.forename: Wei-Wei
authors.initials: WW
authors.lastname: Li
authors.affiliation: Laboratory of Invertebrate Immunological Defense & Reproductive Biology, School of Life Science, East China Normal University, Shanghai, China. Electronic address: qwang@bio.ecnu.edu.cn.
authors.forename: Qun
authors.initials: Q
authors.lastname: Wang
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D001777:Blood Coagulation; D003386:Brachyura / Q000276:immunology*; D003001:Cloning, Molecular; D019143:Evolution, Molecular; D005786:Gene Expression Regulation; D006434:Hemocytes / Q000276:immunology*; D007109:Immunity; D008322:Mammals; D008969:Molecular Sequence Data; D010802:Phylogeny; D017434:Protein Structure, Tertiary / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D013203:Staphylococcal Infections / Q000276:immunology*; D013211:Staphylococcus aureus / Q000276:immunology*; D011503:Transglutaminases / Q000235:genetics / Q000378:metabolism*; D014735:Vibrio Infections / Q000276:immunology*; D014736:Vibrio parahaemolyticus / Q000276:immunology*
chemical_list: D023181:Antimicrobial Cationic Peptides; D034741:RNA, Small Interfering; D011503:Transglutaminases
keywords: Antimicrobial peptides; Bacteria; Chinese mitten crab; RNAi; Transglutaminase