title: Cloning and characterization of a clip domain serine protease and its homolog (masquerade) from Eriocheir sinensis.
abstract: Serine proteinases (SPs) or SP homologs (SPHs) including clip domain SPs (cSPs) or SPHs (cSPHs) play critical roles in digestion, embryonic development, hemolymph coagulation, and melanization. In this study, one cSP (EscSP) and one SPH, similar to Drosophila masquerade (EsMas), were identified from hepatopancreas of the Chinese mittern crab Eriocheir sinensis. They both possess the clip domains at the N-terminal, EscSP has only one clip domain, but EsMas has seven clip domains. One SP or SP-like domain was at the C-terminal of EscSP and EsMas respectively. In contrast to EscSP, absence of a catalytic residue of Ser resulted in the loss of SP activity of EsMas. Tissue distribution analysis showed that EscSP mRNA was mainly expressed in hepatopancreas, nerve and eyestalk tissue; whereas the EsMas transcript was mainly distributed in eyestalk, muscle, nerve and hemocytes. EscSP in hemocytes showed significant increase after a lipopolysaccharide (LPS) or peptidoglycan (PGN) challenge. However, down-regulation of EsMas was observed in hemocytes challenged by LPS from 2 to 24 h, by contrast EsMas could be induced by PGN challenge at 2 and 24 h. All these findings indicated that EscSP and EsMas might be involved in the innate immune defenses in E. sinensis.
authors.affiliation: Jiangsu Key Laboratory for Biodiversity & Biotechnology and Jiangsu Key Laboratory for Aquatic Crustacean Diseases, College of Life Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210046, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Huang
authors.forename: Yu-Ran
authors.initials: YR
authors.lastname: Li
authors.forename: Liang
authors.initials: L
authors.lastname: An
authors.forename: Kai-Min
authors.initials: KM
authors.lastname: Hui
authors.forename: Qian
authors.initials: Q
authors.lastname: Ren
authors.forename: Wen
authors.initials: W
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D060829:Arthropod Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D003386:Brachyura / Q000737:chemistry / Q000235:genetics* / Q000276:immunology*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D008070:Lipopolysaccharides / Q000494:pharmacology; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010457:Peptidoglycan / Q000494:pharmacology; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D016415:Sequence Alignment; D057057:Serine Proteases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D060829:Arthropod Proteins; D018076:DNA, Complementary; D008070:Lipopolysaccharides; D010457:Peptidoglycan; D012333:RNA, Messenger; D057057:Serine Proteases
keywords: Clip domain; Innate immunity; Masquerade; Serine proteases