title: Molecular cloning and characterization of four caspases members in Apostichopus japonicus.
abstract: The caspase family representing aspartate-specific cysteine proteases have been demonstrated to possess key roles in apoptosis and immune response. We previously demonstrated that LPS challenged Apostichopus japonicus coelomocyte could significantly induced apoptosis in vitro. However, apoptosis related molecules were scarcely investigated in this economic species. In the present work, we cloned and characterized four members caspase family from A. japonicus (designated as Ajcaspase-2, Ajcaspase-3, Ajcaspase-6, and Ajcaspase-8, respectively) by RACE. Multiple sequence alignment and structural analysis revealed that all Ajcaspases contained the conservative CASC domain at C terminal, in which some unique features for each Ajcaspase made them different from each other. These specific domains together with phylogenetic analysis supported that all these four identified proteins belonged to novel members of apoptotic signaling pathway in sea cucumber. Tissue distribution analysis revealed that four Ajcaspase genes were constitutively expressed in all examined tissues. The expression of Ajcaspase-2 was tightly correlated with that of Ajcaspase-8 in each detected tissues. Ajcaspase-3 and Ajcaspase-6 transcripts were both highly expressed in immune tissue of coelomocytes. Furthermore, the Vibrio splendidus challenged sea cucumber coelomocytes could significantly up-regulate the mRNA expressions of four genes. The expression levels of Ajcaspase-2 and Ajcaspase-8 were relative earlier than those of Ajcaspase-6 and Ajcaspase-3, respectively, which could be inferred that Ajcapase-2 might directly modulate Ajcaspase-6, and Ajcaspase-8 initiate the expression of Ajcaspase-3. The induce expressions differed among each Ajcaspase depending upon their roles such as initiator or effector caspase. All our results demonstrated that four Ajcaspases present diversified functions in apoptotic cascade signaling pathway of sea cucumber under immune response.
authors.affiliation: School of Marine Sciences, Ningbo University, Ningbo 315211, PR China.
authors.forename: Yina
authors.initials: Y
authors.lastname: Shao
authors.affiliation: School of Marine Sciences, Ningbo University, Ningbo 315211, PR China. Electronic address: lichenghua@nbu.edu.cn.
authors.forename: Chenghua
authors.initials: C
authors.lastname: Li
authors.affiliation: School of Marine Sciences, Ningbo University, Ningbo 315211, PR China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: School of Marine Sciences, Ningbo University, Ningbo 315211, PR China.
authors.forename: Xuemei
authors.initials: X
authors.lastname: Duan
authors.affiliation: School of Marine Sciences, Ningbo University, Ningbo 315211, PR China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Li
authors.affiliation: School of Marine Sciences, Ningbo University, Ningbo 315211, PR China.
authors.forename: Chunhua
authors.initials: C
authors.lastname: Jin
authors.affiliation: School of Marine Sciences, Ningbo University, Ningbo 315211, PR China.
authors.forename: Jinbo
authors.initials: J
authors.lastname: Xiong
authors.affiliation: School of Marine Sciences, Ningbo University, Ningbo 315211, PR China.
authors.forename: Qiongfen
authors.initials: Q
authors.lastname: Qiu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D020169:Caspases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D007113:Immunity, Innate / Q000235:genetics*; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment / Q000662:veterinary; D015398:Signal Transduction; D047528:Stichopus / Q000201:enzymology* / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D015854:Up-Regulation; D014733:Vibrio / Q000502:physiology
chemical_list: D018076:DNA, Complementary; D012333:RNA, Messenger; D020169:Caspases
keywords: Apoptosis; Apostichopus japonicus; Caspase; Immune response