title: Interaction study of a novel Macrobrachium rosenbergii effector caspase with B2 and capsid proteins of M. rosenbergii nodavirus reveals their roles in apoptosis.
abstract: Apoptosis is an essential immune response to protect invertebrates from virus infected cells. In shrimp, virus infection has been reported to induce apoptosis. Macrobrachium rosenbergii (Mr) was considered to be a disease-resistant host when compared to penaeid shrimps. Caspase-3 was classified as an executioner caspase which played a key role in virus-induced apoptosis. In this study, an effector caspase gene of M. rosenbergii (Mrcasp) was cloned and characterized. The open reading frame (ORF) of Mrcasp was 957 nucleotide encoding 318 amino acid with a deduced molecular mass of 35.87 kDa. RT-PCR analysis showed the presence of Mrcasp in all examined tissues. The phylogenetic tree indicated that Mrcasp was closely related with caspase 3 of shrimp. The functions of the Mrcasp, B2 and capsid proteins of M. rosenbergii nodavirus (MrNV) were assayed in Sf-9 cells. The results showed that Mrcasp induce apoptotic morphology cells; however, capsid protein of MrNV could inhibit apoptotic cells whereas B2 could neither induce nor inhibit apoptotic cells by DAPI staining. The protein interaction between Mrcasp and viral MrNV structure revealed that Mrcasp did not bind to B2 or capsid protein whereas B2 and capsid proteins could bind directly to each other. This study reported a novel sequence of a full-length Mrcasp and its functional studies indicated that Mrcasp could induce apoptotic cells. Our data is the first report demonstrating the direct protein-protein interaction between capsid protein and B2 protein of MrNV.
authors.affiliation: Department of Biology, Faculty of Science, Srinakharinwirot University, Bangkok 10110, Thailand.
authors.forename: Supak
authors.initials: S
authors.lastname: Youngcharoen
authors.affiliation: Center of Excellence for Shrimp Molecular Biology and Biotechnology, Mahidol University, Bangkok 10400, Thailand; National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathumthani 12120, Thailand. Electronic address: saengchan@biotech.or.th.
authors.forename: Saengchan
authors.initials: S
authors.lastname: Senapin
authors.affiliation: National Metal and Materials Technology Center, National Science and Technology Development Agency, Pathumthani 12120, Thailand.
authors.forename: Tareerat
authors.initials: T
authors.lastname: Lertwimol
authors.affiliation: Department of Biology, Faculty of Science, Srinakharinwirot University, Bangkok 10110, Thailand.
authors.forename: Siwaporn
authors.initials: S
authors.lastname: Longyant
authors.affiliation: Department of Biology, Faculty of Science, Srinakharinwirot University, Bangkok 10110, Thailand.
authors.forename: Paisarn
authors.initials: P
authors.lastname: Sithigorngul
authors.affiliation: Center of Excellence for Shrimp Molecular Biology and Biotechnology, Mahidol University, Bangkok 10400, Thailand; National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathumthani 12120, Thailand.
authors.forename: Timothy W
authors.initials: TW
authors.lastname: Flegel
authors.affiliation: Department of Biology, Faculty of Science, Srinakharinwirot University, Bangkok 10110, Thailand. Electronic address: parin@swu.ac.th.
authors.forename: Parin
authors.initials: P
authors.lastname: Chaivisuthangkura
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D020169:Caspases / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D030381:Nodaviridae; D033541:Palaemonidae / Q000235:genetics; D010802:Phylogeny; D014764:Viral Proteins / Q000378:metabolism*
chemical_list: D018076:DNA, Complementary; D029941:Fish Proteins; D014764:Viral Proteins; D020169:Caspases
keywords: Apoptosis; B2; Capsid protein; Caspase; Macrobrachium rosenbergii; MrNV; Protein interaction