title: Viral ubiquitin ligase WSSV222 is required for efficient white spot syndrome virus replication in shrimp.
abstract: The E3 ligase WSSV222 of white spot syndrome virus (WSSV) is involved in anti-apoptosis regulation by ubiquitin-mediated degradation of tumour suppressor-like protein (TSL), a shrimp tumour suppressor. In the present study, WSSV222 gene expression was silenced by using specific small interfering RNA (siRNA) in Sf9 and BHK cells. Based on the results of the in vitro silencing, WSSV-challenged shrimp were treated with anti-WSSV222 siRNA to knock down WSSV222 protein expression. The survival rate of shrimp and the efficiency of WSSV replication were assessed to evaluate the efficacy of anti-WSSV222 siRNA in regulating WSSV infection in shrimp. The anti-WSSV222 siRNA reduced the cumulative mortality in shrimp challenged with 10(3) copies of WSSV and delayed the mean time to death in shrimp challenged with the higher dose of 10(6) copies. The results of real-time quantitative PCR showed that virus replication was delayed and reduced in WSSV-challenged shrimp treated with anti-WSSV222 siRNA in comparison with challenged shrimp treated with random-control siRNA. Co-immunoprecipitation assays revealed that WSSV222 silencing inhibited the degradation of TSL in WSSV-challenged shrimp, indicating the requirement for WSSV222 for efficient replication of WSSV in shrimp.
authors.affiliation: Animal Health Biotechnology, Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore 117604, Singapore.
authors.forename: Fang
authors.initials: F
authors.lastname: He
authors.affiliation: Animal Health Biotechnology, Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore 117604, Singapore.
authors.forename: Syed Musthaq
authors.initials: SM
authors.lastname: Syed
authors.affiliation: OIE Reference Laboratory for WTD, Department of Zoology, C. Abdul Hakeem College, Melvisharam 632 509, Vellore Dist., Tamil Nadu, India.
authors.forename: A S Sahul
authors.initials: ASS
authors.lastname: Hameed
authors.affiliation: Department of Microbiology, Faculty of Medicine, National University of Singapore, Block MD4, 5 Science Drive 2, Singapore 117597, Singapore.|Animal Health Biotechnology, Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore 117604, Singapore.
authors.forename: Jimmy
authors.initials: J
authors.lastname: Kwang
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology / Q000627:therapeutic use; D002460:Cell Line; D020868:Gene Silencing; D033561:Penaeidae / Q000821:virology*; D034741:RNA, Small Interfering / Q000235:genetics / Q000494:pharmacology / Q000627:therapeutic use; D012367:RNA, Viral / Q000096:biosynthesis; D016019:Survival Analysis; D044767:Ubiquitin-Protein Ligases / Q000037:antagonists & inhibitors / Q000502:physiology*; D014764:Viral Proteins / Q000502:physiology*; D014779:Virus Replication; D046848:White spot syndrome virus 1 / Q000502:physiology*
chemical_list: D000998:Antiviral Agents; D034741:RNA, Small Interfering; D012367:RNA, Viral; D014764:Viral Proteins; D044767:Ubiquitin-Protein Ligases