title: The viral ankyrin repeat protein (ORF124L) from infectious spleen and kidney necrosis virus attenuates nuclear factor-κB activation and interacts with IκB kinase β.
abstract: The ankyrin (ANK) repeat is one of the most common protein-protein interaction motifs, found predominantly in eukaryotes and bacteria, but the functions of the ANK repeat are rarely researched in animal viruses, with the exception of poxviruses. Infectious spleen and kidney necrosis virus (ISKNV) is a typical member of the genus Megalocytivirus in the family Iridoviridae and is a causative agent of epizootics in fish. The genome of ISKNV contains four putative viral ANK (vANK) repeat proteins and their functions remain largely unknown. In the present study, it was found that ORF124L, a vANK repeat protein in ISKNV, encodes a protein of 274 aa with three ANK repeats. Transcription of ORF124L was detected at 12 h post-infection (p.i.) and reached a peak at 40 h p.i. ORF124L was found to localize to both the nucleus and the cytoplasm in mandarin fish fry cells. ISKNV ORF124L interacted with the mandarin fish IκB kinase β protein (scIKKβ), and attenuated tumour necrosis factor alpha (TNF-α)- or phorbol myristate acetate (PMA)-induced activity of a nuclear factor κB (NF-κB)-luciferase reporter but did not interfere with the activity of an activator protein 1 (AP-1)-luciferase reporter. Phosphorylation of IκBα and nuclear translocation of NF-κB were also impaired by ISKNV ORF124L. In summary, ORF124L was identified as a vANK repeat protein and its role in inhibition of TNF-α-induced NF-κB signalling was investigated through interaction with the mandarin fish IKKβ. This work may help to improve our understanding of the function of fish iridovirus ANK repeat proteins.
authors.affiliation: State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.|Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.
authors.forename: Chang-Jun
authors.initials: CJ
authors.lastname: Guo
authors.affiliation: State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.
authors.forename: Wei-Jian
authors.initials: WJ
authors.lastname: Chen
authors.affiliation: State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.
authors.forename: Li-Qun
authors.initials: LQ
authors.lastname: Yuan
authors.affiliation: State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.
authors.forename: Li-Shi
authors.initials: LS
authors.lastname: Yang
authors.affiliation: State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.
authors.forename: Shao-Ping
authors.initials: SP
authors.lastname: Weng
authors.affiliation: Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, MO 64110, USA.
authors.forename: Xiao-Qiang
authors.initials: XQ
authors.lastname: Yu
authors.affiliation: State Key Laboratory for Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.|Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China.
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: He
mesh_terms: D000818:Animals; D017089:Ankyrin Repeat; D002460:Cell Line; D004266:DNA Virus Infections / Q000201:enzymology / Q000378:metabolism* / Q000662:veterinary* / Q000821:virology; D005393:Fish Diseases / Q000201:enzymology / Q000235:genetics / Q000378:metabolism* / Q000821:virology; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism*; D051550:I-kappa B Kinase / Q000235:genetics / Q000378:metabolism*; D007497:Iridoviridae / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D010473:Perciformes; D011485:Protein Binding; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D029941:Fish Proteins; D016328:NF-kappa B; D014764:Viral Proteins; D051550:I-kappa B Kinase