SUMO Modification Stabilizes Dengue Virus Nonstructural Protein 5 To Support Virus Replication.
Bottom Line: By expressing various NS5 mutants, we found that the SUMO acceptor sites are located in the N-terminal domain of NS5 and that a putative SUMO-interacting motif (SIM) of this domain is crucial for its SUMOylation.SUMOylation-defective mutants also failed to suppress the induction of STAT2-mediated host antiviral interferon signaling.Here, we found that the replicase of DENV, nonstructural protein 5 (NS5), can be SUMOylated.
Affiliation: Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.Show MeSH
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Mentions: SUMOpylation occurs on lysine residues of the targeted substrates. There are 64 lysines in DENV NS5 protein that might serve as the SUMO acceptors. To delineate the SUMOylated residues in NS5, various HA-tagged NS5 truncation mutants were generated (Fig. 3A) and subjected to in vivo SUMOylation assay. Given that the SUMO modification machinery is predominantly nuclear and that NLS are important for the SUMOylation of nuclear proteins (19, 41), we preserved the NLS in all of these deletion mutants. By in vivo SUMOylation assay, we found that EGFP-tagged SUMO1 was only detected on the NS5 fragments containing the 71 to 300 residues at the N terminus (Fig. 3B, lanes 1 to 8), whereas the C-terminal half of NS5 seemed not to be critical for SUMOylation (Fig. 3B, lanes 9 to 14). These results suggested that two acceptor lysine sites for SUMOylation are located in the N-terminal 71 to 300 residues of NS5.
Affiliation: Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.