title: Sumoylation of the nucleocapsid protein of severe acute respiratory syndrome coronavirus.
abstract: Severe acute respiratory syndrome coronavirus (SARS-CoV) encodes a highly basic nucleocapsid (N) protein of 422 amino acids. Similar to other coronavirus N proteins, SARS-CoV N protein is predicted to be phosphorylated and may contain nuclear localization signals, serine/arginine-rich motif, RNA binding domain and regions responsible for self-association and homo-oligomerization. In this study, we demonstrate that the protein is posttranslationally modified by covalent attachment to the small ubiquitin-like modifier. The major sumoylation site was mapped to the (62)lysine residue of the N protein. Further expression and characterization of wild type N protein and K62A mutant reveal that sumoylation of the N protein drastically promotes its homo-oligomerization, and plays certain roles in the N protein-mediated interference of host cell division. This is the first report showing that a coronavirus N protein undergoes posttranslational modification by sumoylation, and the functional implication of this modification in the formation of coronavirus ribouncleoprotein complex, virion assembly and virus-host interactions.
authors.affiliation: School of Biological Sciences, Nanyang Technological University, Singapore.
authors.forename: Frank Qisheng
authors.initials: FQ
authors.lastname: Li
authors.forename: Han
authors.initials: H
authors.lastname: Xiao
authors.forename: James P
authors.initials: JP
authors.lastname: Tam
authors.forename: D X
authors.initials: DX
authors.lastname: Liu
mesh_terms: D002455:Cell Division; D006367:HeLa Cells; D006801:Humans; D019590:Nucleocapsid Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D045473:Severe acute respiratory syndrome-related coronavirus / Q000235:genetics / Q000378:metabolism*; D025841:Small Ubiquitin-Related Modifier Proteins / Q000378:metabolism*
chemical_list: D019590:Nucleocapsid Proteins; D025841:Small Ubiquitin-Related Modifier Proteins