title: Truncation of the C-terminal region of Toscana Virus NSs protein is critical for interferon-β antagonism and protein stability.
abstract: Toscana Virus (TOSV) is a Phlebovirus responsible for central nervous system (CNS) injury in humans. The TOSV non-structural protein (NSs), which interacting with RIG-I leads to its degradation, was analysed in the C terminus fragment in order to identify its functional domains. To this aim, two C-terminal truncated NSs proteins, Δ1C-NSs (aa 1-284) and Δ2C-NSs (aa 1-287) were tested. Only Δ1C-NSs did not present any inhibitory effect on RIG-I and it showed a greater stability than the whole NSs protein. Moreover, the deletion of the TLQ aa sequence interposed between the two ΔC constructs caused a greater accumulation of the protein with a weak inhibitory effect on RIG-I, indicating some involvement of these amino acids in the NSs activity. Nevertheless, all the truncated proteins were still able to interact with RIG-I, suggesting that the domains responsible for RIG-I signaling and RIG-I interaction are mapped on different regions of the protein.
authors.affiliation: Department of Medical Biotechnologies, Microbiology Section, University of Siena, Italy.
authors.forename: Gianni
authors.initials: G
authors.lastname: Gori Savellini
authors.affiliation: Department of Medical Biotechnologies, Microbiology Section, University of Siena, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Gandolfo
authors.affiliation: Department of Medical Biotechnologies, Microbiology Section, University of Siena, Italy. Electronic address: cusi@unisi.it.
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Cusi
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases / Q000235:genetics / Q000378:metabolism; D006801:Humans; D016899:Interferon-beta / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010217:Phlebotomus Fever / Q000235:genetics / Q000378:metabolism* / Q000821:virology; D055550:Protein Stability; D011971:Receptors, Immunologic; D029301:Sandfly fever Naples virus / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017384:Sequence Deletion; D017361:Viral Nonstructural Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D011971:Receptors, Immunologic; D017361:Viral Nonstructural Proteins; D016899:Interferon-beta; C452820:RIGI protein, human; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases
keywords: C-terminal deleted protein; Non-structural protein; RIG-I; Toscana Virus