Ubiquitin and Not Only Unfolded Domains Drives Toscana Virus Non-Structural NSs Protein Degradation

The non-structural protein NSs of the <i>Phenuiviridae</i> family members appears to have a role in the host immunity escape. The stability of Toscana virus (TOSV) NSs protein was tested by a cycloheximide (CHX) chase approach on cells transfected with NSs deleted versions fused to a rep...

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Main Authors: Gianni Gori Savellini, Luca Bini, Assunta Gagliardi, Gabriele Anichini, Claudia Gandolfo, Shibily Prathyumnan, Maria Grazia Cusi
Format: Article
Language:English
Published: MDPI AG 2020-10-01
Series:Viruses
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Online Access:https://www.mdpi.com/1999-4915/12/10/1153
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author Gianni Gori Savellini
Luca Bini
Assunta Gagliardi
Gabriele Anichini
Claudia Gandolfo
Shibily Prathyumnan
Maria Grazia Cusi
author_facet Gianni Gori Savellini
Luca Bini
Assunta Gagliardi
Gabriele Anichini
Claudia Gandolfo
Shibily Prathyumnan
Maria Grazia Cusi
author_sort Gianni Gori Savellini
collection DOAJ
description The non-structural protein NSs of the <i>Phenuiviridae</i> family members appears to have a role in the host immunity escape. The stability of Toscana virus (TOSV) NSs protein was tested by a cycloheximide (CHX) chase approach on cells transfected with NSs deleted versions fused to a reporter gene. The presence of intrinsically disordered regions (IDRs) both at the C- and N-terminus appeared to affect the protein stability. Indeed, the NSsΔC and NSsΔN proteins were more stable than the wild-type NSs counterpart. Since TOSV NSs exerts its inhibitory function by triggering RIG-I for proteasomal degradation, the interaction of the ubiquitin system and TOSV NSs was further examined. Chase experiments with CHX and the proteasome inhibitor MG-132 demonstrated the involvement of the ubiquitin-proteasome system in controlling NSs protein amount expressed in the cells. The analysis of TOSV NSs by mass spectrometry allowed the direct identification of K<sub>104</sub>, K<sub>109</sub>, K<sub>154</sub>, K<sub>180</sub>, K<sub>244</sub>, K<sub>294</sub>, and K<sub>298</sub> residues targeted for ubiquitination. Analysis of NSs K-mutants confirmed the presence and the important role of lysine residues located in the central and the C-terminal parts of the protein in controlling the NSs cellular level. Therefore, we directly demonstrated a new cellular pathway involved in controlling TOSV NSs fate and activity, and this opens the way to new investigations among more pathogenic viruses of the <i>Phenuiviridae</i> family.
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spelling doaj.art-143948ca9ce347d9b7ba4bed8b77607e2023-11-20T16:44:29ZengMDPI AGViruses1999-49152020-10-011210115310.3390/v12101153Ubiquitin and Not Only Unfolded Domains Drives Toscana Virus Non-Structural NSs Protein DegradationGianni Gori Savellini0Luca Bini1Assunta Gagliardi2Gabriele Anichini3Claudia Gandolfo4Shibily Prathyumnan5Maria Grazia Cusi6Department of Medical Biotechnologies, University of Siena, 53100 Siena, ItalyDepartment of Life Sciences, University of Siena, 53100 Siena, ItalyDepartment of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Laboratory of Synthetic and Structural Vaccinology, 38122 Trento, ItalyDepartment of Medical Biotechnologies, University of Siena, 53100 Siena, ItalyDepartment of Medical Biotechnologies, University of Siena, 53100 Siena, ItalyDepartment of Medical Biotechnologies, University of Siena, 53100 Siena, ItalyDepartment of Medical Biotechnologies, University of Siena, 53100 Siena, ItalyThe non-structural protein NSs of the <i>Phenuiviridae</i> family members appears to have a role in the host immunity escape. The stability of Toscana virus (TOSV) NSs protein was tested by a cycloheximide (CHX) chase approach on cells transfected with NSs deleted versions fused to a reporter gene. The presence of intrinsically disordered regions (IDRs) both at the C- and N-terminus appeared to affect the protein stability. Indeed, the NSsΔC and NSsΔN proteins were more stable than the wild-type NSs counterpart. Since TOSV NSs exerts its inhibitory function by triggering RIG-I for proteasomal degradation, the interaction of the ubiquitin system and TOSV NSs was further examined. Chase experiments with CHX and the proteasome inhibitor MG-132 demonstrated the involvement of the ubiquitin-proteasome system in controlling NSs protein amount expressed in the cells. The analysis of TOSV NSs by mass spectrometry allowed the direct identification of K<sub>104</sub>, K<sub>109</sub>, K<sub>154</sub>, K<sub>180</sub>, K<sub>244</sub>, K<sub>294</sub>, and K<sub>298</sub> residues targeted for ubiquitination. Analysis of NSs K-mutants confirmed the presence and the important role of lysine residues located in the central and the C-terminal parts of the protein in controlling the NSs cellular level. Therefore, we directly demonstrated a new cellular pathway involved in controlling TOSV NSs fate and activity, and this opens the way to new investigations among more pathogenic viruses of the <i>Phenuiviridae</i> family.https://www.mdpi.com/1999-4915/12/10/1153ubiquitin-proteasome systemNSs proteinprotein stability
spellingShingle Gianni Gori Savellini
Luca Bini
Assunta Gagliardi
Gabriele Anichini
Claudia Gandolfo
Shibily Prathyumnan
Maria Grazia Cusi
Ubiquitin and Not Only Unfolded Domains Drives Toscana Virus Non-Structural NSs Protein Degradation
Viruses
ubiquitin-proteasome system
NSs protein
protein stability
title Ubiquitin and Not Only Unfolded Domains Drives Toscana Virus Non-Structural NSs Protein Degradation
title_full Ubiquitin and Not Only Unfolded Domains Drives Toscana Virus Non-Structural NSs Protein Degradation
title_fullStr Ubiquitin and Not Only Unfolded Domains Drives Toscana Virus Non-Structural NSs Protein Degradation
title_full_unstemmed Ubiquitin and Not Only Unfolded Domains Drives Toscana Virus Non-Structural NSs Protein Degradation
title_short Ubiquitin and Not Only Unfolded Domains Drives Toscana Virus Non-Structural NSs Protein Degradation
title_sort ubiquitin and not only unfolded domains drives toscana virus non structural nss protein degradation
topic ubiquitin-proteasome system
NSs protein
protein stability
url https://www.mdpi.com/1999-4915/12/10/1153
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