Inhibition of Apoptosis and NF-kappa B Activation by Vaccinia Protein N1 Occur via Distinct Binding Surfaces and Make Different Contributions to Virulence
Vaccinia virus (VACV) protein N1 is an intracellular virulence factor and belongs to a family of VACV B-cell lymphoma (Bcl)-2-like proteins whose members inhibit apoptosis or activation of pro-inflammatory transcription factors, such as interferon (IFN) regulatory factor-3 (IRF-3) and nuclear factor...
| Main Authors: | , , , , , , , , , |
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| Format: | Journal article |
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2011
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| _version_ | 1797061180503621632 |
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| author | de Motes, C Cooray, S Ren, H Almeida, G McGourty, K Bahar, M Stuart, D Grimes, J Graham, S Smith, G |
| author_facet | de Motes, C Cooray, S Ren, H Almeida, G McGourty, K Bahar, M Stuart, D Grimes, J Graham, S Smith, G |
| author_sort | de Motes, C |
| collection | OXFORD |
| description | Vaccinia virus (VACV) protein N1 is an intracellular virulence factor and belongs to a family of VACV B-cell lymphoma (Bcl)-2-like proteins whose members inhibit apoptosis or activation of pro-inflammatory transcription factors, such as interferon (IFN) regulatory factor-3 (IRF-3) and nuclear factor-κB (NF-κB). Unusually, N1 inhibits both apoptosis and NF-κB activation. To understand how N1 exerts these different functions, we have mutated residues in the Bcl-2-like surface groove and at the interface used to form N1 homodimers. Mutagenesis of the surface groove abolished only the N1 anti-apoptotic activity and protein crystallography showed these mutants differed from wild-type N1 only at the site of mutation. Conversely, mutagenesis of the dimer interface converted N1 to a monomer and affected only inhibition of NF-κB activation. Collectively, these data show that N1 inhibits pro-inflammatory and pro-apoptotic signalling using independent surfaces of the protein. To determine the relative contribution of each activity to virus virulence, mutant N1 alleles were introduced into a VACV strain lacking N1 and the virulence of these viruses was analysed after intradermal and intranasal inoculation in mice. In both models, VACV containing a mutant N1 unable to inhibit apoptosis had similar virulence to wild-type virus, whereas VACV containing a mutant N1 impaired for NF-κB inhibition induced an attenuated infection similar to that of the N1-deleted virus. This indicates that anti-apoptotic activity of N1 does not drive virulence in these in vivo models, and highlights the importance of pro-inflammatory signalling in the immune response against viral infections. |
| first_indexed | 2024-03-06T20:27:22Z |
| format | Journal article |
| id | oxford-uuid:2fd7c7bd-6d80-414f-91cc-ac920047b011 |
| institution | University of Oxford |
| last_indexed | 2024-03-06T20:27:22Z |
| publishDate | 2011 |
| record_format | dspace |
| spelling | oxford-uuid:2fd7c7bd-6d80-414f-91cc-ac920047b0112022-03-26T12:57:56ZInhibition of Apoptosis and NF-kappa B Activation by Vaccinia Protein N1 Occur via Distinct Binding Surfaces and Make Different Contributions to VirulenceJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:2fd7c7bd-6d80-414f-91cc-ac920047b011Symplectic Elements at Oxford2011de Motes, CCooray, SRen, HAlmeida, GMcGourty, KBahar, MStuart, DGrimes, JGraham, SSmith, GVaccinia virus (VACV) protein N1 is an intracellular virulence factor and belongs to a family of VACV B-cell lymphoma (Bcl)-2-like proteins whose members inhibit apoptosis or activation of pro-inflammatory transcription factors, such as interferon (IFN) regulatory factor-3 (IRF-3) and nuclear factor-κB (NF-κB). Unusually, N1 inhibits both apoptosis and NF-κB activation. To understand how N1 exerts these different functions, we have mutated residues in the Bcl-2-like surface groove and at the interface used to form N1 homodimers. Mutagenesis of the surface groove abolished only the N1 anti-apoptotic activity and protein crystallography showed these mutants differed from wild-type N1 only at the site of mutation. Conversely, mutagenesis of the dimer interface converted N1 to a monomer and affected only inhibition of NF-κB activation. Collectively, these data show that N1 inhibits pro-inflammatory and pro-apoptotic signalling using independent surfaces of the protein. To determine the relative contribution of each activity to virus virulence, mutant N1 alleles were introduced into a VACV strain lacking N1 and the virulence of these viruses was analysed after intradermal and intranasal inoculation in mice. In both models, VACV containing a mutant N1 unable to inhibit apoptosis had similar virulence to wild-type virus, whereas VACV containing a mutant N1 impaired for NF-κB inhibition induced an attenuated infection similar to that of the N1-deleted virus. This indicates that anti-apoptotic activity of N1 does not drive virulence in these in vivo models, and highlights the importance of pro-inflammatory signalling in the immune response against viral infections. |
| spellingShingle | de Motes, C Cooray, S Ren, H Almeida, G McGourty, K Bahar, M Stuart, D Grimes, J Graham, S Smith, G Inhibition of Apoptosis and NF-kappa B Activation by Vaccinia Protein N1 Occur via Distinct Binding Surfaces and Make Different Contributions to Virulence |
| title | Inhibition of Apoptosis and NF-kappa B Activation by Vaccinia Protein N1 Occur via Distinct Binding Surfaces and Make Different Contributions to Virulence |
| title_full | Inhibition of Apoptosis and NF-kappa B Activation by Vaccinia Protein N1 Occur via Distinct Binding Surfaces and Make Different Contributions to Virulence |
| title_fullStr | Inhibition of Apoptosis and NF-kappa B Activation by Vaccinia Protein N1 Occur via Distinct Binding Surfaces and Make Different Contributions to Virulence |
| title_full_unstemmed | Inhibition of Apoptosis and NF-kappa B Activation by Vaccinia Protein N1 Occur via Distinct Binding Surfaces and Make Different Contributions to Virulence |
| title_short | Inhibition of Apoptosis and NF-kappa B Activation by Vaccinia Protein N1 Occur via Distinct Binding Surfaces and Make Different Contributions to Virulence |
| title_sort | inhibition of apoptosis and nf kappa b activation by vaccinia protein n1 occur via distinct binding surfaces and make different contributions to virulence |
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