Progress 02/01/15 to 01/31/20
Outputs
Target Audience:Researchers working on animal viruses and diseases Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Keethi Gottipati, the post-doctoral researcher working on the project was promoted to scientist. How have the results been disseminated to communities of interest?We have published twojournal publications and two presentations. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
1. We determined the substrate specificity of Nprousing an Npro-GFP assay system Due to lack ofin vitroprotease activity assays, Npro's protease activity and its involvement in interferon-antagonistic function are not well understood. Using our recently developed Npro-GFP fusion protein assay, we will define structural requirements of the C-terminal cleavage site, and identify residues that can be mutated to affect the Npro's autoproteolysis efficiency. We completed this aim while the application was under review.We have expressed 14 Npro-GFP fusion proteins, each of which containing a single amino acid changes in either active site (Glu22, Cys69, Arg100) or the cleavage site (Cys168) in Npro.Contrary to previous reports, we show that Npro's catalytic activity does not involve Glu22, which may instead be involved in protein stability. Furthermore, Nprodoes not have specificity for Cys168 at the cleavage site even though this residue is conserved throughout the pestivirus genus. The result was publishedin"Gottipati K, Acholi S, Ruggli N, Choi KH.Autocatalytic activity and substrate specificity of the pestivirus N-terminal protease Npro(2014).Virology452-453:303-9". 2.We identified the regions and species of interferon regulatory factor 3 (IRF3) that Nprointeracts The BVDV and CSFV Nproproteins shut offs the host interferon response by degrading the interferon regulatory factor 3 (IRF3), a transcription factor for interferon response.In uninfected cells, IRF3 exists as an inactive monomer in the cytoplasm. Upon virus infection, IRF3 undergoes a conformational change from an inactive monomer to an activated, phosphorylated dimer, and translocates to the nucleus.We determined that CSFV Nprointeraction with IRF3 requires both DNA-binding and regulatory domains of IRF3, and that Nprobinds both the IRF3 monomer and dimer.Thus, Nprolikely targeting all forms of IRF3 species for degradation in cells. The results were published in"Gottipati K, Holthauzen LM, Ruggli N, Choi KH. Pestivirus Nprodirectly interacts with interferon regulatory factor 3 monomer and dimer (2016). J Virol. 90(17):7740-7". 3. We determined that the newly discovered atypical porcine pestivirus (APPV) Nprolikely have a similar N-terminal protease domain, but not the C-terminal zinc-binding domain. Recently, a genetically distinct novel pestivirus, atypical porcine pestivirus (APPV) was shown to be responsible for the "shaken piglet" syndrome.APPV genome was identified in the cerebellum and peripheral nerves of piglets with congenital tremor (i.e., shaken piglets) but not in healthy piglets from the same herd.Sequence alignment of Nproproteins shows that APPV Nprohas low sequence identity (~20%) with BVDV and CSFV Npro;although the catalytic site (His49 and Cys69) in the N-terminal protease domain are conserved, the C-terminal zinc-binding domain does not show any homology.Thus, APPV Nprolikely have a similarly N-terminal protease domain, but the differently folded C-terminal domain (Gottipati et al., PLoS Pathogens, 2013).We determined that APPV Nproindeed has a similar protease activity as CSFV Nproand self-cleaves at its own C-terminus.In addition, we have determined with collaboration with Dr. Chen (Yangzhou University, China) that APPV Nprowas able to subvert interferon response, similar to BVDV and CSFV Npro. 4. Structural studies of the Npro-IRF3 complex To determine the mechanism by which pestivirus Nprotargets IRF3, we focused on the crystallization of the Nproand IRF3 complex.We have previously shown that Nprointeracts with IRF3 at 1:1 ratio (Gottipati et al., JVI, 2016).However, when we used separate Nproand IRF3 proteins to isolate the Npro-IRF3 complex, the complex was not homogeneous enough for structural studies.To obtain the homogeneous Npro-IRF3 complex, we designed several Npro-IRF3 fusion proteins that contain both Nproand IRF3 in a single polypeptide chain with various linker regions between the two proteins.This fusion strategy ensures a 1:1 ratio of both proteins, and we were able to obtain a stable and homogeneous protein.Initial crystallization trials did not yield any crystals yet.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2016
Citation:
Pestivirus Npro directly interacts with interferon regulatory factor 3 monomer and dimer (2016). Gottipati K, Holthauzen LM, Ruggli N, Choi KH. J Virol. 90(17):7740-7.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Comparison of classical swine fever virus and atypical porcine pestivirus Npro, CRWAD (Conference of Research Workers in Animal Diseases), Chicago, Dec 2-4, 2018
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2019
Citation:
Interaction of classical swine fever virus Npro and interferon regulatory factor 3, CRWAD, Chicago, Nov 2-5, 2019
|
Progress 02/01/18 to 01/31/19
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?A oral presentation titled "Comparison of classical swine fever virus and atypical porcine pestivirus Npro"was presented at the CRWAD (Conference of Research Workers in Animal Diseases) inChicago, Dec 2-4, 2018 What do you plan to do during the next reporting period to accomplish the goals?We will continue to characterizeAPPV Npro, and determine whether APPV Npro inhibits interferon response via the same mechanism as CSFV and BVDV Npro, i.e., Npro-induced degradation of IRF3. We will analyze APPV Npro interactions with IRF3 and determine the crystal structure of APPV Npro. We will also continue our efforts to structurally and biochemical analyze the Npro-IRF3 complex.
Impacts
What was accomplished under these goals?
Bovine viral diarrhea (BVD) is the most costly viral disease in US cattle herds, costing an estimated 2 billion dollars per year. Similarly, classical swine fever (CSF) or hog cholera is a highly infectious viral disease causing serious economic losses in the pig industry. More recently, a new type of pig virus called atypical porcine pestivirus (APPV) has been reported to be the cause of the "shaken piglet" syndrome in newborn piglets. Despite the significant impacts of these animal viruses on the agriculture industry, there is no cure or treatment available for these diseases. In both BVD and CSF viruses (also in recently discovered APPV), a viral protein called "Npro" is responsible for disarming the host immune system. In this project, we will study the structure and function of Npro in proteolytic activity and host interferon response. We will then use this information to engineer a virus that has a non-functional Npro. Without the ability to disable the immune system, such a virus could be used as a vaccine to protect cows and pigs from future exposure to BVDV and CSFV, respectively. This year we have focused in two areas, 1) characterizing the newly discovered APPV Npro, and 2) obtain structural information on the Npro-IRF3 complex. 1. Characterization of APPV Npro Agenetically distinct novel pestivirus, APPVwas recently shown to be responsible for the "shaken piglet" syndrome. APPV genome was identified in the cerebellum and peripheral nerves of piglets with congenital tremor (i.e., shaken piglets) but not in healthy piglets from the same herd. Sequence alignment among APPV and other pestivirus Npro proteins shows that APPV Npro has low sequence identity (~20%) with BVDV and CSFV Npro. The catalytic site residues (His49 and Cys69) in the N-terminal protease domain are conserved, but there is no homology in the C-terminal zinc-binding domain. Thus, APPV Npro likely hasa similarly folded N-terminal protease domain to BVDV and CSFV Npro, but adifferently folded C-terminal domain (Gottipati et al., PLoS Pathogens, 2013). We have indeed determined that APPV Npro has a similar protease activity as CSFV Npro, and self-cleaves at its own C-terminus. In addition,with collaboration with Dr. Chen (Yangzhou University, China) we have determined that APPV Npro was able to subvert interferon response in infected cells, similar to BVDV and CSFV Npro. The BVDV and CSFV Npro proteins shut offthe host interferon response by degrading the interferon regulatory factor 3 (IRF3), a transcription factor for interferon genes. In uninfected cells, IRF3 exists as an inactive monomer in the cytoplasm. Upon virus infection, IRF3 undergoes a conformational change from an inactive monomer to an activated, phosphorylated dimer, and translocates to the nucleus. We have previously shown that CSFV Npro binds both the IRF3 monomer and dimer using recombinant IRF3 monomer and phosphomimetic dimer (Gottipati et al., J Virol. 2016). To understand the interferon antagonistic function of APPV Npro, we are currently determining the interaction between APPV Npro and various IRF3 constructs. 2.Structural studies of the Npro-IRF3 complex To determine the mechanism of how pestivirus Npro invades host innate immune system by targeting IRF3, we need to understand howNprorecognizesIRF3 for interaction. Structure of the Npro-IRF3 complex would provide detailed information regarding the interaction between Nproand IRF3.We have previously shown that Npro interacts with IRF3 at 1:1 ratio (Gottipati et al., JVI, 2016). However, theNpro-IRF3 complex isolated using twoseparate Npro and IRF3 proteins was not homogenous enough for biochemical and structural studies. To obtain the homogeneous Npro-IRF3 complex (1:1 ratio of both proteins), we designed several Npro-IRF3 fusion proteins that contain both Npro and IRF3 in a single polypeptide chain with various linker regions between the two proteins. We were able to obtain a homogeneous protein from a IRF3-Npro construct consisting the N-terminal IRF3 and the C-terminal Npro, but crystallization trials did not yield any crystals. We thus designed additional IRF3-Npro constructs, where the mutations in IRF3 induce dimerization of IRF3. These fusion proteins are now being used for their biochemical and crystallization tests.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Comparison of classical swine fever virus and atypical porcine pestivirus Npro, CRWAD (Conference of Research Workers in Animal Diseases), Chicago, Dec 2-4, 2018
|
Progress 02/01/17 to 01/31/18
Outputs
Target Audience:Animal virus researchers Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Dr. Keerthi Gottipati was promoted to the research scientist position (permanant staff). How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?We will continue our efforts to structurally and biochemical analyze the Npro-IRF3 complex (Aim 2a). Additionally, we have expanded our studies to atypical porcine pestivirus (APPV) Npro. Recently, a genetically distinct novel pestivirus, atypical porcine pestivirus (APPV) was shown to be responsible for the "shaken piglet" syndrome. APPV genome was identified in the cerebellum and peripheral nerves of piglets with congenital tremor (i.e., shaken piglets) but not in healthy piglets from the same herd. In our preliminary data, APPV Npro also inhibits the interferon response, similar to BVDV and CSFV Npro. However, APPV Npro has low sequence identity (~20%) with BVDV and CSFV Npro. The catalytic site residues (His49 and Cys69) in the N-terminal protease domain are conserved, but there is no homology in the C-terminal zinc-binding domain. We thus have tested if APPV Npro has the same domain arrangement as the CSFV Npro, consisting of an N-terminal protease domain and a C-terminal zinc-binding domain using limited proteolysis. APPV Npro was not cleaved in the region between the protease and the zinc-binding domains, suggesting that APPV Npro may have a different structure from CSFV Npro. Consequently, it is not clear whether APPV Npro inhibits interferon response via the same mechanism as CSFV and BVDV Npro, i.e., Npro-induced degradation of IRF3. We will analyze APPV Npro interactions with IRF3 and determine the crystal structure of APPV Npro.
Impacts
What was accomplished under these goals?
Bovine viral diarrhea (BVD) is the most costly viral disease in US cattle herds, costing an estimated 2 billion dollars per year. Similarly, classical swine fever (CSF) or hog cholera is a highly infectious viral disease causing serious economic losses in the pig industry. More recently, a new type of pig virus called atypical porcine pestivirus (APPV) has been reported to be the cause of the "shaken piglet" syndrome in newborn piglets. Despite the significant impacts of these animal viruses on the agriculture industry, there is no cure or treatment available for these diseases. In both BVD and CSF viruses (also in recently discovered APPV), a viral protein called "Npro" is responsible for disarming the host immune system. In this project, we will study the structure and function of Npro in proteolytic activity and host interferon response. We will then use this information to engineer a virus that has a non-functional Npro. Without the ability to disable the immune system, such a virus could be used as a vaccine to protect cows and pigs from future exposure to BVDV and CSFV, respectively. Aim 1. To determine substrate specificity of Npro using an Npro-GFP assay system Due to lack of in vitro protease activity assays, Npro's protease activity and its involvement in interferon-antagonistic function are not well understood. Using the Npro-GFP fusion protein assay we developed, we defined structural requirements of the C-terminal cleavage site in Npro, and identified residues that can be mutated to affect the Npro's autoproteolysis efficiency. We have completed this aim, and the result is published in Gottipati K, Acholi S, Ruggli N, Choi KH (2014) Autocatalytic activity and substrate specificity of the pestivirus N-terminal protease Npro. Virology 452-453:303-9. Aim 2a. Determine the involvement of N- and C-terminal Npro residues in interferon regulatory factor 3 (IRF3) binding The viral Npro protein shuts offs the host interferon response by degrading the interferon regulatory factor 3 (IRF3), a signaling protein for interferon response. To determine the mechanism of how pestivirus Npro invades host innate immune system by targeting IRF3, we focused on Npro and IRF3 interaction this year. We have previously shown that Npro interacts with IRF3 at 1:1 ratio (Gottipati et al., 2016, JVI). However, when we used separate Npro and IRF3 proteins to isolate the Npro-IRF3 complex, the complex was not homogeneous enough for biochemical and structural studies. To purify the homogeneous Npro-IRF3 complex, we designed three Npro-IRF3 fusion proteins that contain both Npro and IRF3 in a single polypeptide chain with various linker regions between the two proteins. This fusion strategy ensures a 1:1 ratio of both proteins. One of the constructs, IRF3-Npro consisting IRF3 and Npro at the N- and C-terminus of the fusion protein, shows a single monomeric peak in size-exclusion chromatography, suggesting that a homogeneous population of the Npro-IRF3 complex is formed. This construct is now being used for biochemical and crystallization tests to obtain detailed information regarding the interaction between Npro and IRF3. Aim 2b. Identify IRF3 species that Npro interacts with In uninfected cells, IRF3 exists as an inactive monomer in the cytoplasm. Upon virus infection, IRF3 undergoes a conformational change from an inactive monomer to an activated, phosphorylated dimer, and translocates to the nucleus. It is currently not clear if Npro targets both IRF3 monomer and dimer for degradation. We have determined that Npro binds both the IRF3 monomer and dimer using recombinant IRF3 monomer and phosphomimetic IRF3 dimer, and that both DNA-binding and regulatory domains of IRF3 are required for Npro interaction. We have completed this aim, and the result is published in Gottipati K, Holthauzen LM, Ruggli N, Choi KH. Pestivirus Npro directly interacts with interferon regulatory factor 3 monomer and dimer (2016). J Virol. 90(17): 7740-7. Aim 3. To determine pathogenicity of mutant virus containing Npro substitutions Not started yet.
Publications
|
Progress 02/01/16 to 01/31/17
Outputs
Target Audience:Target audienceis researcherswho work on the animal diseases. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Keerthi Gottipati is a post-doctoral fellow working on the project. She presented her data as a platform presentation at the annual meeting of American Society for Virology. She alsoparticipated the UTMB-sponsered post-doc training program"Preparing for Proposals and Publications" How have the results been disseminated to communities of interest?We have published 2 manuscripts. Dr. Gottipatigave an oral presentation at the annual meetings of American Society for Virology (1 abstract). What do you plan to do during the next reporting period to accomplish the goals?Aim 1.To determine substrate specificity of Npro using an Npro-GFP assay system: completed Aim 2a.Determine the involvement of N- and C-terminal Npro residues in IRF3 binding: We will generate N- and C-terminal Npro mutants and determine their interactions with IRF3. We also plan to generate Npro-IRF3 fusion protein to determine the feasibility of crystallographic studies of the complex. Aim 2b.Identify IRF3 species that Npro interacts with: completed Aim 3.To determine pathogenicity of mutant virus containing Npro substitutions: none
Impacts
What was accomplished under these goals?
Bovine viral diarrhea (BVD) is the most costly viral disease in US cattle herds, costing an estimated 2 billion dollars per year. Similarly, classical swine fever (CSF)or hog cholera is a highly infectious viral disease causing serious economic losses inthe pig industry. Despite their significant impacts on the agriculture industry, there is no cure or treatment available for eitherdisease. In both BVD and CSF, a viral protein called "Npro" is responsible for disarming the host immune system by degradingthe interferon regulatory factor 3 (IRF3), a signaling protein for interferon response. In this project, we will study how Nproself-activatesand how activated Npro shuts off the host interferon response at the molecular level. We will then use thisinformation to engineer a virus that has a non-functional Npro. Without the ability to disable the immune system, such a viruscould be used as a vaccine to protect cows and pigs from future exposure to BVDV and CSFV, respectively. Aim 1. To determine substrate specificity of Npro using an Npro-GFP assay system Due to lack of in vitro protease activity assays, Npro's protease activity and its involvement in interferon-antagonistic functionare not well understood. Using our recently developed Npro-GFP fusion protein assay, we will define structural requirements ofthe C-terminal cleavage site, and identify residues that can be mutated to affect the Npro's autoproteolysis efficiency. Progress: We have completed this aim and reported in 2016. The result was published in "Gottipati K, Acholi S, Ruggli N, Choi KH (2014) Autocatalytic activity and substrate specificity of the pestivirus N-terminalprotease Npro. Virology 452-453:303-9" Aim 2a. Determine the involvement of N- and C-terminal Npro residues in IRF3 binding Identification of binding sites on both Npro and IRF3 is the first step toward understanding the molecular basis of Npro-IRF3 interaction. Many mutations in Npro that affect its ability to inhibit type I interferon induction have been identified, but the mechanism by which these residues block the interferon response is not known. In light of the Npro crystal structure, we hypothesize that the N-terminal protease and C-terminal zinc-binding domains of Npro have different but essential functions in the anti-interferon response, i.e., direct interaction with IRF3 vs inducing a downstream response leading to degradation of IRF3. We will test this hypothesis by determining whether residues in bothdomains are required to interact directly with IRF3. Progress: We willtake both biochemical and structural approaches to this aim. We have initiated site-directed mutagenesis to generate Npro mutants that selectively substitute the N- and C-terminal residues. Aim 2b. Identify IRF3 species that Npro interacts with In the latent state, IRF3 exists as an inactive monomer in the cytoplasm of uninfected cells. Upon virus infection, IRF3undergoes aconformational change from an inactive monomer to an activated, phosphorylated dimer. Npro-mediatedproteasomal degradation has been shown for cytoplasmic IRF3, and thus it is likely that IRF3 monomer is the major target forNpro. However, it is not known whether Npro also binds the activated IRF3 dimer and induces its degradation. We willdetermine whether Npro selectively binds the IRF3 monomer or dimerusing recombinant IRF3 monomer and phosphomimeticIRF3 dimer, and identify IRF3 regions that are involved in Npro interaction. Progress: We have generated multiple forms of IRF3 and determined which IRF3 species that Npro interact with. Npro binds IRF3 directlywithout any additional proteins, and forms a soluble 1:1 complex. The interaction between Npro and IRF3 requires the fulllengthIRF3, and Npro did not bind to individual domains of IRF3. The interaction between Npro and IRF3 is not dependent onthe activation state of IRF3, and Npro binds to a constitutively active form of IRF3 in the presence of its transcriptionalcoactivator CREB-binding protein. Thus, Npro recognizes bothinactivated IRF3 monomer and phosphomimetic IRF3 dimer forbinding, likely targeting all forms of IRF3 species for degradation in cells. The results are now published in "Gottipati K, Holthauzen LM, Ruggli N, Choi KH. Pestivirus Npro directly interacts with interferon regulatory factor 3 monomer and dimer (2016). J Virol. 90(17):7740-7." Aim 3. To determine pathogenicity of mutant virus containing Npro substitutions Not started yet. Overall Impacts We are beginning to understand the details of Npro and IRF3 interaction. We discovered that Npro likely interacts (and thus degrades) all forms of IRF3. Thus, if we figure out the interaction site between Npro and IRF3, we will be able to modify Npro to prevent such interaction in vaccine candidates. Percentage of completion: Aim 1, 100%; Aim 2, 20%; Aim 3, 0% Projection for the next year: Aim 1, 100%; Aim 2, 40%; Aim 3, 0%
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2016
Citation:
Pestivirus Npro directly interacts with interferon regulatory factor 3 monomer and dimer (2016). Gottipati K, Holthauzen LM, Ruggli N, Choi KH. J Virol. 90(17):7740-7.
|
Progress 02/01/15 to 01/31/16
Outputs
Target Audience:
Nothing Reported
Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?Our results from Aim 1 is published in a scientific journal. "Gottipati K,Acholi S,Ruggli N,Choi KH(2014) Autocatalytic activity and substrate specificity of the pestivirus N-terminal protease Npro.Virology452-453:303-9" What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Bovine viral diarrhea (BVD) is the most costly viral disease in US cattle herds, costing an estimated 2 billion dollars per year. Similarly, classical swine fever (CSF), or hog cholera is a highly infectious viral disease causing serious economic losses in the pig industry. Despite their significant impacts on the agriculture industry, there is no cure or treatment available for either disease. In both BVD and CSF, a viral protein called "Npro" is responsible for disarming the host immune system by degrading the interferon regulatory factor 3 (IRF3), a signaling protein for interferon response. In this project, we will study how Npro self-activates and how activated Npro shuts off the host interferon response at the molecular level. We will then use this information to engineer a virus that has a non-functional Npro. Without the ability to disable the immune system, such a virus could be used as a vaccine to protect cows and pigs from future exposure to BVDV and CSFV, respectively. Aim 1. To determine substrate specificity of Npro using an Npro-GFP assay system Due to lack of in vitro protease activity assays, Npro's protease activity and its involvement in interferon-antagonistic function are not well understood. Using our recently developed Npro-GFP fusion protein assay, we will define structural requirements of the C-terminal cleavage site, and identify residues that can be mutated to affect the Npro's autoproteolysis efficiency. Progress: We have completed this aim while the application was under review. We have expressed 14 Npro-GFP fusion proteins, each of which containing a single amino acid changes in either active site (Glu22, Cys69, Arg100) or the cleavage site (Cys168) in Npro. Contrary to previous reports, we show that Npro's catalytic activity does not involve Glu22, which may instead be involved in proteinstability. Furthermore, Npro does not have specificity for Cys168 at the cleavage site even though this residue is conserved throughout the pestivirus genus. The result was published in "Gottipati K, Acholi S, Ruggli N, Choi KH (2014) Autocatalytic activity and substrate specificity of the pestivirus N-terminal protease Npro. Virology 452-453:303-9" Aim 2. To understand interactions between Npro and IRF3 2a. Determine the involvement of N- and C-terminal Npro residues in IRF3 binding No progress for this aim. 2b. Identify IRF3 species that Npro interacts with In the latent state, IRF3 exists as an inactive monomer in the cytoplasm of uninfected cells. Upon virus infection, IRF3 undergoes a conformational change from an inactive monomer to an activated, phosphorylated dimer. Npro-mediated proteasomal degradation has been shown for cytoplasmic IRF3, and thus it is likely that IRF3 monomer is the major target for Npro. However, it is not known whether Npro also binds the activated IRF3 dimer and induces its degradation. We will determine whether Npro selectively binds the IRF3 monomer or dimer using recombinant IRF3 monomer and phosphomimetic IRF3 dimer, and identify IRF3 regions that are involved in Npro interaction. Progress: We have generated multiple forms of IRF3 and determined which IRF3 species that Npro interact with. Npro binds IRF3 directly without any additional proteins, and forms a soluble 1:1 complex. The interaction between Npro and IRF3 requires the full-length IRF3, and Npro did not bind to individual domains of IRF3. The interaction between Npro and IRF3 is not dependent on the activation state of IRF3, and Npro binds to a constitutively active form of IRF3 in the presence of its transcriptional coactivator CREB-binding protein. Thus, Npro recognizes both inactivated IRF3 monomer and phosphomimetic IRF3 dimer for binding, likely targeting all forms of IRF3 species for degradation in cells. Aim 3. To determine pathogenicity of mutant virus containing Npro substitutions No progress for this aim.
Publications
|
|