Structural insights into the CP312R protein of the African swine fever virus

Chen, Lifei; Chen, Leiqing; Chen, Huan; Zhang, Hong; Dong, Panpan; Sun, Lifang; Huang, Xiaojing; Lin, Pingdong; Wu, Linjiao; Jing, Dingding; Qian, Yingjuan; Wu, Yunkun

doi:10.1016/j.bbrc.2022.07.091

Cited by 6 publications

(8 citation statements)

References 33 publications

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“…These identified epitopes were detected by their respective mAbs during the IFA analyses in HEK-293T cells. The ssDNA interaction region of CP312R [ 31 ] is consistent with previous reports which state that it is conserved among the OB-fold complexes [ 52 ]. In the CP312R structural study, the indicated K94, R98, R194, K196, R257, and Y46 AA residues may be important in the ssDNAs’ interaction [ 31 ]; K122 and Y122 AA residues of the antigenic epitope of CP312R recognized by the five mAbs, as well as R83 in the second epitope detected by two mAbs, may contribute to the ssDNA interaction.…”

Section: Discussionsupporting

confidence: 88%

“…Even though it is still poorly defined [ 15 ], very few previous reports have identified the CP312R protein as a vital potential target protein for the development of a vaccine or inhibitor drug against the ASFV infection. Its ability to mount antigen-specific responses to virally vectored CP312R [ 28 , 47 ] and its SSB core site [ 31 ] may contribute to the prevention of ASFV DNA replication during the virus’s infection in host cells.…”

Section: Discussionmentioning

confidence: 99%

“…Both the antigenic regions are enriched of glutamic acid (E), 30% of the total AA composition of each epitope; any manipulation (substitution/mutation) works consider that the charged amino acids, such as R83, aspartic acid (D78) and glutamic acid (E79, E80, E87, E124, E127, E128), could contribute to the electrostatic interaction, which is a vital force for maintaining conformational stability in the outer part of protein [ 56 , 57 ]. Generally, the epitopes found in the region toward the N-terminal of the identified SSB domain of CP312R protein (61–278 AAs) [ 31 ] may be targeted for the development of a vaccine or epitope-based inhibitory antiviral therapeutic options. Because the SSBs are vital in viral DNA replication, repair, and recombination in both eukaryotes and prokaryotes [ 58 , 59 ], and because they interact with other proteins that are able to bind DNA [ 59 , 60 , 61 ], SSBs regulate viral replication.…”

Section: Discussionmentioning

confidence: 99%

“…Since the epitopes specifically interact with chemical groups that play a role in the antigenicity, their combination has the potential to distinguish different courses of the disease [ 62 ]. CP312R is a multistage expressed ASFV protein [ 50 ] that has a ssDNA binding site [ 31 ]. This study, in addition to verifying the CP312R immunogenicity and mAb production, identified two linear epitopes that are located in the ssDNA binding core region of the CP312R protein.…”

Section: Discussionmentioning

confidence: 99%

“…CP312R is one of those understudied ASFV genes [ 15 ]. The existing research only reports that it is immunogenic in a pooled viral vector expression [ 28 , 29 , 30 ], and based on its crystal structural analysis, it has single-stranded DNA binding activity [ 31 ]. This study initially verified the target antigen’s capability of inducing the immune system.…”

Section: Introductionmentioning

confidence: 99%

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Novel Epitopes Mapping of African Swine Fever Virus CP312R Protein Using Monoclonal Antibodies

Hagoss

Shen

Zhang

et al. 2023

Viruses

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African Swine Fever (ASF) is a highly contagious and lethal pig disease and poses a huge threat to the pig industry worldwide. ASF virus (ASFV) encodes more than 150 different proteins, but the biological properties of most viral proteins are still unknown. ASFV CP312R protein has been proven to be one of the most immunogenic proteins during ASFV infection in pigs; however, its specific epitopes have yet to be identified. In this study, we verified the immunogenicity of CP312R protein in the sera from attenuated ASFV-inoculated pigs. We generated seven anti-ASFV CP312R mouse monoclonal antibodies (mAbs) from mice immunized with recombinant CP312R protein (rCP312R). All seven mAbs are the IgG2b-Kappa isotype and specifically interacted with the CP312R protein expressed in various cells that were infected by ASFVs or transfected with plasmid CP312R. The epitope mapping was performed by using these characterized mAbs and the peptide scanning (Pepscan) method followed by Western blot. As a result, two antigenic determinant regions were identified: two of the seven mAbs recognized the 122KNEQGEEIYP131 amino acids, and the remaining five mAbs recognized the 78DEEVIRMNAE87 amino acids of the CP312R protein. These antigenic determinants of CP312R are conserved in different ASFV strains of seven genotypes. By using the characterized mAb, confocal microscopy observation revealed that the CP312R was mainly localized in the cytoplasm and, to some extent, in nuclei and on the nuclear membrane of infected host cells. In summary, our results benefit our understanding on the antigenic regions of ASFV CP312R and help to develop better serological diagnosis of ASF and vaccine research.

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Section: Discussionsupporting

confidence: 88%