scholarly journals Interaction of Structural Glycoprotein E2 of Classical Swine Fever Virus with Protein Phosphatase 1 Catalytic Subunit Beta (PPP1CB)

Viruses ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 307 ◽  
Author(s):  
Elizabeth Vuono ◽  
Elizabeth Ramirez-Medina ◽  
Lauren Holinka ◽  
Ryan Baker-Branstetter ◽  
Manuel Borca ◽  
...  
Keyword(s):  
Classical Swine Fever Virus ◽  
Protein Phosphatase ◽  
Specific Binding ◽  
Classical Swine Fever ◽  
Viral Envelope ◽  
Fever Virus ◽  
Catalytic Subunit ◽  
Protein Phosphatase 1 ◽  
Proximity Ligation Assay ◽  
Negative Effect

Classical swine fever virus (CSFV) E2 protein, the major virus structural glycoprotein, is an essential component of the viral envelope. E2 is involved in virus absorption, induction of a protective immune response and is critical for virulence in swine. Using the yeast two-hybrid system, we identified protein phosphatase 1 catalytic subunit beta (PPP1CB), which is part of the Protein Phosphatase 1 (PP1) complex, as a specific binding host partner for E2. We further confirmed the occurrence of this interaction in CSFV-infected swine cells by using two independent methodologies: Co-immunoprecipitation and Proximity Ligation Assay. In addition, we demonstrated that pharmacological activation of the PP1 pathway has a negative effect on CSFV replication while inhibition of the PP1 pathway or knockdown of PPP1CB by siRNA had no observed effect. Overall, our data suggests that the CSFV E2 and PPP1CB protein interact in infected cells, and that activation of the PP1 pathway decreases virus replication.

scholarly journals SERTA Domain Containing Protein 1 (SERTAD1) Interacts with Classical Swine Fever Virus Structural Glycoprotein E2, Which Is Involved in Virus Virulence in Swine

Viruses ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 421
Author(s):  
Elizabeth A. Vuono ◽  
Elizabeth Ramirez-Medina ◽  
Paul Azzinaro ◽  
Keith A. Berggren ◽  
Ayushi Rai ◽  
...  
Keyword(s):  
Protein Interaction ◽  
Classical Swine Fever Virus ◽  
Critical Role ◽  
Hybrid Approach ◽  
Classical Swine Fever ◽  
Fever Virus ◽  
Proximity Ligation Assay ◽  
Yeast Two Hybrid ◽  
Clinically Normal ◽  
Two Hybrid

E2 is the major structural glycoprotein of the classical swine fever virus (CSFV). E2 has been shown to be involved in important virus functions such as replication and virulence in swine. Using the yeast two-hybrid system, we previously identified several host proteins specifically interacting with CSFV E2. Here, we analyze the protein interaction of E2 with SERTA domain containing protein 1 (SERTAD1), a factor involved in the stimulation of the transcriptional activities of different host genes. We have confirmed that the interaction between these two proteins occurs in CSFV-infected swine cells by using a proximity ligation assay and confocal microscopy. Amino acid residues in the CSFV E2 protein that are responsible for mediating the interaction with SERTAD1 were mapped by a yeast two-hybrid approach using a randomly mutated E2 library. Using that information, a recombinant CSFV mutant (E2ΔSERTAD1v) that harbors substitutions in those residues mediating the protein-interaction with SERTAD1 was developed and used to study the role of the E2-SERTAD1 interaction in viral replication and virulence in swine. CSFV E2ΔSERTAD1v, when compared to the parental BICv, showed a clearly decreased ability to replicate in the SK6 swine cell line and a more severe replication defect in primary swine macrophage cultures. Importantly, 80% of animals infected with E2ΔSERTAD1v survived infection, remaining clinically normal during the 21-day observational period. This result would indicate that the ability of CSFV E2 to bind host SERTAD1 protein during infection plays a critical role in virus virulence.

scholarly journals The MyD116 African Swine Fever Virus Homologue Interacts with the Catalytic Subunit of Protein Phosphatase 1 and Activates Its Phosphatase Activity

2007 ◽  
Vol 81 (6) ◽  
pp. 2923-2929 ◽  
Author(s):  
José Rivera ◽  
Charles Abrams ◽  
Bruno Hernáez ◽  
Alberto Alcázar ◽  
José M. Escribano ◽  
...  
Keyword(s):  
Protein Phosphatase ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Catalytic Subunit ◽  
Protein Phosphatase 1 ◽  
Initiation Factor ◽  
Wild Type ◽  
Α Subunit ◽  
Initiation Factor 2

ABSTRACT The DP71L protein of African swine fever virus (ASFV) shares sequence similarity with the herpes simplex virus ICP34.5 protein over a C-terminal domain. We showed that the catalytic subunit of protein phosphatase 1 (PP1) interacts specifically with the ASFV DP71L protein in a yeast two-hybrid screen. The chimeric full-length DP71L protein, from ASFV strain Badajoz 71 (BA71V), fused to glutathione S-transferase (DP71L-GST) was expressed in Escherichia coli and shown to bind specifically to the PP1-α catalytic subunit expressed as a histidine fusion protein (6×His-PP1α) in E. coli. The functional effects of this interaction were investigated by measuring the levels of PP1 and PP2A in ASFV-infected Vero cells. This showed that infection with wild-type ASFV strain BA71V activated PP1 between two- and threefold over that of mock-infected cells. This activation did not occur in cells infected with the BA71V isolate in which the DP71L gene had been deleted, suggesting that expression of DP71L leads to PP1 activation. In contrast, no effect was observed on the activity of PP2A following ASFV infection. We showed that infection of cells with wild-type BA71V virus resulted in decreased phosphorylation of the α subunit of eukaryotic initiation factor 2 (eIF-2α). ICP34.5 recruits PP1 to dephosphorylate the α subunit of eukaryotic translational initiation factor 2 (also known as eIF-2α); possibly the ASFV DP71L protein has a similar function.

scholarly journals Different evolutionary patterns of classical swine fever virus envelope proteins

2016 ◽  
Vol 62 (3) ◽  
pp. 210-219 ◽  
Author(s):  
Yan Li ◽  
Zexiao Yang ◽  
Mingwang Zhang
Keyword(s):  
Classical Swine Fever Virus ◽  
Functional Divergence ◽  
Classical Swine Fever ◽  
Acid Sites ◽  
Envelope Proteins ◽  
Viral Envelope ◽  
Fever Virus ◽  
Host Cells ◽  
Virus Envelope ◽  
Evolutionary Patterns

Classical swine fever virus (CSFV) is the causative agent of classical swine fever, which is a highly contagious disease of the domestic pig as well as wild boar. The proteins Erns, E1, and E2 are components of the viral envelope membrane. They are also implicated in virus attachment and entry, replication, and (or) anti-immune response. Here, we studied the genetic variations of these envelope proteins in the evolution of CSFV. The results reveal that the envelope proteins underwent different evolutionary fates. In Ernsand E1, but not E2, a number of amino acid sites experienced functional divergence. Furthermore, the diversification in Ernsand E1 was generally episodic because the divergence-related changes of E1 only occurred with the separation of 2 major groups of CSFV and that of Ernstook place with the division of 1 major group. The major divergence-related sites of Ernsare located on one of the substrate-binding regions of the RNase domain and C-terminal extension. These functional domains have been reported to block activation of the innate immune system and attachment and entry into host cells, respectively. Our results may shed some light on the divergent roles of the envelope proteins.

scholarly journals Generation and immunogenicity analysis of recombinant classical swine fever virus glycoprotein E2 and Erns expressed in baculovirus expression system

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Qiang Wei ◽  
Yilin Bai ◽  
Yapeng Song ◽  
Yunchao Liu ◽  
Wei Yu ◽  
...  
Keyword(s):  
Immune Responses ◽  
Classical Swine Fever Virus ◽  
Expression System ◽  
Classical Swine Fever ◽  
Neutralizing Antibody ◽  
Baculovirus Expression System ◽  
Viral Envelope ◽  
Fever Virus ◽  
Complete Protection ◽  
Glycoprotein E2

AbstractClassical swine fever (CSF) caused by the classical swine fever virus (CSFV) is a highly contagious swine disease resulting in large economical losses worldwide. The viral envelope glycoprotein E2 and Erns are major targets for eliciting antibodies against CSFV in infected animals. In this report, the glycoprotein E2 and Erns were expressed using the baculovirus system and their protective immunity in rabbits were tested. Twenty CSFV seronegative rabbits were randomly divided into five groups. Each rabbit was intramuscularly immunized with CSFV-E2, CSFV-Erns, or their combination (CSFV-E2 + Erns). Besides, a commercial CSFV vaccine (C-strain) and PBS were used as positive or negative controls, respectively. Four weeks after the second immunization, all the rabbits were challenged with 100 RID50 of CSFV C-strain. High levels of CSFV E2-specific antibody, neutralizing antibody and cellular immune responses to CSFV were elicited in the rabbits inoculated with C-strain, CSFV-E2, and CSFV-E2 + Erns. And the rabbits inoculated with the three vaccines received complete protection against CSFV C-strain. However, no neutralizing antibody was detected in the Erns vaccinated rabbits and the rabbits exhibited fever typical of CSFV, suggesting the Erns alone is not able to induce a protective immune response. Taken together, while the Erns could not confer protection against CSFV, E2 and E2 + Erns could not only elicit humoral and cell-mediated immune responses but also confer complete protection against CSFV C-strain in rabbits.

scholarly journals The African Swine Fever Virus DP71L Protein Recruits the Protein Phosphatase 1 Catalytic Subunit To Dephosphorylate eIF2α and Inhibits CHOP Induction but Is Dispensable for These Activities during Virus Infection

2010 ◽  
Vol 84 (20) ◽  
pp. 10681-10689 ◽  
Author(s):  
Fuquan Zhang ◽  
Alice Moon ◽  
Kay Childs ◽  
Stephen Goodbourn ◽  
Linda K. Dixon
Keyword(s):  
Amino Acids ◽  
Protein Phosphatase ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Catalytic Subunit ◽  
Translation Initiation Factor ◽  
Protein Phosphatase 1 ◽  
Resting Cells ◽  
Eif2α Phosphorylation

ABSTRACT The African swine fever virus (ASFV) DP71L protein is present in all isolates as either a short form of 70 to 72 amino acids or a long form of about 184 amino acids, and both of these share sequence similarity to the C-terminal domain of the herpes simplex virus ICP34.5 protein and cellular protein GADD34. In the present study we expressed DP71L in different mammalian cells and demonstrated that DP71L causes dephosphorylation of eukaryotic translation initiation factor 2 alpha (eIF2α) in resting cells and during chemical-induced endoplasmic reticulum stress and acts to enhance expression of cotransfected reporter genes. We showed that DP71L binds to all the three isoforms (α, β, and γ) of the protein phosphatase 1 catalytic subunit (PP1c) and acts by recruiting PP1c to eIF2α. We also showed that DP71L inhibits the induction of ATF4 and its downstream target, CHOP. We investigated the eIF2α phosphorylation status and induction of CHOP in porcine macrophages infected by two ASFV field isolates, Malawi Lil20/1 and Benin 97/1, and two DP71L deletion mutants, MalawiΔNL and E70ΔNL. Our results showed that deletion of the DP71L gene did not cause an increase in the level of eIF2α phosphorylation or induction of CHOP, indicating that DP71L is not the only factor required by the virus to control the phosphorylation level of eIF2α during infection. We therefore hypothesize that ASFV has other mechanisms to prevent the eIF2α phosphorylation and the subsequent protein synthesis inhibition.

ARFGAP1 binds to classical swine fever virus NS5A protein and enhances CSFV replication in PK-15 cells

2021 ◽  
Vol 255 ◽  
pp. 109034
Author(s):  
Liang Zhang ◽  
Mingxing Jin ◽  
Mengzhao Song ◽  
Shanchuan Liu ◽  
Tao Wang ◽  
...  
Keyword(s):  
Classical Swine Fever Virus ◽  
Classical Swine Fever ◽  
Fever Virus ◽  
Ns5a Protein

Genome Variability of Classical Swine Fever Virus during the 2018–2020 Epidemic in Japan

2021 ◽  
pp. 109128
Author(s):  
Tatsuya Nishi ◽  
Katsuhiko Fukai ◽  
Tomoko Kato ◽  
Kotaro Sawai ◽  
Takehisa Yamamoto
Keyword(s):  
Classical Swine Fever Virus ◽  
Classical Swine Fever ◽  
Fever Virus ◽  
Genome Variability

scholarly journals A Novel E2 Glycoprotein Subunit Marker Vaccine Produced in Plant Is Able to Prevent Classical Swine Fever Virus Vertical Transmission after Double Vaccination

Vaccines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 418
Author(s):  
Youngmin Park ◽  
Yeonsu Oh ◽  
Miaomiao Wang ◽  
Llilianne Ganges ◽  
José Alejandro Bohórquez ◽  
...  
Keyword(s):  
Vertical Transmission ◽  
Classical Swine Fever Virus ◽  
Neutralizing Antibodies ◽  
Subunit Vaccine ◽  
Vaccine Dose ◽  
Classical Swine Fever ◽  
Fever Virus ◽  
Tissue Samples ◽  
Marker Vaccine ◽  
E2 Glycoprotein

The efficacy of a novel subunit vaccine candidate, based in the CSFV E2 glycoprotein produced in plants to prevent classical swine fever virus (CSFV) vertical transmission, was evaluated. A Nicotiana benthamiana tissue culture system was used to obtain a stable production of the E2-glycoprotein fused to the porcine Fc region of IgG. Ten pregnant sows were divided into three groups: Groups 1 and 2 (four sows each) were vaccinated with either 100 μg/dose or 300 μg/dose of the subunit vaccine at 64 days of pregnancy. Group 3 (two sows) was injected with PBS. Groups 1 and 2 were boosted with the same vaccine dose. At 10 days post second vaccination, the sows in Groups 2 and 3 were challenged with a highly virulent CSFV strain. The vaccinated sows remained clinically healthy and seroconverted rapidly, showing efficient neutralizing antibodies. The fetuses from vaccinated sows did not show gross lesions, and all analyzed tissue samples tested negative for CSFV replication. However, fetuses of non-vaccinated sows had high CSFV replication in tested tissue samples. The results suggested that in vaccinated sows, the plant produced E2 marker vaccine induced the protective immunogenicity at challenge, leading to protection from vertical transmission to fetuses.

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