scholarly journals African Swine Fever Virus pB119L Protein Is a Flavin Adenine Dinucleotide-Linked Sulfhydryl Oxidase

2006 ◽  
Vol 80 (7) ◽  
pp. 3157-3166 ◽  
Author(s):  
Irene Rodríguez ◽  
Modesto Redrejo-Rodríguez ◽  
Javier M. Rodríguez ◽  
Alí Alejo ◽  
José Salas ◽  
...  
Keyword(s):  
Disulfide Bonds ◽  
Flavin Adenine Dinucleotide ◽  
Virus Assembly ◽  
Nonstructural Protein ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Structural Protein ◽  
Sulfhydryl Oxidase ◽  
Infected Cells

ABSTRACT Protein pB119L of African swine fever virus belongs to the Erv1p/Alrp family of sulfhydryl oxidases and has been described as a late nonstructural protein required for correct virus assembly. To further our knowledge of the function of protein pB119L during the virus life cycle, we have investigated whether this protein possesses sulfhydryl oxidase activity, using a purified recombinant protein. We show that the purified protein contains bound flavin adenine dinucleotide and is capable of catalyzing the formation of disulfide bonds both in a protein substrate and in the small molecule dithiothreitol, the catalytic activity being comparable to that of the Erv1p protein. Furthermore, protein pB119L contains the cysteines of its active-site motif CXXC, predominantly in an oxidized state, and forms noncovalently bound dimers in infected cells. We also show in coimmunoprecipitation experiments that protein pB119L interacts with the viral protein pA151R, which contains a CXXC motif similar to that present in thioredoxins. Protein pA151R, in turn, was found to interact with the viral structural protein pE248R, which contains disulfide bridges and belongs to a class of myristoylated proteins related to vaccinia virus L1R, one of the substrates of the redox pathway encoded by this virus. These results suggest the existence in African swine fever virus of a system for the formation of disulfide bonds constituted at least by proteins pB119L and pA151R and identify protein pE248R as a possible final substrate of this pathway.

scholarly journals Comparison of the genome sequences of non-pathogenic and pathogenic African swine fever virus isolates

2008 ◽  
Vol 89 (2) ◽  
pp. 397-408 ◽  
Author(s):  
David A. G. Chapman ◽  
Vasily Tcherepanov ◽  
Chris Upton ◽  
Linda K. Dixon
Keyword(s):  
Virus Assembly ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Open Reading Frames ◽  
Structural Protein ◽  
Genome Sequences ◽  
Virus Genotype ◽  
Pathogenic Isolate ◽  
Virus Isolates

The genomic coding sequences, apart from the inverted terminal repeats and cross-links, have been determined for two African swine fever virus (ASFV) isolates from the same virus genotype, a non-pathogenic isolate from Portugal, OURT88/3, and a highly pathogenic isolate from West Africa, Benin 97/1. These genome sequences were annotated and compared with that of a tissue culture-adapted isolate, BA71V. The genomes range in length between 170 and 182 kbp and encode between 151 and 157 open reading frames (ORFs). Compared to the Benin 97/1 isolate, the OURT88/3 and BA71V isolates have deletions of 8–10 kbp that encode six copies of the multigene family (MGF) 360 and either one MGF 505/530 copy in the BA71V or two copies in the OURT88/3 isolate. The BA71V isolate has a deletion, close to the right end of the genome, of 3 kbp compared with the other isolates. The five ORFs in this region include an additional copy of an ORF similar to that encoding the p22 virus structural protein. The OURT88/3 isolate has interruptions in ORFs that encode a CD2-like and a C-type lectin protein. Variation between the genomes is observed in the number of copies of five different MGFs. The 109 non-duplicated ORFs conserved in the three genomes encode proteins involved in virus replication, virus assembly and modulation of the host's defences. These results provide information concerning the genetic variability of African swine fever virus isolates that differ in pathogenicity.

scholarly journals Generation of Filamentous Instead of Icosahedral Particles by Repression of African Swine Fever Virus Structural Protein pB438L

2006 ◽  
Vol 80 (23) ◽  
pp. 11456-11466 ◽  
Author(s):  
Carolina Epifano ◽  
Jacomine Krijnse-Locker ◽  
María L. Salas ◽  
José Salas ◽  
Javier M. Rodríguez
Keyword(s):  
Virus Assembly ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Integral Membrane Protein ◽  
Fever Virus ◽  
Icosahedral Symmetry ◽  
Structural Protein ◽  
Viral Origin ◽  
Virus Particles ◽  
Capsid Formation

ABSTRACT The mechanisms involved in the construction of the icosahedral capsid of the African swine fever virus (ASFV) particle are not well understood at present. Capsid formation requires protein p72, the major capsid component, but other viral proteins are likely to play also a role in this process. We have examined the function of the ASFV structural protein pB438L, encoded by gene B438L, in virus morphogenesis. We show that protein pB438L associates with membranes during the infection, behaving as an integral membrane protein. Using a recombinant ASFV that inducibly expresses protein pB438L, we have determined that this structural protein is essential for the formation of infectious virus particles. In the absence of the protein, the virus assembly sites contain, instead of icosahedral particles, large aberrant tubular structures of viral origin as well as bilobulate forms that present morphological similarities with the tubules. The filamentous particles, which possess an aberrant core shell domain and an inner envelope, are covered by a capsid-like layer that, although containing the major capsid protein p72, does not acquire icosahedral morphology. This capsid, however, is to some extent functional, as the filamentous particles can move from the virus assembly sites to the plasma membrane and exit the cell by budding. The finding that, in the absence of protein pB438L, the viral particles formed have a tubular structure in which the icosahedral symmetry is lost supports a role for this protein in the construction or stabilization of the icosahedral vertices of the virus particle.

scholarly journals Migration of Mitochondria to Viral Assembly Sites in African Swine Fever Virus-Infected Cells

1998 ◽  
Vol 72 (9) ◽  
pp. 7583-7588 ◽  
Author(s):  
Gema Rojo ◽  
Margarita Chamorro ◽  
María L. Salas ◽  
Eladio Viñuela ◽  
JoséM. Cuezva ◽  
...  
Keyword(s):  
Virus Assembly ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Vero Cells ◽  
Viral Assembly ◽  
Fever Virus ◽  
Infected Cells ◽  
Dramatic Shift ◽  
Large Clusters ◽  
Viral Factory

ABSTRACT An examination by electron microscopy of the viral assembly sites in Vero cells infected with African swine fever virus showed the presence of large clusters of mitochondria located in their proximity. These clusters surround viral factories that contain assembling particles but not factories where only precursor membranes are seen. Immunofluorescence microscopy revealed that these accumulations of mitochondria are originated by a massive migration of the organelle to the virus assembly sites. Virus infection also promoted the induction of the mitochondrial stress-responsive proteins p74 and cpn 60 together with a dramatic shift in the ultrastructural morphology of the mitochondria toward that characteristic of actively respiring organelles. The clustering of mitochondria around the viral factory was blocked in the presence of the microtubule-disassembling drug nocodazole, indicating that these filaments are implicated in the transport of the mitochondria to the virus assembly sites. The results presented are consistent with a role for the mitochondria in supplying the energy that the virus morphogenetic processes may require and make of the African swine fever virus-infected cell a paradigm to investigate the mechanisms involved in the sorting of mitochondria within the cell.

scholarly journals African Swine Fever Virus Structural Protein pE120R Is Essential for Virus Transport from Assembly Sites to Plasma Membrane but Not for Infectivity

2001 ◽  
Vol 75 (15) ◽  
pp. 6758-6768 ◽  
Author(s):  
Germán Andrés ◽  
Ramón Garcı́a-Escudero ◽  
Eladio Viñuela ◽  
Marı́a L. Salas ◽  
Javier M. Rodrı́guez
Keyword(s):  
Plasma Membrane ◽  
African Swine Fever Virus ◽  
Growth Curves ◽  
African Swine Fever ◽  
Fever Virus ◽  
Virus Yield ◽  
Virus Infectivity ◽  
Structural Protein ◽  
Virus Growth ◽  
Extracellular Virus

ABSTRACT This report examines the role of African swine fever virus (ASFV) structural protein pE120R in virus replication. Immunoelectron microscopy revealed that protein pE120R localizes at the surface of the intracellular virions. Consistent with this, coimmunoprecipitation assays showed that protein pE120R binds to the major capsid protein p72. Moreover, it was found that, in cells infected with an ASFV recombinant that inducibly expresses protein p72, the incorporation of pE120R into the virus particle is dependent on p72 expression. Protein pE120R was also studied using an ASFV recombinant in which E120R gene expression is regulated by the Escherichia coli lacrepressor-operator system. In the absence of inducer, pE120R expression was reduced about 100-fold compared to that obtained with the parental virus or the recombinant virus grown under permissive conditions. One-step virus growth curves showed that, under conditions that repress pE120R expression, the titer of intracellular progeny was similar to the total virus yield obtained under permissive conditions, whereas the extracellular virus yield was about 100-fold lower than in control infections. Immunofluorescence and electron microscopy demonstrated that, under restrictive conditions, intracellular mature virions are properly assembled but remain confined to the replication areas. Altogether, these results indicate that pE120R is necessary for virus dissemination but not for virus infectivity. The data also suggest that protein pE120R might be involved in the microtubule-mediated transport of ASFV particles from the viral factories to the plasma membrane.

scholarly journals Characterization of the African Swine Fever Virus Structural Protein p14.5: A DNA Binding Protein

Virology ◽  
1997 ◽  
Vol 229 (1) ◽  
pp. 201-211 ◽  
Author(s):  
Luisa Martinez-Pomares ◽  
Carmen Simon-Mateo ◽  
Carlos Lopez-Otin ◽  
Eladio Viñuela
Keyword(s):  
Dna Binding ◽  
African Swine Fever Virus ◽  
Binding Protein ◽  
African Swine Fever ◽  
Dna Binding Protein ◽  
Fever Virus ◽  
Structural Protein

Structure basis of non-structural protein pA151R from African Swine Fever Virus

2020 ◽  
Vol 532 (1) ◽  
pp. 108-113
Author(s):  
Jian-Wen Huang ◽  
Du Niu ◽  
Ke Liu ◽  
Qian Wang ◽  
Lixin Ma ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Structural Protein

scholarly journals Crystal structure of the African swine fever virus structural protein p35 reveals its role for core shell assembly

2020 ◽  
Vol 11 (8) ◽  
pp. 600-605
Author(s):  
Guobang Li ◽  
Dan Fu ◽  
Guangshun Zhang ◽  
Dongming Zhao ◽  
Mingyu Li ◽  
...  
Keyword(s):  
Crystal Structure ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Core Shell ◽  
Structural Protein

scholarly journals The African Swine Fever Virus Nonstructural Protein pB602L Is Required for Formation of the Icosahedral Capsid of the Virus Particle

2006 ◽  
Vol 80 (24) ◽  
pp. 12260-12270 ◽  
Author(s):  
Carolina Epifano ◽  
Jacomine Krijnse-Locker ◽  
María L. Salas ◽  
Javier M. Rodríguez ◽  
José Salas
Keyword(s):  
Virus Particle ◽  
Capsid Protein ◽  
Recombinant Virus ◽  
Nonstructural Protein ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Viral Assembly ◽  
Fever Virus ◽  
Assembly Process ◽  
Icosahedral Capsid

ABSTRACT African swine fever virus (ASFV) protein pB602L has been described as a molecular chaperone for the correct folding of the major capsid protein p72. We have studied the function of protein pB602L during the viral assembly process by using a recombinant ASFV, vB602Li, which inducibly expresses the gene coding for this protein. We show that protein pB602L is a late nonstructural protein, which, in contrast with protein p72, is excluded from the viral factory. Repression of protein pB602L synthesis inhibits the proteolytic processing of the two viral polyproteins pp220 and pp62 and leads to a decrease in the levels of protein p72 and a delocalization of the capsid protein pE120R. As shown by electron microscopy analysis of cells infected with the recombinant virus vB602Li, the viral assembly process is severely altered in the absence of protein pB602L, with the generation of aberrant “zipper-like” structures instead of icosahedral virus particles. These “zipper-like” structures are similar to those found in cells infected under restrictive conditions with the recombinant virus vA72 inducibly expressing protein p72. Immunoelectron microscopy studies show that the abnormal forms generated in the absence of protein pB602L contain the inner envelope protein p17 and the two polyproteins but lack the capsid proteins p72 and pE120R. These findings indicate that protein pB602L is essential for the assembly of the icosahedral capsid of the virus particle.

Sign in / Sign up

Export Citation Format

Share Document