scholarly journals The Rift Valley Fever Virus Nonstructural Protein NSs Is Phosphorylated at Serine Residues Located in Casein Kinase II Consensus Motifs in the Carboxy-Terminus

Virology ◽  
1999 ◽  
Vol 263 (2) ◽  
pp. 517-525 ◽  
Author(s):  
Alain Kohl ◽  
Vincenzo di Bartolo ◽  
Michèle Bouloy
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Nonstructural Protein ◽  
Rift Valley Fever Virus ◽  
Casein Kinase Ii ◽  
Casein Kinase ◽  
Fever Virus ◽  
Carboxy Terminus ◽  
Valley Fever ◽  
Consensus Motifs

scholarly journals A ΩXaV motif in the Rift Valley fever virus NSs protein is essential for degrading p62, forming nuclear filaments and virulence

2015 ◽  
Vol 112 (19) ◽  
pp. 6021-6026 ◽  
Author(s):  
Normand Cyr ◽  
Cynthia de la Fuente ◽  
Lauriane Lecoq ◽  
Irene Guendel ◽  
Philippe R. Chabot ◽  
...  
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Excision Repair ◽  
Rna Virus ◽  
Nonstructural Protein ◽  
Rift Valley Fever Virus ◽  
Hemorrhagic Fever ◽  
Fever Virus ◽  
Valley Fever ◽  
Infected Cells

Rift Valley fever virus (RVFV) is a single-stranded RNA virus capable of inducing fatal hemorrhagic fever in humans. A key component of RVFV virulence is its ability to form nuclear filaments through interactions between the viral nonstructural protein NSs and the host general transcription factor TFIIH. Here, we identify an interaction between a ΩXaV motif in NSs and the p62 subunit of TFIIH. This motif in NSs is similar to ΩXaV motifs found in nucleotide excision repair (NER) factors and transcription factors known to interact with p62. Structural and biophysical studies demonstrate that NSs binds to p62 in a similar manner as these other factors. Functional studies in RVFV-infected cells show that the ΩXaV motif is required for both nuclear filament formation and degradation of p62. Consistent with the fact that the RVFV can be distinguished from otherBunyaviridae-family viruses due to its ability to form nuclear filaments in infected cells, the motif is absent in the NSs proteins of otherBunyaviridae-family viruses. Taken together, our studies demonstrate that p62 binding to NSs through the ΩXaV motif is essential for degrading p62, forming nuclear filaments and enhancing RVFV virulence. In addition, these results show how the RVFV incorporates a simple motif into the NSs protein that enables it to functionally mimic host cell proteins that bind the p62 subunit of TFIIH.

scholarly journals Evaluation of the Efficacy, Potential for Vector Transmission, and Duration of Immunity of MP-12, an Attenuated Rift Valley Fever Virus Vaccine Candidate, in Sheep

2015 ◽  
Vol 22 (8) ◽  
pp. 930-937 ◽  
Author(s):  
Myrna M. Miller ◽  
Kristine E. Bennett ◽  
Barbara S. Drolet ◽  
Robbin Lindsay ◽  
James O. Mecham ◽  
...  
Keyword(s):  
Rift Valley ◽  
Neutralizing Antibodies ◽  
Rift Valley Fever ◽  
Nonstructural Protein ◽  
Rift Valley Fever Virus ◽  
Clinical Signs ◽  
Fever Virus ◽  
Vector Transmission ◽  
Valley Fever ◽  
Virulent Challenge

ABSTRACTRift Valley fever virus (RVFV) causes serious disease in ruminants and humans in Africa. In North America, there are susceptible ruminant hosts and competent mosquito vectors, yet there are no fully licensed animal vaccines for this arthropod-borne virus, should it be introduced. Studies in sheep and cattle have found the attenuated strain of RVFV, MP-12, to be both safe and efficacious based on early testing, and a 2-year conditional license for use in U.S. livestock has been issued. The purpose of this study was to further determine the vaccine's potential to infect mosquitoes, the duration of humoral immunity to 24 months postvaccination, and the ability to prevent disease and viremia from a virulent challenge. Vaccination experiments conducted in sheep found no evidence of a potential for vector transmission to 4 North American mosquito species. Neutralizing antibodies were elicited, with titers of >1:40 still present at 24 months postvaccination. Vaccinates were protected from clinical signs and detectable viremia after challenge with virulent virus, while control sheep had fever and high-titered viremia extending for 5 days. Antibodies to three viral proteins (nucleocapsid N, the N-terminal half of glycoprotein GN, and the nonstructural protein from the short segment NSs) were also detected to 24 months using competitive enzyme-linked immunosorbent assays. This study demonstrates that the MP-12 vaccine given as a single dose in sheep generates protective immunity to a virulent challenge with antibody duration of at least 2 years, with no evidence of a risk for vector transmission.

scholarly journals Genetic Evidence for an Interferon-Antagonistic Function of Rift Valley Fever Virus Nonstructural Protein NSs

2001 ◽  
Vol 75 (3) ◽  
pp. 1371-1377 ◽  
Author(s):  
Michèle Bouloy ◽  
Christian Janzen ◽  
Pierre Vialat ◽  
Huot Khun ◽  
Jovan Pavlovic ◽  
...  
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Nonstructural Protein ◽  
Rift Valley Fever Virus ◽  
Fever Virus ◽  
Sub Saharan Africa ◽  
Wild Type ◽  
Valley Fever ◽  
Viral Virulence ◽  
Deficient Mice

ABSTRACT Rift Valley fever virus (RVFV), a phlebovirus of the family Bunyaviridae, is a major public health threat in Egypt and sub-Saharan Africa. The viral and host cellular factors that contribute to RVFV virulence and pathogenicity are still poorly understood. All pathogenic RVFV strains direct the synthesis of a nonstructural phosphoprotein (NSs) that is encoded by the smallest (S) segment of the tripartite genome and has an undefined accessory function. In this report, we show that MP12 and clone 13, two attenuated RVFV strains with mutations in the NSs gene, were highly virulent in IFNAR−/− mice lacking the alpha/beta interferon (IFN-α/β) receptor but remained attenuated in IFN-γ receptor-deficient mice. Both attenuated strains proved to be excellent inducers of early IFN-α/β production. In contrast, the virulent strain ZH548 failed to induce detectable amounts of IFN-α/β and replicated extensively in both IFN-competent and IFN-deficient mice. Clone 13 has a defective NSs gene with a large in-frame deletion. This defect in the NSs gene results in expression of a truncated protein which is rapidly degraded. To investigate whether the presence of the wild-type NSs gene correlated with inhibition of IFN-α/β production, we infected susceptible IFNAR−/− mice with S gene reassortant viruses. When the S segment of ZH548 was replaced by that of clone 13, the resulting reassortants became strong IFN inducers. When the defective S segment of clone 13 was exchanged with the wild-type S segment of ZH548, the reassortant virus lost the capacity to stimulate IFN-α/β production. These results demonstrate that the ability of RVFV to inhibit IFN-α/β production correlates with viral virulence and suggest that the accessory protein NSs is an IFN antagonist.

scholarly journals Rift Valley fever virus: a new avenue of research on the biological functions of amyloids?

2021 ◽  
Author(s):  
Ke Peng ◽  
Pierre-Yves Lozach
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Biological Function ◽  
Nonstructural Protein ◽  
Rift Valley Fever Virus ◽  
Febrile Illness ◽  
Fever Virus ◽  
Biological Functions ◽  
Valley Fever ◽  
Great Rift Valley

Rift Valley fever is a mosquito-borne viral zoonosis that was first discovered in the Great Rift Valley, Kenya, in 1930. Rift Valley fever virus (RVFV) primarily infects domestic animals and humans, with clinical outcomes ranging from self-limiting febrile illness to acute hepatitis and encephalitis. The virus left Africa a few decades ago, and there is a risk of introduction into southern Europe and Asia. From this perspective, we introduce RVFV and focus on the capacity of its virulence factor, the nonstructural protein NSs, to form amyloid-like fibrils. Here, we discuss the implications for the NSs biological function, the ability of RVFV to evade innate immunity, and RVFV virulence and neurotoxicity.

Complement fixation reaction of Rift Valley fever virus

1950 ◽  
Vol 5 (5) ◽  
pp. 243-247
Author(s):  
Minoru MATSUMOTO ◽  
Saburo IWASA ◽  
Motosige ENDO
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Complement Fixation ◽  
Rift Valley Fever Virus ◽  
Fever Virus ◽  
Valley Fever ◽  
Fixation Reaction

scholarly journals The Use of Nanotrap Particles in the Enhanced Detection of Rift Valley Fever Virus Nucleoprotein

PLoS ONE ◽  
2015 ◽  
Vol 10 (5) ◽  
pp. e0128215 ◽  
Author(s):  
Nazly Shafagati ◽  
Lindsay Lundberg ◽  
Alan Baer ◽  
Alexis Patanarut ◽  
Katherine Fite ◽  
...  
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Fever Virus ◽  
Valley Fever

scholarly journals Production of small ruminant morbillivirus, rift valley fever virus and lumpy skin disease virus in CelCradle™ -500A bioreactors

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Halima Rhazi ◽  
Najete Safini ◽  
Karima Mikou ◽  
Meryeme Alhyane ◽  
Khalid Omari Tadlaoui ◽  
...  
Keyword(s):  
Disease Virus ◽  
Skin Disease ◽  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Fever Virus ◽  
Valley Fever ◽  
Lumpy Skin Disease ◽  
Lumpy Skin Disease Virus ◽  
Cell Factories

Abstract Background Animal vaccination is an important way to stop the spread of diseases causing immense damage to livestock and economic losses and the potential transmission to humans. Therefore effective method for vaccine production using simple and inexpensive bioprocessing solutions is very essential. Conventional culture systems currently in use, tend to be uneconomic in terms of labor and time involved. Besides, they offer a limited surface area for growth of cells. In this study, the CelCradle™-500A was evaluated as an alternative to replace conventional culture systems in use such as Cell factories for the production of viral vaccines against small ruminant morbillivirus (PPR), rift valley fever virus (RVF) and lumpy skin disease virus (LSD). Results Two types of cells Vero and primary Lamb Testis cells were used to produce these viruses. The study was done in 2 phases as a) optimization of cell growth and b) virus cultivation. Vero cells could be grown to significantly higher cell densities of 3.04 × 109 using the CelCradle™-500A with a shorter doubling time as compared to 9.45 × 108 cells in Cell factories. This represents a 19 fold increase in cell numbers as compared to seeding vs only 3.7 fold in Cell factories. LT cells achieved modestly higher cell densities of 6.7 × 108 as compared to 6.3 × 108 in Cell factories. The fold change in densities for these cells was 3 fold in the CelCradle™-500A vs 2.5 fold in Cell factories. The titers in the conventional system and the bioreactor were not significantly different. However, the Cell-specific virus yield for rift valley fever virus and lumpy skin disease virus are higher (25 virions/cell for rift valley fever virus, and 21.9 virions/cell for lumpy skin disease virus versus 19.9 virions/cell for rift valley fever virus and 10 virions/cell for lumpy skin disease virus). Conclusions This work represents a novel study for primary lamb testis cell culture in CellCradle™-500A bioreactors. In addition, on account of the high cell densities obtained and the linear scalability the titers could be further optimized using other culture process such us perfusion.

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