Abstract
Unlike all the other Rift Valley fever virus strains (Bunyaviridae, Phlebovirus) studied so far, clone 13, a naturally attenuated virus, does not form the filaments composed of the NSs nonstructural protein in the nuclei of infected cells (R. Muller, J. F. Saluzzo, N. Lopez, T. Drier, M. Turell, J. Smith, and M. Bouloy, Am. J. Trop. Med. Hyg. 53:405-411, 1995). This defect is correlated with a large in-frame deletion in the NSs coding region of the S segment of the tripartite genome. Here, we show that the truncated NSs protein of clone 13 is expressed and remains in the cytoplasm, where it is degraded rapidly by the proteasome. Through the analysis of reassortants between clone 13 and a virulent strain, we localized the marker(s) of attenuation in the S segment of this attenuated virus. This result raises questions regarding the role of NSs in pathogenesis and highlights, for the first time in the Bunyaviridae family, a major role of the S segment in virulence and attenuation, possibly associated with a defect in the nonstructural protein.
MeSH Terms
Animals
Chlorocebus aethiops
Cysteine Endopeptidases/metabolism
Cytoplasm/metabolism
Genome, Viral
Mice
Multienzyme Complexes/metabolism
Proteasome Endopeptidase Complex
Reassortant Viruses/physiology
Rift Valley fever virus/genetics,growth & development,pathogenicity
Vero Cells
Viral Nonstructural Proteins/genetics,metabolism
Viral Plaque Assay
Virulence
Chemicals
Multienzyme Complexes
Viral Nonstructural Proteins
Cysteine Endopeptidases
Proteasome Endopeptidase Complex
Authors & Affiliations
4 authors, click to expand affiliations / ORCID
Vialat P
Groupe des Bunyaviridés, Institut Pasteur, 75724 Paris, Cedex 15, France.
Billecocq A
Kohl A
Bouloy M
References (26)
26 references, click to expand
-
Neuroattenuation of an avirulent bunyavirus variant maps to the L RNA segment.
J Virol. 1991 Oct;65(10):5465-70
PMID: 1895395
-
Use of reassortant viruses to map attenuating and temperature-sensitive mutations of the Rift Valley fever virus MP-12 vaccine.
Vaccine. 1990 Aug;8(4):369-75
PMID: 2396475
-
Non-random reassortment between the tripartite RNA genomes of La Crosse and snowshoe hare viruses.
J Gen Virol. 1992 Sep;73 ( Pt 9):2255-65
PMID: 1402816
-
Polygenic control of neuroinvasiveness in California serogroup bunyaviruses.
J Virol. 1993 Jul;67(7):3861-7
PMID: 8510208
-
Characterization of clone 13, a naturally attenuated avirulent isolate of Rift Valley fever virus, which is altered in the small segment.
Am J Trop Med Hyg. 1995 Oct;53(4):405-11
PMID: 7485695
-
Normal replication of vesicular stomatitis virus without C proteins.
Virology. 1996 Feb 15;216(2):309-16
PMID: 8607260
-
Persistent infection of mammalian cells by Rift Valley fever virus.
J Gen Virol. 1996 Dec;77 ( Pt 12):3053-62
PMID: 9000097
-
The paramyxovirus, Sendai virus, V protein encodes a luxury function required for viral pathogenesis.
EMBO J. 1997 Feb 3;16(3):578-87
PMID: 9034340
-
Evaluation of the susceptibility of the 3C proteases of hepatitis A virus and poliovirus to degradation by the ubiquitin-mediated proteolytic system.
Biochem Biophys Res Commun. 1997 Sep 8;238(1):119-25
PMID: 9299463
-
Mapping of the mutations present in the genome of the Rift Valley fever virus attenuated MP12 strain and their putative role in attenuation.
Virus Res. 1997 Nov;52(1):43-50
PMID: 9453143
-
Genetic reassortment among viruses causing hantavirus pulmonary syndrome.
Virology. 1998 Mar 1;242(1):99-106
PMID: 9501041
-
Antiviral activity of the proteasome on incoming human immunodeficiency virus type 1.
J Virol. 1998 May;72(5):3845-50
PMID: 9557668
-
An outbreak of Rift Valley Fever, eastern Africa, 1997-1998.
Wkly Epidemiol Rec. 1998 Apr 10;73(15):105-9
PMID: 9577708
-
Reovirus growth in cell culture does not require the full complement of viral proteins: identification of a sigma1s-null mutant.
J Virol. 1998 Nov;72(11):8597-604
PMID: 9765398
-
The paramyxovirus SV5 small hydrophobic (SH) protein is not essential for virus growth in tissue culture cells.
Virology. 1998 Oct 10;250(1):30-40
PMID: 9770417
-
Nonstructural C protein is required for efficient measles virus replication in human peripheral blood cells.
J Virol. 1999 Feb;73(2):1695-8
PMID: 9882382
-
Generation of bovine respiratory syncytial virus (BRSV) from cDNA: BRSV NS2 is not essential for virus replication in tissue culture, and the human RSV leader region acts as a functional BRSV genome promoter.
J Virol. 1999 Jan;73(1):251-9
PMID: 9847328
-
Altered growth characteristics of recombinant respiratory syncytial viruses which do not produce NS2 protein.
J Virol. 1999 Jan;73(1):466-73
PMID: 9847352
-
The carboxy-terminal acidic domain of Rift Valley Fever virus NSs protein is essential for the formation of filamentous structures but not for the nuclear localization of the protein.
J Virol. 1999 Jun;73(6):5018-25
PMID: 10233964
-
Genetic reassortment of Rift Valley fever virus in nature.
J Virol. 1999 Oct;73(10):8196-200
PMID: 10482570
-
Sindbis virus RNA polymerase is degraded by the N-end rule pathway.
Proc Natl Acad Sci U S A. 1991 Oct 15;88(20):8967-71
PMID: 1924357
-
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 Oct 25;263(2):517-25
PMID: 10544123
-
Protein synthesis in Rift Valley fever virus-infected cells.
Virology. 1984 Apr 15;134(1):118-24
PMID: 6710870
-
Mutagen-directed attenuation of Rift Valley fever virus as a method for vaccine development.
J Gen Virol. 1985 Oct;66 ( Pt 10):2271-7
PMID: 4045430
-
Neuroattenuated bunyavirus variant: derivation, characterization, and revertant clones.
J Virol. 1990 May;64(5):1927-33
PMID: 2182907
-
A new generation of animal cell expression vectors based on the Semliki Forest virus replicon.
Biotechnology (N Y). 1991 Dec;9(12):1356-61
PMID: 1370252