Perrine Caillet-Fauquet

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The nonstructural protein NS1 of the autonomous parvovirus minute virus of mice (MVMp) is cytolytic when expressed in transformed cells. Before causing extensive cell lysis, NS1 induces a multistep cell cycle arrest in G(1), S, and G(2), well reproducing the arrest in S and G(2) observed upon MVMp infection. In this work we investigated the molecular(More)
Ultraviolet mutagenesis of phage λ is produced by host functions which are inducible by ultraviolet irradiation of the host cell. Induction kinetics and the half life of the inducible mutagenic DNA repair (SOS-repair) in E. coli have been determined using phage λ assays. At 37°C, both mutagenic and repair activities are maximal approximately 30 min(More)
Although its dependence on the target cell type is well established, the cytopathogenicity of parvoviruses has remained elusive to date as far as its mechanism is concerned. However, indirect evidence suggested that parvoviral non-structural (NS) proteins may be the cytotoxic effectors. In order to test this hypothesis, a molecular clone of parvovirus MVMp(More)
The nonstructural protein NS1 of the autonomous parvovirus minute virus of mice interferes with cell division and can cause cell death, depending on the cell transformation state. Upon infection, the synthesis of NS1 protein is massively initiated during S phase. In this article, we show that minute virus of mice-infected cells accumulate in this phase. To(More)
Autonomous parvoviruses exert lytic and cytostatic effects believed to contribute to their antineoplastic activity. Studies with inducible clones have demonstrated a direct involvement of parvovirus nonstructural proteins (NS) in oncolysis. Human and rat fibroblasts have been stably transfected with MVM(p) (minute virus of mice prototype strain) NS genes(More)
We have used bacteriophage lambda to characterize the mutator effect of the SOS response induced by u.v. irradiation of Escherichia coli. Mutagenesis of unirradiated phages grown in irradiated or unirradiated bacteria was detected by measuring forward mutagenesis in the immunity genes or reversion mutagenesis of an amber codon in the R gene. Relative to the(More)
The SOS hypothesis postulated that the mutator effect on undamaged DNA that generates phage-untargeted mutagenesis (UTM) results directly from the mechanism of targeted mutagenesis. RecA protein, which stimulates the cleavage of both the LexA repressor and UmuD protein, and the UmuDC gene products are required for UV-induced targeted mutagenesis. The use of(More)
Viruses depend on the host's machineries to replicate and express their genome. Actively replicating cells have large pools of deoxynucleotides and high levels of key enzyme activities that viruses exploit to their own needs. Some viruses have developed strategies for driving quiescent cells into the S phase of the cell cycle, e.g. adenovirus, others, such(More)