The NS1 protein from influenza A viruses contains a four-amino-acid sequence at its carboxyl terminus that is termed the PDZ-binding motif (PBM). The NS1 PBM is predicted to bind to cellular PDZ proteins and functions as a virulence determinant in infected mice. ESEV is the consensus PBM sequence of avian influenza viruses, while RSKV is the consensus sequence of human viruses. Currently circulating highly pathogenic H5N1 influenza viruses encode an NS1 protein with the ESEV PBM. We identified cellular targets of the avian ESEV PBM and identified molecular mechanisms involved in its function. Using glutathione S-transferase (GST) pull-down assays, we found that the ESEV PBM enables NS1 to associate with the PDZ proteins Scribble, Dlg1, MAGI-1, MAGI-2, and MAGI-3. Because Scribble possesses a proapoptotic activity, we investigated the interaction between NS1 and Scribble. The association between NS1 and Scribble is direct and requires the ESEV PBM and two Scribble PDZ domains. We constructed recombinant H3N2 viruses that encode an H6N6 avian virus NS1 protein with either an ESEV or mutant ESEA PBM, allowing an analysis of the ESEV PBM in infections in mammalian cells. The ESEV PBM enhanced viral replication up to 4-fold. In infected cells, NS1 with the ESEV PBM relocalized Scribble into cytoplasmic puncta concentrated in perinuclear regions and also protected cells from apoptosis. In addition, the latter effect was eliminated by small interfering RNA (siRNA)-mediated Scribble depletion. This study shows that one function of the avian ESEV PBM is to reduce apoptosis during infection through disruption of Scribble's proapoptotic function.

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Background Bacillus spores are notoriously resistant to unfavorable conditions such as UV radiation, γ-radiation, H2O2, desiccation, chemical disinfection, or starvation. Bacillus pumilus SAFR-032 survives standard decontamination procedures of the Jet Propulsion Lab spacecraft assembly facility, and both spores and vegetative cells of this strain exhibit elevated resistance to UV radiation and H2O2 compared to other Bacillus species.Principal FindingsThe genome of B. pumilus SAFR-032 was sequenced and annotated. Lists of genes relevant to DNA repair and the oxidative stress response were generated and compared to B. subtilis and B. licheniformis. Differences in conservation of genes, gene order, and protein sequences are highlighted because they potentially explain the extreme resistance phenotype of B. pumilus. The B. pumilus genome includes genes not found in B. subtilis or B. licheniformis and conserved genes with sequence divergence, but paradoxically lacks several genes that function in UV or H2O2 resistance in other Bacillus species.SignificanceThis study identifies several candidate genes for further research into UV and H2O2 resistance. These findings will help explain the resistance of B. pumilus and are applicable to understanding sterilization survival strategies of microbes.

We report four near-complete genome sequences of vesicular stomatitis virus (VSV) Indiana obtained with Sanger and Illumina next-generation sequencing, namely, laboratory strains HR (heat resistant) and T1026R1 and isolates 22-20 and 22-25. Previously, only the M gene of these viruses had been sequenced, and these sequences were not deposited in GenBank.