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Different effect of proteasome inhibition on vesicular stomatitis virus and poliovirus replication.

Neznanov N, Dragunsky EM, Chumakov KM, Neznanova L, Wek RC, Gudkov AV, Banerjee AK - PLoS ONE (2008)

Bottom Line: We found that the proteasome inhibitors significantly suppressed VSV protein synthesis, virus accumulation, and protected infected cells from toxic effect of VSV replication.We also found that inhibition of proteasomes stimulated stress-related processes, such as accumulation of chaperone hsp70, phosphorylation of eIF2alpha, and overall inhibition of translation.Inhibition of proteasome activity suppressed cellular and VSV protein synthesis, but did not reduce poliovirus protein synthesis.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio, United States of America. neznann@ccf.org

ABSTRACT
Proteasome activity is an important part of viral replication. In this study, we examined the effect of proteasome inhibitors on the replication of vesicular stomatitis virus (VSV) and poliovirus. We found that the proteasome inhibitors significantly suppressed VSV protein synthesis, virus accumulation, and protected infected cells from toxic effect of VSV replication. In contrast, poliovirus replication was delayed, but not diminished in the presence of the proteasome inhibitors MG132 and Bortezomib. We also found that inhibition of proteasomes stimulated stress-related processes, such as accumulation of chaperone hsp70, phosphorylation of eIF2alpha, and overall inhibition of translation. VSV replication was sensitive to this stress with significant decline in replication process. Poliovirus growth was less sensitive with only delay in replication. Inhibition of proteasome activity suppressed cellular and VSV protein synthesis, but did not reduce poliovirus protein synthesis. Protein kinase GCN2 supported the ability of proteasome inhibitors to attenuate general translation and to suppress VSV replication. We propose that different mechanisms of translational initiation by VSV and poliovirus determine their sensitivity to stress induced by the inhibition of proteasomes. To our knowledge, this is the first study that connects the effect of stress induced by proteasome inhibition with the efficiency of viral infection.

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Different activation of eIF2α phosphorylation by VSV and poliovirus infections.HeLa cells were infected with VSV for 4 h, infected with poliovirus for 4 h, or treated with 1 µM of thapsigargin for 1 hour. Cytoplasmic protein extracts from these and control cells were analyzed with Abs against eIF2α and phosphorylated form of eIF2α (panel A). Same membrane was analyzed with Abs against VSV P- protein and poliovirus capsid proteins (panel B).
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pone-0001887-g011: Different activation of eIF2α phosphorylation by VSV and poliovirus infections.HeLa cells were infected with VSV for 4 h, infected with poliovirus for 4 h, or treated with 1 µM of thapsigargin for 1 hour. Cytoplasmic protein extracts from these and control cells were analyzed with Abs against eIF2α and phosphorylated form of eIF2α (panel A). Same membrane was analyzed with Abs against VSV P- protein and poliovirus capsid proteins (panel B).

Mentions: Virus infection is often connected with stress-related cellular processes, including induction of PKR- specific phosphorylation of eIF2α by double stranded viral RNAs [44], [48]. We analyzed the ability of poliovirus and VSV to activate eIF2α phosphorylation at 4 h after infection (Fig. 11). Poliovirus infection stimulated phosphorylation of translation initiation factor at 4 h after infection. In contrast, VSV infection did not induce phosphorylation of eIF2α at this time of infection. Our data coincide with earlier reports [49], [50]. According to these publications, eIF2α phosphorylation may be detected in poliovirus infected cells starting from 3 h post-infection, but in VSV infected cells eIF2α phosphorylation was detected only after 8 h of infection [49], [50]. Thus, there is a correlation between the ability of viral infection to stimulate eIF2α phosphorylation and its resistance to this phosphorylation stimulated by other stimuli, such as proteasome inhibitors.


Different effect of proteasome inhibition on vesicular stomatitis virus and poliovirus replication.

Neznanov N, Dragunsky EM, Chumakov KM, Neznanova L, Wek RC, Gudkov AV, Banerjee AK - PLoS ONE (2008)

Different activation of eIF2α phosphorylation by VSV and poliovirus infections.HeLa cells were infected with VSV for 4 h, infected with poliovirus for 4 h, or treated with 1 µM of thapsigargin for 1 hour. Cytoplasmic protein extracts from these and control cells were analyzed with Abs against eIF2α and phosphorylated form of eIF2α (panel A). Same membrane was analyzed with Abs against VSV P- protein and poliovirus capsid proteins (panel B).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2268745&req=5

pone-0001887-g011: Different activation of eIF2α phosphorylation by VSV and poliovirus infections.HeLa cells were infected with VSV for 4 h, infected with poliovirus for 4 h, or treated with 1 µM of thapsigargin for 1 hour. Cytoplasmic protein extracts from these and control cells were analyzed with Abs against eIF2α and phosphorylated form of eIF2α (panel A). Same membrane was analyzed with Abs against VSV P- protein and poliovirus capsid proteins (panel B).
Mentions: Virus infection is often connected with stress-related cellular processes, including induction of PKR- specific phosphorylation of eIF2α by double stranded viral RNAs [44], [48]. We analyzed the ability of poliovirus and VSV to activate eIF2α phosphorylation at 4 h after infection (Fig. 11). Poliovirus infection stimulated phosphorylation of translation initiation factor at 4 h after infection. In contrast, VSV infection did not induce phosphorylation of eIF2α at this time of infection. Our data coincide with earlier reports [49], [50]. According to these publications, eIF2α phosphorylation may be detected in poliovirus infected cells starting from 3 h post-infection, but in VSV infected cells eIF2α phosphorylation was detected only after 8 h of infection [49], [50]. Thus, there is a correlation between the ability of viral infection to stimulate eIF2α phosphorylation and its resistance to this phosphorylation stimulated by other stimuli, such as proteasome inhibitors.

Bottom Line: We found that the proteasome inhibitors significantly suppressed VSV protein synthesis, virus accumulation, and protected infected cells from toxic effect of VSV replication.We also found that inhibition of proteasomes stimulated stress-related processes, such as accumulation of chaperone hsp70, phosphorylation of eIF2alpha, and overall inhibition of translation.Inhibition of proteasome activity suppressed cellular and VSV protein synthesis, but did not reduce poliovirus protein synthesis.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio, United States of America. neznann@ccf.org

ABSTRACT
Proteasome activity is an important part of viral replication. In this study, we examined the effect of proteasome inhibitors on the replication of vesicular stomatitis virus (VSV) and poliovirus. We found that the proteasome inhibitors significantly suppressed VSV protein synthesis, virus accumulation, and protected infected cells from toxic effect of VSV replication. In contrast, poliovirus replication was delayed, but not diminished in the presence of the proteasome inhibitors MG132 and Bortezomib. We also found that inhibition of proteasomes stimulated stress-related processes, such as accumulation of chaperone hsp70, phosphorylation of eIF2alpha, and overall inhibition of translation. VSV replication was sensitive to this stress with significant decline in replication process. Poliovirus growth was less sensitive with only delay in replication. Inhibition of proteasome activity suppressed cellular and VSV protein synthesis, but did not reduce poliovirus protein synthesis. Protein kinase GCN2 supported the ability of proteasome inhibitors to attenuate general translation and to suppress VSV replication. We propose that different mechanisms of translational initiation by VSV and poliovirus determine their sensitivity to stress induced by the inhibition of proteasomes. To our knowledge, this is the first study that connects the effect of stress induced by proteasome inhibition with the efficiency of viral infection.

Show MeSH
Related in: MedlinePlus