Effect of ribosome-inactivating proteins on virus-infected cells. Inhibition of virus multiplication and of protein synthesis

1982 ◽  
Vol 71 (4) ◽  
pp. 323-332 ◽  
Author(s):  
L. Fo�-Tomasi ◽  
G. Campadelli-Fiume ◽  
L. Barbieri ◽  
F. Stirpe
Keyword(s):  
Protein Synthesis ◽  
Virus Multiplication ◽  
Ribosome Inactivating Proteins ◽  
Infected Cells

Protein synthesis in japanese encephalitis virus-infected cells

Virology ◽  
1973 ◽  
Vol 56 (1) ◽  
pp. 95-109 ◽  
Author(s):  
Daniel Shapiro ◽  
Kathleen A. Kos ◽  
Philip K. Russell
Keyword(s):  
Protein Synthesis ◽  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Encephalitis Virus ◽  
Infected Cells

Protein synthesis in bluetongue virus-infected cells

Virology ◽  
1979 ◽  
Vol 92 (2) ◽  
pp. 385-396 ◽  
Author(s):  
Hendrik Huismans
Keyword(s):  
Protein Synthesis ◽  
Bluetongue Virus ◽  
Infected Cells

scholarly journals Protein Kinase R Is Responsible for the Phosphorylation of eIF2α in Rotavirus Infection

2010 ◽  
Vol 84 (20) ◽  
pp. 10457-10466 ◽  
Author(s):  
Margarito Rojas ◽  
Carlos F. Arias ◽  
Susana López
Keyword(s):  
Protein Synthesis ◽  
Kinase Domain ◽  
Cell Protein ◽  
Protein Kinase R ◽  
Viral Protein Synthesis ◽  
Α Subunit ◽  
Rotavirus Infection ◽  
Eif2α Phosphorylation ◽  
Infected Cells ◽  
Interferon System

ABSTRACT The eukaryotic initiation translation factor 2 (eIF2) represents a key point in the regulation of protein synthesis. This factor delivers the initiator Met-tRNA to the ribosome, a process that is conserved in all eukaryotic cells. Many types of stress reduce global translation by triggering the phosphorylation of the α subunit of eIF2, which reduces the formation of the preinitiation translation complexes. Early during rotavirus infection, eIF2α becomes phosphorylated, and even under these conditions viral protein synthesis is not affected, while most of the cell protein synthesis is blocked. Here, we found that the kinase responsible for the phosphorylation of eIF2α in rotavirus-infected cells is PKR, since in mouse embryonic fibroblasts deficient in the kinase domain of PKR, or in MA104 cells where the expression of PKR was knocked down by RNA interference, eIF2α was not phosphorylated upon rotavirus infection. The viral component responsible for the activation of PKR seems to be viral double-stranded RNA, which is found in the cytoplasm of infected cells, outside viroplasms. Taken together, these results suggest that rotaviruses induce the PKR branch of the interferon system and have evolved a mechanism to translate its proteins, surpassing the block imposed by eIF2α phosphorylation.

scholarly journals Posttranscriptional regulation of hsp70 expression in human cells: effects of heat shock, inhibition of protein synthesis, and adenovirus infection on translation and mRNA stability.

1987 ◽  
Vol 7 (12) ◽  
pp. 4357-4368 ◽  
Author(s):  
N G Theodorakis ◽  
R I Morimoto
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Posttranscriptional Regulation ◽  
High Efficiency ◽  
Hsp70 Expression ◽  
Mrna Levels ◽  
Protein Synthesis Inhibitors ◽  
Hsp70 Mrna ◽  
Infected Cells ◽  
The Stability

We have examined the posttranscriptional regulation of hsp70 gene expression in two human cell lines, HeLa and 293 cells, which constitutively express high levels of HSP70. HSP70 mRNA translates with high efficiency in both control and heat-shocked cells. Therefore, heat shock is not required for the efficient translation of HSP70 mRNA. Rather, the main effect of heat shock on translation is to suppress the translatability of non-heat shock mRNAs. Heat shock, however, has a marked effect on the stability of HSP70 mRNA; in non-heat-shocked cells the half-life of HSP70 mRNA is approximately 50 min, and its stability increases at least 10-fold upon heat shock. Moreover, HSP70 mRNA is more stable in cells treated with protein synthesis inhibitors, suggesting that a heat shock-sensitive labile protein regulates its turnover. An additional effect on posttranscriptional regulation of hsp70 expression can be found in adenovirus-infected cells, in which HSP70 mRNA levels decline precipititously late during infection although hsp70 transcription continues unabated.

Modification of protein synthesis initiation factors and the shut-off of host protein synthesis in adenovirus-infected cells

Virology ◽  
1989 ◽  
Vol 168 (1) ◽  
pp. 112-118 ◽  
Author(s):  
Robert P. O'Malley ◽  
Roger F. Duncan ◽  
John W.B. Hershey ◽  
Michael B. Mathews
Keyword(s):  
Protein Synthesis ◽  
Host Protein ◽  
Initiation Factors ◽  
Infected Cells ◽  
Protein Synthesis Initiation ◽  
Host Protein Synthesis
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