ISSN:
1573-4935
Keywords:
2-aminopurine
;
capsid
;
eIF-2
;
inhibition
;
initiation factor
;
p53: phosphorylation
;
PKR
;
protein kinase
;
Semliki Forest virus
;
translation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract We investigated the possible translational role which elevated concentrations of highly purified Semliki Forest virus (SFV) capsid (C)-protein molecules may play in a cell-free translation system. Here we decomonstrate that in the absence of double-stranded RNA high concentrations of C protein triggered the phosphorylation of the interferon-induced, double-stranded RNA-activated protein kinase, PKR. Activated PKR in turn phosphorylated its natural substrate, the α subunit of eukaryotic initiation factor 2 (eIF-2), thereby inhibiting initiation of host cell translation. These findings were further strengthened by experiments showing that during natural infection with SFV the maximum phosphorylation of PKR coincided with the maximum synthesis of C protein 4–9 hours post infection. Thus, our results demonstrate that high concentrations of C-protein molecules may act in a hitherto novel mechanism on PKR to inhibit host cell protein synthesis during viral infection.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01198464
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