scholarly journals Proteins surrounding hairpin IIIe of the hepatitis C virus internal ribosome entry site on the human 40S ribosomal subunit

2006 ◽  
Vol 34 (7) ◽  
pp. 2027-2036 ◽  
Author(s):  
E. Laletina
2004 ◽  
Vol 24 (15) ◽  
pp. 6861-6870 ◽  
Author(s):  
Mauro Costa-Mattioli ◽  
Yuri Svitkin ◽  
Nahum Sonenberg

ABSTRACT Translation of poliovirus and hepatitis C virus (HCV) RNAs is initiated by recruitment of 40S ribosomes to an internal ribosome entry site (IRES) in the mRNA 5′ untranslated region. Translation initiation of these RNAs is stimulated by noncanonical initiation factors called IRES trans-activating factors (ITAFs). The La autoantigen is such an ITAF, but functional evidence for the role of La in poliovirus and HCV translation in vivo is lacking. Here, by two methods using small interfering RNA and a dominant-negative mutant of La, we demonstrate that depletion of La causes a dramatic reduction in poliovirus IRES function in vivo. We also show that 40S ribosomal subunit binding to HCV and poliovirus IRESs in vitro is inhibited by a dominant-negative form of La. These results provide strong evidence for a function of the La autoantigen in IRES-dependent translation and define the step of translation which is stimulated by La.


1999 ◽  
Vol 292 (3) ◽  
pp. 513-529 ◽  
Author(s):  
Jeffrey S. Kieft ◽  
Kaihong Zhou ◽  
Ronald Jubin ◽  
Michael G. Murray ◽  
Johnson Y.N. Lau ◽  
...  

2002 ◽  
Vol 30 (2) ◽  
pp. 140-145 ◽  
Author(s):  
J. Gallego ◽  
G. Varani

The hepatitis C virus (HCV) is the main causative agent of non-A, non-B hepatitis in humans and a major cause of mortality and morbidity in the world. Currently there is no effective treatment available for the infection caused by this virus, whose replication depends on an unusual translation-initiation mechanism. The viral RNA contains an internal ribosome-entry site (IRES) that is recognized specifically by the small ribosomal subunit and by eukaryotic initiation factor 3, and these interactions allow cap (7-methylguanine nucleotide)-independent initiation of viral protein synthesis. In this article, we review the structure and mechanism of translation initiation of the HCV IRES, and its potential as a target for novel antivirals.


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