Document Detail


The 5' UTR of HIV-1 full-length mRNA and the Tat viral protein modulate the programmed -1 ribosomal frameshift that generates HIV-1 enzymes.
MedLine Citation:
PMID:  22286970     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Translation of the full-length messenger RNA (mRNA) of the human immunodeficiency virus type 1 (HIV-1) generates the precursor of the viral enzymes via a programmed -1 ribosomal frameshift. Here, using dual-luciferase reporters, we investigated whether the highly structured 5' untranslated region (UTR) of this mRNA, which interferes with translation initiation, can modulate HIV-1 frameshift efficiency. We showed that, when the 5' UTR of HIV-1 mRNA occupies the 5' end of the reporter mRNA, HIV-1 frameshift efficiency is increased about fourfold in Jurkat T-cells, compared with a control dual-luciferase reporter with a short unstructured 5' UTR. This increase was related to an interference with cap-dependent translation initiation by the TAR-Poly(A) region at the 5' end of the messenger. HIV-1 mRNA 5' UTR also contains an internal ribosome entry site (IRES), but we showed that, when the cap-dependent initiation mode is available, the IRES is not used or is weakly used. However, when the ribosomes have to use the IRES to translate the dual-luciferase reporter, the frameshift efficiency is comparable to that of the control dual-luciferase reporter. The decrease in cap-dependent initiation and the accompanying increase in frameshift efficiency caused by the 5' UTR of HIV-1 mRNA is antagonized, in a dose-dependent way, by the Tat viral protein. Tat also stimulates the IRES-dependent initiation and decreases the corresponding frameshift efficiency. A model is presented that accounts for the variations in frameshift efficiency depending on the 5' UTR and the presence of Tat, and it is proposed that a range of frameshift efficiencies is compatible with the virus replication.
Authors:
Johanie Charbonneau; Karine Gendron; Gerardo Ferbeyre; Léa Brakier-Gingras
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2012-01-27
Journal Detail:
Title:  RNA (New York, N.Y.)     Volume:  18     ISSN:  1469-9001     ISO Abbreviation:  RNA     Publication Date:  2012 Mar 
Date Detail:
Created Date:  2012-02-16     Completed Date:  2012-04-12     Revised Date:  2013-04-15    
Medline Journal Info:
Nlm Unique ID:  9509184     Medline TA:  RNA     Country:  United States    
Other Details:
Languages:  eng     Pagination:  519-29     Citation Subset:  IM    
Affiliation:
Département de biochimie, Université de Montréal, Montréal, Québec H3T1J4, Canada.
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MeSH Terms
Descriptor/Qualifier:
5' Untranslated Regions / genetics*
Frameshifting, Ribosomal / genetics*
Gene Expression Regulation, Viral
Gene Order
Gene Products, tat / metabolism*
Genes, Reporter
Genetic Vectors
HEK293 Cells
HIV-1 / enzymology,  genetics*,  metabolism
Humans
Jurkat Cells
RNA, Messenger / chemistry*
RNA, Viral / chemistry*
Grant Support
ID/Acronym/Agency:
HOP-86864//Canadian Institutes of Health Research
Chemical
Reg. No./Substance:
0/5' Untranslated Regions; 0/Gene Products, tat; 0/RNA, Messenger; 0/RNA, Viral
Comments/Corrections

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