Like most cellular mRNAs, the 5' end of HIV mRNAs is capped and the 3' end matured by the process of\r\npolyadenylation. There are, however, several rather unique and interesting aspects of these post-transcriptional\r\nprocesses on HIV transcripts. Capping of the highly structured 5' end of HIV mRNAs is influenced by the viral TAT\r\nprotein and a population of HIV mRNAs contains a trimethyl-G cap reminiscent of U snRNAs involved in splicing.\r\nHIV polyadenylation involves active repression of a promoter-proximal polyadenylation signal, auxiliary upstream\r\nregulatory elements and moonlighting polyadenylation factors that have additional impacts on HIV biology outside\r\nof the constraints of classical mRNA 3� end formation. This review describes these post-transcriptional novelties of\r\nHIV gene expression as well as their implications in viral biology and as possible targets for therapeutic intervention.
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