Generation of G-to-A and C-to-U changes in HIV-1 transcripts by RNA editing

RNA editing involves posttranscriptional alterations of messenger RNA (mRNA ) sequences modifying the information content encoded by the genetic messag e. Here, it is shown that, in chronically infected H9 cells, human immunode ficiency virus-type 1 (HIV-1) mRNAs undergo guanine-to-adenine (G-to-A) and cytosine-to-uracil (C-to-U) changes. C-to-A modification in the untranslat ed region of exon 1 was present only in spliced HIV-1 mRNAs. The creation o f stop codons in HIV-1 mRNAs may function to control the translation of vir al proteins, such as viral protein R, that are involved in the regulation o f HIV-1 expression and the survival of chronically infected cells.