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 message. Here, it is shown that, in chronically infected H9 cells, human immunodeficiency virus-type 1 (HIV-1) mRNAs undergo guanine-to-adenine (G-to-A) and cytosine-to-uracil (C-to-U) changes. G-to-A modification in the untranslated region of exon 1 was present only in spliced HIV-1 mRNAs. The creation of stop codons in HIV-1 mRNAs may function to control the translation of viral proteins, such as viral protein R, that are involved in the regulation of HIV-1 expression and the survival of chronically infected cells.