Biochemical and functional interactions between HIV-1 Tat protein and TAR RNA

HIV-1 trans-activator of transcription (Tat) is an unusual transcriptional activator in being an RNA-binding protein rather than a DNA-binding protein . Recent findings have greatly advanced our understanding of the transcript ional function(s) of this protein. Here we review how Tat interacts with tr ans-activation responsive RNA and how this interaction contributes to trans cription. We discuss the biological implications of recent studies showing an association of Tat with cellular kinases(s) and protein acetylases. Evid ence for nontranscriptional activities of the Tat protein is also summarize d. (C) 1999 Academic Press.