HIV-1 Tat Protein Trans-Activates Transcription in Vitro

Cell. 1990 Nov 16;63(4):791-802. doi: 10.1016/0092-8674(90)90145-5.


Tat protein of human immunodeficiency virus 1 is a potent trans-activator of viral gene expression. We show that purified Tat protein stimulates transcription from viral promoters greater than 10-fold in vitro. A Tat protein mutant that does not trans-activate in vivo did not stimulate transcription in vitro. Tat trans-activation required a functional TAR RNA sequence; trans-activation was competed by the addition of in vitro synthesized wild-type TAR RNA but not by mutant TAR RNAs. That Tat protein directly interacts with the TAR RNA during trans-activation in vitro was suggested by competition with Tat peptides. Preliminary evidence suggests the involvement of a cellular factor in recognition of TAR RNA during Tat trans-activation. Analysis of Tat trans-activation in vitro will provide new mechanistic insights into this process and allow a more detailed study of the relationship between Tat protein structure and function.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cell Nucleus / metabolism
  • Gene Products, tat / metabolism*
  • HIV-1 / genetics*
  • Molecular Sequence Data
  • Nucleic Acid Hybridization
  • Plasmids
  • RNA, Viral / genetics
  • Templates, Genetic
  • Transcription, Genetic*
  • Transcriptional Activation*
  • tat Gene Products, Human Immunodeficiency Virus


  • Gene Products, tat
  • RNA, Viral
  • tat Gene Products, Human Immunodeficiency Virus