Subcellular localization of the interaction between the human immunodeficiency virus transactivator Tat and the nucleosome assembly protein 1

Amino Acids. 2010 May;38(5):1583-93. doi: 10.1007/s00726-009-0378-9. Epub 2009 Nov 4.


The histone chaperone nucleosome assembly protein, hNAP-1, is a host cofactor for the activity of the human immunodeficiency virus type 1 (HIV-1) transactivator Tat. The interaction between these two proteins has been shown to be important for Tat-mediated transcriptional activation and for efficient viral infection. Visualization of HIV-1 transcription and fluorescence resonance energy transfer experiments performed in this work demonstrate that hNAP-1 is not recruited to the site of Tat activity but the two proteins interact at the nuclear rim. These data are consistent with a mechanism that requires hNAP-1 for the transport of Tat within the nucleus rather than for the remodeling of nucleosomes on the provirus. Protein-protein docking and molecular modeling of the complex suggest that this interaction occurs between the basic domain of Tat and the histone-binding domain. The combination of theoretical and whole cell studies provided new insights into the functional significance of the Tat:hNAP-1 recognition.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Fluorescent Antibody Technique
  • Gene Products, tat / metabolism*
  • HIV / metabolism*
  • Humans
  • Nucleosome Assembly Protein 1 / metabolism*
  • RNA, Small Interfering
  • Subcellular Fractions / metabolism*


  • Gene Products, tat
  • Nucleosome Assembly Protein 1
  • RNA, Small Interfering