Dual roles of p300 in chromatin assembly and transcriptional activation in cooperation with nucleosome assembly protein 1 in vitro

Mol Cell Biol. 2002 May;22(9):2974-83. doi: 10.1128/mcb.22.9.2974-2983.2002.


In a yeast two-hybrid screen to identify proteins that bind to the KIX domain of the coactivator p300, we obtained cDNAs encoding nucleosome assembly protein 1 (NAP-1), a 60-kDa histone H2A-H2B shuttling protein that promotes histone deposition. p300 associates preferentially with the H2A-H2B-bound form of NAP-1 rather than with the unbound form of NAP-1. Formation of NAP-1-p300 complexes was found to increase during S phase, suggesting a potential role for p300 in chromatin assembly. In micrococcal nuclease and supercoiling assays, addition of p300 promoted efficient chromatin assembly in vitro in conjunction with NAP-1 and ATP-utilizing chromatin assembly and remodeling factor; this effect was dependent in part on the intrinsic histone acetyltransferase activity of p300. Surprisingly, NAP-1 potently inhibited acetylation of core histones by p300, suggesting that efficient assembly requires acetylation of either NAP-1 or p300 itself. As p300 acted cooperatively with NAP-1 in stimulating transcription from a chromatin template in vitro, our results suggest a dual role of NAP-1-p300 complexes in promoting chromatin assembly and transcriptional activation.

Publication types

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

MeSH terms

  • Animals
  • Blotting, Western
  • Cell Cycle Proteins
  • Cell Nucleus / metabolism
  • Chromatin / chemistry
  • Chromatin / genetics
  • Chromatin / metabolism*
  • DNA / metabolism
  • Drosophila
  • Drosophila Proteins
  • Electrophoresis, Polyacrylamide Gel
  • HeLa Cells
  • Humans
  • Nuclear Proteins / metabolism*
  • Nucleosome Assembly Protein 1
  • Nucleosomes / chemistry
  • Nucleosomes / genetics
  • Nucleosomes / metabolism
  • Protein Binding
  • Proteins / metabolism*
  • Recombinant Proteins / metabolism
  • Trans-Activators / metabolism*
  • Transcription, Genetic
  • Transcriptional Activation*
  • Two-Hybrid System Techniques
  • Yeasts


  • Cell Cycle Proteins
  • Chromatin
  • Drosophila Proteins
  • NAP1L1 protein, human
  • Nap1 protein, Drosophila
  • Nuclear Proteins
  • Nucleosome Assembly Protein 1
  • Nucleosomes
  • Proteins
  • Recombinant Proteins
  • Trans-Activators
  • DNA