Dual Roles of p300 in Chromatin Assembly and Transcriptional Activation in Cooperation with Nucleosome Assembly Protein 1 In Vitro

AUTOR(ES)

Asahara, Hiroshi

FONTE

American Society for Microbiology

RESUMO

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.

Documentos Relacionados

• p300 and PCAF Act Cooperatively To Mediate Transcriptional Activation from Chromatin Templates by Notch Intracellular Domains In Vitro
• Biochemical Analysis of Distinct Activation Functions in p300 That Enhance Transcription Initiation with Chromatin Templates
• Interaction of Human Immunodeficiency Virus Type 1 Tat with the Transcriptional Coactivators p300 and CREB Binding Protein
• A Role for CREB Binding Protein and p300 Transcriptional Coactivators in Ets-1 Transactivation Functions
• HIV transcriptional activation by the accessory protein, VPR, is mediated by the p300 co-activator