Synergistic functions of SII and p300 in productive activator-dependent transcription of chromatin templates.
We have reconstituted a highly purified RNA polymerase II transcription system containing chromatin templates assembled with purified histones and assembly factors, the histone acetyltransferase p300, and components of the general transcription machinery that, by themselves, suffice for activated transcription (initiation and elongation) on DNA templates. We show that this system mediates activator-dependent initiation, but not productive elongation, on chromatin templates. We further report the purification of a chromatin transcription-enabling activity (CTEA) that, in a manner dependent upon p300 and acetyl-CoA, strongly potentiates transcription elongation through several contiguous nucleosomes as must occur in vivo. The transcription elongation factor SII is a major component of CTEA and strongly synergizes with p300 (histone acetylation) at a step subsequent to preinitiation complex formation. The purification of CTEA also identified HMGB2 as a coactivator that, while inactive on its own, enhances SII and p300 functions.
Guermah
Mohamed
M
Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA. guermam@mail.rockefeller.edu
Palhan
Vikas B
VB
Tackett
Alan J
AJ
Chait
Brian T
BT
Roeder
Robert G
RG
D000105:Acetyl Coenzyme A / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism*; D050881:E1A-Associated p300 Protein / Q000235:genetics / Q000378:metabolism*; D024261:HMGB2 Protein / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D009707:Nucleosomes / Q000378:metabolism; D010448:Peptide Initiation Factors / Q000235:genetics / Q000378:metabolism; D012319:RNA Polymerase II / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D035602:Transcriptional Elongation Factors / Q000235:genetics / Q000378:metabolism*
D002843:Chromatin; D024261:HMGB2 Protein; D009707:Nucleosomes; D010448:Peptide Initiation Factors; D011994:Recombinant Proteins; D035602:Transcriptional Elongation Factors; C018648:transcription factor S-II; D000105:Acetyl Coenzyme A; D050881:E1A-Associated p300 Protein; D012319:RNA Polymerase II