Binding of TATA Binding Protein to a Naturally Positioned Nucleosome Is Facilitated by Histone Acetylation

Abstract

The TATA sequence of the human, estrogen-responsive pS2 promoter is complexed in vivo with a rotationally and translationally positioned nucleosome (NUC T). Using a chromatin immunoprecipitation assay, we demonstrate that TATA binding protein (TBP) does not detectably interact with this genomic binding site in MCF-7 cells in the absence of transcriptional stimuli. Estrogen stimulation of these cells results in hyperacetylation of both histones H3 and H4 within the pS2 chromatin encompassing NUC T and the TATA sequence. Concurrently, TBP becomes associated with the pS2 promoter region. The relationship between histone hyperacetylation and the binding of TBP was assayed in vitro using an in vivo-assembled nucleosomal array over the pS2 promoter. With chromatin in its basal state, the binding of TBP to the pS2 TATA sequence at the edge of NUC T was severely restricted, consistent with our in vivo data. Acetylation of the core histones facilitated the binding of TBP to this nucleosomal TATA sequence. Therefore, we demonstrate that one specific, functional consequence of induced histone acetylation at a native promoter is the alleviation of nucleosomemediated repression of the binding of TBP. Our data support a fundamental role for histone acetylation at genomic promoters in transcriptional activation by nuclear receptors and provide a general mechanism for rapid and reversible transcriptional activation from a chromatin template.Transcription by RNA polymerase II (RNA pol II) from most eukaryotic promoters requires the evolutionarily conserved interaction of TATA binding protein (TBP) with a TATA sequence (42) in a chromatin context. Transcriptional activity, at least in yeast, correlates strongly with the degree of TBP occupancy of TATA box elements (30, 32). However, TBP can be severely inhibited from binding DNA sites located within unaltered mononucleosomes (17, 24). Positioning of a nucleosome over the TATA region appears to be a common mechanism for repressing basal transcription. In yeast, the TATA sequences of the inactive PHO5 (2), ADH2 (54), GAL80 (34,35), and CHA1 (37) promoters are all contained within positioned nucleosomes that are disrupted during induction-dependent chromatin rearrangements. Similar mechanisms have been observed in other organisms. Both the repressed human immunodeficiency virus type 1 promoter in unstimulated human T cells (53) and the inactive beta phaseolin gene in vegetative tobacco tissues (31) contain nucleosomes that occlude their respective TATA sequences and are subsequently disrupted concomitant with transcriptional activation.Of the multiple modifications required for conversion of chromatin from an inactive to active state, one consistent feature of active chromatin is the highly acetylated state of the core histones in the nucleosomes (13, 22, 52). Core histone acetylation influences both the interaction of specific proteins with nucleosomal DNA and the activation of gene expression (reviewed in reference 57). A broad range of transcriptional regulatory proteins possess ...

The faah gene is the first direct target of estrogen in the testis: role of histone demethylase LSD1

“…Thus, the latter dose was used in further experiments. Incidentally, it should be noted that concentrations in the high-nM range have been largely used to investigate gene transcriptional regulation by E 2 [23][24][25][26][27] or metabolic effect of this hormone [28]. Moreover, it has been shown that intratesticular concentrations are much higher than serum levels of E 2 [29].…”

Inhibition of MMTV transcription by HDAC inhibitors occurs independent of changes in chromatin remodeling and increased histone acetylation

“…Other studies have addressed the question of histone acetylation and TBP binding. In one case, TBP binding to chromatin-assembled SV40 minichromosomes was facilitated by histone acetylation at an underlying nucleosome (Sewack et al, 2001). However, in yeast gene systems, binding of TBP to promoters does not appear to strictly correlate with the acetylation status of promoter histones (Sekinger and Gross 2001;Katan-Khaykovich and Struhl 2002;Kristjuhan et al, 2002).…”

An Unmethylated 3' Promoter-proximal Region is Required for Efficient Transcription Initiation

“…Acetylation of histone tails in promoter regions facilitates efficient remodeling of nucleosomes via recruitment of SWI/SNF chromatin remodeling complexes and/or TFIID [29,33,47,48], and a recent analysis of PIC formation in 29 ENCODE regions in human cells reveals a very strong correlation between H3 acetylation and the presence of a PIC [49]. As the unmethylated promoter region of the patchmethylated cassette described here is hypo-acetylated relative to the identical but unmethylated control cassette integrated at the same site, we propose that the observed decrease in histone H3 acetylation reduces nucleosome ''fluidity'' in the promoter proximal region, which inhibits repositioning of the nucleosome around the TATA-box and in turn, recruitment of TBP.…”

“…Acetylation of histone tails neutralizes the positive charge on lysines and is believed to promote an allosteric change in nucleosome conformation that renders nucleosomal DNA more accessible to the transcription machinery [25,26], perhaps by altering higher order chromatin structure [27]. While binding of TBP to the TATA box is severely inhibited by incorporation of template DNA into a nucleosome [28], histone acetylation can facilitate TBP binding to a naturally positioned nucleosome [29]. Furthermore, in vitro and in vivo experiments are consistent with the model that histone acetylation is an early step in the cascade of events leading to transcription initiation [30][31][32][33].…”