Precise nucleosome positioning and the TATA box dictate requirements for the histone H4 tail and the bromodomain factor Bdf1.
Acetylation of histone tails plays a key role in chromatin dynamics and is associated with the potential for gene expression. We show here that a 2-3 bp mispositioning of the nucleosome covering the TATA box at PHO5 induces a dependency on the acetylatable lysine residues of the histone H4 N-terminal region and on the TFIID-associated bromodomain factor Bdf1. This dependency arises either through fusion of the PHO5 promoter to a lacZ reporter or by mutation of the TATA box in the natural gene. The results suggest that promoters in which the TATA box is either absent or poorly accessible on the surface of a nucleosome may compensate by using Bdf1 bromodomains and acetylated H4 tails to anchor TFIID to the promoter during the initial stages of transcription activation. We propose that nucleosome positioning at the nucleotide level provides a subtle, but highly effective, mechanism for gene regulation.
Martinez-Campa
Carlos
C
Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, United Kingdom.
Politis
Panagiotis
P
Moreau
Jean-Luc
JL
Kent
Nick
N
Goodall
Jane
J
Mellor
Jane
J
Goding
Colin R
CR
D000107:Acetylation; D000135:Acid Phosphatase; D020137:Base Pair Mismatch / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D015966:Gene Expression Regulation, Fungal / Q000235:genetics; D006657:Histones / Q000235:genetics / Q000378:metabolism*; D007763:Lac Operon / Q000235:genetics; D008239:Lysine / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D009707:Nucleosomes / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D016385:TATA Box / Q000235:genetics*; D035362:Transcription Factor TFIID / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation / Q000235:genetics*; D000092468:Bromodomain Containing Proteins
D000135:Acid Phosphatase; D002352:Carrier Proteins; D006657:Histones; D008239:Lysine; D009707:Nucleosomes; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; D035362:Transcription Factor TFIID; D014157:Transcription Factors; C091342:BDF1 protein, S cerevisiae; D000092468:Bromodomain Containing Proteins; C026989:thiamine-binding protein; C488913:PHO3 protein, S cerevisiae; C488916:PHO5 protein, S cerevisiae