Activation domains drive nucleosome eviction by SWI/SNF.
ATP-dependent chromatin remodeling complexes play a critical role in chromatin dynamics. A large number of in vitro studies have pointed towards nucleosome sliding as the principal remodeling outcome of SWI/SNF action, whereas few have described histone octamer transfer as the principal outcome. In contrast, recent in vivo studies have linked the activity of SWI/SNF to histone eviction in trans from gene promoters. In this study, we have found that the chimeric transcription factor Gal4-VP16 can enhance SWI/SNF histone octamer transfer activity, resulting in targeted histone eviction from a nucleosome probe. This effect is dependent on the presence of the activation domain. We observed that under conditions mimicking the in vivo relative abundance of SWI/SNF with respect to the total number of nucleosomes in a cell nucleus, the accessibility of the transcription factor binding site is the first determinant in the sequence of events leading to nucleosome remodeling. We propose a model mechanism for this transcription factor-mediated enhancement of SWI/SNF octamer transfer activity.
Gutiérrez
José L
JL
Stowers Institute for Medical Research, Kansas City, MO 64110, USA.
Chandy
Mark
M
Carrozza
Michael J
MJ
Workman
Jerry L
JL
D000251:Adenosine Triphosphatases; D001483:Base Sequence; D042002:Chromatin Assembly and Disassembly / Q000235:genetics / Q000502:physiology*; D015342:DNA Probes / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism*; D008954:Models, Biological; D008969:Molecular Sequence Data; D009707:Nucleosomes / Q000235:genetics / Q000502:physiology*; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D015342:DNA Probes; D004268:DNA-Binding Proteins; C052130:GAL4 protein, S cerevisiae; D009707:Nucleosomes; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D000251:Adenosine Triphosphatases; C499333:SNF2 protein, S cerevisiae