Octamer transfer and creation of stably remodeled nucleosomes by human SWI-SNF and its isolated ATPases.
Chromatin remodeling complexes help regulate the structure of chromatin to facilitate transcription. The multisubunit human (h) SWI-SNF complex has been shown to remodel mono- and polynucleosome templates in an ATP-dependent manner. The isolated hSWI-SNF ATPase subunits BRG1 and hBRM also have these activities. The intact complex has been shown to produce a stable remodeled dimer of mononucleosomes as a product. Here we show that the hSWI-SNF ATPases alone can also produce this product. In addition, we show that hSWI-SNF and its ATPases have the ability to transfer histone octamers from donor nucleosomes to acceptor DNA. These two reactions are characterized and compared. Our results are consistent with both products of SWI-SNF action being formed as alternative outcomes of a single remodeling mechanism. The ability of the isolated ATPase subunits to catalyze these reactions suggests that these subunits play a key role in determining the mechanistic capabilities of the SWI-SNF family of remodeling complexes.
Department of Molecular Biology, Massachusetts General Hospital, Boston 02114, USA.
M L
ML
Phelan
G R
GR
Schnitzler
R E
RE
Kingston
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D018797:Cell Cycle Proteins; D002843:Chromatin / Q000378:metabolism*; D004247:DNA / Q000378:metabolism; D004265:DNA Helicases; D019281:Dimerization; D029721:Drosophila Proteins; D006367:HeLa Cells; D006657:Histones / Q000378:metabolism; D006801:Humans; D015636:Magnesium Chloride / Q000494:pharmacology; D008954:Models, Biological; D009687:Nuclear Proteins / Q000378:metabolism; D009707:Nucleosomes / Q000378:metabolism*; D010957:Plasmids / Q000378:metabolism; D011189:Potassium Chloride / Q000494:pharmacology; D013997:Time Factors; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry* / Q000378:metabolism*
D018797:Cell Cycle Proteins; D002843:Chromatin; D029721:Drosophila Proteins; D006657:Histones; D009687:Nuclear Proteins; D009707:Nucleosomes; D015534:Trans-Activators; D014157:Transcription Factors; C086469:brm protein, Drosophila; D015636:Magnesium Chloride; D011189:Potassium Chloride; D000255:Adenosine Triphosphate; D004247:DNA; D000251:Adenosine Triphosphatases; C084108:SMARCA4 protein, human; D004265:DNA Helicases