Purification of a human SRCAP complex that remodels chromatin by incorporating the histone variant H2A.Z into nucleosomes.
The Snf-2-related CREB-binding protein activator protein (SRCAP) serves as a coactivator for a number of transcription factors known to interact with CBP. Swr1, the closest Saccharomyces cerevisiae ortholog of SRCAP, is a component of the chromatin remodeling complex SWR-C, which catalyzes exchange of the histone variant H2A.Z into nucleosomes. In this report, we use a combination of conventional chromatography and anti-SRCAP immunoaffinity chromatography to purify a native human SRCAP complex with a polypeptide composition similar to that of SWR-C, and we show for the first time that this SRCAP-containing complex supports ATP-dependent exchange of histone dimers containing H2B and H2A.Z into mononucleosomes reconstituted with recombinant H2A, H2B, H3, and H4. Our findings, together with previous evidence implicating H2A.Z in transcriptional regulation, suggest that SRCAP's coactivator function may depend on its ability to promote incorporation of H2A.Z into chromatin.
Ruhl
Donald D
DD
Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, Saint Louis, Missouri 63104, USA.
Jin
Jingji
J
Cai
Yong
Y
Swanson
Selene
S
Florens
Laurence
L
Washburn
Michael P
MP
Conaway
Ronald C
RC
Conaway
Joan Weliky
JW
Chrivia
John C
JC
D000251:Adenosine Triphosphatases / Q000302:isolation & purification* / Q000378:metabolism*; D002843:Chromatin / Q000187:drug effects / Q000378:metabolism*; D002852:Chromatography, Ion Exchange / Q000379:methods; D006657:Histones / Q000378:metabolism*; D046912:Multiprotein Complexes / Q000302:isolation & purification* / Q000378:metabolism*; D009707:Nucleosomes / Q000378:metabolism*; D040901:Proteomics; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*
D002843:Chromatin; D006657:Histones; C493530:Htz1 protein, S cerevisiae; D046912:Multiprotein Complexes; D009707:Nucleosomes; D029701:Saccharomyces cerevisiae Proteins; D000251:Adenosine Triphosphatases; C119652:SRCAP protein, human