SWI/SNF remodeling and p300-dependent transcription of histone variant H2ABbd nucleosomal arrays.
A histone variant H2ABbd was recently identified, but its function is totally unknown. Here we have studied the structural and functional properties of nucleosome and nucleosomal arrays reconstituted with this histone variant. We show that H2ABbd can replace the conventional H2A in the nucleosome, but this replacement results in alterations of the nucleosomal structure. The remodeling complexes SWI/SNF and ACF are unable to mobilize the variant H2ABbd nucleosome. However, SWI/SNF was able to increase restriction enzyme access to the variant nucleosome and assist the transfer of variant H2ABbd-H2B dimer to a tetrameric histone H3-H4 particle. In addition, the p300- and Gal4-VP16-activated transcription appeared to be more efficient for H2ABbd nucleosomal arrays than for conventional H2A arrays. The intriguing mechanisms by which H2ABbd affects both nucleosome remodeling and transcription are discussed.
Angelov
Dimitar
D
Ecole Normale Supérieure de Lyon, CNRS-UMR 5161, Lyon, France.
Verdel
André
A
An
Woojin
W
Bondarenko
Vladimir
V
Hans
Fabienne
F
Doyen
Cécile-Marie
CM
Studitsky
Vassily M
VM
Hamiche
Ali
A
Roeder
Robert G
RG
Bouvet
Philippe
P
Dimitrov
Stefan
S
D000107:Acetylation; D000818:Animals; D042002:Chromatin Assembly and Disassembly / Q000235:genetics / Q000502:physiology; D002868:Chromosomal Proteins, Non-Histone / Q000502:physiology*; D018983:DNA Footprinting; D003850:Deoxyribonuclease I; D019281:Dimerization; D006657:Histones / Q000378:metabolism*; D009687:Nuclear Proteins / Q000502:physiology*; D009707:Nucleosomes / Q000378:metabolism*; D012341:RNA, Ribosomal, 5S / Q000737:chemistry; D015534:Trans-Activators / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology*; D014158:Transcription, Genetic; D014981:Xenopus / Q000502:physiology
D002868:Chromosomal Proteins, Non-Histone; C070633:Gal-VP16; D006657:Histones; D009687:Nuclear Proteins; D009707:Nucleosomes; D012341:RNA, Ribosomal, 5S; C445179:SWI-SNF-B chromatin-remodeling complex; D015534:Trans-Activators; D014157:Transcription Factors; D003850:Deoxyribonuclease I