MacroH2A allows ATP-dependent chromatin remodeling by SWI/SNF and ACF complexes but specifically reduces recruitment of SWI/SNF.
The variant histone macroH2A helps maintain X inactivation and gene silencing. Previous work implied that nucleosomes containing macroH2A cannot be remodeled by ISWI and SWI/SNF chromatin remodeling enzymes. Using approaches that prevent misassembly of macroH2A nucleosomes, we find that macroH2A nucleosomes are excellent substrates for both enzyme families. Interestingly, SWI/SNF, which is involved in gene activation, preferentially binds H2A nucleosomes over macroH2A nucleosomes, but ACF, an ISWI complex implicated in gene repression, shows no preference. Thus, macroH2A may help regulate the balance between activating and repressive remodeling complexes.
Chang
Evelyn Y
EY
Department of Biochemistry and Biophysics, University of California, San Francisco, California 94158, USA.
Ferreira
Helder
H
Somers
Joanna
J
Nusinow
Dmitri A
DA
Owen-Hughes
Tom
T
Narlikar
Geeta J
GJ
D000255:Adenosine Triphosphate / Q000737:chemistry; D002467:Cell Nucleus / Q000378:metabolism; D002843:Chromatin / Q000737:chemistry; D042002:Chromatin Assembly and Disassembly; D019281:Dimerization; D005786:Gene Expression Regulation; D020868:Gene Silencing; D006657:Histones / Q000737:chemistry / Q000502:physiology*; D007700:Kinetics; D008954:Models, Biological; D009707:Nucleosomes / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism
D002843:Chromatin; D006657:Histones; D009707:Nucleosomes; D029701:Saccharomyces cerevisiae Proteins; C120756:macroH2A histone; D000255:Adenosine Triphosphate