Histone acetylation readers Bdf1 and Yaf9 guide targeting of SWR1 remodeler to +1 nucleosome
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ABSTRACT: The histone variant H2A.Z marking permissive chromatin is preferentially deposited at promoter-proximal +1 nucleosomes by the multicomponent SWR1 chromatin remodeler. Although SWR1 targeting to nucleosome-depleted regions (NDRs) is directed by its free DNA length sensing module, how the remodeler is guided preferentially to flanking +1 nucleosomes has been enigmatic. Here, we show by live-cell, single-molecule tracking (SMT) that SWR1 subunits Bdf1 and Yaf9 harboring bromo and YEATS acetyl-histone reader domains are required for quantitative chromatin binding via distinct kinetic mechanisms: Bdf1 increases SWR1 association, Yaf9-YEATS reduces disassociation. Notably, SMT and genome-wide ChIP-exo reveals Bdf1 and Yaf9 contributions to SWR1 targeting globally and histone exchange at +1 nucleosomes. Our findings highlight the native biochemistry of histone readers and suggest a broadly applicable, two-stage mechanism wherein acetyl-histone interactions initially constrain 3D diffusion of SWR1 to increase local concentration, followed by stochastic 1D diffusion at NDRs with directional capture by acetylated +1 nucleosomes.
ORGANISM(S): Saccharomyces cerevisiae
PROVIDER: GSE273028 | GEO | 2024/07/29
REPOSITORIES: GEO
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