Ahmad

B. Loppin

Boehm

Bonnefoy

Campos

Cardoso

Corona

Elsaesser

G. A. Orsi

Goldberg

J. I. Schneiderman

K. Ahmad

K. T. Hughes

Loppin

McDowell

Mito

Otani

Petesch

Ray-Gallet

Rubin

Sakai

Tagami

Tyler

Umemori


            Most nucleosomes that package eukaryotic DNA are assembled during DNA replication, but chromatin structure is routinely disrupted in active regions of the genome. Replication-independent nucleosome replacement using the H3.3 histone variant efficiently repackages these regions, but how histones are recruited to these sites is unknown. Here, we use an inducible system that produces nucleosome-depleted chromatin at the
            Hsp70
            genes in
            Drosophila
            to define steps in the mechanism of nucleosome replacement. We find that the Xnp chromatin remodeler and the Hira histone chaperone independently bind nucleosome-depleted chromatin. Surprisingly, these two factors are only displaced when new nucleosomes are assembled. H3.3 deposition assays reveal that Xnp and Hira are required for efficient nucleosome replacement, and double-mutants are lethal. We propose that Xnp and Hira recognize exposed DNA and serve as a binding platform for the efficient recruitment of H3.3 predeposition complexes to chromatin gaps. These results uncover the mechanisms by which eukaryotic cells actively prevent the exposure of DNA in the nucleus.
          </jats:p

Jonathan I. Schneiderman

Guillermo A. Orsi

Kelly T. Hughes

Benjamin Loppin

Kami Ahmad

Crossref

Proceedings of the National Academy of Sciences

Nucleosome-depleted chromatin gaps recruit assembly factors for the H3.3 histone variant

Nucleosome-depleted chromatin gaps recruit assembly factors for the H3.3 histone variant

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