Related Experiment Video
Updated: May 17, 2026

Laser Microirradiation to Study In Vivo Cellular Responses to Simple and Complex DNA Damage
Published on: January 31, 2018
Histone H2A.Z controls a critical chromatin remodeling step required for DNA double-strand break repair
Ye Xu1, Marina K Ayrapetov, Chang Xu
1Division of Genome Stability and DNA Repair, Department of Radiation Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02215, USA.
Abstract:
Chromatin remodeling during DNA double-strand break (DSB) repair is required to facilitate access to and repair of DSBs. This remodeling requires increased acetylation of histones and a shift in nucleosome organization to create open, relaxed chromatin domains. However, the underlying mechanism driving changes in nucleosome structure at DSBs is poorly defined. Here, we demonstrate that histone H2A.Z is exchanged onto nucleosomes at DSBs by the p400 remodeling ATPase. H2A.Z exchange at DSBs shifts the chromatin to an open conformation and is required for acetylation and ubiquitination of histones and for loading of the brca1 complex. H2A.Z exchange also restricts single-stranded DNA production by nucleases and is required for loading of the Ku70/Ku80 DSB repair protein. H2A.Z exchange therefore promotes specific patterns of histone modification and reorganization of the chromatin architecture, leading to the assembly of a chromatin template that is an efficient substrate for the DSB repair machinery.
Related Concept Videos
Homologous Recombination
Fixing Double-strand Breaks
Fixing Double-strand Breaks
Nucleosome Remodeling
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
DNA Damage can Stall the Cell Cycle
DNA Damage Can Stall the Cell Cycle

