The histone chaperone ANP32B regulates chromatin incorporation of the atypical human histone variant macroH2A
Imke K. Mandemaker,
Evelyn Fessler,
David Corujo,
Christiane Kotthoff,
Andreas Wegerer,
Clément Rouillon,
Marcus Buschbeck,
Lucas T. Jae,
Francesca Mattiroli,
Andreas G. Ladurner
Affiliations
Imke K. Mandemaker
Biomedical Center (BMC), Department of Physiological Chemistry, Faculty of Medicine, LMU Munich, 82152 Planegg-Martinsried, Germany; Hubrecht Institute, Uppsalalaan 8, 3584CT Utrecht, the Netherlands; Corresponding author
Evelyn Fessler
Gene Center and Department of Biochemistry, LMU Munich, 81377 Munich, Germany
David Corujo
Applied Epigenetics Program, Myeloid Neoplasm Program, Josep Carreras Leukaemia Research Institute (IJC), Campus ICO-GTP-UAB, 08916 Badalona, Barcelona, Spain; Germans Trias I Pujol Research Institute (IGTP), 08916 Badalona, Barcelona, Spain
Christiane Kotthoff
Biomedical Center (BMC), Department of Physiological Chemistry, Faculty of Medicine, LMU Munich, 82152 Planegg-Martinsried, Germany
Andreas Wegerer
Biomedical Center (BMC), Department of Physiological Chemistry, Faculty of Medicine, LMU Munich, 82152 Planegg-Martinsried, Germany
Clément Rouillon
Hubrecht Institute, Uppsalalaan 8, 3584CT Utrecht, the Netherlands
Marcus Buschbeck
Applied Epigenetics Program, Myeloid Neoplasm Program, Josep Carreras Leukaemia Research Institute (IJC), Campus ICO-GTP-UAB, 08916 Badalona, Barcelona, Spain; Germans Trias I Pujol Research Institute (IGTP), 08916 Badalona, Barcelona, Spain
Lucas T. Jae
Gene Center and Department of Biochemistry, LMU Munich, 81377 Munich, Germany
Francesca Mattiroli
Hubrecht Institute, Uppsalalaan 8, 3584CT Utrecht, the Netherlands; Corresponding author
Andreas G. Ladurner
Biomedical Center (BMC), Department of Physiological Chemistry, Faculty of Medicine, LMU Munich, 82152 Planegg-Martinsried, Germany; Eisbach Bio GmbH, 82152 Planegg-Martinsried, Germany; Corresponding author
Summary: All vertebrate genomes encode for three large histone H2A variants that have an additional metabolite-binding globular macrodomain module, macroH2A. MacroH2A variants impact heterochromatin organization and transcription regulation and establish a barrier for cellular reprogramming. However, the mechanisms of how macroH2A is incorporated into chromatin and the identity of any chaperones required for histone deposition remain elusive. Here, we develop a split-GFP-based assay for chromatin incorporation and use it to conduct a genome-wide mutagenesis screen in haploid human cells to identify proteins that regulate macroH2A dynamics. We show that the histone chaperone ANP32B is a regulator of macroH2A deposition. ANP32B associates with macroH2A in cells and in vitro binds to histones with low nanomolar affinity. In vitro nucleosome assembly assays show that ANP32B stimulates deposition of macroH2A-H2B and not of H2A-H2B onto tetrasomes. In cells, depletion of ANP32B strongly affects global macroH2A chromatin incorporation, revealing ANP32B as a macroH2A histone chaperone.
