KAP-1 phosphorylation regulates CHD3 nucleosome remodeling during the DNA double-strand break response

• Published in: Nature structural & molecular biology Vol. 18; no. 7; pp. 831 - 839
• Main Authors: Goodarzi, Aaron A, Jeggo, Penelope A, Kurka, Thomas
• Format: Journal Article
• Language: English
• Published: New York Nature Publishing Group US 01-07-2011; Nature Publishing Group
• Subjects: 631/337/1427; 631/337/176; 631/337/474/538; Animals; Ataxia Telangiectasia Mutated Proteins; Biochemistry; Biological Microscopy; Biomedical and Life Sciences; Cell Cycle Proteins - physiology; Chromatin; Deoxyribonucleic acid; DNA; DNA Breaks, Double-Stranded; DNA damage; DNA Helicases - chemistry; DNA Helicases - metabolism; DNA Helicases - physiology; DNA Repair; DNA-Binding Proteins - physiology; HEK293 Cells; HeLa Cells; Heterochromatin - metabolism; Histones - metabolism; Humans; Inactivation; Irradiation; Life Sciences; Membrane Biology; Methylation; Mi-2 Nucleosome Remodeling and Deacetylase Complex; Mice; Molecular biology; Morpholines - pharmacology; NIH 3T3 Cells; Nuclear Proteins - chemistry; Nuclear Proteins - metabolism; Nuclear Proteins - physiology; Nucleosomes; Nucleosomes - drug effects; Nucleosomes - metabolism; Phosphorylation; Physiological aspects; Protein Structure; Protein-Serine-Threonine Kinases - physiology; Pyrones - pharmacology; Repressor Proteins - chemistry; Repressor Proteins - metabolism; Repressor Proteins - physiology; SUMO-1 Protein - chemistry; SUMO-1 Protein - metabolism; SUMO-1 Protein - physiology; Sumoylation; Tripartite Motif-Containing Protein 28; Tumor Suppressor Proteins - physiology; United Kingdom
• ISSN: 1545-9993; 1545-9985
• DOI: 10.1038/nsmb.2077

Heterochromatin factor KAP-1 is phosphorylated by ATM during the DNA damage response. Now the functional consequences of this modification are explored, revealing that the phosphorylated C-terminal region of KAP-1 perturbs the interaction between auto-SUMOylated KAP-1 and CHD3/Mi-2a, a component of the chromatin remodeler NuRD. This results in CHD3 dispersion from heterochromatin and allows DNA repair to proceed.
KAP-1 poses a substantial barrier to DNA double-strand break (DSB) repair within heterochromatin that is alleviated by ATM-dependent KAP-1 phosphorylation (pKAP-1). Here we address the mechanistic consequences of pKAP-1 that promote heterochromatic DSB repair and chromatin relaxation. KAP-1 function involves autoSUMOylation and recruitment of nucleosome deacetylation, methylation and remodeling activities. Although heterochromatin acetylation or methylation changes were not detected, radiation-induced pKAP-1 dispersed the nucleosome remodeler CHD3 from DSBs and triggered concomitant chromatin relaxation; pKAP-1 loss reversed these effects. Depletion or inactivation of CHD3, or ablation of its interaction with KAP-1
SUMO1
, bypassed pKAP-1's role in repair. Though KAP-1 SUMOylation was unaffected after irradiation, CHD3 dissociated from KAP-1
SUMO1
in a pKAP-1–dependent manner. We demonstrate that KAP-1
Ser824
phosphorylation generates a motif that directly perturbs interactions between CHD3′s SUMO-interacting motif and SUMO1, dispersing CHD3 from heterochromatin DSBs and enabling repair.