TY - JOUR
T1 - Histone H1 couples initiation and amplification of ubiquitin signalling after DNA damage
AU - Thorslund, Tina
AU - Ripplinger, Anita
AU - Hoffmann, Saskia
AU - Wild, Thomas
AU - Uckelmann, Michael
AU - Villumsen, Bine
AU - Narita, Takeo
AU - Sixma, Titia K
AU - Choudhary, Chuna Ram
AU - Bekker-Jensen, Simon
AU - Mailand, Niels
PY - 2015/11/19
Y1 - 2015/11/19
N2 - DNA double-strand breaks (DSBs) are highly cytotoxic DNA lesions that trigger non-proteolytic ubiquitylation of adjacent chromatin areas to generate binding sites for DNA repair factors. This depends on the sequential actions of the E3 ubiquitin ligases RNF8 and RNF168 (refs 1, 2, 3, 4, 5, 6), and UBC13 (also known as UBE2N), an E2 ubiquitin-conjugating enzyme that specifically generates K63-linked ubiquitin chains. Whereas RNF168 is known to catalyse ubiquitylation of H2A-type histones, leading to the recruitment of repair factors such as 53BP1 (refs 8, 9, 10), the critical substrates of RNF8 and K63-linked ubiquitylation remain elusive. Here we elucidate how RNF8 and UBC13 promote recruitment of RNF168 and downstream factors to DSB sites in human cells. We establish that UBC13-dependent K63-linked ubiquitylation at DSB sites is predominantly mediated by RNF8 but not RNF168, and that H1-type linker histones, but not core histones, represent major chromatin-associated targets of this modification. The RNF168 module (UDM1) recognizing RNF8-generated ubiquitylations is a high-affinity reader of K63-ubiquitylated H1, mechanistically explaining the essential roles of RNF8 and UBC13 in recruiting RNF168 to DSBs. Consistently, reduced expression or chromatin association of linker histones impair accumulation of K63-linked ubiquitin conjugates and repair factors at DSB-flanking chromatin. These results identify histone H1 as a key target of RNF8-UBC13 in DSB signalling and expand the concept of the histone code by showing that posttranslational modifications of linker histones can serve as important marks for recognition by factors involved in genome stability maintenance, and possibly beyond.
AB - DNA double-strand breaks (DSBs) are highly cytotoxic DNA lesions that trigger non-proteolytic ubiquitylation of adjacent chromatin areas to generate binding sites for DNA repair factors. This depends on the sequential actions of the E3 ubiquitin ligases RNF8 and RNF168 (refs 1, 2, 3, 4, 5, 6), and UBC13 (also known as UBE2N), an E2 ubiquitin-conjugating enzyme that specifically generates K63-linked ubiquitin chains. Whereas RNF168 is known to catalyse ubiquitylation of H2A-type histones, leading to the recruitment of repair factors such as 53BP1 (refs 8, 9, 10), the critical substrates of RNF8 and K63-linked ubiquitylation remain elusive. Here we elucidate how RNF8 and UBC13 promote recruitment of RNF168 and downstream factors to DSB sites in human cells. We establish that UBC13-dependent K63-linked ubiquitylation at DSB sites is predominantly mediated by RNF8 but not RNF168, and that H1-type linker histones, but not core histones, represent major chromatin-associated targets of this modification. The RNF168 module (UDM1) recognizing RNF8-generated ubiquitylations is a high-affinity reader of K63-ubiquitylated H1, mechanistically explaining the essential roles of RNF8 and UBC13 in recruiting RNF168 to DSBs. Consistently, reduced expression or chromatin association of linker histones impair accumulation of K63-linked ubiquitin conjugates and repair factors at DSB-flanking chromatin. These results identify histone H1 as a key target of RNF8-UBC13 in DSB signalling and expand the concept of the histone code by showing that posttranslational modifications of linker histones can serve as important marks for recognition by factors involved in genome stability maintenance, and possibly beyond.
KW - Chromatin
KW - DNA Breaks, Double-Stranded
KW - DNA Damage
KW - DNA Repair
KW - DNA-Binding Proteins
KW - Histones
KW - Humans
KW - Lysine
KW - Protein Structure, Tertiary
KW - Signal Transduction
KW - Ubiquitin
KW - Ubiquitin-Conjugating Enzymes
KW - Ubiquitin-Protein Ligases
KW - Ubiquitination
U2 - 10.1038/nature15401
DO - 10.1038/nature15401
M3 - Letter
C2 - 26503038
SN - 0028-0836
VL - 527
SP - 389
EP - 393
JO - Nature
JF - Nature
IS - 7578
ER -