RAD18 mediates DNA double-strand break-induced ubiquitination of chromatin protein.
J Biochem
; 170(1): 33-40, 2021 Sep 22.
Article
em En
| MEDLINE
| ID: mdl-33508099
ABSTRACT
The E3 ubiquitin ligase RAD18 mono-ubiquitinates PCNA to promote bypass of replication fork-stalling DNA lesions. On the other hand, RAD18 also contributes to DNA double-strand break (DSB) repair. RAD18 is recruited to ionizing radiation (IR)-induced DSB and colocalizes with ubiquitinated chromatin proteins. RAD18 interacts with the ubiquitinated chromatin proteins via its ubiquitin-binding Zinc finger (UBZ) domain and is proposed to propagate DNA DSB signalling and recruit DNA repair proteins. We found that purified human RAD18 protein complexed with RAD6B (RAD6B-RAD18) catalyzes mono- and poly-ubiquitination of histone H2A in vitro while UBZ domain-mutated RAD18 complexed with RAD6B protein catalyzes mono- but not poly-ubiquitination of histone H2A. Human RAD18-/-cells synchronized at the G1 phase show a reduced signal of ubiquitinated protein in chromatin after IR when compared to that of wild-type control cells. The reduced signal of ubiquitinated protein in RAD18-/-cells is rescued by the introduction of RAD18 cDNA but to a lesser extent by the introduction of cDNA coding RAD18 lacking UBZ domain. Taken together, these results indicate that RAD18 mediates DSB-induced ubiquitination of chromatin protein during the G1 phase.
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Base de dados:
MEDLINE
Assunto principal:
Cromatina
/
Histonas
/
Ubiquitina-Proteína Ligases
/
Proteínas de Ligação a DNA
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article