Identification of RNF8 as a ubiquitin ligase involved in targeting the p12 subunit of DNA polymerase δ for degradation in response to DNA damage.
J Biol Chem
; 288(5): 2941-50, 2013 Feb 01.
Article
em En
| MEDLINE
| ID: mdl-23233665
ABSTRACT
DNA polymerase δ consists of four subunits, one of which, p12, is degraded in response to DNA damage through the ubiquitin-proteasome pathway. However, the identities of the ubiquitin ligase(s) that are responsible for the proximal biochemical events in triggering proteasomal degradation of p12 are unknown. We employed a classical approach to identifying a ubiquitin ligase that is involved in p12 degradation. Using UbcH5c as ubiquitin-conjugating enzyme, a ubiquitin ligase activity that polyubiquitinates p12 was purified from HeLa cells. Proteomic analysis revealed that RNF8, a RING finger ubiquitin ligase that plays an important role in the DNA damage response, was the only ubiquitin ligase present in the purified preparation. In vivo, DNA damage-induced p12 degradation was significantly reduced by shRNA knockdown of RNF8 in cultured human cells and in RNF8(-/-) mouse epithelial cells. These studies provide the first identification of a ubiquitin ligase activity that is involved in the DNA damage-induced destruction of p12. The identification of RNF8 allows new insights into the integration of the control of p12 degradation by different DNA damage signaling pathways.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Dano ao DNA
/
Ubiquitina-Proteína Ligases
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Proteínas de Ligação a DNA
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DNA Polimerase III
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Proteólise
Tipo de estudo:
Diagnostic_studies
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article