Phosphorylation Alters the Properties of Pol η: Implications for Translesion Synthesis.
iScience
; 6: 52-67, 2018 Aug 31.
Article
em En
| MEDLINE
| ID: mdl-30240625
ABSTRACT
There are significant ambiguities regarding how DNA polymerase η is recruited to DNA lesion sites in stressed cells while avoiding normal replication forks in non-stressed cells. Even less is known about the mechanisms responsible for Pol η-induced mutations in cancer genomes. We show that there are two safeguards to prevent Pol η from adventitious participation in normal DNA replication. These include sequestration by a partner protein and low basal activity. Upon cellular UV irradiation, phosphorylation enables Pol η to be released from sequestration by PDIP38 and activates its polymerase function through increased affinity toward monoubiquitinated proliferating cell nuclear antigen (Ub-PCNA). Moreover, the high-affinity binding of phosphorylated Pol η to Ub-PCNA limits its subsequent displacement by Pol δ. Consequently, activated Pol η replicates DNA beyond the lesion site and potentially introduces clusters of mutations due to its low fidelity. This mechanism could account for the prevalence of Pol η signatures in cancer genome.
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Base de dados:
MEDLINE
Tipo de estudo:
Risk_factors_studies
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article