解旋酶
同源重组
DNA修复
细胞生物学
生物
聚合酶
非同源性末端接合
DNA
化学
RNA解旋酶A
分子生物学
遗传学
基因
核糖核酸
作者
Pedro A. Mateos‐Gómez,Tatiana Kent,Sarah Deng,Shane McDevitt,Ekaterina Kashkina,Trung Hoang,Richard T. Pomerantz,Agnel Sfeir
摘要
Mammalian polymerase theta (Polθ) is a multifunctional enzyme that promotes error-prone DNA repair by alternative nonhomologous end joining (alt-NHEJ). Here we present structure-function analyses that reveal that, in addition to the polymerase domain, Polθ-helicase activity plays a central role during double-strand break (DSB) repair. Our results show that the helicase domain promotes chromosomal translocations by alt-NHEJ in mouse embryonic stem cells and also suppresses CRISPR-Cas9- mediated gene targeting by homologous recombination (HR). In vitro assays demonstrate that Polθ-helicase activity facilitates the removal of RPA from resected DSBs to allow their annealing and subsequent joining by alt-NHEJ. Consistent with an antagonistic role for RPA during alt-NHEJ, inhibition of RPA1 enhances end joining and suppresses recombination. Taken together, our results reveal that the balance between HR and alt-NHEJ is controlled by opposing activities of Polθ and RPA, providing further insight into the regulation of repair-pathway choice in mammalian cells.
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