Dual loss of human POLQ and LIG4 abolishes random integration

Posted on Posted in AMRC Research

Date: 11 Jul 2017


Homologous recombination-mediated gene targeting has greatly contributed to genetic analysis in a wide range of species, but is highly inefficient in human cells because of overwhelmingly frequent random integration events, whose molecular mechanism remains elusive. Here we show that DNA polymerase θ, despite its minor role in chromosomal DNA repair, substantially contributes to random integration, and that cells lacking both DNA polymerase θ and DNA ligase IV, which is essential for non-homologous end joining (NHEJ), exhibit 100% efficiency of spontaneous gene targeting by virtue of undetectable levels of random integration. Thus, DNA polymerase θ-mediated end joining is the sole homology-independent repair route in the absence of NHEJ and, intriguingly, their combined absence reveals rare Alu-Alu recombination events utilizing a stretch of homology. Our findings provide new insights into the mechanics of foreign DNA integration and the role of DNA polymerase θ in human genome maintenance.


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For inquiries regarding this press release

Noritaka Adachi

E-mail: nadachi@yokohama-cu.ac.jp   Phone: +81 45 787 2228

Department of Life and Environmental System Science,
Yokohama City University, Graduate School of Nanobioscience
22-2 Seto, Kanazawa-ku, Yokohama 236-0027 JAPAN