| First Author | Li Y | Year | 2011 |
| Journal | Genes Cells | Volume | 16 |
| Issue | 9 | Pages | 973-83 |
| PubMed ID | 21883722 | Mgi Jnum | J:189375 |
| Mgi Id | MGI:5445451 | Doi | 10.1111/j.1365-2443.2011.01550.x |
| Citation | Li Y, et al. (2011) Comparison of two POLQ mutants reveals that a polymerase-inactive POLQ retains significant function in tolerance to etoposide and gamma-irradiation in mouse B cells. Genes Cells 16(9):973-83 |
| abstractText | DNA polymerase theta (POLQ) is a family A polymerase that contains an intrinsic helicase domain. POLQ has been implicated in tolerance to DNA damage but whether this depends solely on its polymerase domain remains unknown. In this study, we generated POLQ-null CH12F3 B cells by gene targeting and compared their sensitivity to DNA-damaging agents with previously established POLQ-inactive CH12F3 cells in which only the polymerase core domain was deleted. Compared with WT cells, POLQ-null and POLQ-inactive cells exhibited similarly increased sensitivity to mitomycin C, cisplatin, and ultraviolet radiation, suggesting that tolerance to these DNA-damaging agents depends largely on POLQ polymerase activity. Intriguingly, POLQ-null cells exhibited higher sensitivity than did POLQ-inactive cells to etoposide and gamma-irradiation, both of which induce double-strand breaks (DSBs). This observation indicates that the polymerase-deleted POLQ, expressed in POLQ-inactive cells, retains significant function in tolerance to these agents. Class switch recombination of immunoglobulin genes, which involves repair of activation-induced cytidine deaminase (AID)-triggered DSBs, however, was unaffected in both POLQ-null and POLQ-inactive cells. These results suggest that the polymerase and other functional domains of POLQ both play important roles in tolerance to etoposide and gamma-irradiation but are dispensable for AID-mediated class switch recombination. |
