| First Author | Sun H | Year | 2021 |
| Journal | Science | Volume | 374 |
| Issue | 6572 | Pages | 1252-1258 |
| PubMed ID | 34855483 | Mgi Jnum | J:317224 |
| Mgi Id | MGI:6834014 | Doi | 10.1126/science.abj1013 |
| Citation | Sun H, et al. (2021) Error-prone, stress-induced 3' flap-based Okazaki fragment maturation supports cell survival. Science 374(6572):1252-1258 |
| abstractText | How cells with DNA replication defects acquire mutations that allow them to escape apoptosis under environmental stress is a long-standing question. Here, we report that an error-prone Okazaki fragment maturation (OFM) pathway is activated at restrictive temperatures in rad27Delta yeast cells. Restrictive temperature stress activated Dun1, facilitating transformation of unprocessed 5' flaps into 3' flaps, which were removed by 3' nucleases, including DNA polymerase delta (Poldelta). However, at certain regions, 3' flaps formed secondary structures that facilitated 3' end extension rather than degradation, producing alternative duplications with short spacer sequences, such as pol3 internal tandem duplications. Consequently, little 5' flap was formed, suppressing rad27Delta-induced lethality at restrictive temperatures. We define a stress-induced, error-prone OFM pathway that generates mutations that counteract replication defects and drive cellular evolution and survival. |
