A concomitant loss of dormant origins and FANCC exacerbates genome instability by impairing DNA replication fork progression

Spencer W. Luebben, Tsuyoshi Kawabata, Charles S. Johnson, M. Gerard O'sullivan, Naoko Shima

Research output: Contribution to journalArticlepeer-review

19 Scopus citations

Abstract

Accumulating evidence suggests that dormant DNA replication origins play an important role in the recovery of stalled forks. However, their functional interactions with other fork recovery mechanisms have not been tested. We previously reported intrinsic activation of the Fanconi anemia (FA) pathway in a tumor-prone mouse model (Mcm4chaos3) with a 60% loss of dormant origins. To understand this further, we introduced a null allele of Fancc (Fancc-), encoding a member of the FA core complex, into the Mcm4chaos3 background. Primary embryonic fibroblasts double homozygous for Mcm4chaos3 and Fancc- (Mcm4 chaos3/chaos3;Fancc-/-) showed significantly increased levels of markers of stalled/collapsed forks compared to either single homozygote. Interestingly, a loss of dormant origins also increased the number of sites in which replication was delayed until prophase, regardless of FA pathway activation. These replication defects coincided with substantially elevated levels of genome instability in Mcm4chaos3/chaos3;Fancc -/- cells, resulting in a high rate of perinatal lethality of Mcm4chaos3/chaos3;Fancc-/- mice and the accelerated tumorigenesis of surviving mice. Together, these findings uncover a specialized role of dormant origins in replication completion while also identifying important functional overlaps between dormant origins and the FA pathway in maintaining fork progression, genome stability, normal development and tumor suppression.

Original languageEnglish (US)
Pages (from-to)5605-5615
Number of pages11
JournalNucleic acids research
Volume42
Issue number9
DOIs
StatePublished - May 2014

Fingerprint Dive into the research topics of 'A concomitant loss of dormant origins and FANCC exacerbates genome instability by impairing DNA replication fork progression'. Together they form a unique fingerprint.

Cite this