Building Tools to Identify Interacting Partners of Rev1 Polymerase in its Novel Role in DNA Damage Tolerance by Template Switching.
Tomarchio, Gina M.
- DNA replication is a dynamic and tightly regulated cellular process involving a complex cast of players but when the replication machinery encounters lesions or physical blockages in the DNA template, there is a threat to the integrity of the replication forks. If these lesions are not bypassed, replication forks will stall and eventually collapse and thus cells have evolved a set of mechanisms ... read morefor bypassing lesions during replication, known as DNA Damage Tolerance (DDT). In eukaryotes, DDT is separated into two pathways, translesion synthesis (TLS) and template switching (TS). TLS involves use of specialized polymerases to synthesize past the lesion while TS uses a homology-directed mechanism and a sister chromatid template to replicate past the lesion. The coordination between the two separate DDT pathways remains to be fully understood. Also, despite the critical nature of the lesion bypass pathways, their exact mechanisms and players remain somewhat mysterious, especially in the TS pathway. Recent, unpublished work from our lab has provided evidence for a hierarchy of DDT pathway choice in Drosophila with TS serving as a back-up to bypass via TLS. This study aims to elucidate if this hierarchy is phenomenon specific to rapidly proliferating tissues by comparing our previous results to the effects of chemically induced fork-stalling in Drosophila cell culture. Also, this study was successful in building tools for further clarifying the mechanisms and players involved in the TS pathway in Drosophila. Specifically, we are interested in using these tools to identify new interacting partners of TLS polymerase, Rev1, which other recent unpublished studies from out lab have implicated to have a role in lesion bypass via TS, separate from its known function in TLS.read less