DNA damage causes replication forks to stall, which can ultimately lead to double strand breaks, chromosomal rearrangements, and cell death. Proliferating cell nuclear antigen is a clamp protein which encircles DNA and acts as a sliding platform for proteins that will act on the DNA, including polymerases. Replication fork stalling causes PCNA to be mono-ubiquitylated, resulting in a polymerase switch from the classical polymerases that perform replication to the Y-family polymerases which conduct translesion synthesis (TLS) to bypass the DNA damage and allow replication to continue. Y-family polymerases include DNA polymerases eta, kappa, iota, and Rev1. The mechanism by which these polymerases are assembled into multi-protein complexes which include PCNA has previously not been well-understood. The studies outlined below demonstrate that ternary complexes involving PCNA, Rev1, and pol η can adopt multiple conformations which can rapidly interconvert. Additionally, I have demonstrated that ubiquitin stimulates the catalytic activity of DNA polymerase eta through a novel interaction with the catalytic core. These studies represent significant progress towards understand the regulation of TLS polymerase activity through both recruitment to and activation by ubiquitylated PCNA.
| Identifer | oai:union.ndltd.org:uiowa.edu/oai:ir.uiowa.edu:etd-7196 |
| Date | 01 August 2016 |
| Creators | Boehm, Elizabeth Marie |
| Contributors | Washington, M. Todd |
| Publisher | University of Iowa |
| Source Sets | University of Iowa |
| Language | English |
| Detected Language | English |
| Type | dissertation |
| Format | application/pdf |
| Source | Theses and Dissertations |
| Rights | Copyright © 2016 Elizabeth Marie Boehm |
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