DNA polymerase interactions and their role In translesion synthesis substitutions.

Translesion synthesis (TLS) is a DNA damage tolerance mechanism that allows DNA replication to continue after a high fidelity (HiFi) polymerase stalls at a lesion. Upon stalling, the HiFi polymerase must be substituted with a TLS polymerase. The reverse substitution must occur promptly after lesion bypass to minimize error-prone synthesis by TLS polymerases opposite undamaged DNA templates. For each TLS process, multiple polymerase substitutions are necessary. To progress the polymerase research of the Trakselis laboratory, I have performed in vitro assays with archaeal enzymes to improve the understanding of regulatory mechanisms that may have evolved to limit error-prone synthesis of TLS polymerases after bypass of a lesion. As this research is foundational for studies of the human replisome, I then optimized expression and purification protocols to yield human PCNA, RFC, Pol delta, and Pol eta to allow in vitro experimentation of the more complex human system. Through interrogation of a direct interaction between human HiFi Pol delta and TLS Pol eta, experimental results show the significance of this polymerase-polymerase contact in TLS past multiple lesions. Human Pol eta is capable of TLS past ultraviolet (UV)-induced cyclobutane pyrimidine dimers (CPDs) as well as cisplatin-induced Pt-GG intrastrand crosslinks. Cisplatin is a well-known cancer treatment used to damage the DNA of cancer cells by generating lesions such as the Pt-GG intrastrand crosslink. By examining the bypass mechanisms of human Pol eta past both CPD and Pt-GG lesions, this research has significant biochemical and oncological implications.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Doctoral

Grantor

Baylor University.

Year dc:date.issued

2023

Author dc:creator

• Kaszubowski, Joseph D., 1993-

Advisor dc:contributor.advisor

• Trakselis, Michael A.

• Translesion synthesis.
• DNA damage tolerance.
• DNA polymerase.
• Polymerase substitution.

Statement dc:rights

• Baylor University works are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. Contact libraryquestions@baylor.edu for inquiries about permission.

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/2104/12818

OAI identifier oai:identifier

oai:baylor-ir.tdl.org:2104/12818