Publication Date
2024
Document Type
Thesis
Committee Members
Yong-jie Xu, M.D., Ph.D (Advisor); Ravi P. Sahu, Ph.D (Committee Member); Michael Kemp, Ph.D (Committee Member)
Degree Name
Master of Science (MS)
Abstract
Eukaryotic SSB, also known as replication protein A (RPA), is a single-stranded DNA binding protein that is highly conserved in eukaryotes. It is essential in multiple cellular functions such as DNA replication, repair, recombination, and cell cycle checkpoint signaling. Studying SSB’s or RPA’s checkpoint functions in cells is challenging due to its crucial role in cell survival. Exploring this possibility, we performed an extensive genetic screening of ssb1, which encodes the largest subunit of RPA, looking for nonlethal mutants that lack the checkpoint function. This screen has identified 25 primary mutants that are sensitive to genotoxins namely HU and MMS. Among these mutants, mutant ssb1-20 stood out for its unique response to genotoxins. The mutant cells significantly elongate in the presence of HU. In this study, we examined the cellular response of ssb1-20 to HU, MMS, and other DNA-damaging agents at different doses and various exposure times. Our results demonstrated that ssb1-20 exhibits a significantly increased cell elongation phenotype than wild-type cells when subjected to the treatment with HU, but not with the DNA-damaging agents. This observation suggests a unique response of the ssb1-20 mutant to the HU-induced stress. Further investigation is needed to understand the underlying molecular mechanisms. Overall, our study unveils the unique cell elongation phenotype of ssb1-20 in HU and suggests a novel function of RPA in the maintenance of genomic stability in eukaryotes.
Page Count
59
Department or Program
Department of Pharmacology and Toxicology
Year Degree Awarded
2024
Copyright
Copyright 2024, all rights reserved. My ETD will be available under the "Fair Use" terms of copyright law.
ORCID ID
009-0009-7305-0555
