Publication Date
2023
Document Type
Thesis
Committee Members
Michael G. Kemp, Ph.D. (Advisor); Ravi P. Sahu, Ph.D. (Committee Member); Yong-jie Xu, M.D., Ph.D. (Committee Member)
Degree Name
Master of Science (MS)
Abstract
The various environmental factors like toxic chemicals, chemotherapeutic agents and UV radiation impact human health by altering physiological functions of the normal living cells. One of the main consequences of exposure to these factors is DNA damage. Although, living system have inherent DNA repair mechanisms such as Nucleotide Excision Repair (NER), which removes DNA lesions from the genome in the form of small, approximately 30-nt-long DNA oligonucleotides. The accumulation of unrepaired DNA adducts as a result of this NER deficiency causes a variety of syndromes, including Xeroderma Pigmentosum (XP), Cockayne Syndrome, Neurological syndrome, and carcinoma of skin. To understand more about NER and to prevent these disorders we need proper experimental/cell line model. Transcription factor II-H (TFIIH) is a ten-subunit protein complex that plays a role in RNA polymerase II (Pol II) transcription initiation and in NER. The excised oligonucleotides released from DNA by NER initially associate with TFIIH and likely specifically with the XPD subunit. To better understand how the excised oligonucleotides bind to and are released from XPD to promote the recycling of TFIIH for new rounds of NER, in this project we characterized an XPD mutant CHO cell line expressing a Flag-tagged human XPD. We found that expression of this protein promoted cellular resistance to UV and other agents that generate DNA adducts repaired by NER and enabled UV photoproduct removal from the genome. However, problems were encountered in detecting the excised oligonucleotide products of NER in these cell lines, and thus various approaches aimed at improving assay conditions. Nonetheless, our results suggest that these cell lines will be useful to characterize XPD function and association with the excised oligonucleotide products of NER.
Page Count
94
Department or Program
Department of Pharmacology and Toxicology
Year Degree Awarded
2023
Copyright
Copyright 2023, all rights reserved. My ETD will be available under the "Fair Use" terms of copyright law.
ORCID ID
0000-0002-5824-7749
