Advisor(s)
Hui-Ting Lee
Committee Member(s)
Aaron Lucius
Alexa Mattheyses
Fengbin Wang
Jun Zhang
School
College of Arts and Sciences
Document Type
Dissertation
Department (new version)
Chemistry
Date of Award
9-11-2025
Degree Name
Doctor of Philosophy (PhD)
Abstract
In eukaryotes, the telomere serves as a safeguard against DNA damage and loss during replication and other events. To do so, telomeric DNA folds into a variety of protective secondary and tertiary structures whose formation and conformational dynamics have not been well characterized. We have identified a slow conformational rearrangement in telomeric single stranded DNA that results in a G-Quadruplex (G4) that cannot be unfolded by a complementary strand. We have also determined how the accessibility of G4 forming sequences changes in response to different high K+ environments, which may have implications on how the nascent telomeric overhang interacts with proteins and telomerase. The telomeric overhang can also interact with its own duplex to form a Telomeric Loop (T-loop). However, the molecular mechanism of T-loop formation has not been solved, as techniques to track T-Loop formation have been limited. In this dissertation, we have developed a novel system to study the dynamics of TRF2-induced T-Loop formation at the single molecule level. This system allows us to study telomeric model DNAs that detect aspects of T-loop formation such as overhang unfolding by TRF2 and overhang looping to the upstream telomeric dsDNA. Beyond studying the dynamics of a single telomere, it is important to study the movement of chromatin as a whole. Understanding the dynamics governing the accessibility of chromatin overall is crucial for insight into mechanisms of gene regulation, DNA replication, and cell division. Extensive research has been done to track chromatin dynamics to explain how cells function and how diseases develop, in the hope of this knowledge leading to future therapeutics utilizing proteins or drugs that modify the accessibility or expression of disease-related genes. In our work, we present a selection of recently developed methods of chromatin tracking and their applications in fixed and live cells. This dissertation overall presents an in-depth look at the folding and unfolding pathways of telomeric DNA at different structural levels in response to cation environments, TRF2 and well as a review into methodologies to track chromatin on a cell wide basis.
ProQuest ID
Recommended Citation
Lacen, Arianna, "Analysis Of Telomeric Conformational Dynamics At The Single Molecule Level" (2025). All ETDs from UAB. 7387.
https://digitalcommons.library.uab.edu/etd-collection/7387
