Date of Award
5-28-2025
Publication Type
Thesis
Degree Name
M.Sc.
Department
Biological Sciences
Keywords
Proximity-dependent Biotin Identification; Cell cycle; Tuberin; Tumour
Supervisor
Lisa A. Porter
Rights
info:eu-repo/semantics/embargoedAccess
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Abstract
Environmental and nutrient sensing are fundamental processes that have been hardwired into the biology of cells through millions of years of evolution. In mammals, this is clearly seen with highly orchestrated phases of growth and division known as the cell cycle, during which a cell evaluates whether conditions are favorable before progressing to the next stage. The transition between the last stage of growth (G2) into the process of division or mitosis represents a critical window of time for a cell to properly gauge if it has met sufficient size and genomic integrity criteria. Our lab has previously shown that the nutrient sensing protein, Tuberin (encoded by TSC2) modulates the rate of this transition by binding to and restraining the main mitotic cyclin, Cyclin B1 (encoded by CCNB1) with its CDK1 partner within the cytoplasm, functionally delaying their activity in triggering mitosis. Building on these initial observations, we determine that this interaction precipitously rises throughout the course of the G2-phase, and highest at the G2/M checkpoint. We provide interesting insights into the potential compartmentalization sites of this key regulatory protein complex within cells, opening new questions about the mechanisms that regulate this complex in a spatiotemporal context. In addition, when this interaction is perturbed by Tuberin loss-of-function mutations, the regulation seen at this checkpoint is lost leading to aberrant phenotypes and proliferation rates in cells. Finally, CRISPR/Cas9-based approaches developed aim to provide platforms for evaluating the various homeostatic roles Tuberin plays in mammalian cells under endogenous conditions, such as efforts to establish cell lines stably expressing miRFP720 fluorescently labelled Tuberin for live-cell applications. By dissecting the molecular processes underlying Tuberin regulation, this work contributes to a deeper understanding of cell cycle control and cellular homeostasis, with potential implications for uncovering the mechanisms by which proliferative diseases, such as cancer and other tumourigenic conditions arise.
Recommended Citation
Nadi, Ali, "Dissecting the Roles and Dynamics of the Tumour Suppressor, Tuberin, in Cell Cycle Regulation" (2025). Electronic Theses and Dissertations. 9736.
https://scholar.uwindsor.ca/etd/9736