Date of Award


Publication Type

Master Thesis

Degree Name



Biological Sciences


cell cycle, CRISPR, cyclin B1, mitosis, Tuberin, Tuberous Sclerosis


Lisa A. Porter


Elizabeth Fidalgo da Silva




Tuberous Sclerosis is a genetic disorder that causes benign tumours to form in the kidneys, brain, skin, and other organs. This disease is caused by inactivating mutations in either the TSC1 or TSC2 gene encoding for Hamartin and Tuberin, respectively. Mechanistically, Hamartin and Tuberin form a tumour suppressor complex by negatively regulating the mTORC1 pathway and inhibiting protein synthesis. Our lab has characterized how Tuberin regulates the G2/M transition through binding to and controlling the localization of Cyclin B1 (Cyc B1). We have determined that phosphorylation of five key residues in the cytoplasmic retention sequence (CRS) of Cyc B1 decreases this binding interaction and permits the accumulation of Cyc B1 in the nucleus and mitotic onset to occur. We have developed two fluorescent systems to monitor the regulation of mitotic onset by the Tuberin/Cyc B1 complex; Cyc B1 GFP tagged CRS variants and a fluorescent HEK-293 cell line which contains an iRFP 720 tag inserted into the genomic DNA at the amino terminus and carboxy terminus of Tuberin. These tools will be fundamental in studying the formation of this protein complex and the role of Tuberin in other cellular pathways.