Cell cycle remodelling during human embryonic stem cell differentiation
File(s)
Author(s)
Padgett, Joseph
Type
Thesis
Abstract
The cell cycle is a highly coordinated series of events that leads to the duplication and segregation of the cells’ DNA into two daughter cells. While the molecular and mechanistic details of cell cycle regulation have been well studied in proliferating, somatic cells, the cell cycle is context-dependent on the specific cell type. How cell cycle networks adapt and change in different contexts is a fundamental, unanswered question. Human embryonic stem cells (hESCs) are a great system to address this question. In their pluripotent state, hESCs are highly proliferative and undergo rapid cell division cycles. The cell cycle of hESC is characterised by truncated gap phases, high activity of cyclin dependent kinases and low levels of CDK inhibitor proteins. Upon differentiation the cell cycle undergoes a remodelling process whereby fully formed gap phases are formed along with the establishment of precise checkpoint control. Here, we have combined advanced live cell imaging of hESC with cell cycle biosensors and computational analyses to monitor cell cycle remodelling at a single cell level during BMP4-driven differentiation of hESCs. By tracking single cells through several lineages, we have quantitatively characterised changes in cell cycle dynamics and the key role of CDK2 during this transition. We see that hESCs exhibit three levels of CDK2 levels: high, intermediate and low. During pluripotency, CDK2 is characterised by a unique, high activity dynamics and as cells undergo differentiation, CDK2 activity lowers to medium or low levels and becomes cyclic. We further show that maintenance of the CDK2 high state requires the synergistic activity of the ubiquitin ligase components Skp2 and Cdh1...
Version
Open Access
Date Issued
2023-04-26
Date Awarded
01/12/2023
License URL
Advisor
Santos, Silvia
Publisher Department
Institute of Clinical Sciences
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)