Characterisation of Ataxia Telangiectasia Mutated in RPE-1 cells and its role in cellular sensitivity to hypo-osmotic stress

Abstract

Maintenance of genome stability is achieved through an integrated cellular network that is critical for normal cell function. This is coordinated in part by the DNA damage response (DDR). Central in this network is the kinase ATM that couples genome surveillance to a plethora of cell biological processes where it co-ordinates DNA repair with cell cycle control and transcriptional regulation. Over recent years, ATM has become implicated in responses beyond DNA damage, with roles in telomere maintenance, oxidative stress, and hypoxia. I first explore an expansive role for ATM in cell migration in both 2D cell migration and in vivo following on from work done by my previous supervisor. Since this avenue of research did nor prove fruitful, I go on to characterise an ATM-deficient RPE-1 cell line showing a distinct nuclear phenotype with abrogated chromatin condensation and altered nuclear lamina. These changes to the nuclear structure also impinge on the cells as a whole, where cells also reveal a stiffer cytoplasm. Given this mechanosensitive response, and the global changes to nuclear architecture seen in ATM-/- cells, this work supports the idea that ATM is not simply a DDR mediator but a protein required for global cell health. Understanding of the roles of such central surveillance proteins has wide-reaching implications in both the maintenance of cellular homeostasis, and in the pathologies which arise upon their dysregulation.

Date of Award	26 Nov 2020
Original language	English
Awarding Institution	University of Bristol
Supervisor	Harry H Mellor (Supervisor) & Will J Wood (Supervisor)