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Publication Date
2025-06-25
Type
doctoral thesis
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Citation
Abstract
DNA in cells is subject to various exogenous and endogenous damaging agents, each capable of introducing harmful mutations to the DNA sequence. To counteract DNA damage, cells have evolved multiple signalling pathways aimed at preserving genomic stability. The ATR kinase plays a crucial role both in the DNA damage response (DDR) and in DNA replication stress response (RSR). Its critical role in regulating DNA replication explains why ATR is essential for cellular viability. Furthermore, mutations in ATR have been implicated in several human diseases, including Seckel Syndrome (SS) and cancer.
Recent advancements in cryo-electron microscopy have enabled detailed structural studies of the ATR protein complex. Comparative analysis with its yeast homolog, Mec1, which has higher resolution structures, has further elucidation ATR activation. Our analysis of the ATR primary sequence and molecular dynamic simulations of the ATR complex have provided further insights into ATR structure and function.
In particular, we have focussed upon the effects of two non-Seckel ATR mutations on ATR structure and function. Specifically, our analysis of the ‘Indiana’ mutation (ATR-Q2144R), a cancer-predisposing variant, suggests that this mutation results in abrogation of kinase activity via allosteric inhibition. Additionally, we have investigated the ‘Cleveland’ mutations (ATR-D47V), a mutation within the linker connecting HEAT repeats 1 and 2, and shown this mutation impairs ATR’s interaction with its partner protein, ATRIP, thereby diminishing ATR signalling.
Our findings underscore the significant impact of emerging non-Seckel missense mutations in ATR, that impair its function. Furthermore, this study highlights the advantages of integrating in silico modelling with in vivo and in vitro biochemical approaches to advance our understanding of ATR function and its role in maintaining genome integrity.
Publisher
University of Galway
Publisher DOI
Rights
Attribution-NonCommercial-NoDerivatives 4.0 International