Investigating how actomyosin contractility damages DNA (360G-Wellcome-211979_Z_18_Z)

DNA damage can lead to deleterious mutations, cell death, and is a driver of diseases such as cancer. Although exogenous sources, such as radiation, have long been characterized as DNA damaging agents, we have recently discovered that in normal cells, DNA is also damaged during normal DNA synthesis; leading to cell cycle arrest mediated by the Cyclin Dependent Kinase Inhibitor p21 (p21WAF1/CIP1, CDKN1A) (Barr et al., Nature Communications 2017; Heldt et al., PNAS 2018). The mechanism behind this damage is not clear, but a number of recent studies suggest that mechanical forces, including those generated by the cell's own actomyosin contractile machinery, can damage DNA. Actomyosin contractility is a key regulator of cell shape, and is particularly high when cells are attached to stiff matrices such as in bone or fibrotic tissue, or when cultured on stiff tissue culture plastic. We will determine if actomyosin contractility, generated by the cell’s own cytoskeleton, causes DNA damage during S-phase during proliferation. The student will monitor DNA damage in living single cells during by imaging the dynamics of endogenously tagged p21 after manipulating actomyosin contractility using chemical or bioengineering approaches. This work will provide new insights into the source of endogenous DNA damage.