Focal adhesions under force (360G-Wellcome-210887_Z_18_Z)

Cellular development and function is influenced by the mechanical rigidity of the surrounding environment. A complex of proteins, known as focal adhesions (FAs), form a physical connection between the cytoskeleton and the extracellular matrix, transmitting and transducing mechanical stimuli. Focal adhesion kinase (FAK) is a unique player in this complex that functions as both a scaffolding and signalling protein. Furthermore, FAK can also detach from the FA and shuttle into the nucleus to modulate gene expression. Despite FAK’s physiological importance, the mechanisms that regulate its function remain poorly understood. Here I will investigate how mechanical force alters the function and localization of FAK using a combination of single-molecule and single-cell approaches. I will first test, at the single-molecule level, whether mechanical force perturbs the structure of FAK, switching it into an active conformation (Obj.1). I will then perform cellular experiments to determine whether cellular tension modulates the conformation of FAK, and if this is instrumental in converting forces into biochemical signals. I will then use a combination of single-molecule and single-cell approaches to study whether mechanical unfolding of FAK exposes key residues that can become chemically modified, leading to the translocation of FAK from the cytoplasm into the nucleus (Obj.2).