After a decade of new insights into single molecule mechanics, my key interests are now directed towards asking how (a) mechanical forces can alter the structure-function relationship of proteins and (b) whether such force-regulated structural alterations are of physiological significance. Since forces are applied by cells via the transmembrane integrin junctions to the extracellular matrix, my goal is to decipher how the extracellular matrix protein fibronectin, integrins, and cytoplasmic scaffolding proteins that link integrins to the cytoskeleton are functionally regulated by force. Using high performance computational approaches, we will derive with Angstrom precision how their structures are changed when stretched using Molecular (MD) and Steered Molecular Dynamics (SMD). Knowledge how tensile forces alter the structure of proteins is central to develop experimentally testable mechanisms how force might regulate various functions. Experimentally, we will first address how the many different functions of fibronectin are regulated by force. This will involve quantitative studies how the interaction of fibronectin fibers with various serum proteins and growth factors is altered when mechanically strained. Preliminary studies show already that the strain-dependent binding can vary greatly among different serum proteins. We will then investigate whether the stretching and unfolding of extracellular matrix proteins co-regulates cell phenotypes. Finally, understanding the principles of mechanotransduction is not only crucial to gain far deeper insight into how cells work, but new technologies might be derived from these novel insights. Our longer-range goals are thus to develop new technologies that exploit proteins as mechanically regulated switches, from the design and screening of drugs that target mechanically strain proteins, to deriving new design principles how to better engineer tissue scaffolds that exploit mechano-regulated cell-matrix interactions.