Cell adhesion is key to many important processes such as cell differentiation and migration, which all involve bi-directional signaling across the plasma membrane. At sites of adhesion a large assembly of macromolecules, called focal adhesions, function together in order to orchestrate complex signaling events. It is not yet clear how molecules in focal adhesions communicate with one another causing the signals to be transmitted through their interaction. Cells sense and respond to both chemical and mechanical signals suggesting that individual focal adhesion molecules should act as mechanosensors. Mechanical forces from the extracellular matrix (ECM) are detected by integrin receptors on the plasma membrane and transmitted to actin cytoskeleton through focal adhesions, which is called out-side-in signaling. The reverse process is also possible in which acto-myosin forces are applied to the ECM. Some proteins play key roles in regulating focal adhesions and their function may shed light on the order of events in a certain signaling pathway. Talin, alpha-actinin and filamin are among a few molecules that directly bind to both actin and integrin, and thus focal adhesions are largely affected by their function. It has been shown that talin plays a significant role in integrin activation, which is essential for initiating focal adhesion formation, while filamin inhibits integrin activation. The role of alpha-actinin is somehow controversial, i.e. it is not yet clear whether it inhibits or promotes activation since both observations have been made. We use all-atom molecular dynamics simulations to investigate the role of each of these molecules both in isolation and in competition with one another. Our results reveal how the presence of one molecule would affect the interaction of others suggesting possible cooperative functions in some cases.