Redox Regulation of Nonmuscle Myosin Heavy Chain during Integrin Engagement
Figure 4
Proposed model for the MHC oxidation during fibroblasts adhesion and muscle differentiation. In a rounded cell, where level of ROS are low, both nmMHC and actin are reduced and associated ((a), left). In the early stage of fibroblast adhesion, the engagement of integrin receptors generates a burst of ROS leading to oxidation of nmMHC and decreased its binding with actin ((a), right). It is likely that the redox-dependent nmMHC/actin association is functional to the cytoskeleton dynamics during cell motility. Myotubes, where a stable and static cytoskeletal structure has been formed, are characterized by a low ROS content. In this environment, nmMHC is not redox-regulated and the increased nmMHC/actin association is a redox-independent mechanism that guarantees contraction (b).
