RhoGTPases as Key Players in Mammalian Cell Adaptation to Microgravity

Figure 2

RhoGTPase actions on the cytoskeleton and cell dynamics (modified from [14]). Integrins are necessary for translating the mechanical properties of the extracellular environment into intracellular RhoGTPase-signaling pathways. RhoA influences filopodia formation and focal adhesion assembly and maturation, in addition to controlling stress fiber formation and intracellular tension. Rac1 primarily controls actin assembly and formation of lamellipodia to ensure cell migration. Fibrillogenesis is controlled positively by RhoA and negatively by Rac1. Both RhoA and Rac1 are controlled by specific activators (GEF) and inhibitors (GAP, GDI). Cell adaptation to mechanical/gravitational challenges triggers activation of pathways integrated by RhoGTPases.