Migration component dynamics in epithelial cell motility

• Kritika Sahni
• Dmytro Kotsur
• Galiya Sakaeva
• Georg Dreissen
• Julian Mattes
• Bernd Hoffmann
• Rudolf Merkel

Cell migration is a fundamental process in development and maintenance of multicellular organisms. A coordinated assembly and release of focal adhesion complexes has been reported to be crucial for harmonious cellular movement. Actin and myosin IIA are pivotal components of the cytoskeletal network that work in accord with each other, to facilitate directed cellular movement. In this study, we have analyzed distribution kinetics of vinculin in nascent FA, mature FA and focal complexes at cell rear. We have also inspected the kinetics of actin and non-muscle myosin IIA in different types of stress fiber structures of EGF stimulated primary human epidermal keratinocytes, using a photo-transformable fluorescent tag, Dendra2. Different focal adhesion complexes have implied varied vinculin exchange kinetics depending on their location in a polarized cell, indicating divergent levels of front-rear FA kinetics. We have also scrutinized the dynamics of actin and myosin in transversal arcs and ventral stress fibers. Actin polymerization into the ventral stress fiber appears to depends on the retrograde actin flow from the retraction tails behind the cell. However, Myosin IIA in this fiber depicts an affinity dependent exchange along the F-actin filament. Actin in transversal arcs show no significant turnover, whereas myosin dynamics was seen to be higher in these stress fiber structures. Our data therefore reflects the dynamics of prime cell migration components and indicates a location dependent molecular kinetics in polarized cell motility.