Roman Avanesyan
We have created computational model of actin polymerization with force calculations. Formin localizes to the barbed end of actin filaments and the process occurs with transitions of energy between formin deformation states. Myosin pulling forces applied on barbed end and on the filament which causes polymerization at barbed end and depolymerization at the pointed end. Formin-tipped, elongating actin filaments which flow backwards in unison. In vitro motility assay with myosin immobilized on surface and propelling actin movement. The main goal of this work that we created the model in which we have turning over of actin filament, so we can observe process during long time and also we have maintenance of tension for long time.
Actin filament treadmilling by monomer addition at the barbed end (right) and monomer loss at the pointed end (left). Filament undergoes 1-D Brownian motion and some monomers are colored yellow to serve as fiduciary marks. |
Force driven actin treadmilling occurs as bound myosins (blue) generate and through the attached monomers (green) transmit force to the optically trapped formin dimer (red). Tension deforms the formin into an open state (red/yellow) which allows for barbed-end monomer addition. Actin filament movement towards the pointed ends (right) allows myosin motors to detach (cyan) and complete their hydrolysis cycle. |
