Interplay between myosin II and actin dynamics in chemotactic amoeba
Citable Link (URL):http://resolver.sub.uni-goettingen.de/purl?gs-1/17236
The actin cytoskeleton and its response to external chemical stimuli is fundamental to the mechano-biology of eukaryotic cells and their functions. One of the key players that governs the dynamics of theactin network is the motor protein myosin II. Based on a phase space embedding we have identifiedfrom experiments three phases in the cytoskeletal dynamics of starvedDictyostelium discoideuminresponse to a precisely controlled chemotactic stimulation. In thefirst two phases the dynamics ofactin and myosin II in the cortex is uncoupled, while in the third phase the time scale for the recoveryof cortical actin is determined by the myosin II dynamics. We report a theoretical model that capturesthe experimental observations quantitatively. The model predicts an increase in the optimal responsetime of actin with decreasing myosin II-actin coupling strength highlighting the role of myosin II inthe robust control of cell contraction.