A tug of war between filament treadmilling and myosin induced contractility generates actin ring

• DOI: 10.1101/2021.06.06.447254
• Publication Date: 2021-06-07T08:10:36Z
• Authors: Qin Ni; Kaustubh Wagh; Aashli Pathni; Haoran Ni; Vishavdeep Vashisht; Arpita Upadhyaya; Garegin A. Papoian
• Keywords: Treadmilling; Actin remodeling

In most eukaryotic cells, actin filaments assemble into a shell-like cortex under the plasma membrane, controlling cellular morphology, mechanics, and signaling. The is highly polymorphic, adopting diverse forms such as ring-like structures found in podosomes, axonal rings, immune synapses. biophysical principles that underlie formation of rings cortices remain unknown. Using molecular simulation platform, called MEDYAN, we discovered varying filament treadmilling rate myosin concentration induces finite size phase transition actomyosin network structures. We networks condense clusters at low rates or high but form cortex-like concentration. This mechanism supported by our corroborating experiments on live T which exhibit upon activation stimulatory antibody. Upon disruption enhancement activity, pre-existing are disrupted collapse towards center respectively. Our analyses suggest structure preferred state mechanical energy, is, importantly, only reachable sufficiently rates.