Zachary Sun

Zachary Gao Sun ‘25

(he/him)

Home Department: Physics (Murrell Lab)

Research Project: F-actin architecture governs self-organized criticality in the cytoskeleton

Self-Organized criticality (SOC) is observed across diverse natural phenomena, including earthquakes, avalanches, and landslides. These critical phenomena are often accompanied by cascading dissipative events. During complex behaviors of the cell such as migration and division, the F-actin cytoskeleton undergoes dramatic changes in structure, organization, and dynamics. To explore criticality in the dynamics of the cytoskeleton, we reconstruct an experimental model of the cytoskeleton in vitro, composed of purified protein polymers (F-actin) and motors (myosin II), in which the organization and activity of the proteins are controlled precisely.  We find that without regard to organization, the accumulation of stress is slow, but relaxation is dramatic, as marked by high dissipative events.  

Relevant Publications

Camelia G. Muresan*, Zachary Gao Sun*, Vikrant Yadav, A. Pasha Tabatabai, Laura Lanier, June Hyung Kim, Taeyoon Kim, and Michael P. Murrell. (2022) F-actin architecture determines constraints on myosin thick filament motion

Zachary Gao Sun, Vikrant Yadav, Sorosh Amiri, Wenxiang Cao, Enrique M. De La Cruz, and Michael Murrell. (2024) Cofilin-mediated actin filament network flexibility facilitates 2d to 3d actomyosin shape change

Sheng Chen, Zachary Gao Sun, and Michael P Murrell. (2022) In vitro reconstitution of the actin cytoskeleton inside giant unilamellar vesicles

Sun, Z. G., & Murrell, M. (2024). Cofilin-Mediated Filament Softening and Crosslinking Counterbalance to Enhance Actin Network Flexibility.