Principles that govern competition or co-existence in Rho-GTPase driven polarization
Speaker:
邱澗庚 （Jian-geng Chiou)
Time:
08/19 (Sat.) 15:00 PDT, 16:00 MDT, 17:00 CDT, 18:00 EDT
08/20 (Sun.) 06:00 Taiwan
Link:
Join the talk on BlueJeans: https://bluejeans.com/6366170552/
Rho-GTPases are master regulators of polarity establishment and cell morphology. Positive feedback enables concentration of Rho-GTPases into clusters at the cell cortex, from where they regulate the cytoskeleton. Different cell types reproducibly generate either one (e.g. the front of a migrating cell) or several clusters (e.g. the multiple dendrites of a neuron), but the mechanistic basis for uni-polar or multi-polar outcomes is unclear. The design principles of Rho-GTPase circuits are captured by reaction-diffusion models based on conserved aspects of Rho-GTPase biochemistry. Some such models display rapid winner-takes-all competition between clusters, yielding a unipolar outcome. Other models allow prolonged co-existence of clusters. We derive a “saturation rule” general to all relevant models that governs the timescale of competition, and thereby predicts whether the system will generate uni-polar or multi-polar outcomes. We suggest that the saturation rule is a fundamental property of the Rho-GTPase polarity machinery, regardless of the specific feedback mechanism.
