XJ Xu, Yale University

Rhythmic contractility on multiple timescales

RhoA and Cdc42 are two Rho GTPases that play major roles in coordinating actomyosin-driven contractility in animal cells. We describe how periodic and mixed-mode RhoA oscillations with multiple timescales correlate with contractile behavior in mitotic mast cells. The transition between periodic and mixed-mode oscillations is captured with a phenomenological model. Then we show the roles and mechanisms of the phosphoinositide network underlying the RhoA oscillations. Lastly, we discuss the emergence of Cdc42 traveling waves and the associated open questions regarding the collective dynamics of RhoA and Cdc42.