Brian Burkel used a photo-activatable version of a probe that binds to active Rho to measure the dynamics of Rho turnover within the lifetime of a wound-healing response in frog oocytes.  The wound-healing response repairs the cell cortex in the minutes following a plasma membrane breach, which in this case was induced with a focused laser.  The basis of the wound-healing response is the local activation of actin assembly and myosin recruitment, creating a “wound array” which constricts rapidly around the wound site.  The Rho-family small GTPases control the spatial patterning of actomyosin organization.

Brian’s data, depicted here in an animation which first shows the time-lapse video and then a kymocube rendering thereof, showed that there are significant differences in the Rho turnover rate from the leading edge of the wound array (where Rho turnover is slower) to the immediate periphery.  In addition, the turnover rate slows as the wound response develops and closes over the breach.

— text by George von Dassow