Really excited to explore in the future what this could mean for cells. ROS are everywhere in cells and known to strongly increase actin polymerization. So this relatively simple mechanism could play an important physiological role. [5/5]

We also see this effect with a bacterial actin homolog, ParM …which can lead to more fun patterns. [4/5]

This happens with all labeled actins we tried, but even with unlabeled actin, if we add free fluorophores to our experiments. [3/5]

The mechanism is surprisingly simple: excited fluorophores create ROS, which sever filaments via oxidation, resulting in more filaments. Because actin polymerization is nucleation-limited, more filaments = more polymerization. [2/5]