Light-sensing structure steers algae to safety

A photoresponsive protein that modulates molecular motors in single-celled algae can direct the cells to swim away from damagingly bright light.

Organisms from algae to humans produce cells covered with beating hair-like structures called flagella or cilia. These structures provide motion to single cells and drive fluid flow in multicellular structures such as the lining of our airways. Flagella and cilia motion is driven by molecular motors called dyneins.

Now, an team led by researchers at Tsukuba University in Japan has found that a dynein-associated protein called DYBLUP can directly control motor activity in response to light. Strong blue light slows the beating of flagella on the illuminated side of unicellular green algae, thereby steering the organism away from damaging light exposure. This light-avoiding behaviour is lost in cells that lack DYBLUP.