Gelsolin regulates the actin cytoskeleton and membrane signaling

Gelsolin C (red) and polymerized actin (green) in a fibroblast.

Gelsolin is a key player in the regulation of the actin cytoskeleton in life and death. It is regulated by Ca2+ and PIP2 to sever the actin scaffold, and it is activated by caspase cleavage during apoptosis. Overexpression of gelsolin modulates membrane signaling . 

Using multiple biophysical approaches, we probed the mechanisms by which Ca2+ and PIP2 regulate gelsolin interaction with actin, and identified several PIP2 binding sites. 

We now want to know how gelsolin and gelsolin-like proteins behave in living cells. We are developing a fluorescence energy transfer reporter to monitor gelsolin activation in live cells.