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.