Gelsolin/GSN Proteins and Enzymes

Gelsolin is a calcium regulated actin binding protein. Gelsolin is a regulator of actin filament assembly and disassembly and consists of six homologous subdomains (S1-S6). When C-terminal tail (S6) is bound to calcium ion, it straightens and exposes actin binding sites located on S2s helices, leading to Gelsolin actin-serving activity (1). Gelsolin is inhibited by phosphatidylinositol (4,5)-bisphosphate (PIP2), where PIP2 will bind to S1, S2, and S3 sites. Gelsolin is involved in podosome formation and has been linked to inhibition of apoptosis by preventing release of cytochrome C (2).