Septin 6, also known as SEPT6, is a 434 amino acid protein that belongs to the septin family. The highly conserved septin family of GTP-binding cytoskeletal proteins is implicated in membrane transport, apoptosis, cell polarity, cell cycle regulation, cytokinesis and other cellular functions. Septins polymerize into heterooligomeric protein complexes that form filaments, and can associate with cellular membranes, actin filaments and microtubules. Filaments are assembled from asymmetrical heterotrimers, composed of Septin 2, Septin 6 and Septin 7 that associate head-to-head to form a hexameric unit, however interaction with Septin 12 alters filament structure. Septin 6 shares 40% identity with CDC10 and contains an ATP/GTP-binding site motif. The Septin 6 protein demonstrates nearly ubiquitous expression, with highest level in thymus. The Septin 6 protein is phosphorylated upon DNA damage, probably by Atm or ATR.