ELUCIDATING THE ROLE OF AAA-ATPASE VPS4 IN CYTOKINETIC ABSCISSION

The ESCRT machinery (composed of 5 subfamilies: 0, I, II, III and VPS4) is designated as a system for membrane fission within the cell. During cytokinesis, the last step of cell division, the ESCRT machinery mediates the cutting of the intercellular membrane bridge that connects two daughter cells. Abscission occurs immediately after accumulation and arrangement of ESCRT-III and the AAA-ATPase VPS4 at the bridge .The mechanism for ESCRT-driven membrane fission is unknown. ESCRT-III and VPS4 are the minimal, evolutionary conserved complex essential for fission. ESCRT-III proteins self-assemble into cortical filaments on membranes and VPS4 can remodel and disassembly ESCRT-III filaments. Understanding the role of VPS4 (A+B), the only energy source within the ESCRT system, is crucial for unlocking the mechanism by which the ESCRT machine remodels and cut membrane. Therefore, in this study we intend to shed more light about each one of VPS4 isoforms by monitoring abscission in VPS4 KO (knock out) cells using advanced techniques.