Resolving ESCRT-III Spirals at the Intercellular Bridge of Dividing Cells Using 3D STORM

• Main Authors: Inna Goliand, Shai Adar-Levor, Inbar Segal, Dikla Nachmias, Tali Dadosh, Michael M. Kozlov, Natalie Elia
• Format: Article
• Language: English
• Published: Elsevier 2018-08-01
• Series: Cell Reports
• Online Access: http://www.sciencedirect.com/science/article/pii/S2211124718311549

Summary: The ESCRT machinery mediates membrane fission in a variety of processes in cells. According to current models, ESCRT-III proteins drive membrane fission by assembling into helical filaments on membranes. Here, we used 3D STORM imaging of endogenous ESCRT-III component IST1 to reveal the evolution of the structural organization of ESCRT-III in mammalian cytokinetic abscission. Using this approach, ESCRT-III ring and spiral assemblies were resolved and characterized at different stages of abscission. Visualization of IST1 structures in cells lacking the microtubule-severing enzyme spastin and in cells depleted of specific ESCRT-III components or the ATPase VPS4 demonstrated the contribution of these components to the organization and function of ESCRTs in cells. This work provides direct evidence that ESCRT-III proteins form helical filaments to mediate their function in cells and raises new mechanistic scenarios for ESCRT-driven cytokinetic abscission. : The ESCRT complex drives membrane constriction and fission in a variety of process in cells. In this work, Goliand et al. used 3D STORM imaging to resolve the structure of the ESCRT-III complex during abscission of the intercellular bridge connecting two dividing cells, highlighting mechanistic steps in ESCRT cellular function. Keywords: super resolution microscopy, cytokinesis, abscission, ESCRT machinery, membrane fission