Fig. 3

Cryo-electron microscopy of septins bound to LUVs. a Cryo-EM images of septins bound to vesicles. Stars indicate vesicles with septins bound. Left: flattened vesicles with protrusions. The arrow points to septin networks of filaments. Insert 1: Control without septins, insert 2: After septin addition. Middle: example of a ruptured vesicle. The arrows point at the broken membrane. Right: vesicle covered with an array of parallel filaments. Scale bars = 50 nm, inserts: circular holes of 1 µm in diameter. b Electron cryo-tomography: segmentation within cryo-tomograms of septins bound to vesicles. The membrane is highlighted in yellow. Filaments are modeled in blue. Middle and left image correspond to a vesicle covered with septin filaments. Right image: deformed membrane covered with filaments. Scale bars = 200 nm. c Cryo-tomography of septin filaments around protrusions. Left: slice within a tomogram with the segmentation highlighted in the middle panel. Right: filaments wrapping around a protrusion. Scale bars = 200 nm. d Cryo-tomography of septins rupturing vesicles. Left (slice in a tomogram) and middle (segmentation only): filaments breaking the membrane. Scale bars = 200 nm. Right: filaments inside a vesicle aligning within a protrusion. Scale bars = 100 nm