Fig. 2: CHMP2B-ΔC and CHMP2A-ΔC/CHMP3 essentially assemble on positively curved tubes.

a HS-AFM image of CHMP2B-ΔC rings on a flat, non-deformable SLB. The quantification of ring diameters is shown. b Confocal images corresponding to a GUV fusion experiment in which CHMP2B-ΔC is exposed to a geometry (iv) induced by the I-BAR domain of IRSp53 (non-fluorescent), tubulating the membrane when present on the exterior of the GUV. N = 7. Scale bar: 10 µm. c Confocal images corresponding to a GUV fusion experiment in which CHMP2A-ΔC + CHMP3 are binding in geometry (iii). CHMP3 is unlabeled. Left GUV: tube diameter = 65 nm. Right GUV: tube diameter = 23 nm. Scale bars: 10 µm. d Confocal images corresponding to a GUV fusion experiment in which CHMP2A-ΔC + CHMP3 are binding in geometry (iv), showing the affinity of the assembly for internal positively curved tubes. Scale bar: 10 µm. e Left: Confocal images corresponding to a GUV fusion experiment in which CHMP2A-ΔC + CHMP3 are binding in geometry (ii). CHMP3 is unlabeled. Scale bar: 10 µm. Right: Quantification of the sorting ratio for 24 nanotubes of variable diameters from 25 GUVs in 9 independent GUV preparations. For each nanotube diameter, N measurements have been performed: <20 nm: N = 20; 20–40 nm: N = 74; 40–60 nm: N = 41; 60–80 nm: N = 6; >80 nm: N = 4. Center line: mean, box limits: SD. The red dashed line corresponds to a sorting ratio equal to 1. Scale bar: 10 µm. f Cryo-EM image of CHMP2A-ΔC/CHMP3 filaments polymerized outside deformable membrane nanotubes. Top: Raw image, Below: Guide for the eyes. Scale bar: 50 nm. g Cryo-EM image of CHMP2A-ΔC/CHMP3 filaments polymerized outside non-deformable GlaCer tubes. Top: Raw image, Bottom: Guide for the eyes. Scale bar: 50 nm. a, e Source data are provided as a Source Data file.