Relaxation of Loaded ESCRT-III Spiral Springs Drives Membrane Deformation.
Bottom Line: We reasoned that Snf7 spirals could function as spiral springs.Furthermore, we observed that the elastic expansion of compressed Snf7 spirals generated an area difference between the two sides of the membrane and thus curvature.This spring-like activity underlies the driving force by which ESCRT-III could mediate membrane deformation and fission.
Affiliation: University of Geneva, Department of Biochemistry, quai Ernest Ansermet 30, 1211 Geneva 4, Switzerland.Show MeSH
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Mentions: AFM images of packed arrays of spirals showed that filaments at the contact zone between spirals were flattened, resulting in spirals acquiring a polygonal shape that was more pronounced for longer incubation times (Figure 5A). Moreover, the central area of some of these polygons was pushed toward the substrate, as seen in the height profile of AFM images (Figure 5B). Also, the centers of these spirals were often found to be stiffer as seen in AFM mechanical maps (Figure 5B). We reasoned that this deformation reflected lateral compression of the spirals as the membrane became covered with Snf7. To study the correlation between polymerization rate and lateral compression of the Snf7 assemblies, we ought to measure them simultaneously.
Affiliation: University of Geneva, Department of Biochemistry, quai Ernest Ansermet 30, 1211 Geneva 4, Switzerland.