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: Having established that the Snf7 spirals can deform to store significant elastic energy, we wondered if they could release this energy to deform the membrane. After several hours of Snf7 incubation, holes (called “pores” in the following) spontaneously appeared in a few GUVs, releasing membrane tension. Surprisingly, instead of bursting, the GUV membrane shrunk from the rim of the pore toward the opposite side of the GUV (Movie S7). Occasionally, this process stopped before the vesicle had fully collapsed, and stable vesicles with open pores were observed (Figure 6A; Movie S8). In this case, a stronger fluorescence signal is seen at the rim.
Affiliation: University of Geneva, Department of Biochemistry, quai Ernest Ansermet 30, 1211 Geneva 4, Switzerland.