Fig. 2. In presence of ATP Mg²⁺, VPS4B mediates local constriction (asymmetric) of the CHMP2A-CHMP3 tubes before disassembly.

(A) Clips of HS-AFM images captured at 0.5 frame/s, showing that the 5 μM VPS4B-treated CHMP2A-CHMP3 tubes undergo local constriction before disassembly. The constriction normally appears asymmetric (white arrows), i.e., the deformation starts from one side of the tube. Numbers in circles identify three constriction sites in the two tubes. Scale bar, 100 nm. (B) Kymographs of both tubes [green lines in (A)]. The progress of the constrictions (numbers in circles) is identifiable from the kymograph. (C) The height profiles of the tubes in (A) at nonconstricted site (in black curves) and at the constriction site over time derived from (A) and (B). Each color code is similar to the constriction sites (numbers in circles) in (A) and (B).