Fig. 5: Actin cytoskeleton disruption impairs PIEZO2- but not IDR5^del-mediated membrane indentation-evoked currents.

a Example traces of poking-evoked PIEZO2 (left) and IDR5^del (right) whole-cell currents recorded under the indicated conditions. b Displacement-responses curves of peak current amplitudes of PIEZO2 (left) and IDR5^del (right) in the absence (control) or after treatment with Cytochalasin-D (15 min, 1 µM). Displacement-responses curves of peak current amplitudes of PIEZO2 and IDR5^del in the absence (control) or in the presence of Nocodazole (30 min, 1 µM) (d) or Jasplakinolide (1 h, 200 nM) (c). For b–d symbols are mean ± s.e.m. Comparison of treated vs. untreated cells using Mann–Whitney test: P-Values for PIEZO2-Ctl vs PIEZO2-Cyto-D (from left to right): *0.047, *0.019, **0.009, **0.004, ***0.0009. N-numbers of cells per group are indicated in respective graph legend. Representative example traces of pressure-evoked currents recorded at -100mV in the cell-attached mode from untreated (control, left), Cytochalasin-D treated (middle) and nocodazole treated (right) N2a cells expressing PIEZO2 (e) and IDR5^del (f) as well as comparison of the proportions of cells responding to stretch under the respective conditions. Fisher’s exact test, PIEZO2-control vs Cytochalasin-D *p = 0.0441. N-number of cells are indicated in the graph. Pressure-responses curves of PIEZO2 (g) and IDR5^del (h) mediated pressure-evoked currents recorded in the indicated conditions. Symbols represent means ± s.e.m., which were compared using the Kruskal–Wallis test. N-number of cells per group is indicated in the graph legend. i Cartoon depicting the possible gating mechanisms of PIEZO2 in the pressure-clamp and the poking assays. Negative pressure applied to cell-attached patches (suction, left) stretches the membrane and supposedly activates PIEZOs by force-from-lipids. Poking of the cell surface with a fire-polished glass pipette inevitable causes both, stretch and cytoskeletal movements. Hence, in this configuration PIEZOs might be activated by (1) force-from-lipids, (2) by forces directly transmitted to channel by the cytoskeleton (force-from-filament), or (3) the cytoskeleton might relay forces to the membrane such that PIEZOs are eventually gated by membrane stretch (force-from-lipids-via-filament). Source data are provided as a Source Data file.