Fig. 4: Modeling of the tension-biased regulation of nucleus-cytoplasmic volumetric coupling.
a Scatter plot representing different nucleus-cytoplasm volumetric coupling relationships (variations of nuclear volume as a function of cytoplasmic volume, normalized to resting values) in hyperosmotic shock (green, n = 13), detachment (yellow, n = 20) and spreading (orange, untreated cells, n = 40) experiments (mean ± SE). Here, time progression is coded with a color gradient (from light to dark). The green and orange solid lines are predictions from the theoretical model with parameter values: 20% fraction NLS/NES proteins (in the absence of applied tension), and an external tension-transport bias of 4·103 m/N (estimated from ref. 31). The orange line is a prediction for a variation of the tension caused by external forces σext from 0 to 10−4 N/m. Reference cytoplasmic volume (for the model) VC = 2000 µm3, reference nuclear volume VN = 354 µm3. b Sketch of the theoretical model. Here, πc and πn represent the oncotic pressure of the cytoplasm and the nucleus, respectively, while sigma is the NE tension (c) Scatter plot of the mean value of nucleus to cytoplasm ratio of the GFP-NLS mean intensity in function of the inverted FRET index (mean ± SE) in the different condition considered. Number of cells analyzed per conditions (GFP-NLS ratio/iFRET index): Ctrl 58/156, ivermectin 44/85, y compound 44/119, suspended 39/91, latrunculin 45/129. Source data are provided as a Source Data file. “n” represents the number of cells examined over at least three independent experiments.
