Fig. 6: Importins α/β inhibit TPX2 condensation and activity.

a Epifluorescent images of TPX2-tubulin co-condensates (green and magenta, respectively) in vitro prepared with importins-α/β at indicated excess (0 × = no importins-α/β) TPX2 and tubulin both at 500 nM. Scale bar, 1 µm. b TIRF Images of TPX2-mediated MT nucleation in Xenopus meiotic cytosol with TPX2 and importins-α/β added at 100 nM TPX2 and indicated excess of importins-α/β. Cy5-labeled tubulin (red) and mCherry-EB1 (green) highlight microtubules and growing microtubule plus ends, respectively. Images taken at 1800 s. Scale bar, 10 µm. See Supplementary Movie 9. c Quantification of data in b. d Quantification of relative tubulin signal (partition coefficient) as a function of excess importins-α/β. Mean values (points) with ± 1 SD as error bars are shown, n = 522 and 420 condensates for 0× and 1× importins-α/β, respectively. e Rate of MT nucleation as a function of excess importins-α/β, normalized to 0× importins-α/β. Data pooled from three experimental replicates of (b, c). Line of best fit shown. Source data are provided as a Source Data file.