Figure S1.

Related to Figure 1

A: Fluorescence images from live-cell time-lapse movies of HeLa cells expressing G3BP1-mCherry filmed with lattice light sheet microscopy (LLSM, bottom) and conventional widefield microscopy (Convent., top). White arrows: intracellular G3BP1 foci. B: Fluorescence images of a LLSM movie of oxidatively stressed HeLa cells expressing G3BP1-mCherry. Time series starts 26 min after exposure to 1 mM sodium arsenate. Inset focuses on late G3BP1-positive SGs. Upon encounter, SGs coalesce with one another. C: Quantification of the number, volume and intensity of G3BP1-positive SGs as a function of time. Quantifications are shown for the mean averages of four time-lapse movies. Standard deviation is shown in gray. D: Fluorescence images of a partial photobleaching experiment of G3BP1-positive SGs in HeLa cells. Images show one granule before, the first frame and 120 s after photobleaching. Quantification shows the normalized mean fluorescence recovery curve (black dots), fit to the data (cyan) and SD (gray), n = 10. E: Still fluorescence images of a photobleaching experiment used to evaluate the internal diffusion of G3BP1 within SGs in HeLa cells (top). Kymograph of the signal intensity of the bleached G3BP1-positive SG as a function of time (x axis) along the SG distance (cyan bar indicated in the still images on top). Recovery of fluorescence occurs from the inside of the SG. F: Fluorescence images of an oxidatively stressed HeLa cell with G3BP1-mCherry SGs. The intact cell was permeabilized and treated with buffer (w/o RNase) or RNase A (w/ RNase). Scale bar 10 μm, except in D where it is 2 μm.