Fig. 4.

Wild-type SPOP suppresses, while the prostate cancer-associated mutants of SPOP enhances stress granules formation. a Representative immunofluorescence images of C4–2 cells transfected with indicated plasmids, treated with DMSO (upper panel) or AS (100 μM, 2 h) (lower panel) stained with SPOP(HA), Caprin1, EIF4G and DAPI. Scale bar, 20 μm. b SGs in (a) were quantified by defining a SG index (SG area/cell area) based on eIF4G immunofluorescence. Data are presented as arbitrary units (A.U.). Data are shown as means ± SD (n = 3) in which about 10 cells were quantified. c Representative immunofluorescence images of SPOP ^F102C MEFs, treated with AS (100 μM, 2 h), stained with G3BP1 and PABP. Scale bar, 20 μm. d SGs in (c) were quantified based on G3BP1 immunofluorescence. (e Western blot of indicated proteins in WCLs and co-IP samples of IgG or anti-G3BP1 antibody obtained from the cell extracts of C4–2 cells stably overexpressing EV, SPOP-ΔNLS or SPOP-F133 L