Figure 7A. SG area in mock, TRAPPC2 TRAPPC3, TRAPPC8, and TRAPPC9-depleted cells treated with SA. Data are shown in box-and-whisker plots: Box-plot central line, median; box limits, upper and lower quartiles; whiskers show the minimum to maximum. N=3. ***p<0.001, ****p<0.0001, One-way ANOVA with Dunnett's multiple comparison test. B. HeLa cells microinjected with control IgG or a TRAPPC3-specific antibody (right panels in green) were treated with SA. The TRAPPC3 Ab disrupts the Golgi (Yu et al, 2006), monitored using an anti-TGN46 Ab. Anti-G3BP was used to stain SGs. The graph shows quantification of the SG area. Mean ± s.e.m. three independent experiments; n>80. ****p<0.0001, Student's unpaired two-tailed t-test. Scale bar, 10 µm. C. Structured Illumination Microscopy (SIM)-Super resolution (SR) images of endogenous TRAPPC2 and GFP-Sec23 localizing at SGs, stained for G3BP. Scale bar 5 µm. Right, magnification of boxed area. Scale bar, 0.5 µm. Localization of Raptor (D) in mock, TRAPPC3-KD and TRAPPC2-KD HeLa cells treated with SA. G3BP was used to stain SGs. Scale bar, 10 µm. Each graph shows the quantification (mean intensity) of the respective protein in SG spots expressed as a percentage of the mock (TRL). Mean ± S.D. three independent replicates. *p<0.02; **p<0.009 in (D) , One-way ANOVA with Dunnett's multiple comparison test. Localization of RACK1 (E) in mock, TRAPPC3-KD and TRAPPC2-KD HeLa cells treated with SA. G3BP was used to stain SGs. Scale bar, 10 µm. Each graph shows the quantification (mean intensity) of the respective protein in SG spots expressed as a percentage of the mock (TRL). Mean ± S.D. independent replicates. , *p<0.05; ****p<0.0001 in (E), One-way ANOVA with Dunnett's multiple comparison test. Immunoprecipitation (IP) with an anti-TRAPPC2 Ab or IgG from cells with or without SA treatment, as indicated, followed by SDS-PAGE and Western blot with ant-Raptor (F) Abs. Input: cell lysate (40 µg for TRAPPC2, 10 µg for Raptor). Immunoprecipitation (IP) with an anti-TRAPPC2 Ab or IgG from cells with or without SA treatment, as indicated, followed by SDS-PAGE and Western blot with anti-RACK1 (G) Abs. Input: cell lysate (40 µg for TRAPPC2, 10 µg for RACK1 Localization of Raptor (H) untreated cells or cells pre-treated with the indicated CDK inhibitor (1 µM, 150 min) and then with SA (300 µM, 30 min). G3BP was used to stain SGs. Scale bar, 10 µm. Graphs show quantification of the localization of the respective protein with SGs, expressed as a percentage of the control. Mean ± s.e.m. of one representative experiment out of three independent replicates, n=60-80. ****p<0.0001, One-way ANOVA with Dunnett's multiple comparison test. Localization of RACK1 (I) in untreated cells or cells pre-treated with the indicated CDK inhibitor (1 µM, 150 min) and then with SA (300 µM, 30 min). G3BP was used to stain SGs. Scale bar, 10 µm. Graphs show quantification of the localization of the respective protein with SGs, expressed as a percentage of the control. Mean ± s.e.m. of one representative experiment out of three independent replicates, n=60-80. ****p<0.0001, One-way ANOVA with Dunnett's multiple comparison test. J. Analysis of cell death after overnight recovery of HeLa cells treated or untreated with CDKi (SNS-032; Flavopiridol or Dinaciclib, 1 µM, 150 min) and then treated or not with SA (500 µM, 3 h). Images were acquired automatically by OPERETTA microscope. Values indicate the percentage of the total number of nuclei (stained with DAPI) positive for BoBo-3 staining. Mean ± s.d. of one representative experiment out of three independent replicates. ns: not significant, ****p<0.0001, One-way ANOVA with Dunnett's multiple comparison test. K. Analysis of cell death in HeLa cells that were left untreated, treated with non-targeting siRNAs or siRNAs against TRAPPC2, and in two cell clones knocked out for TRAPPC2, with and without SA treatment. Mean ± s.d. of three independent replicates.