Fig. 2: ERES disintegrate in TEPCR2 deficient cells.

a Immunoblot analysis of TECPR2 WT and MUT cells as well as TECPR2 MUT cells re-expressing TECPR2 WT and L440Rfs. PCNA served as loading control. b TECPR2 WT and MUT cells were fixed and immunolabeled with anti-SEC13 or -SEC24C. Nuclei were stained with DRAQ5. Statistical two-sided t-test analysis of normalized SEC24C and SEC13 spots (n = 4 independent experiments). Error bars represent mean ± SEM, p value = 0.00003 and 0.01064 for SEC24C and p value <0.00001 and =0.00846 for SEC13. Scale bars 10 µm. c Immunoblotting of fibroblasts expressing WT or L440Rfs*19-mutant TECPR2. d Fibroblasts were fixed and immunolabeled with anti-SEC13 or -SEC24C. Nuclei were stained with DRAQ5. Statistical two-sided t-test analysis of normalized SEC24C and SEC13 spots (n = 4 independent experiments). Error bars represent mean ± SEM, p value = 0.00001 for SEC24C and p value = 0.00021 for SEC13. Scale bars 10 µm. e TECPR2 WT and MUT cells were fixed and immunolabeled with anti-SEC13 or -SEC24C together with an anti-SEC31A antibody. Insets show magnification of boxed areas. Scale bars 10 µm. Quantification of area overlap SEC13/SEC24C with SEC31A (normalized to WT, two-sided t-test analysis, n = 4 independent experiments, error bars represent mean ± SEM, p value <0.00001 for SEC13 and p value = 0.00699 for SEC24C.). f TECPR2 WT and MUT cells expressing APEX2-SEC13 were subjected to biotinylation followed by lysis and streptavidin pulldown (S-PD). TL, total lysates. TECPR2 WT and MUT cells expressing APEX2-SEC13 (g) or APEX2-SEC16A (h) were subjected to biotinylation followed by lysis and streptavidin pulldown (S-PD). TL total lysates. i Homogenates from TECPR2 WT cells were left untreated or incubated with proteinase K, RapiGest or both. BiP and Tubulin served as controls. Source data are provided as a Source Data file.