Figure 7. SEC16A mutant with the phosphomimetic S846D overcomes the defect in ER-to-Golgi trafficking and prevents activation of the UPR in ULK-deficient cells.
(A) Mean percentages (±SEM) of cells with nuclear staining of CHOP. Data were acquired from 3 independent experiments, and more than 100 GFP+ cells per population were scored in each experiment. *P <0.001 (ANOVA) when compared with empty vector-transduced cells. (B) Representative pseudocolored images of WT and Ulk1-ko MEFs transfected with indicated GFP-tagged cargo [i.e, (−), empty vector; VSVG-GFP or SERT-GFP] stained with an antibody against CHOP and DAPI. Scale bar: 10 μm. (C) Mean percentages (±SEM) of cells with nuclear staining of CHOP. Data were acquired from 3 independent experiments, and more than 100 GFP+DDK+ cells per population were scored in each experiment. *P <0.001 (ANOVA) when compared with empty vector- transduced cells. SA: S846A SEC16A mutant; SD, S846D SEC16A mutant. (D) Representative pseudocolored images of MEFs stained with antibodies against MYC-DDK-tagged SEC16A (channel not shown) and CHOP and DAPI. Scale bar: 10 μm. See also Figure S7.