Fig. 5: Loss of PGRMC1 causes mutant proinsulin accumulation at a defined ER subdomain.

a HEK 293 T cells expressing A16P-Myc and either FLAG-ERLIN1 or FLAG-PGRMC1 were subjected to FLAG IP as in Fig. 2f. N = 3 independent experiments. b COS-7 cells expressing A16P-Myc and co-transfected with either scrambled, PGRMC1, RTN3, or Beclin1 siRNA were fixed, stained, and imaged by confocal microscopy. N = 3 independent experiments. c Quantification of b in which A16P-Myc puncta that are >0.2 μm are scored; each condition represents at least 50 cells per experiment, N = 3 independent experiments. Data are represented as mean ± SD. One-tailed Standard Student’s t-test was used to determine statistical significance. From left to right, corresponding p-values are: <0.002, <0.005, <0.002. d–f COS-7 cells expressing A16P-Myc or FLAG-NHK were treated with siRNA against Beclin1, fixed, stained, and imaged by confocal microscopy. N = 3 independent experiments. *P ≤ 0.05; **P ≤ 0.005. Source data are provided as a Source Data file. See also Fig. S4.