ACBD5–VAPB coexpression increases PO–ER association. (A–F) COS-7 cells were transfected with Myc-VAPB alone (A) or Myc-VAPB coexpressed with GFP-ACBD5, FLAG-ACBD5, FLAG-ACBD5-AcB, FLAG-ACBD5-FFAT, and GFP-Sec61β (B–F). Myc-VAPB is labeled in red and Pex14/ACBD5 in green, except in F, where ACBD5 is in red (B–D, arrows highlight PO–ER association; A, E, and F, arrows highlight lack of PO–ER association). (G) Quantification of overlap of PO–ER fluorescent signals. Note this analysis has limitations because of the proximity of POs and the ER. αPEX14, PO marker. Data are presented as mean ± SEM. Bars: (main) 20 µm; (insets) 5 µm.