Figure 1.
Bap31 is a component of ER quality control compartments. (A) Localization of Bap31 in intact COS-7 cells. Arrows indicate the prominent juxtanuclear accumulation of Bap31. (B) COS-7 cells were treated with dimethyl sulfoxide or 25 μM lactacystin for 5 h (top and second rows) or with 5 μM MG132 for 16 h (bottom row), and stained for Bap31, BiP, or calnexin. (C) COS-7 cells expressing GFP-CFTRΔF508 were incubated with 5 μM MG132 for 8 h, and then they were stained for Bap31. (D and E) COS-7 cells (D) or HeLa cells (E) were incubated with 10 μM lactacystin for 6 h (Lactacystin), for 5.5 h and then plus 10 μM BFA for 0.5 h (Lactacystin→BFA), or for 3 h and then plus 5 μg/ml Noc for 3 h (Lactacystin→Noc), and stained for Bap31 (D) or double stained for Bap31 and ERGIC-53 (E). (F) Control COS-7 cells (left) or cells expressing FLAG-dynamitin (middle and right) were incubated with lactacystin for 6 h, and stained for Bap31 (left) or double stained for Bap31 (middle) and FLAG (right). Bars, 10 μm.