Figure 3. Reversibility of the ERAD defect requires back-transfection of enzymatically active CyPB.

A Down-regulation of CyPB and back-transfections of active or catalytically inactive (R62A) CyPB were assessed by immunoblot of total cell lysates. Tubulin is a loading control. B Radiolabeled BACE457Δ was immunoisolated at the end of the chase times from detergent-extracts of cells expressing normal levels of CyPB (siSCR, lanes 1–3), in cells with reduced level of CyPB (siCyPB, lanes 4–6), in cells with reduced level of CyPB back-transfected with active (siCyPB+CyPB, lanes 7–9) or catalytically inactive CyPB (siCyPB+CyPB_R62A, lanes 10–12). C Quantification of the labeled polypeptide bands. Error bars represent SD from at least two independent experiments.