Figure 7.

Agents that raise cGMP increase the degradation of proteins by the UPS, but not by autophagy. Proteins in SY5Y cells were prelabeled with ³H-phenylanine for 20 h to label long-lived cell proteins as described previously [62,64]. Proteasomal degradation reflects the net decrease in total protein breakdown in the presence of the proteasome inhibitor bortezomib. Lysosomal degradation represents the net decrease in the presence of the inhibitor of lysosome acidification concanamycin A (adapted from [16]).