Ordered Organelle Degradation during

Upon starvation cells undergo autophagy, a cellular deg-radation pathway important in the turnover of whole or-ganelles and long lived proteins. Starvation-induced pro-tein degradation has been regarded as an unspecific bulk degradation process. We studied global protein dynamics during amino acid starvation-induced autophagy by quan-titative mass spectrometry and were able to record nearly 1500 protein profiles during 36 h of starvation. Cluster analysis of the recorded protein profiles revealed that cytosolic proteins were degraded rapidly, whereas pro-teins annotated to various complexes and organelles were degraded later at different time periods. Inhibition of protein degradation pathways identified the lysosomal/ autophagosomal system as the main degradative route. Thus, starvation induces degradation via autophagy