Ordered organelle degradation during starvation-induced autophagy.
Upon starvation cells undergo autophagy, a cellular degradation pathway important in the turnover of whole organelles and long lived proteins. Starvation-induced protein degradation has been regarded as an unspecific bulk degradation process. We studied global protein dynamics during amino acid starvation-induced autophagy by quantitative 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 proteins 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, which appears to be selective and to degrade proteins in an ordered fashion and not completely arbitrarily as anticipated so far.
Kristensen
Anders Riis
AR
Center of Experimental BioInformatics, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, 5230 Odense, Denmark.
Schandorff
Søren
S
Høyer-Hansen
Maria
M
Nielsen
Maria Overbeck
MO
Jäättelä
Marja
M
Dengjel
Jörn
J
Andersen
Jens S
JS
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000172:deficiency*; D001343:Autophagy; D045744:Cell Line, Tumor; D016000:Cluster Analysis; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D008928:Mitochondria / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000032:analysis / Q000737:chemistry; D015388:Organelles / Q000378:metabolism*; D010588:Phagosomes / Q000378:metabolism; D011499:Protein Processing, Post-Translational
D000596:Amino Acids; D009363:Neoplasm Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins