Ordered bulk degradation via autophagy

• Published in: Autophagy 2008-11, Vol.4 (8), p.1057-1059
• Main Authors: Dengjel, Jörn, Kristensen, Anders Riis, Andersen, Jens S.
• Format: Article
• Language: English
• Subjects: Amino Acids - metabolism; Autophagy; Binding; Biology; Bioscience; Calcium; Cancer; Cell; Cell Line, Tumor; Cycle; Cytosol - metabolism; Green Fluorescent Proteins - genetics; Green Fluorescent Proteins - metabolism; Humans; Isotope Labeling; Landes; Microtubule-Associated Proteins - genetics; Microtubule-Associated Proteins - metabolism; Organogenesis; Proteasome Endopeptidase Complex - metabolism; Proteins; Proteins - metabolism; Proteomics; Ribosomes - metabolism
• ISSN: 1554-8627; 1554-8635
• DOI: 10.4161/auto.6824

During amino acid starvation cells undergo macroautophagy which is regarded as an unspecific bulk degradation process. Lately, more and more organelle-specific autophagy subtypes such as reticulophagy, mitophagy, and ribophagy have been described and it could be shown, depending on the experimental setup, that autophagy specifically can remove certain subcellular components. We used an unbiased quantitative proteomics approach relying on stable isotope labeling by amino acids in cell culture (SILAC) to study global protein dynamics during amino acid starvation-induced autophagy. Looking at proteasomal and lysosomal degradation ample cross-talk between the two degradation pathways became evident. Degradation via autophagy appeared to be ordered and regulated at the protein complex/organelle level. This raises several important questions such as: can macroautophagy itself be specific and what is its role during starvation? Addendum to: Kristensen AR, Schandorff S, Høyer-Hansen M, Nielsen MO, Jäättelä M, Dengjel J, Andersen JS. Ordered organelle degradation during starvation-induced autophagy. Mol Cell Proteomics 2008; In press.