Ordered bulk degradation via autophagy.
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?
Dengjel
Jörn
J
Center of Experimental BioInformatics, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark. dengjel@bmb.sdu.dk
Kristensen
Anders Riis
AR
Andersen
Jens S
JS
D000596:Amino Acids / Q000378:metabolism*; D001343:Autophagy; D045744:Cell Line, Tumor; D003600:Cytosol / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007553:Isotope Labeling; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D040901:Proteomics; D012270:Ribosomes / Q000378:metabolism
D000596:Amino Acids; C477012:MAP1LC3A protein, human; D008869:Microtubule-Associated Proteins; D011506:Proteins; D049452:Green Fluorescent Proteins; D046988:Proteasome Endopeptidase Complex