GATE-16 and GABARAP are authentic modifiers mediated by Apg7 and Apg3.
GATE-16, GABARAP, and LC3 are three mammalian counterparts of yeast Apg8p/Aut7p. Here, we show that GATE-16 and GABARAP are authentic modifiers, as is the case of LC3 modification. The C-terminal Phe(117) of proGATE-16 and the C-terminal Leu(117) of proGABARAP are post-translationally cleaved to expose an essential Gly(116) within GATE-16 and GABARAP, with the products designated GATE-16-I and GABARAP-I, respectively. The Gly(116) within GATE-16 and GABARAP are essential for further formation of the intermediates between them and Apg7p(C572S) and Apg3p(C264S). When Apg7p and Apg3p are expressed, GATE-16-I and GABARAP-I are modified to a secondary ubiquitin-like modified form, GATE-16-II and GABARAP-II, respectively. GATE-16-I and GABARAP-I, but not LC3-I, localize to membrane compartments before their modification. These results indicate that GATE-16 and GABARAP are authentic modifiers, but that they have different biochemical characteristics from those of LC3.
Tanida
Isei
I
Department of Biochemistry, Juntendo University School of Medicine, Tokyo 113-8421, Japan.
Komatsu
Masaaki
M
Ueno
Takashi
T
Kominami
Eiki
E
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D051017:Apoptosis Regulatory Proteins; D000071190:Autophagy-Related Protein 8 Family; D000071183:Autophagy-Related Proteins; D001665:Binding Sites / Q000502:physiology; D016466:CHO Cells; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002451:Cell Compartmentation / Q000502:physiology; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D006224:Cricetinae; D006801:Humans; D008025:Ligases / Q000235:genetics / Q000378:metabolism*; D008840:Microfilament Proteins; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D009842:Oligopeptides; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D010455:Peptides / Q000235:genetics; D011485:Protein Binding / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D044763:Ubiquitin-Conjugating Enzymes
D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; D000071190:Autophagy-Related Protein 8 Family; D000071183:Autophagy-Related Proteins; D002352:Carrier Proteins; C116741:GABARAP protein, human; C498698:GABARAPL2 protein, human; C477012:MAP1LC3A protein, human; D008840:Microfilament Proteins; D008869:Microtubule-Associated Proteins; D009842:Oligopeptides; D010455:Peptides; D011993:Recombinant Fusion Proteins; C085706:FLAG peptide; D010088:Oxidoreductases; D044763:Ubiquitin-Conjugating Enzymes; D008025:Ligases; C455621:ATG3 protein, human