Formation of the ∼350-kDa Apg12-Apg5·Apg16 Multimeric Complex, Mediated by Apg16 Oligomerization, Is Essential for Autophagy in Yeast*

By Akiko Kuma, N. Mizushima, Naotada Ishihara, Y. Ohsumi. Journal of Biological Chemistry, 2002

371 citations recorded by the source corpus.

Autophagy, responsible for the delivery of cytoplasmic components to the lysosome/vacuole for degradation, is the major degradative pathway in eukaryotic cells. This process requires a ubiquitin-like protein conjugation system, in which Apg12 is covalently bound to Apg5. In the yeast Saccharomyces cerevisiae, the Apg12-Apg5 conjugate further interacts with a small coiled-coil protein, Apg16. The Apg12-Apg5 and Apg16 are localized in the cytosol and pre-autophagosomal structures and play an essential role in autophagosome formation. Here we show that the Apg12-Apg5 conjugate and Apg16 form a ∼350-kDa complex in the cytosol. Because Apg16 was suggested to form a homo-oligomer, we generated an in vivosystem that allowed us to control the oligomerization state of Apg16. With this system, we demonstrated that formation of the ∼350-kDa complex and autophagic activity depended on the oligomerization state of Apg16. These results suggest that the Apg12-Apg5 conjugate and Apg16 form a multimeric complex mediated by the Apg16 homo-oligomer, and formation of the ∼350-kDa complex is required for autophagy in yeast.

Subfields: Cell Biology, Epidemiology, Parasitology

View Paper: https://www.semanticscholar.org/paper/59c48377546d307efcfce237c967461b9ed5947e

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Cell Biology

1. D. Klionsky
2. N. Mizushima
3. Y. Ohsumi
4. Zhifen Yang
5. T. Yoshimori
6. Beth Levine
7. A. Yamamoto
8. I. Slaninová

In Epidemiology

1. D. Klionsky
2. N. Mizushima
3. Y. Ohsumi
4. Zhifen Yang
5. T. Yoshimori
6. Beth Levine
7. I. Slaninová
8. A. Yamamoto

In Parasitology

1. D. Klionsky
2. N. Mizushima
3. Zhifen Yang
4. Y. Ohsumi
5. T. Yoshimori
6. Zhiping Xie
7. Kuninori Suzuki
8. Beth Levine

Citations in the corpus

• The Atg8 and Atg12 ubiquitin‐like conjugation systems in macroautophagy (2008, background): “…et al, 1999). the molecular weight of this multimeric complex is approximately 350 kDa and it probably represents a tetramer of atg12–atg5-atg16 (Kuma et al, 2002). although the overall sequence of atg7 shows little similarity to E1 enzymes in yeast, and so far only atg7 has been shown to…”
• Mitochondria supply membranes for autophagosome biogenesis during starvation (2010, background): “Oligomerization of this complex, reported in (Kuma et al., 2002; Mizushima et al., 2003), could then form a coat and expand the initiation site.”
• Autophagy as a cell death and tumor suppressor mechanism (2004, background): “Apg12/Apg5 conjugation reaction occurs just after its synthesis and almost all Apg12 molecules in a cell are found in a conjugated form (Kuma et al., 2002).”
• Atg8 controls phagophore expansion during autophagosome formation. (2008, background): “The formation of this complex itself also involves a conjugation reaction, in which the ubiquitin-like protein Atg12 is attached to Atg5 by Atg7 and the E2-like enzyme Atg10 (Mizushima et al., 1998a,b, 2003; Kuma et al., 2002).”
• Hierarchy of Atg proteins in pre‐autophagosomal structure organization (2007, background): “Subsequently, the conjugate associates with Atg16p to form the Atg12p-Atg5p·Atg16p complex (Kuma et al. 2002).”
• Mouse Apg16L, a novel WD-repeat protein, targets to the autophagic isolation membrane with the Apg12-Apg5 conjugate (2003, methodology): “As a result, Apg12Apg5 and Apg16 form a ~350 kDa protein complex thought to contain four sets of Apg12-Apg5 and Apg16 (Kuma et al., 2002).”