Dissection of Autophagosome Formation Using Apg5-Deficient Mouse Embryonic Stem Cells

• Noboru Mizushima

  aUnit Process and Combined Circuit, PRESTO, Japan Science and Technology Corporation, Kawaguchi 332-0012, Japan

• Akitsugu Yamamoto

  cDepartment of Physiology, Kansai Medical University, Moriguchi 570-8506, Japan

• Masahiko Hatano

  dDepartment of Developmental Genetics, Chiba University Graduate School of Medicine, Chiba 260-8670, Japan

• Yoshinori Kobayashi

  bDepartment of Cell Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan

• Yukiko Kabeya

  bDepartment of Cell Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan

• Kuninori Suzuki

  bDepartment of Cell Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan

• Takeshi Tokuhisa

  dDepartment of Developmental Genetics, Chiba University Graduate School of Medicine, Chiba 260-8670, Japan

• Yoshinori Ohsumi

  bDepartment of Cell Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan

• Tamotsu Yoshimori

  bDepartment of Cell Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan

抄録

In macroautophagy, cytoplasmic components are delivered to lysosomes for degradation via autophagosomes that are formed by closure of cup-shaped isolation membranes. However, how the isolation membranes are formed is poorly understood. We recently found in yeast that a novel ubiquitin-like system, the Apg12-Apg5 conjugation system, is essential for autophagy. Here we show that mouse Apg12-Apg5 conjugate localizes to the isolation membranes in mouse embryonic stem cells. Using green fluorescent protein–tagged Apg5, we revealed that the cup-shaped isolation membrane is developed from a small crescent-shaped compartment. Apg5 localizes on the isolation membrane throughout its elongation process. To examine the role of Apg5, we generated Apg5-deficient embryonic stem cells, which showed defects in autophagosome formation. The covalent modification of Apg5 with Apg12 is not required for its membrane targeting, but is essential for involvement of Apg5 in elongation of the isolation membranes. We also show that Apg12-Apg5 is required for targeting of a mammalian Aut7/Apg8 homologue, LC3, to the isolation membranes. These results suggest that the Apg12-Apg5 conjugate plays essential roles in isolation membrane development.

収録刊行物

• The Journal of Cell Biology

  The Journal of Cell Biology 152 (4), 657-668, 2001-02-12

  Rockefeller University Press

キーワード

• Cell Biology

詳細情報

• CRID: 1360855568838804224
• NII論文ID: 80012508879
• DOI: 10.1083/jcb.152.4.657
• ISSN: 15408140
• ISSN: 00219525
• ISSN: http://id.crossref.org/issn/00219525
• Web Site: https://rupress.org/jcb/article-pdf/152/4/657/1510698/0011086.pdf
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