• Register
X
Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

X

Leaving Community

Are you sure you want to leave this community? Leaving the community will revoke any permissions you have been granted in this community.

No
Yes

Mouse Apg16L, a novel WD-repeat protein, targets to the autophagic isolation membrane with the Apg12-Apg5 conjugate.

Macroautophagy is the major intracellular degradation system delivering cytoplasmic components to the lysosome/vacuole. We have shown that, in yeast and mammalian cells, the Apg12-Apg5 protein conjugate, which is formed by a ubiquitin-like system, is essential for autophagosome formation. In yeast, the Apg12-Apg5 conjugate interacts with a small coiled-coil protein, Apg16, to form a approximately 350 kDa multimeric complex. We demonstrate that the mouse Apg12-Apg5 conjugate forms a approximately 800 kDa protein complex containing a novel WD-repeat protein. Because the N-terminal region of this novel protein shows homology with yeast Apg16, we have designated it mouse Apg16-like protein (Apg16L). Apg16L, however, has a large C-terminal domain containing seven WD repeats that is absent from yeast Apg16. Apg16L interacts with both Apg5 and additional Apg16L monomers; neither interaction, however, depends on the WD-repeat domain. In conjunction with Apg12-Apg5, Apg16L associates with the autophagic isolation membrane for the duration of autophagosome formation. Because these features are similar to yeast Apg16, we concluded Apg16L is the functional counterpart of the yeast Apg16. We also found that membrane targeting of Apg16L requires Apg5 but not Apg12. Because WD-repeat proteins provide a platform for protein-protein interactions, the approximately 800 kDa complex is expected to function in autophagosome formation, further interacting with other proteins in mammalian cells.

Pubmed ID: 12665549

Authors

  • Mizushima N
  • Kuma A
  • Kobayashi Y
  • Yamamoto A
  • Matsubae M
  • Takao T
  • Natsume T
  • Ohsumi Y
  • Yoshimori T

Journal

Journal of cell science

Publication Data

May 1, 2003

Associated Grants

None

Mesh Terms

  • Amino Acid Sequence
  • Animals
  • Autophagy
  • Base Sequence
  • Carrier Proteins
  • Cells, Cultured
  • DNA, Complementary
  • HeLa Cells
  • Histone Deacetylases
  • Humans
  • Intracellular Membranes
  • Macromolecular Substances
  • Membrane Proteins
  • Mice
  • Microscopy, Immunoelectron
  • Molecular Sequence Data
  • Molecular Weight
  • Proteins
  • Recombinant Fusion Proteins
  • Repetitive Sequences, Amino Acid
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors