Format

Send to

Choose Destination
Science. 2016 Nov 25;354(6315):1036-1041. Epub 2016 Oct 20.

The ATG conjugation systems are important for degradation of the inner autophagosomal membrane.

Author information

1
Department of Biochemistry and Molecular Biology, Graduate School and Faculty of Medicine, The University of Tokyo, Tokyo 113-0033, Japan.
2
Research Center for Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo 113-8510, Japan.
3
Departments of Cell Biology and Neuroscience, Juntendo University Graduate School of Medicine, Bunkyo-Ku, Tokyo 113-8421, Japan.
4
Department of Biochemistry and Molecular Biology, Graduate School and Faculty of Medicine, The University of Tokyo, Tokyo 113-0033, Japan. nmizu@m.u-tokyo.ac.jp.

Abstract

In macroautophagy, cytoplasmic contents are sequestered into the double-membrane autophagosome, which fuses with the lysosome to become the autolysosome. It has been thought that the autophagy-related (ATG) conjugation systems are required for autophagosome formation. Here, we found that autophagosomal soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) syntaxin 17-positive autophagosome-like structures could be generated even in the absence of the ATG conjugation systems, although at a reduced rate. These syntaxin 17-positive structures could further fuse with lysosomes, but degradation of the inner autophagosomal membrane was significantly delayed. Accordingly, autophagic activity in ATG conjugation-deficient cells was strongly suppressed. We suggest that the ATG conjugation systems, which are likely required for the closure (i.e., fission) of the autophagosomal edge, are not absolutely essential for autolysosome formation but are important for efficient degradation of the inner autophagosomal membrane.

Comment in

PMID:
27885029
DOI:
10.1126/science.aaf6136
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center