A short isoform of ATG7 fails to lipidate LC3/GABARAP

Sci Rep. 2018 Sep 26;8(1):14391. doi: 10.1038/s41598-018-32694-7.

Abstract

Autophagy is a degradation pathway important for cellular homeostasis. The E1-like enzyme ATG7 is a key component of the autophagy machinery, with the main function of mediating the lipidation of LC3/GABARAP during autophagosome formation. By analysing mRNA-sequencing data we found that in addition to the full-length ATG7 isoform, various tissues express a shorter isoform lacking an exon of 27 amino acids in the C-terminal part of the protein, termed ATG7(2). We further show that ATG7(2) does not bind LC3B and fails to mediate the lipidation of members of the LC3/GABARAP family. We have thus identified an isoform of ATG7 that is unable to carry out the best characterized function of the protein during the autophagic response. This short isoform will have to be taken into consideration when further studying the role of ATG7.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / metabolism*
  • Amino Acid Sequence
  • Animals
  • Apoptosis Regulatory Proteins
  • Autophagy
  • Autophagy-Related Protein 7 / chemistry
  • Autophagy-Related Protein 7 / metabolism*
  • HEK293 Cells
  • Humans
  • Lipid Metabolism
  • Mice
  • Microtubule-Associated Proteins / metabolism*
  • Models, Molecular
  • Protein Binding
  • Protein Isoforms / chemistry
  • Protein Isoforms / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • Apoptosis Regulatory Proteins
  • GABARAP protein, human
  • MAP1LC3B protein, human
  • Microtubule-Associated Proteins
  • Protein Isoforms
  • ATG7 protein, human
  • Autophagy-Related Protein 7