GABARAPL1 (GEC1) associates with autophagic vesicles

Autophagy. 2010 May;6(4):495-505. doi: 10.4161/auto.6.4.11819. Epub 2010 May 16.

Abstract

Gabarapl1 (gec1) was first described as an estrogen regulated gene which shares a high sequence homology with the gabarap gene. We previously demonstrated that GABARAPL1, like GABARAP, interacts with the GABAA receptor and tubulin and promotes tubulin polymerization. Previous work has demonstrated that the GABARAP family members (GABARAP, LC3, GATE-16 and Atg8) are not only involved in the transport of proteins or vesicles but are also implicated in various mechanisms such as autophagy, cell death, cell proliferation and tumor progression. We therefore asked whether GABARAPL1 might also play a role in autophagy. First, we showed that GABARAPL1 is cleaved at glycine 116, a residue which is conserved in other members of the family. We also demonstrated that GABARAPL1 is linked to phospholipids, delipidated by Atg4B, associated with intracellular membranes and accumulated in intracellular vesicles after inhibition of lysosomal activity. Finally, we showed that GABARAPL1 partially colocalizes with LC3 or Lysotracker green in intracellular vesicles. Taken together, our results demonstrate that GABARAPL1 associates with autophagic vesicles.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amines / metabolism
  • Animals
  • Autophagy*
  • Autophagy-Related Protein 5
  • Autophagy-Related Proteins
  • Cell Membrane / metabolism
  • Cysteine Endopeptidases / metabolism
  • Cytoplasmic Vesicles / metabolism*
  • Embryo, Mammalian / cytology
  • Fibroblasts / metabolism
  • Glycine / metabolism
  • Green Fluorescent Proteins / metabolism
  • HEK293 Cells
  • Humans
  • Intracellular Space / metabolism
  • Lysosomes / metabolism
  • MCF-7 Cells
  • Mice
  • Microtubule-Associated Proteins / deficiency
  • Microtubule-Associated Proteins / metabolism*
  • Phospholipids / metabolism
  • Protein Transport
  • Recombinant Fusion Proteins / metabolism
  • Staining and Labeling

Substances

  • Amines
  • Atg5 protein, mouse
  • Autophagy-Related Protein 5
  • Autophagy-Related Proteins
  • MAP1LC3A protein, human
  • Microtubule-Associated Proteins
  • Phospholipids
  • Recombinant Fusion Proteins
  • Red DND-99
  • Green Fluorescent Proteins
  • ATG4B protein, human
  • Cysteine Endopeptidases
  • Glycine