Identification of glucose-6-phosphate transporter as a key regulator functioning at the autophagy initiation step

Hye-Hyun Ahn; Yumin Oh; Huikyong Lee; WonJae Lee; Jae-Woong Chang; Ha-Kyung Pyo; Do hyung Nah; Yong-Keun Jung

doi:10.1016/j.febslet.2015.05.018

Identification of glucose-6-phosphate transporter as a key regulator functioning at the autophagy initiation step

FEBS Lett. 2015 Jul 22;589(16):2100-9. doi: 10.1016/j.febslet.2015.05.018. Epub 2015 May 15.

Authors

Hye-Hyun Ahn¹, Yumin Oh², Huikyong Lee³, WonJae Lee³, Jae-Woong Chang⁴, Ha-Kyung Pyo³, Do hyung Nah¹, Yong-Keun Jung⁵

Affiliations

¹ Global Research Laboratory, School of Biological Science, Seoul National University, Gwanak-gu, Seoul, Republic of Korea; Interdisciplinary Graduate Program in Genetic Engineering, Seoul National University, Gwanak-gu, Seoul, Republic of Korea.
² Russel H. Morgan Department of Radiology and Radiological Science, Johns Hopkins School of Medicine, Baltimore, MD, USA.
³ Global Research Laboratory, School of Biological Science, Seoul National University, Gwanak-gu, Seoul, Republic of Korea.
⁴ Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.
⁵ Global Research Laboratory, School of Biological Science, Seoul National University, Gwanak-gu, Seoul, Republic of Korea; Interdisciplinary Graduate Program in Genetic Engineering, Seoul National University, Gwanak-gu, Seoul, Republic of Korea. Electronic address: [email protected].

PMID: 25982172
DOI: 10.1016/j.febslet.2015.05.018

Abstract

Autophagy is a catabolic process involving autophagosome formation via lysosome. However, the initiation step of autophagy is largely unknown. We found an interaction between ULK1 and ATG9 in mammalian cells and utilized the interaction to identify novel regulators of autophagy upstream of ULK1. We established a cell-based screening assay employing bimolecular fluorescence complementation. By performing gain-of-function screening, we identified G6PT as an autophagy activator. G6PT enhanced the interaction between N-terminal Venus-tagged ULK1 and C-terminal Venus-tagged ATG9, and increased autophagic flux independent of its transport activity. G6PT negatively regulated mTORC1 activity, demonstrating that G6PT functions upstream of mTORC1 in stimulating autophagy.

Keywords: ATG9; Autophagy modulator; G6PT; Screening; ULK1.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Amino Acid Substitution
Animals
Antiporters / antagonists & inhibitors
Antiporters / genetics
Antiporters / metabolism*
Autophagy*
Autophagy-Related Protein-1 Homolog
Autophagy-Related Proteins
Cell Line
Cricetulus
Hepatocytes / cytology
Hepatocytes / enzymology
Hepatocytes / metabolism*
Humans
Huntingtin Protein
Intracellular Signaling Peptides and Proteins / chemistry
Intracellular Signaling Peptides and Proteins / genetics
Intracellular Signaling Peptides and Proteins / metabolism
Mechanistic Target of Rapamycin Complex 1
Membrane Proteins / chemistry
Membrane Proteins / genetics
Membrane Proteins / metabolism
Models, Biological*
Monosaccharide Transport Proteins / antagonists & inhibitors
Monosaccharide Transport Proteins / genetics
Monosaccharide Transport Proteins / metabolism*
Multiprotein Complexes / antagonists & inhibitors*
Multiprotein Complexes / metabolism
Mutant Proteins / chemistry
Mutant Proteins / metabolism
Nerve Tissue Proteins / chemistry
Nerve Tissue Proteins / genetics
Nerve Tissue Proteins / metabolism
Peptide Fragments / chemistry
Peptide Fragments / genetics
Peptide Fragments / metabolism
Phagosomes / enzymology
Phagosomes / metabolism*
Protein Interaction Domains and Motifs
Protein Serine-Threonine Kinases / chemistry
Protein Serine-Threonine Kinases / genetics
Protein Serine-Threonine Kinases / metabolism
Protein Transport
RNA Interference
Recombinant Fusion Proteins / chemistry
Recombinant Fusion Proteins / metabolism
Recombinant Proteins / chemistry
Recombinant Proteins / genetics
Recombinant Proteins / metabolism
TOR Serine-Threonine Kinases / antagonists & inhibitors*
TOR Serine-Threonine Kinases / metabolism
Up-Regulation*
Vesicular Transport Proteins / chemistry
Vesicular Transport Proteins / genetics
Vesicular Transport Proteins / metabolism

Substances

Antiporters
ATG9A protein, human
Autophagy-Related Proteins
HTT protein, human
Huntingtin Protein
Intracellular Signaling Peptides and Proteins
Membrane Proteins
Monosaccharide Transport Proteins
Multiprotein Complexes
Mutant Proteins
Nerve Tissue Proteins
Peptide Fragments
Recombinant Fusion Proteins
Recombinant Proteins
SLC37A4 protein, human
Vesicular Transport Proteins
Autophagy-Related Protein-1 Homolog
Mechanistic Target of Rapamycin Complex 1
Protein Serine-Threonine Kinases
TOR Serine-Threonine Kinases
ULK1 protein, human