A genome-wide RNA interference screen disentangles the Golgi tropism of LC3

Giulia Cerrato; Oliver Kepp; Allan Sauvat; Guido Kroemer

doi:10.1080/15548627.2020.1861836

A genome-wide RNA interference screen disentangles the Golgi tropism of LC3

Autophagy. 2021 Mar;17(3):820-822. doi: 10.1080/15548627.2020.1861836. Epub 2020 Dec 23.

Authors

Giulia Cerrato^{1

2

3}, Oliver Kepp^{1

2}, Allan Sauvat^{1

2}, Guido Kroemer^{1

2

4

5

6}

Affiliations

¹ Equipe labellisée par la Ligue contre le cancer, Université de Paris, Sorbonne Université, INSERM UMR1138, Centre de Recherche des Cordeliers, Paris, France.
² Metabolomics and Cell Biology Platforms, Gustave Roussy, Villejuif, France.
³ Faculty of Medicine, Université Paris Sud, Paris Saclay, Kremlin Bicêtre, France.
⁴ Pôle de Biologie, Hôpital Européen Georges Pompidou, AP-HP, Paris, France.
⁵ Suzhou Institute for Systems Medicine, Chinese Academy of Medical Sciences, Suzhou, China.
⁶ Karolinska Institute, Department of Women's and Children's Health, Karolinska University Hospital, Stockholm, Sweden.

Abstract

Oleate, the most abundantly occurring cis-unsaturated fatty acid, has the particularity to induce the accumulation of MAP1LC3B/LC3 (microtubule associated protein 1 light chain 3 beta) at the trans-Golgi apparatus. A genome-wide RNA interference screen designed to identify the mechanisms of this LC3 redistribution led to the identification of a BECN1-PIK3C3-independent pathway that, however, requires the ATG12-ATG5 and ATG7-dependent conjugation system, and several genes/proteins involved in endoplasmic reticulum (ER)-to-Golgi anterograde protein transport, as well as the unfolded protein response, including the integrated stress response that results in the phosphorylation of EIF2A/eIF2α (eukaryotic translation initiation factor 2A). Functional experiments revealed that oleate blocks conventional protein secretion, stalling the process at the level of the trans-Golgi network. Oleate-induced blockade of protein secretion occurred even after depletion of ATG5, suggesting that it does not rely on the recruitment of LC3 to the Golgi apparatus (which does require ATG5). Rather, it appears that oleate and other pharmacological inhibitors of protein secretion with a similar mode of action provoke a perturbation of the trans-Golgi compartment that secondarily results in the local enrichment of LC3.

Keywords: Autophagy; fatty acids; oleate; protein secretion; unfolded protein response.

Publication types

Comment

MeSH terms

Autophagy*
Golgi Apparatus
Oleic Acid*
Protein Transport
RNA Interference
Tropism
trans-Golgi Network

Substances

Oleic Acid

Grants and funding

GC is supported by a scholarship of the Fondation pour la Recherche Médicale. GK is supported by the Ligue contre le Cancer (équipe labellisée); Agence National de la Recherche (ANR) – Projets blancs; ANR under the frame of E-Rare-2, the ERA-Net for Research on Rare Diseases; AMMICa US23/CNRS UMS3655; Association pour la recherche sur le cancer (ARC); Association “Le Cancer du Sein, Parlons-en!”; Cancéropôle Ile-de-France; Chancelerie des universités de Paris (Legs Poix), Fondation pour la Recherche Médicale (FRM); a donation by Elior; European Research Area Network on Cardiovascular Diseases (ERA-CVD, MINOTAUR); Gustave Roussy Odyssea, the European Union Horizon 2020 Project Oncobiome; Fondation Carrefour; High-end Foreign Expert Program in China [GDW20171100085 and GDW20181100051], Institut National du Cancer (INCa); Inserm (HTE); Institut Universitaire de France; LeDucq Foundation; the LabEx Immuno-Oncology [ANR-18-IDEX-0001]; the RHU Torino Lumière; the Seerave Foundation; the SIRIC Stratified Oncology Cell DNA Repair and Tumor Immune Elimination (SOCRATE); and the SIRIC Cancer Research and Personalized Medicine (CARPEM).