AMBRA1 regulates mitophagy by interacting with ATAD3A and promoting PINK1 stability

Martina Di Rienzo; Alessandra Romagnoli; Fabiola Ciccosanti; Giulia Refolo; Veronica Consalvi; Giuseppe Arena; Enza Maria Valente; Mauro Piacentini; Gian Maria Fimia

doi:10.1080/15548627.2021.1997052

AMBRA1 regulates mitophagy by interacting with ATAD3A and promoting PINK1 stability

Autophagy. 2022 Aug;18(8):1752-1762. doi: 10.1080/15548627.2021.1997052. Epub 2021 Nov 19.

Authors

Affiliations

¹ Department of Epidemiology, Preclinical Research and Advanced Diagnostics, National Institute for Infectious Diseases Irccs "L. Spallanzani", Rome, Italy.
² Department of Molecular Medicine, University of Rome "Sapienza", Rome, Italy.
³ Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Belvaux, Luxembourg.
⁴ Department of Molecular Medicine, University of Pavia, Pavia, Italy.
⁵ Neurogenetics Research Centre, IRCCS Mondino Foundation, Pavia, Italy.
⁶ Laboratory of Molecular Medicine, Institute of Cytology of the Russian Academy of Sciences, Saint Petersburg, Russia.

Abstract

PINK1 accumulation at the outer mitochondrial membrane (OMM) is a key event required to signal depolarized mitochondria to the autophagy machinery. How this early step is, in turn, modulated by autophagy proteins remains less characterized. Here, we show that, upon mitochondrial depolarization, the proautophagic protein AMBRA1 is recruited to the OMM and interacts with PINK1 and ATAD3A, a transmembrane protein that mediates mitochondrial import and degradation of PINK1. Downregulation of AMBRA1 expression results in reduced levels of PINK1 due to its enhanced degradation by the mitochondrial protease LONP1, which leads to a decrease in PINK1-mediated ubiquitin phosphorylation and mitochondrial PRKN/PARKIN recruitment. Notably, ATAD3A silencing rescues defective PINK1 accumulation in AMBRA1-deficient cells upon mitochondrial damage. Overall, our findings underline an upstream contribution of AMBRA1 in the control of PINK1-PRKN mitophagy by interacting with ATAD3A and promoting PINK1 stability. This novel regulatory element may account for changes of PINK1 levels in neuropathological conditions.Abbreviations: ACTB/β-actin: actin beta; AMBRA1: autophagy and beclin 1 regulator 1; ATAD3A: ATPase family AAA domain containing 3A; BCL2L1/BCL-xL: BCL2 like 1; CCCP: carbonyl cyanide m-chlorophenyl hydrazone; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; OMA1: OMA1 zinc metallopeptidase; OMM: outer mitochondrial membrane; PARL: presenilin associated rhomboid like; PARP: poly(ADP-ribose) polymerase; PD: Parkinson disease; PINK1: PTEN induced kinase 1; PRKN/PARKIN: parkin RBR E3 ubiquitin protein ligase; SDHA: succinate dehydrogenase complex flavoprotein subunit A; TOMM70: translocase of outer mitochondrial membrane 70.

Keywords: Autophagy; LONP1; PRKN/PARKIN; TOMM complex; ubiquitin phosphorylation.

Publication types

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

MeSH terms

Adaptor Proteins, Signal Transducing*
Autophagy
Carbonyl Cyanide m-Chlorophenyl Hydrazone / pharmacology
Mitochondria / metabolism
Mitophagy*
Protein Kinases* / metabolism
Ubiquitin-Protein Ligases / metabolism

Substances

AMBRA1 protein, human
Adaptor Proteins, Signal Transducing
Carbonyl Cyanide m-Chlorophenyl Hydrazone
Ubiquitin-Protein Ligases
Protein Kinases

Grants and funding

This work was supported by the Fondazione Cariplo [2017-0575]; Ministero della Salute [Ricerca Corrente]; Ministero della Salute [Ricerca Corrente]; Fonds National de la Recherche Luxembourg [FNR, MiRisk-PD, C17/BM/11676395]; Associazione Italiana per la Ricerca sul Cancro [21880]; Ministero dell’Istruzione, dell’Università e della Ricerca [20152CB22L]; Sapienza Università di Roma [RG120172B73EDDC5]; Russian Government Program for the Recruitment of the leading scientists into the Russian Institutions of Higher Education [14. W03.31.0029]; Regione Lazio [Gruppi di Ricerca”2018].