Stabilization of 14-3-3 protein-protein interactions with Fusicoccin-A decreases alpha-synuclein dependent cell-autonomous death in neuronal and mouse models

• Published in: Neurobiology of disease 2023-07, Vol.183, p.106166-106166, Article 106166
• Main Authors: Vinueza-Gavilanes, Rodrigo, Bravo-González, Jorge Juan, Basurco, Leyre, Boncristiani, Chiara, Fernández-Irigoyen, Joaquín, Santamaría, Enrique, Marcilla, Irene, Pérez-Mediavilla, Alberto, Luquin, María Rosario, Vales, Africa, González-Aseguinolaza, Gloria, Aymerich, María Soledad, Aragón, Tomás, Arrasate, Montserrat
• Format: Article
• Language: English
• Subjects: 14-3-3 epsilon; 14-3-3 Proteins - genetics; 14-3-3 Proteins - metabolism; Adenoassociated virus AAV9; Alpha-synuclein; alpha-Synuclein - metabolism; Animals; BioID2; Dopaminergic Neurons - metabolism; Fusicoccin-A; HEK293 Cells; Humans; Longitudinal survival analysis; Mice; Mice, Transgenic; Neuronal death; Parkinson's disease; Proximity biotinylation; Synucleinopathies
• ISSN: 0969-9961; 1095-953X
• DOI: 10.1016/j.nbd.2023.106166

Synucleinopathies are a group of neurodegenerative diseases without effective treatment characterized by the abnormal aggregation of alpha-synuclein (aSyn) protein. Changes in levels or in the amino acid sequence of aSyn (by duplication/triplication of the aSyn gene or point mutations in the encoding region) cause familial cases of synucleinopathies. However, the specific molecular mechanisms of aSyn-dependent toxicity remain unclear. Increased aSyn protein levels or pathological mutations may favor abnormal protein-protein interactions (PPIs) that could either promote neuronal death or belong to a coping response program against neurotoxicity. Therefore, the identification and modulation of aSyn-dependent PPIs can provide new therapeutic targets for these diseases. To identify aSyn-dependent PPIs we performed a proximity biotinylation assay based on the promiscuous biotinylase BioID2. When expressed as a fusion protein, BioID2 biotinylates by proximity stable and transient interacting partners, allowing their identification by streptavidin affinity purification and mass spectrometry. The aSyn interactome was analyzed using BioID2-tagged wild-type (WT) and pathological mutant E46K aSyn versions in HEK293 cells. We found the 14-3-3 epsilon isoform as a common protein interactor for WT and E46K aSyn. 14‐3-3 epsilon correlates with aSyn protein levels in brain regions of a transgenic mouse model overexpressing WT human aSyn. Using a neuronal model in which aSyn cell-autonomous toxicity is quantitatively scored by longitudinal survival analysis, we found that stabilization of 14‐3-3 protein-proteins interactions with Fusicoccin-A (FC-A) decreases aSyn-dependent toxicity. Furthermore, FC-A treatment protects dopaminergic neuronal somas in the substantia nigra of a Parkinson's disease mouse model. Based on these results, we propose that the stabilization of 14‐3-3 epsilon interaction with aSyn might reduce aSyn toxicity, and highlight FC-A as a potential therapeutic compound for synucleinopathies. •Proximity biotinylation identifies 14–3-3 epsilon as an aSyn interactor protein.•Fusicoccin-A (FC-A) decreases aSyn-dependent toxicity in a neuronal model.•FC-A protects substantia nigra dopaminergic somas in a Parkinson's disease model.