Alpha-Synuclein Phosphomimetic Y39E and S129D Knock-In Mice Show Cytosolic Alpha-Synuclein Localization without Developing Neurodegeneration or Motor Deficits

Authors

YoungDoo Kim
Bhupesh Vaidya
Joseph McInnes
Huda Y Zoghbi

Publication Date

4-1-2025

Journal

eNeuro

DOI

10.1523/ENEURO.0357-24.2025

PMID

40164505

PMCID

PMC11998964

PubMedCentral® Posted Date

4-10-2025

PubMedCentral® Full Text Version

Post-print

Published Open-Access

yes

Keywords

Animals, alpha-Synuclein, Phosphorylation, Gene Knock-In Techniques, Disease Models, Animal, Mice, Transgenic, Cytosol, Mice, Parkinson Disease, Mice, Inbred C57BL, Brain, Male, Mutation, Substantia Nigra, Female, alpha-synuclein, phosphomimetic mutants, S129D, Y39E

Abstract

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by motor and nonmotor symptoms. Its pathological hallmarks include the accumulation of misfolded alpha-synuclein (α-Syn) in Lewy bodies and Lewy neurites. Phosphorylation of α-Syn is a prominent feature of these inclusions, but its role in disease pathogenesis remains unclear. To identify the role of α-Syn phosphorylation in synucleinopathy, we generated two Snca knock-in (KI) mouse models carrying phosphomimetic mutations at SncaY39 or SncaS129 (Snca^Y39E or Snca^S129D) which manipulated epitopes phosphorylated in the PD brain. Both Snca^Y39E and Snca^S129D KI mice displayed increased α-Syn phosphorylation, enhanced oligomer formation, and a shift of α-Syn localization from membrane-bound to cytoplasm. However, neurodegeneration in the substantia nigra was not observed up to 24 months of age. These findings demonstrate that mimicking the phosphorylation of Y39 or S129 can induce endogenous α-Syn phosphorylation. Still, a single phosphomimetic mutation alone is insufficient to induce PD-like behavior and pathology in the mouse's lifespan. Overall, our study provides a mouse model for investigating the role of phosphorylation at Y39 and S129 α-Syn epitopes in vivo.