Saturation mutagenesis of α-synuclein reveals monomer fold that modulates aggregation

Navigating through the complexities of synucleinopathies: Insights into pathogenesis, heterogeneity, and future perspectives

The aggregation of alpha-synuclein (aSyn) represents a neuropathological hallmark observed in a group of neurodegenerative disorders collectively known as synucleinopathies. Despite their shared characteristics, these disorders manifest diverse clinical and pathological phenotypes. The mechanism underlying this heterogeneity is thought to be due to the diversity in the aSyn strains present across the diseases. In this perspective, we will explore recent findings on aSyn strains and discuss recent discoveries about Lewy bodies' composition. We further discuss the current hypothesis for aSyn spreading and emphasize the emerging biomarker field demonstrating promising results. A comprehension of these mechanisms holds substantial promise for future clinical applications. This understanding can pave the way for the development of personalized medicine strategies, specifically targeting the unique underlying causes of each synucleinopathy. Such advancements can revolutionize therapeutic approaches and significantly contribute to more effective interventions in the intricate landscape of neurodegenerative disorders.

Ensemble-based design of tau to inhibit aggregation while preserving biological activity

The microtubule-associated protein tau is implicated in neurodegenerative diseases characterized by amyloid formation. Mutations associated with frontotemporal dementia increase tau aggregation propensity and disrupt its endogenous microtubule-binding activity. The structural relationship between aggregation propensity and biological activity remains unclear. We employed a multi-disciplinary approach, including computational modeling, NMR, cross-linking mass spectrometry, and cell models to design tau sequences that stabilize its structural ensemble. Our findings reveal that substitutions near the conserved 'PGGG' beta-turn motif can modulate local conformation, more stably engaging in interactions with the 306VQIVYK311 amyloid motif to decrease aggregation in vitro and in cells. Designed tau sequences maintain microtubule binding and explain why 3R isoforms of tau exhibit reduced pathogenesis over 4R isoforms. We propose a simple mechanism to reduce the formation of pathogenic species while preserving biological function, offering insights for therapeutic strategies aimed at reducing protein misfolding in neurodegenerative diseases.

Ensemble-based design of tau to inhibit aggregation while preserving biological activity

The microtubule-associated protein tau is implicated in neurodegenerative diseases characterized by amyloid formation. Mutations associated with frontotemporal dementia increase tau aggregation propensity and disrupt its endogenous microtubule-binding activity. The structural relationship between aggregation propensity and biological activity remains unclear. We employed a multi-disciplinary approach, including computational modeling, NMR, cross-linking mass spectrometry, and cell models to design tau sequences that stabilize its structural ensemble. Our findings reveal that substitutions near the conserved 'PGGG' beta-turn motif can modulate local conformation, more stably engaging in interactions with the 306 VQIVYK 311 amyloid motif to decrease aggregation in vitro and in cells. Designed tau sequences maintain microtubule binding and explain why 3R isoforms of tau exhibit reduced pathogenesis over 4R isoforms. We propose a simple mechanism to reduce the formation of pathogenic species while preserving biological function, offering insights for therapeutic strategies aimed at reducing protein misfolding in neurodegenerative diseases.