A Targetable N-Terminal Motif Orchestrates α-Synuclein Oligomer-to-Fibril Conversion.

Area of Science:

• Neuroscience
• Biochemistry
• Structural Biology

Background:

• Oligomeric α-synuclein species are implicated in Parkinson's disease pathogenesis.
• Targeting these oligomers is challenging due to limited structural knowledge.
• Phenol-soluble modulin α3 (PSMα3) binds α-synuclein oligomers and inhibits fibril conversion.

Purpose of the Study:

• To elucidate the structural basis of PSMα3 binding to α-synuclein oligomers.
• To understand the mechanism by which PSMα3 inhibits oligomer-to-fibril conversion.
• To identify novel therapeutic targets within α-synuclein oligomers.

Main Methods:

• Investigated PSMα3 binding to α-synuclein oligomers.
• Characterized the structural role of the α-synuclein N-terminal motif (residues 36-61).
• Analyzed the impact of the G51D mutation on α-synuclein conformation and aggregation.

Main Results:

• PSMα3 selectively binds to an α-synuclein N-terminal motif (residues 36-61) in oligomeric states.
• This motif is crucial for oligomer-to-fibril conversion; its absence prevents fibril formation.
• The Parkinson's-associated G51D mutation induces conformational changes in this region, delaying conversion and promoting chaperone-resistant oligomers.

Conclusions:

• Identified a novel, targetable region (α-synuclein residues 36-61) in α-synuclein oligomers.
• Advanced understanding of the molecular mechanisms underlying α-synuclein oligomer-to-fibril conversion.
• Revealed new insights into the pathogenic role of α-synuclein mutations in Parkinson's disease.