The docking of synaptic vesicles on the presynaptic membrane induced by ?-synuclein is modulated by lipid composition.

ABSTRACT: ?-Synuclein (?S) is a presynaptic disordered protein whose aberrant aggregation is associated with Parkinson's disease. The functional role of ?S is still debated, although it has been involved in the regulation of neurotransmitter release via the interaction with synaptic vesicles (SVs). We report here a detailed characterisation of the conformational properties of ?S bound to the inner and outer leaflets of the presynaptic plasma membrane (PM), using small unilamellar vesicles. Our results suggest that ?S preferentially binds the inner PM leaflet. On the basis of these studies we characterise in vitro a mechanism by which ?S stabilises, in a concentration-dependent manner, the docking of SVs on the PM by establishing a dynamic link between the two membranes. The study then provides evidence that changes in the lipid composition of the PM, typically associated with neurodegenerative diseases, alter the modes of binding of ?S, specifically in a segment of the sequence overlapping with the non-amyloid component region. Taken together, these results reveal how lipid composition modulates the interaction of ?S with the PM and underlie its functional and pathological behaviours in vitro.

SUBMITTER: Man WK 

PROVIDER: S-EPMC7876145 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature