inStem (Institute for Stem Cell Science and Regenerative Medicine)

Department of Biotechnology
Department of Biotechnology
inStem (Institute for Stem Cell Science and Regenerative Medicine)

Parkinson’s disease-specific α-Synuclein variants potentially drive Lewy body formation by engaging in promiscuous and non-functional interactions.

Publication Type

Journal Article

Date of Publication

January 8, 2026

Journal

Communications biology

Volume/Issue

9/1

ISSN

2399-3642

Lewy bodies (LBs), a pathological hallmark of synucleinopathies, are heterogeneous inclusions that contain α-Synuclein (αSyn) alongside numerous proteins, lipids, and damaged organelles. Current αSyn-fibrillization centric aggregation/phase separation models fail to explain how diverse cellular components are sequestered by disease-specific αSyn variants during LB formation. In the crowded intracellular milieu, proteins constantly encounter one another, but functional protein-protein interactions must outweigh disease-causing ‘hydrophobicity’ driven non-functional interactions. Although αSyn wild-type () has a hydrophobic (NAC) core, it is shielded by long-range intramolecular interactions, rendering it “inert.” In contrast, Parkinson’s disease (PD)-specific αSyn variants-S129 phosphorylation and C-terminal truncations-aggregate and phase separate more rapidly, suggesting hydrophobic exposure. We hypothesize that exposed hydrophobic core in PD-specific αSyn variants not only drives aggregation and phase separation but also promotes promiscuous, non-functional binding to diverse proteins. Using various biochemical and biophysical approaches, we demonstrate that αSyn engages in functional interactions, whereas C-terminal acidic tail truncated αSyn and S129-phosphomimicking () mutant are “reactive,” displaying broad, non-functional aberrant binding and impairing chaperone-mediated refolding. Based on our study, we propose a ‘Multifactorial Random Disorder Model’ outlining how PD-specific αSyn variants drive LB formation through non-functional heterotypic interactions.

Alternate Journal

Commun Biol

PubMed ID

41507378

PubMed Central ID

PMC12877186

Authors

Jos S
Shivanandaswamy N
Sharma A
Prasad TK
Kashyap R
Kamariah N
Bharath MMS
Sharma D
Nath S
Padmanabhan B
Padavattan S

Keywords

Humans
Protein Binding
Mutation
alpha-Synuclein
Parkinson Disease
Phosphorylation
Hydrophobic and Hydrophilic Interactions
Lewy Bodies
Protein Aggregation
Pathological