Alpha-synuclein phosphorylation-dominated LLPS hijacks synaptic vesicle condensates driving Parkinson disease pathology

Like RBM45 in ALS, disease-modified alpha-synuclein undergoes altered LLPS behavior that dominantly rewires normal membraneless compartments. In PD neurons, phosphorylated (Ser129) and oxidative-modified alpha-synuclein forms aberrant, stable condensates at synaptic terminals that hijack synaptic vesicle clusters, displacing essential synaptic proteins (complexin, synaptotagmin-1) and vesicular proteins (VAMP2) into aggregation-prone states, driving progressive loss of synaptic function characteristic of PD.

Analogy rationale: Both ALS and PD involve disease-modified proteins (RBM45 and alpha-synuclein respectively) that undergo LLPS alterations, form pathological dominant condensates, and displace essential functional components into aggregation-prone states—the core analogy being condensation dominance hijacking normal liquid organelles.

Like RBM45 in ALS, disease-modified alpha-synuclein undergoes altered LLPS behavior that dominantly rewires normal membraneless compartments. In PD neurons, phosphorylated (Ser129) and oxidative-modified alpha-synuclein forms aberrant, stable condensates at synaptic terminals that hijack synaptic vesicle clusters, displacing essential synaptic proteins (complexin, synaptotagmin-1) and vesicular proteins (VAMP2) into aggregation-prone states, driving progressive loss of synaptic function characteristic of PD.

Analogy rationale: Both ALS and PD involve disease-modified proteins (RBM45 and alpha-synuclein respectively) that undergo LLPS alterations, form pathological dominant condensates, and displace essential functional components into aggregation-prone states—the core analogy being condensation dominance hijacking normal liquid organelles.

Disanalogies: ALS RBM45 pathology is primarily nuclear/cytoplasmic affecting RNA granules, whereas alpha-synuclein functions at presynaptic membranes where hydrophobic interactions dominate over typical LCD-mediated LLPS; also, ALS involves TDP-43/RNA granule displacement while PD involves synaptic vesicle protein displacement—a fundamentally different compartment and cargo set.

Falsifiable prediction: Neuronally differentiated cells from PD patients with SNCA multiplications or GBA mutations will show increased alpha-synuclein Ser129 phosphorylation correlating with dominant coacervate formation at synaptic sites, measurable by fluorescence recovery after photobleaching (FRAP) showing decreased liquid mobility, with displaced synaptic proteins showing increased detergent-insoluble fraction.
This hypothesis was generated from `h-alsmnd-9d62ae58bdc1` in `ALS` — judge it on its own merits but acknowledge the source.