Curated Optogenetic Publication Database

Abstract: Synucleinopathies, including Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy, are triggered by α-synuclein aggregation, triggering progressive neurodegeneration. However, the intracellular α-synuclein aggregation mechanism remains unclear. Herein, we demonstrate that RNA G-quadruplex assembly forms scaffolds for α-synuclein aggregation, contributing to neurodegeneration. Purified α-synuclein binds RNA G-quadruplexes directly through the N terminus. RNA G-quadruplexes undergo Ca2+-induced phase separation and assembly, accelerating α-synuclein sol-gel phase transition. In α-synuclein preformed fibril-treated neurons, RNA G-quadruplex assembly comprising synaptic mRNAs co-aggregates with α-synuclein upon excess cytoplasmic Ca2+ influx, eliciting synaptic dysfunction. Forced RNA G-quadruplex assembly using an optogenetic approach evokes α-synuclein aggregation, causing neuronal dysfunction and neurodegeneration. The administration of 5-aminolevulinic acid, a protoporphyrin IX prodrug, prevents RNA G-quadruplex phase separation, thereby attenuating α-synuclein aggregation, neurodegeneration, and progressive motor deficits in α-synuclein preformed fibril-injected synucleinopathic mice. Therefore, Ca2+ influx-induced RNA G-quadruplex assembly accelerates α-synuclein phase transition and aggregation, potentially contributing to synucleinopathies.

Abstract: Synucleinopathies, including Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy, are primarily neurodegenerative diseases with progressive decline in motor function. Aggregates composed of alpha-synuclein, which are known as Lewy bodies, are a neuropathological hallmark of synucleinopathies; their pathogenesis has been attributed to neuronal loss owing to intracellular alpha-synuclein accumulation. However, the mechanism of alpha-synuclein aggregation remains unclear. Here we show that the RNA G-quadruplexes assembly forms scaffolds for alpha-synuclein aggregation, thereby contributing to neurodegeneration. RNA G-quadruplexes undergo phase separation and form scaffolds for co-aggregation with & alpha-synuclein. Upon pathogenic alpha-synuclein seeds-induced cellular stress and an optogenetic assembly of RNA G-quadruplexes, phase-separated RNA G-quadruplexes served as scaffolds for & alpha-synuclein phase transition, and the co-aggregates initiated synaptic dysfunction and Parkinsonism in mice. Treatment with 5-aminolevulinic acid and protoporphyrin IX, which prevents RNA G-quadruplexes phase separation, attenuates alpha-synuclein phase transition, neurodegeneration, and motor deficits in synucleinopathy model mice. Together, the RNA G-quadruplexes assembly accelerates alpha-synuclein phase transition and aggregation owing to intracellular Ca2+ homeostasis, thereby contributing to the pathogenesis of synucleinopathies.