RNA Bind-N-Seq for purified α-Synuclein and BG4 (scFV for G-quadruplex)

Aggregation of α-synuclein may trigger the development of synucleinopathies, a progressive neurodegenerative disease such as Parkinson's disease and Dementia with Lewy bodies. We demonstrate RNA initiates α-synuclein phase transition in vitro, however, RNA binding ability and its motif remain unclear. Here, we indicate purified human α-synuclein protein preferentially binds to guanine-rich RNA sequences by RNA Bind-N-Seq using a pool of random 24-mer RNA oligonucleotides in vitro. Importantly, these hit motifs were required consecutive guanines not random, suggesting that RNA G-quadruplexes binds to α-synuclein. We also confirmed that GC content and skew of α-synuclein-enriched RNA sequences were similar to that of BG4 (G-quadruplex antibody)-enriched RNA sequences. Taken together, these data suggest that α-synuclein binds to RNA-formed G-quadruplex. To investigate α-synuclein-bound RNA motifs, human α-synuclein was incubated with 24-mers randomized RNA pools. BG4 known as G-quadruplex antibody is utilized for positive control.