Targeting α-synuclein translation: Novel PROTEIMERs as 5’-UTR directed inhibitors

BackgroundAmyloid aggregation of α-Synuclein is a defining feature of several neurodegenerative disorders, including Parkinson's disease (PD), Lewy body dementia (LBD), and Alzheimer's disease (AD). While there have been many attempts to reduce the α-Synuclein burden of neuronal cells through direct targeting of the protein, the conformationally dynamic nature of α-Synuclein make it a particularly difficult target to drug. Given the correlation between α-Synuclein levels and both familial and environmentally induced synucleinopathies, targeting the α-Synuclein mRNA transcript offers an alternative therapeutic avenue.ObjectiveTo develop and evaluate protein-based RNA-binding therapeutics (PROTEIMERs) that selectively bind the 5' untranslated region (UTR) of α-Synuclein mRNA and inhibit its translation to reduce α-Synuclein levels.MethodsWe employed high-throughput phage display to identify novel RNA-binding PROTEIMER candidates targeting the 5'UTR of α-Synuclein mRNA. Binding affinities were assessed via surface plasmon resonance (SPR). Computational structural predictions were used to evaluate PROTEIMER-RNA interactions relative to known regulatory proteins IRP1 and IRP2. RNase domains were fused to the lead PROTEIMERs, and their RNA degradation activity was tested in vitro.ResultsThree PROTEIMERs were identified that bind the α-Synuclein 5'UTR with high affinity. Structural predictions supported specific interactions with the structured RNA region. RNase-fused PROTEIMERs demonstrated targeted RNA degradation and induced decay of α-Synuclein mRNA in vitro, indicating translational suppression capability.ConclusionsOur findings demonstrate the feasibility of using engineered protein therapeutics to target α-Synuclein mRNA via the 5'UTR. These PROTEIMERs represent a promising new strategy for reducing α-Synuclein levels and mitigating neurodegenerative progression in LBD, PD, and AD.