Targeted degradation of alpha-synuclein impedes PFF-induced aggregation

Abstract Accumulation of misfolded α-synuclein protein in intracellular inclusion bodies of dopaminergic neurons underlies the pathogenesis of Synucleinopathies, which include Parkinson’s Disease (PD) and Dementia with Lewy Bodies (DLB). Therefore, preventing the accumulation of misfolded α-synuclein in dopaminergic neurons or their clearance could in principle offer intervention strategies against Synucleinopathies, which currently remain untreatable. In this study, we employ the Affinity-directed PROtein Missile (AdPROM) system consisting of the substrate receptor of the CUL2-E3 ligase complex VHL and a nanobody selectively recognising the human α-synuclein protein and demonstrate targeted degradation of endogenous α-synuclein from human cell lines with remarkable selectivity. We further demonstrate that targeted degradation of α-synuclein impedes the pre-formed fibril (PFF)-induced aggregation of α-synuclein in primary neurons derived from rats expressing human α-synuclein. This approach also represents the first demonstration of nanobody-guided proteasomal degradation of some reported clinically relevant α-synuclein variants.