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Arrayed Genome-Wide Perturbation Screen Identifies Hnrnpk As Rate-Limiting for Prion Propagation

ABSTRACT: A defining characteristic of mammalian prions is their capacity for self-sustained propagation. Theoretical considerations and experimental evidence suggest that prion propagation is modulated by cell-autonomous and non-autonomous modifiers. Using a novel quantitative phospholipase protection assay (QUIPPER) for high-throughput prion measurements, we performed an arrayed genome-wide RNA interference (RNAi) screen aimed at detecting cellular host-factors that can modify prion propagation. We exposed prion-infected cells in high-density microplates to 35'364 ternary pools of 52'746 siRNAs targeting 17'582 genes representing the majority of the mouse protein-coding transcriptome. We identified 1191 modulators of prion propagation. While 1151 modified the expression of both the PrPSc pathological prion protein and its cellular counterpart, PrPC , 40 genes selectively affected PrPSc. Of the latter 40 genes, 20 augmented prion production when suppressed. A prominent limiter of prion propagation was the heterogeneous nuclear ribonucleoprotein Hnrnpk. Psammaplysene A (PSA), which binds Hnrnpk, reduced prion levels in cultured cells and protected them from cytotoxicity. PSA also reduced prion levels in infected cerebellar organotypic slices and alleviated locomotor deficits in prion-infected Drosophila melanogaster expressing ovine PrPC . Hence, genome-wide QUIPPER-based perturbations can discover actionable cellular pathways involved in prion propagation. Further, the unexpected identification of a prion-controlling ribonucleoprotein suggests a role for RNA in the generation of infectious prions.

SUBMITTER: Ms. Merve Avar

PROVIDER: S-SCDT-10_15252-EMBJ_2022112338 | biostudies-other |

REPOSITORIES: biostudies-other

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