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An arrayed genome-wide perturbation screen identifies the ribonucleoprotein Hnrnpk as rate-limiting for prion propagation.

Published version
Peer-reviewed

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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 1,191 modulators of prion propagation. While 1,151 modified the expression of both the pathological prion protein, PrPSc , 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.

Description

Funder: Donation from the Estate of Dr Hans Salvisberg


Funder: Nomis Foundation; Id: http://dx.doi.org/10.13039/501100008483

Keywords

High-throughput screen, Hnrnpk, Neurodegeneration, Prion, Protein aggregation, Mice, Animals, Sheep, Prions, Drosophila melanogaster, Ribonucleoproteins, RNA Interference, RNA, Small Interfering, Prion Diseases, Mammals

Journal Title

EMBO J

Conference Name

Journal ISSN

0261-4189
1460-2075

Volume Title

Publisher

Springer Science and Business Media LLC
Sponsorship
European Research Council (670958)
Swiss National Research Foundation (179040)
Swiss Perfonalized Health Network (SPHN) (2017DRI17)