Project summary
Mammalian prion diseases, such as Creutzfeldt-Jakob disease (CJD), Chronic Wasting Disease
(CWD), bovine spongiform encephalopathy (BSE), and scrapie, are a group of infectious
neurodegenerative disorders caused by the autocatalytic conversion of the host-encoded prion
protein, PrPC, into a group of misfolded, infectious conformers collectively termed PrPSc.
Multiple lines of evidence from biochemical, genetic, and cell biological studies suggest that
PrPC and PrPSc employ specific pathways for biosynthesis, trafficking, and degradation in living
cells. However, full elucidation of these pathways has been hindered the lack of tractable model
organisms for genetic screening. To overcome this obstacle, we recently developed methods to
detect both PrPC and PrPSc in brain-derived CAD5 cells using fluorescence-activated cell sorting
(FACS). We will use these sensitive sorting methods to perform CRISPR (clustered regularly
interspaced short palindromic repeats)/Cas9 whole genome library screens in CAD5 cells
infected with different prion strains. These studies will be the first to fully map the molecular
pathways that control the biosynthesis, trafficking, and degradation of both PrPC and PrPSc
molecules, and thereby greatly advance our fundamental knowledge of prion cell biology. Our
unbiased screens will also reveal the rate limiting steps of prion formation and clearance,
thereby identifying the most susceptible targets for drug therapy.