Prions cause transmissible and genetic neurodegenerative diseases, including scrapie and bovine spongiform encephalopathy of animals and Creutzfeldt-Jakob and Gerstmann-Straussler-Scheinker diseases of humans. Infectious prion particles are composed largely, if not entirely, of an abnormal isoform of the prion protein, which is encoded by a chromosomal gene. A posttranslational process, as yet unidentified, converts the cellular prion protein into an abnormal isoform. Scrapie incubation times, neuropathology, and prion synthesis in transgenic mice are controlled by the prion protein gene. Point mutations in the prion protein genes of animals and humans are genetically linked to development of neuro-degeneration. Transgenic mice expressing mutant prion proteins spontaneously develop neurologic dysfunction and spongiform neuropathology. Understanding prion diseases may advance investigations of other neurodegenerative disorders and of the processes by which neurons differentiate, function for decades, and then grow senescent.

https://science.sciencemag.org/content/sci/252/5012/1515.full.pdf

Molecular biology of prion diseases

A cellular gene encodes scrapie PrP 27-30 protein

https://www.cell.com/cell/pdf/0092-8674(87)90150-4.pdf

Scrapie prion protein contains a phosphatidylinositol glycolipid

Scrapie prions aggregate to form amyloid-like birefringent rods

https://www.zora.uzh.ch/id/eprint/991/1/BasScr86v.pdf

Scrapie and cellular PrP isoforms are encoded by the same chromosomal gene

–In searching for a nucleic acid within the scrapie agent, we employed psoralens which penetrate the coats of most conventional viruses, form photoadducts with their genomes, and block replication of the viruses. Five psoralens, at concentrations up to 500 times greater than those required to inactivate conventional viruses, did not influence scrapie agent titers in partially purified preparations from murine spleen and hamster brain. 3H-psoralens were used to monitor the formation of photoadducts within nucleic acid standards added to preparations of the scrapie agent. Since no inhibition of psoralen photoadduct formation was observed in these preparations, one of three possibilities seems likely: the scrapie agent is devoid of nucleic acid, the psoralens failed to penetrate the protein coat of the agent, or its nucleic acid is unreactive with psoralens.

StephenT. Isaacs

Papers

Resistance of the scrapie agent to inactivation by psoralens.