» Articles » PMID: 1356522

Synthesis and Trafficking of Prion Proteins in Cultured Cells

Overview
Journal Mol Biol Cell
Date 1992 Aug 1
PMID 1356522
Citations 97
Authors
Affiliations
Soon will be listed here.
Abstract

Scrapie prions are composed largely, if not entirely, of the scrapie prion protein (PrPSc) that is encoded by a chromosomal gene. Scrapie-infected mouse neuroblastoma (ScN2a) and hamster brain (ScHaB) cells synthesize PrPSc from the normal PrP isoform (PrPC) or a precursor through a posttranslational process. In pulse-chase radiolabeling experiments, we found that presence of brefeldin A (BFA) during both the pulse and the chase periods prevented the synthesis of PrPSc. Removal of BFA after the chase permitted synthesis of PrPSc to resume. BFA also blocked the export of nascent PrPC to the cell surface but did not alter the distribution of intracellular deposits of PrPSc. Under the same conditions, BFA caused the redistribution of the Golgi marker MG160 into the endoplasmic reticulum (ER). Using monensin as an inhibitor of mid-Golgi glycosylation, we determined that PrP traverses the mid-Golgi stack before acquiring protease resistance. About 1 h after the formation of PrPSc, its N-terminus was removed by a proteolytic process that was inhibited by ammonium chloride, chloroquine, and monensin, arguing that this is a lysosomal event. These results suggest that the ER is not competent for the synthesis of PrPSc and that the synthesis of PrPSc occurs during the transit of PrP between the mid-Golgi stack and lysosomes. Presumably, the endocytic pathway features in the synthesis of PrPSc.

Citing Articles

Prion Protein Endoproteolysis: Cleavage Sites, Mechanisms and Connections to Prion Disease.

Castle A, Westaway D J Neurochem. 2025; 169(1):e16310.

PMID: 39874431 PMC: 11774512. DOI: 10.1111/jnc.16310.


Analysis of genetically determined gene expression suggests role of inflammatory processes in exfoliation syndrome.

Hirbo J, Pasutto F, Gamazon E, Evans P, Pawar P, Berner D BMC Genomics. 2023; 24(1):75.

PMID: 36797672 PMC: 9936777. DOI: 10.1186/s12864-023-09179-7.


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

Avar M, Heinzer D, Thackray A, Liu Y, Hruska-Plochan M, Sellitto S EMBO J. 2022; 41(23):e112338.

PMID: 36254605 PMC: 9713719. DOI: 10.15252/embj.2022112338.


Glycans are not necessary to maintain the pathobiological features of bovine spongiform encephalopathy.

Otero A, Barrio T, Erana H, Charco J, Betancor M, Diaz-Dominguez C PLoS Pathog. 2022; 18(10):e1010900.

PMID: 36206325 PMC: 9581369. DOI: 10.1371/journal.ppat.1010900.


Proteostasis unbalance in prion diseases: Mechanisms of neurodegeneration and therapeutic targets.

Thellung S, Corsaro A, Dellacasagrande I, Nizzari M, Zambito M, Florio T Front Neurosci. 2022; 16:966019.

PMID: 36148145 PMC: 9485628. DOI: 10.3389/fnins.2022.966019.


References
1.
Oda K, Hirose S, Takami N, Misumi Y, Takatsuki A, Ikehara Y . Brefeldin A arrests the intracellular transport of a precursor of complement C3 before its conversion site in rat hepatocytes. FEBS Lett. 1987; 214(1):135-8. DOI: 10.1016/0014-5793(87)80028-5. View

2.
Hunziker W, Whitney J, Mellman I . Selective inhibition of transcytosis by brefeldin A in MDCK cells. Cell. 1991; 67(3):617-27. DOI: 10.1016/0092-8674(91)90535-7. View

3.
Laemmli U . Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970; 227(5259):680-5. DOI: 10.1038/227680a0. View

4.
Griffiths G, Quinn P, Warren G . Dissection of the Golgi complex. I. Monensin inhibits the transport of viral membrane proteins from medial to trans Golgi cisternae in baby hamster kidney cells infected with Semliki Forest virus. J Cell Biol. 1983; 96(3):835-50. PMC: 2112386. DOI: 10.1083/jcb.96.3.835. View

5.
Bolton D, McKinley M, Prusiner S . Identification of a protein that purifies with the scrapie prion. Science. 1982; 218(4579):1309-11. DOI: 10.1126/science.6815801. View