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Expression of Mutant or Cytosolic PrP in Transgenic Mice and Cells Is Not Associated with Endoplasmic Reticulum Stress or Proteasome Dysfunction
- Source :
- PLoS ONE, PLoS ONE, Vol 6, Iss 4, p e19339 (2011)
- Publication Year :
- 2011
- Publisher :
- Public Library of Science (PLoS), 2011.
-
Abstract
- The cellular pathways activated by mutant prion protein (PrP) in genetic prion diseases, ultimately leading to neuronal dysfunction and degeneration, are not known. Several mutant PrPs misfold in the early secretory pathway and reside longer in the endoplasmic reticulum (ER) possibly stimulating ER stress-related pathogenic mechanisms. To investigate whether mutant PrP induced maladaptive responses, we checked key elements of the unfolded protein response (UPR) in transgenic mice, primary neurons and transfected cells expressing two different mutant PrPs. Because ER stress favors the formation of untranslocated PrP that might aggregate in the cytosol and impair proteasome function, we also measured the activity of the ubiquitin proteasome system (UPS). Molecular, biochemical and immunohistochemical analyses found no increase in the expression of UPR-regulated genes, such as Grp78/Bip, CHOP/GADD153, or ER stress-dependent splicing of the mRNA encoding the X-box-binding protein 1. No alterations in UPS activity were detected in mutant mouse brains and primary neurons using the Ub(G76V)-GFP reporter and a new fluorogenic peptide for monitoring proteasomal proteolytic activity in vivo. Finally, there was no loss of proteasome function in neurons in which endogenous PrP was forced to accumulate in the cytosol by inhibiting cotranslational translocation. These results indicate that neither ER stress, nor perturbation of proteasome activity plays a major pathogenic role in prion diseases.
- Subjects :
- PRION
Mutant
lcsh:Medicine
Endoplasmic Reticulum
PC12 Cells
Prion Diseases
Mice
ENDOPLSAMIC RETICULUM
Cytosol
Molecular Cell Biology
Neurobiology of Disease and Regeneration
PROTEASOME
lcsh:Science
Endoplasmic Reticulum Chaperone BiP
Cells, Cultured
Cellular Stress Responses
Neurons
Multidisciplinary
Cell Death
UNFOLDED PROTEIN RESPONSE
Neurodegenerative Diseases
Infectious Diseases
Neurology
Medicine
Research Article
Genetically modified mouse
Proteasome Endopeptidase Complex
Prions
Transgene
Green Fluorescent Proteins
Mice, Transgenic
Biology
Animals
Humans
Secretory pathway
Endoplasmic reticulum
lcsh:R
Molecular biology
Rats
Mice, Inbred C57BL
Proteasome
Protein Biosynthesis
Mutation
Mice, Inbred CBA
Unfolded protein response
lcsh:Q
Peptides
Neuroscience
Subjects
Details
- ISSN :
- 19326203
- Volume :
- 6
- Database :
- OpenAIRE
- Journal :
- PLoS ONE
- Accession number :
- edsair.doi.dedup.....4ee69f738dca333c39a3afef865bf07a