The truncated 23-230 form of the prion protein localizes to the nuclei of inducible cell lines independently of its nuclear localization signals and is not cytotoxic.
The mechanisms of prion-induced neurological dysfunction observed in prion diseases are poorly understood. Transgenic mice expressing a truncated form of the prion protein (23-230 PrP) acquire cerebellar degeneration (Ma and Lindquist, Science, 2002). To decipher the mechanisms of neurodegeneration induced by 23-230 PrP, we established inducible cell lines expressing this truncated form of PrP. We found that 23-230 PrP, expected to be cytosolic, accumulated mostly in the nucleus of the cells and was not cytotoxic. Nuclear localization of this mutant form of PrP is independent of its predicted nuclear localization signals. In contrast to what we previously described for PrPSc, nuclear accumulation of 23-230 PrP does not require a functional microtubule network. We observed that 23-230 PrP interacts with chromatin in vivo, as already described for recombinant PrP and for PrPSc. Our data demonstrate that the 23-230 PrP model does not reflect the situation of a cytosolic PrP but could represent a very useful tool to understand the consequences of the accumulation of the prion protein in the nucleus.
Crozet
Carole
C
Institut de Génétique Humaine, UPR CNRS1142, 141 Rue de la Cardonille, 34396 Montpellier cedex 5, France.
Vézilier
Julien
J
Delfieu
Virginie
V
Nishimura
Takuya
T
Onodera
Takashi
T
Casanova
Danielle
D
Lehmann
Sylvain
S
Béranger
Florence
F
D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015153:Blotting, Western / Q000379:methods; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism*; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D003078:Colchicine / Q000494:pharmacology; D004318:Doxycycline / Q000494:pharmacology; D004622:Embryo, Mammalian; D015870:Gene Expression / Q000187:drug effects / Q000502:physiology; D006624:Hippocampus / Q000166:cytology; D051379:Mice; D018345:Mice, Knockout; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009447:Neuroblastoma; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D019913:Nuclear Localization Signals / Q000378:metabolism*; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism; D011328:Prions / Q000235:genetics / Q000378:metabolism*; D014161:Transduction, Genetic / Q000379:methods
D000900:Anti-Bacterial Agents; D008869:Microtubule-Associated Proteins; C079240:Mtap2 protein, mouse; D019913:Nuclear Localization Signals; D010446:Peptide Fragments; D011328:Prions; D004318:Doxycycline; D003078:Colchicine