The scrapie prion protein is present in flotillin-1-positive vesicles in central- but not peripheral-derived neuronal cell lines.
Abstract Transmissible prion diseases are fatal neurodegenerative diseases associated with the conversion of the normal host prion protein (PrP c) into an abnormal isoform (PrP Sc) that accumulates in brain. This pathology affects neurons of the central nervous system whereas no clear toxic effect has been reported for peripheral neurons. We examined the subcellular distribution of PrP c and PrP Sc in the scrapie-infected mouse neuronal cell lines GT1-7 and N2a, derived, respectively, from the central and peripheral nervous system. We observed that in both cell types, PrP c is present in the endocytic compartment, mainly in LAMP-1-positive late endosomes, but excluded from LYAAT-1-lysosomes. In contrast, PrP Sc was distributed differently in the two cell lines. In infected N2a, PrP Sc and PrP c had comparable distribution patterns. In infected GT1-7, PrP Sc is present in an additional vesicular compartment which is flotillin-1-positive. The level of expression of flotillin-1 is higher in GT1-7 than in N2a cells, but no difference is observed between infected and noninfected cells. In Alzheimer's disease patients, it has been reported that flotillin-1 is abundant in brain areas containing the beta-amyloid protein, which accumulates in endosomal vesicles in primary neurons. We propose that the flotillin compartment could store aggregated proteins and play a role in these neurodegenerative pathologies.
Pimpinelli
Federica
F
Institut de Pharmacologie et Biologie Structurale, Unité Mixte de Recherche 5089-Centre National de la Recherche Scientifique et Université Paul Sabatier, 205 route de Narbonne, 31077 Toulouse, France.
Lehmann
Sylvain
S
Maridonneau-Parini
Isabelle
I
D026905:Amino Acid Transport Systems / Q000378:metabolism; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D015153:Blotting, Western / Q000379:methods; D002460:Cell Line; D002490:Central Nervous System / Q000166:cytology*; D004705:Endocytosis / Q000502:physiology; D010450:Endopeptidases / Q000378:metabolism; D011992:Endosomes / Q000378:metabolism; D005110:Extracellular Space / Q000378:metabolism; D005455:Fluorescent Antibody Technique / Q000379:methods; D051907:Lysosomal Membrane Proteins; D008247:Lysosomes / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D017933:Peripheral Nervous System / Q000166:cytology*; D018621:PrPC Proteins / Q000378:metabolism; D018620:PrPSc Proteins / Q000378:metabolism*; D027981:Symporters; D013997:Time Factors; D014162:Transfection; D033921:Vesicular Transport Proteins; D001619:beta-N-Acetylhexosaminidases / Q000378:metabolism
D026905:Amino Acid Transport Systems; D015703:Antigens, CD; D051907:Lysosomal Membrane Proteins; D008565:Membrane Proteins; D018621:PrPC Proteins; D018620:PrPSc Proteins; C483904:Slc36a1 protein, mouse; D027981:Symporters; D033921:Vesicular Transport Proteins; C093846:early endosome antigen 1; C106354:flotillins; D001619:beta-N-Acetylhexosaminidases; D010450:Endopeptidases