Characterization of intracellular localization of PrPSc in prion-infected cells using a mAb that recognizes the region consisting of aa 119―127 of mouse PrP

• Published in: Journal of general virology 2012-03, Vol.93 (3), p.668-680
• Main Authors: YAMASAKI, Takeshi, SUZUKI, Akio, SHIMIZU, Takeshi, WATARAI, Masahisa, HASEBE, Rie, HORIUCHI, Motohiro
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Microbiology; Miscellaneous; Non conventional transmissible agents; Virology
• ISSN: 0022-1317; 1465-2099
• DOI: 10.1099/vir.0.037101-0

Generation of an abnormal isoform of the prion protein (PrP Sc ) is a key aspect of the propagation of prions. Elucidation of the intracellular localization of PrP Sc in prion-infected cells facilitates the understanding of the cellular mechanism of prion propagation. However, technical improvement in PrP Sc -specific detection is required for precise analysis. Here, we show that the mAb 132, which recognizes the region adjacent to the most amyloidogenic region of PrP, is useful for PrP Sc -specific detection by immunofluorescence assay in cells pre-treated with guanidine thiocyanate. Extensive analysis of the intracellular localization of PrP Sc in prion-infected cells using mAb 132 revealed the presence of PrP Sc throughout endocytic compartments. In particular, some of the granular PrP Sc signals that were clustered at peri-nuclear regions appeared to be localized in an endocytic recycling compartment through which exogenously loaded transferrin, shiga and cholera toxin B subunits were transported. The granular PrP Sc signals at peri-nuclear regions were dispersed to the peripheral regions including the plasma membrane during incubation at 20 °C, at which temperature transport from the plasma membrane to peri-nuclear regions was impaired. Conversely, dispersed PrP Sc signals appeared to return to peri-nuclear regions within 30 min during subsequent incubation at 37 °C, following which PrP Sc at peri-nuclear regions appeared to redisperse again to peripheral regions over the next 30 min incubation. These results suggest that PrP Sc is dynamically transported along with the membrane trafficking machinery of cells and that at least some PrP Sc circulates between peri-nuclear and peripheral regions including the plasma membrane via an endocytic recycling pathway.