NR AQRH
AU Nixon,R.R.; Spilman,P.; DeArmond,S.J.
TI PrPsc is present in the plasma membrane of Sc-N2a cells
QU Journal of Neuropathology and Experimental Neurology 1997; 56(N5): 596 Nr. 101
PT Meeting Abstract
VT The transmissible encepholapathies are a group of progressive, fatal neurodegenerative disorders affecting humans and other mammals. The etiologic agent of these diseases is the prion which is composed principally, if not exclusively of PrPsc (an abnormal conformer of the normally expressed cellular protein PrPc). Most of what we know about the cellular biology of PrPc and PrPsc has been discovered using the neuroblastoma cell line N2a and its stably infected counter part ScN2a. Prior studies revealed PrPc is expressed on the external plasma membrane (PM) while PrPsc appears in an intracellular compartment, probably the lysosomes. These conclusions were based on the indirect findings of immunohistochemistry and the ability of the enzyme PIPLC to release PrP from the PM (indicating the presence of a glycosyl-phosphatidylinositol anchor). In other studies we identified numerous abnormalities involving the PM of PrPsc infected cells including multiple alterations in receptors (increased numbers, decreased affinity, and lack of function) and a 7 fold decrease in PM fluidity. The current studies involved the purification and comparison of the PM from infected and uninfected cell lines to see if compositional differences could be identified. As assayed by Western blot, PrPc was found in the PM fractions from both N2a and ScN2a lines. Following proteinase K digestion of the PM fractions, PrPsc was identified in the PM of ScN2a cells. Furthermore, surface biotinylation of ScN2a cells followed by proteinase K digestion of the isolated PM fractions and immunoprecipitation with a PrP specific antibody revealed biotinviated PrPsc. Thus PrPsc is present on the external PM surface of scrapie infected cells and this may contribute to the decreased PM fluidity.
IN Bei der scrapieinfizierten Neuroblastomzelllinie ScN2a befindet sich offensichtlich das proteaseresistente Prionprotein auch auf der Zelloberfläche.
ZR 0
SP englisch
AD Randal R. Nixon, Patricia Spilman, and Stephen J. DeArmond*. Univ. California, San Francisco, USA, 94143-0506
OR Prion-Krankheiten 6