NR ALER
AU Stockel,J.; Hartl,F.U.
TI Chaperonin-mediated de novo generation of prion protein aggregates
QU Journal of Molecular Biology 2001 Nov 2; 313(4): 861-72
PT journal article
AB The infectious prion protein, PrPsc, a predominantly beta-sheet aggregate, is derived from PrPc, the largely alpha-helical cellular isoform of PrP. Conformational conversion of PrPc into PrPsc has been suggested to involve a chaperone-like factor. Here we report that the bacterial chaperonin GroEL, a close homolog of eukaryotic Hsp60, can catalyze the aggregation of chemically denatured and of folded, recombinant PrP in a model reaction in vitro. Aggregates form upon ATP-dependent release of PrP from chaperonin and have certain properties of PrPsc, including a high beta-sheet content, the ability to bind the dye Congo red, detergent-insolubility and increased protease-resistance. A conserved sequence segment of PrP (residues 90-121), critical for PrPsc generation in vivo, is also required for chaperonin-mediated aggregate formation in vitro. Initial binding of refolded, alpha-helical PrP to chaperonin is mediated by the unstructured N-terminal segment of PrP (residues 23-121) and is followed by a rearrangement of the globular PrP core-domain. These results show that chaperonins of the Hsp60 class can, in principle, mediate PrP aggregation de novo, i.e. independently of a pre-existent PrPsc template.
MH Adenosine Triphosphate/metabolism; Animal; Chaperonin 60/chemistry; Chaperonins/chemistry/*metabolism; Congo Red/metabolism; Conserved Sequence; Endopeptidases/metabolism; GroEL Protein/chemistry/metabolism; GroES Protein/chemistry/metabolism; Hydrogen-Ion Concentration; Mice; Models, Biological; Prions/*chemistry/*metabolism; Protein Binding; Protein Denaturation; Protein Folding; Protein Renaturation; Protein Structure, Secondary; Protein Structure, Tertiary; Recombinant Fusion Proteins/chemistry/metabolism; Solubility; Support, Non-U.S. Gov't
AD Department of Cellular Biochemistry, Max-Planck-Institute of Biochemistry, Martinsried, D-82152, Germany.
SP englisch
PO England