NR AWNZ
AU Solforosi,L.; Bellon,A.; Cruite,J.T.; Abalos,G.C.; Williamson,R.A.
TI Molecular dissection of PrPc-PrPsc interactions
QU International Conference - Prion 2006: Strategies, advances and trends towards protection of society - 3.10.-6.10.2006, Torino, Italy, Lingotto Conference Centre - Poster sessions S-23
PT Konferenz-Poster
AB Direct interaction between endogenous cellular prion protein (PrPc) and misfolded disease-associated (PrPsc) conformers is a key event in prion propagation that precedes templated conversion of PrPc into nascent PrPsc and prion infectivity. Although almost none of the molecular details of this process are understood, the persistence of individual prion strains suggests assembly of the prion replicative complex is mechanistically precise. The aim of our study was to systematically map defined regions of PrP sequence that bind tightly to PrPsc. For this purpose we have generated a panel of 45 motif-grafted antibodies containing overlapping peptide grafts collectively spanning PrP residues 19 to 231. These grafted-antibodies were applied in immunoprecipitation experiments to test their reactivity against PrPsc and PrP27-30. The binding experiments clearly identify only three distinct and independent high-affinity PrPsc recognition motifs. The first of these binding motifs lies at the very N-terminal region of the PrP molecule, within residues PrP 23-33; the second motif lies within PrP residues 89-112; and the third is contained within PrP residues 136-158. Additional binding studies performed with PrP-grafted antibodies containing mutations and truncations of the three PrPsc binding motifs have further defined the core components of these binding regions. The two N-terminal PrPsc recognition peptide motifs 19-33 and 89-112 bear a net positive charge, and elimination or reduction of this charge by exchanging lysine and arginine residues for alanine residues severely reduced or abolished reactivity with misassembled PrP conformers. Further, the reactivity of IgGs containing truncations and mutations of the original 136-158 PrP graft suggest that PrPsc recognition via this motif is chiefly facilitated through two segments of sequence composed of residues 136-140 and 149158. This study identifies three distinct regions of PrPc interacting with PrPsc and yield new insight into critical peptidic components composing one face of the prion replicative interface.
AD Laura Solforosi (lsolf@scripps.edu), Anne Bellon (abellon@scripps.edu), Justin T. Cruite, Gil C. Abalos, R. Anthony Williamson (anthony@scripps.edu), Department of Immunology, The Scripps Research Institute, La Jolla, California 92037, USA
SP englisch
PO Italien