NR AWPU
AU Veith,N.M.; Hüttner,K.; Thaa,B.; Niemann,H.; Brabeck,C.; Bürkle,A.
TI Phenotypic characterisation of microdeletions within the hydrophobic domain (AA 114-121) of the prion protein
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 CE-48
PT Konferenz-Poster
AB Within the N-terminal part of PrP there is a so-called "toxic peptide", a highly conserved segment comprised amino acids (aa) 105-125. Within the toxic peptide, extending from aa 112-119 there is a palindrome sequence (AGAAAAGA), also known as the hydrophobic domain or transmembrane region. This segment of PrP showed the highest tendency to form amyloid structures, and altering the sequence could modulate its structure and toxicity. The high amyloidogenic potential of PrP (aa105125) suggested that this region plays a critical role in the interaction of PrP molecules and their conversion into PrPsc. It was previously shown that PrP mutants with deletion of codons 114 to 121 (114-121) or 112-119 (112-119), which span most part of the subregion AGAAAAGA, were not convertible into PrPsc and additionally their overexpression resulted in a dominant-negative effect, i.e. inhibition of endogenous PrPsc accumulation (Hölscher et al., 1998; Norstrom et al., 2005). Recently we created several additional mutants of PrPc, i.e. 114-121, 114-115, 114-117, 114-119, 116119, 116-121, 118-121, 120-121 and investigated their convertibility into PrPsc. This was done by transfecting scrapie-infected N2a mouse neuroblastoma cells with the deletion mutants carrying a 3F4-tag. All mutants but one mutant, 114-115, were resistant to conversion into PrPsc. To analyse the possible dominant-negative effect of the new mutants we are currently doing co-transfection experiments with 3F4-tagged wild-type PrP combined an untagged PrP-mutant. Loss of 3F4-tagged proteinase K resistant PrP in immunoblots will be indicative of a dominant-negative effect of the mutant to be tested. Our present results indicate that very subtle deletions in the hydrophobic domain of PrP are sufficient to inhibit its conversion into PrPsc. Data about dominant-negative effects of the mutants will be discussed.
AD N.M. Veith, K. Hüttner, B. Thaa, C. Brabeck, A. Bürkle: Molecular Toxicology Group, Department of Biology, University of Konstanz, Germany; H. Niemann: Division of Tumor Virology, German Cancer Research Center, Heidelberg, Germany. E-mail: nathalie.veith@uni-konstanz.de
SP englisch
PO Italien