The objective of my research is to understand how altered conformations of the prion protein (PrP) arise and produce disease. During the project period, I expressed mutant PrP genes in scrapie-infected neuroblastoma (ScN2a) cells and transgenic (Tg) mice, and studied the pathological and biochemical changes induced by these mutations. These studies generated several significant results. (1) I established that a 106 amino acid PrP deletion mutant PrP(delta23-88,delta141- 176), designated PrP106, forms infectious miniprions efficiently in Tg mice. I also found that PrP106 molecules are destabilized and spontaneously adopt a conformation poised to form prions. (2) I discovered that a shorter PrP deletion mutant PrP(delta23-88,delta141-221), designated PrP61, spontaneously forms amyloid rods and causes apoptotic neurodegeneration when expressed in Tg mice. (3) Finally, I demonstrated that three different strains of murine prions cause scrapie in Tg(PrPl06)Prnp 0/0 mice. In this application for a two-year extension to my original award, I propose to pursue three new, important experiments based on my interim results. * I will use PrP106 as a substrate to generate minipdons efficiently in vitro. * I will inoculate synthetic PrP61 peptides into indicator animals to determine whether these peptides can cause infectious prion disease. * Finally, I will use pathological and immunological assays to determine whether passage through Tg(PrP106)Prnpa0/0 mice caused three different murine prion strains to converge into one phenotype or whether they remained distinct.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Clinical Investigator Award (CIA) (K08)
Project #
2K08NS002048-04
Application #
6337775
Study Section
NST-2 Subcommittee (NST)
Program Officer
Kerza-Kwiatecki, a P
Project Start
1998-07-20
Project End
2003-06-30
Budget Start
2001-09-01
Budget End
2002-08-31
Support Year
4
Fiscal Year
2001
Total Cost
$132,300
Indirect Cost
Name
Dartmouth College
Department
Biochemistry
Type
Schools of Medicine
DUNS #
041027822
City
Hanover
State
NH
Country
United States
Zip Code
03755
Nishina, Koren; Deleault, Nathan R; Lucassen, Ralf W et al. (2004) In vitro prion protein conversion in detergent-solubilized membranes. Biochemistry 43:2613-21
Deleault, Nathan R; Dolph, Patrick J; Feany, Mel B et al. (2003) Post-transcriptional suppression of pathogenic prion protein expression in Drosophila neurons. J Neurochem 85:1614-23
Lucassen, Ralf; Nishina, Koren; Supattapone, Surachai (2003) In vitro amplification of protease-resistant prion protein requires free sulfhydryl groups. Biochemistry 42:4127-35
Supattapone, S; Bouzamondo, E; Ball, H L et al. (2001) A protease-resistant 61-residue prion peptide causes neurodegeneration in transgenic mice. Mol Cell Biol 21:2608-16