Mhr Topic 35: Prions

Front 1

3 forms of prion disease and the diseases which fall under each category

Back 1

Sporadic: CJD
Genetic: CJD, GSS, FFI
Infectious: Kuru

Front 2

Clinical factors which characterize prion diseases

Back 2

Incubation is years, symptoms last 6 months to 5 years:
-Demetia
-Ataxia
-Tremor
-Myoclonus
-Death

Front 3

Similarities and differences between prion disease and Alzheimer's disease

Back 3

Sims:
-Both have familial forms
-Dementia
-Amyloid plaques
Difs:
-AD is not infectious
-Origin of amyloid (APP vs PrP for AD and prions respectively).

Front 4

What is the mechanism underlying prion disease?

Back 4

Conformational change of the PrP protein from alpha helical to beta sheet.

Front 5

PrPc vs PrPsc (location, protease sensitivity, solubility)

Back 5

1) c = Normal cell surface protein. sc = Present only in diseased brain.
2) c = protease sensitive. sc = protease resistant.
3) c = Detergent soluable. sc = Insoluable.

Front 6

Evidence for Prion Hypothesis

Back 6

1) PrPsc only seen in diseased brain.
2) Prpsc preparations contain little nucleic acid.
3) Agents which destroy DNA and RNA dont effect infectivity, those which denature protein do.
4) PrP gene sequence controls incubation time and neuropathy.
5) Mutations in PrP gene cause familial prion disease
6) Hamster PrP transgene renders mice susceptible to hamster prion.
7) PrP knockout mice are resistant to scrapie.