EXAM 4 LECTURE 2: PRIONS

prion

contains only protein material

prion

a type of protein that can trigger normal proteins in the brain to fold abnormally

by infected meat products

Prion diseases can affect both humans and animals. How can prion diseases be spread to human?

Prion Hypothesis

suggests that an abnormal conformer (PrPSc) of the cellular prion protein (PrPc) is capable of inducing PrPc to undergo a change of conformation into PrPSc

Brain looks spongy because of the tissues that were destroyed

What does prion folding do?

Bovine Spongiform Encephalopathy

Chronic Wasting Disease

Scrapie

What are some examples of prions found in animals?

Bonvine Spongiform Encephalopathy

a chronic degenerative disease affecting the central nervous system of cattle

"Mad cow disease"

they were fed left over cow meat that had been infected

humans get the disease from eating the contaminated meat (primarily in the brain or spinal cord tissue)

How do cows get bovine spongiform encephalopathy?

How do humans get it?

Chronic Wasting Disease

prion disease in elk and deer

causes them to walk as if they are "drunk"

currently being monitored in Indiana

Creutzfeldt-Jakob disease (CJD)

- prion in humans

- caused by abnormal prions that are not killed by standard methods of sterilizing surgical equipment

- causes those to lose ability to think and move properly and suffer memory loss. The brain SHRINKS

always fatal

1. sporadic/classical - unknown cause

2. familial/infectious - inherited mutation in genes

3. Iatrogenic - contamination in hospital

4. variant - exposure to BSE

What are the four different types of CJD?

Kuru

prion disease in New Guinea by the Fore tribe

After passings, brains were consumed by women and children. (cannibalism)

Symptoms: headache, joint pain, difficulty walking, death

viroids

Infectious particles that cause disease in plants

made up of genetic material

no protein coat

only a little larger than prions

potato spindle viroid

spread through contact between plants