Prion strain mutation determined by prion protein conformational compatibility and primary structure

Area of Science:

• Neuroscience
• Molecular Biology
• Infectious Diseases

Background:

• Prions are misfolded proteins causing neurodegenerative diseases.
• The mechanism of prion strain mutation and CWD strain prevalence remain unclear.
• Chronic Wasting Disease (CWD) is an epidemic affecting cervids.

Purpose of the Study:

• To investigate the mechanism of prion strain mutation in cervids.
• To determine the prevalence and properties of different CWD strains.
• To understand the role of host prion protein structure in CWD propagation.

Main Methods:

• Transmission studies using susceptible transgenic mice.
• Biochemical characterization of PrPSc from different CWD strains.
• Analysis of cervid prion protein primary structures, focusing on residue 226.

Main Results:

• Two distinct CWD strains with different biological properties were identified.
• PrPSc from both strains showed indistinguishable biochemical characteristics.
• Elk PrPC supported stable CWD strain propagation, while deer PrPC showed unstable propagation and strain coexistence.
• A single amino acid difference at residue 226 between deer and elk PrPC was identified.

Conclusions:

• Cervid PrPC primary structure, specifically residue 226, influences CWD strain mutation and propagation.
• Prion strain diversity and propagation are determined by host protein structure and PrPSc conformational compatibility.
• Understanding these mechanisms is crucial for managing the CWD epidemic.