Enabling stop codon read-through translation in bacteria as a probe for amyloid aggregation.

Area of Science:

• Molecular Biology
• Bacterial Genetics
• Protein Chemistry

Background:

• Yeast possess prions like [PSI+], enabling translation read-through of stop codons.
• Bacteria like E. coli lack known functional prions for stop codon read-through, possibly due to robust quality control systems.

Purpose of the Study:

• To engineer a bacterial prion-like system in E. coli for stop codon read-through.
• To develop a novel in vivo screening system for anti-amyloidogenic compounds.

Main Methods:

• Engineered hydrophobic amyloidogenic repeats (RepA-WH1) into E. coli release factor RF1.
• Assessed read-through of a premature UAG stop codon in a beta-galactosidase reporter system.
• Tested the effect of natural polyphenols, including resveratrol, on the engineered RF1 chimeras.

Main Results:

• The engineered RF1 chimeras aggregated and promoted translation read-through of a UAG stop codon.
• This system effectively bypassed the bacterial translation quality checkpoint.
• Resveratrol demonstrated amyloid-solubilizing effects on the chimeras without toxicity or impacting beta-galactosidase activity.

Conclusions:

• Intended aggregation of a termination factor is a novel strategy to overcome bacterial translation quality control.
• Amyloidogenic RF1 chimeras provide a viable, cost-effective system for in vivo screening of anti-amyloidogenesis inhibitors.