Resisting the Heat: Bacterial Disaggregases Rescue Cells From Devastating Protein Aggregation

Area of Science:

• Microbiology
• Molecular Biology
• Biochemistry

Background:

• Bacteria face environmental stress, particularly heat, leading to protein misfolding and aggregation.
• Cellular disaggregases, belonging to the Hsp100/AAA+ family, are crucial for solubilizing and reactivating aggregated proteins, ensuring bacterial survival and recovery.

Purpose of the Study:

• To compare the mechanisms and regulatory modes of two key bacterial Hsp100/AAA+ disaggregases: ClpB and ClpG.
• To elucidate the cooperative and autonomous functions of these disaggregases in protein aggregate repair and heat resistance.

Main Methods:

• Comparative analysis of ClpB and ClpG disaggregase mechanisms.
• Investigation of chaperone interactions, specifically Hsp70's role with ClpB.
• Examination of regulatory control and substrate interaction in disaggregase activity.

Main Results:

• ClpB disaggregase requires Hsp70 for targeting to aggregates and activation, with activity tightly regulated.
• ClpG disaggregase functions autonomously, with activity controlled by substrate interaction, offering enhanced disaggregation.
• ClpG confers significant heat resistance to bacteria, including pathogens, and its genes are horizontally transferable.

Conclusions:

• ClpB and ClpG represent distinct strategies for protein disaggregation in bacteria, with ClpG offering superior heat tolerance.
• The spread of ClpG via horizontal gene transfer poses a significant threat to food safety due to enhanced bacterial heat resistance.