Quantifying chaperone-mediated transitions in the proteostasis network of E. coli

Area of Science:

• Cellular Biology
• Biophysics
• Systems Biology

Background:

• Cellular function requires precise protein concentration maintenance (proteostasis).
• Chaperones manage proteostasis by interacting with client proteins, forming complexes within the proteostasis network.
• The FoldEco computational model simulates the E. coli proteostasis network, detailing species concentrations over time.

Purpose of the Study:

• To analyze the E. coli proteostasis network using a novel mediation probability calculation tool.
• To determine how chaperone systems mediate client protein conformational transitions (folding, misfolding correction).
• To investigate factors influencing chaperone system usage and interdependencies.

Main Methods:

• Application of a transition-path analysis tool to the FoldEco computational model.
• Calculation of mediation probabilities for chaperone systems in client protein conformational changes.
• Analysis of how mediation probabilities vary with different proteins and system parameters (e.g., synthesis rate).

Main Results:

• Chaperone systems do not operate independently and exhibit compensatory behavior when one is impaired.
• The usage of specific chaperone systems is influenced by client protein type and system parameters.
• Analysis of knockout experiments is complicated by chaperone system redundancy.

Conclusions:

• Chaperone systems display significant crosstalk and can compensate for each other.
• Understanding these interactions is crucial for interpreting experimental data, especially from knockout studies.
• The developed transition-path analysis provides a general method for studying complex reaction networks.