Intracellular refolding assay

Area of Science:

• Biochemistry
• Cell Biology
• Molecular Pharmacology

Background:

• Molecular chaperones regulate protein folding, crucial for cell survival under stress.
• Chaperone dysfunction is implicated in cancer and neurodegenerative diseases.
• Targeting chaperones with small molecules is a key therapeutic strategy.

Purpose of the Study:

• To describe a cell-based method for measuring molecular chaperone enzymatic activity.
• To evaluate the effects of compounds on chaperone refolding capabilities.
• To provide a tool for drug discovery in chaperone-related disorders.

Main Methods:

• Co-transfection of HEK-293 cells with chaperone and firefly luciferase genes.
• Inhibition of protein synthesis with cycloheximide, followed by heat shock-induced unfolding.
• Measurement of firefly luciferase activity post-recovery as a readout for chaperone-mediated refolding.
• Normalization using renilla luciferase as a transfection control.

Main Results:

• The assay successfully quantifies molecular chaperone refolding activity in a cellular context.
• The system allows for the assessment of compound effects on chaperone function.
• Heat-shocked cells show reduced luciferase activity, which is restored by chaperone activity.

Conclusions:

• This protocol offers a robust method for studying molecular chaperones and screening potential therapeutics.
• The cell-based assay facilitates the discovery of novel inhibitors or stimulators of chaperone activity.
• This approach has implications for developing treatments for cancer and neurodegenerative diseases.