Live-cell co-translational folding tracking reveals bidirectional coupling between translation and folding

Area of Science:

• Molecular Biology
• Cell Biology
• Biophysics

Background:

• Co-translational folding, the process of protein folding during translation, is crucial for cellular function.
• The coordination between translation elongation and protein folding has been hypothesized but difficult to study directly in live cells.

Purpose of the Study:

• To develop a novel live-cell imaging platform for simultaneous tracking of translation and protein folding from individual mRNAs.
• To investigate the mechanistic relationship between translation elongation rates and protein folding kinetics.

Main Methods:

• Development of co-translational folding tracking (coTFT), a live-cell imaging platform.
• Utilizing reporter proteins with distinct folding kinetics.
• Combining coTFT with mathematical modeling to estimate folding times on translating ribosomes.

Main Results:

• coTFT successfully tracked translation and folding simultaneously in live cells.
• Observed correlations between folding kinetics and translation elongation rates.
• Demonstrated that modulating translation elongation impacts protein folding outcomes.
• Estimated distinct folding times for reporter proteins on translating ribosomes.

Conclusions:

• Translation elongation and protein folding are bidirectionally coupled during co-translational folding.
• The developed coTFT platform provides new insights into the dynamics of co-translational protein folding.