Related Experiment Video
Updated: May 9, 2026
09:33
Rapid Isolation of the Mitoribosome from HEK Cells
Published on: October 4, 2018
Membrane insertion of mitochondrial-encoded proteins regulates ribosome decoding speed
Thomas Schöndorf1,2, Valentyn Petrychenko3, Ilgin Kotan4
1Department of Cellular Biochemistry, University Medical Center Goettingen, Goettingen, Germany.
Nature Structural & Molecular Biology
|May 7, 2026
Summary
Mitochondrial protein synthesis is linked to membrane insertion. We visualized how nascent polypeptides fold and insert into the inner mitochondrial membrane during translation, revealing crucial connections between these processes.
Area of Science:
- Molecular Biology
- Cellular Metabolism
- Mitochondrial Biology
Background:
- The human mitochondrial genome encodes key proteins for oxidative phosphorylation, vital for cellular energy.
- Nascent polypeptide insertion into the inner mitochondrial membrane is facilitated by the OXA1L insertase.
- The precise mechanisms linking translation and membrane insertion of these polypeptides remain unclear.
Purpose of the Study:
- To elucidate the mechanism of nascent polypeptide membrane insertion.
- To understand the functional link between translation and protein folding at the inner mitochondrial membrane.
- To investigate cotranslational folding and insertion dynamics.
Main Methods:
- Ribosome profiling was employed to analyze translation dynamics.
- Cryo-electron microscopy was used to visualize the COX1 ribosome-nascent chain complex.
- Integrated analysis of translation and structural data.
Main Results:
- Membrane topology of the translated product influences translation speed.
- Amphipathic helix positioning within the ribosome vestibule causes structural changes.
- These structural changes correlate with observed translation pausing events.
Conclusions:
- A direct link exists between the translation process and the folding and membrane insertion of nascent polypeptides.
- The study provides structural insights into cotranslational membrane insertion at the inner mitochondrial membrane.
- Findings advance understanding of mitochondrial protein biogenesis and energy metabolism.
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