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Single particle trajectories reveal active endoplasmic reticulum luminal flow
David Holcman1, Pierre Parutto2, Joseph E Chambers3
1Group of Applied Mathematics and Computational Biology, Ecole Normale Superieure, IBENS, Paris, France. david.holcman@ens.fr.
Nature Cell Biology
|September 19, 2018
Summary
Researchers discovered active ER luminal flow, driven by tubule contractions, which is crucial for distributing cellular contents. This finding impacts understanding of neurodegenerative disorders linked to ER structure.
Area of Science:
- Cell Biology
- Molecular Biology
- Neuroscience
Background:
- The endoplasmic reticulum (ER) is vital for protein synthesis and solute transport.
- ER luminal transport relies on molecular mobility, but diffusion alone is insufficient for long-distance transport.
- ER structure-function is critical, as mutations cause neurodegenerative disorders.
Purpose of the Study:
- To investigate the mechanisms of luminal transport within the endoplasmic reticulum.
- To correlate ER topology with luminal content trafficking modes.
- To identify the driving forces behind ER luminal flow.
Main Methods:
- Super-resolution microscopy to visualize ER structure.
- Single particle tracking of ER luminal proteins.
- Analysis of protein trajectories to determine movement patterns.
Main Results:
- ER luminal content exhibits distinct trafficking modes: diffusion in junctions and fast flow in tubules.
- An alternating current of ER contents was observed.
- Energy-dependent tubule contractions were identified as a mechanism for active ER luminal flow.
Conclusions:
- Active ER luminal flow, generated by tubule contractions, facilitates efficient content distribution.
- This active transport mechanism is essential for cellular functions, especially in neurons.
- Understanding ER flow dynamics offers insights into neurodegenerative diseases.
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