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Updated: Jul 2, 2026
12:13
Single-Molecule Imaging of Nuclear Transport
Published on: June 9, 2010
Take the 'A' train: on fast tracks to the cell surface
M Marie1, R Sannerud, H Avsnes Dale
1Section of Anatomy and Cell Biology, Department of Biomedicine, University of Bergen, Jonas Lies Vei 91, 5009 Bergen, Norway.
Cellular and Molecular Life Sciences : CMLS
|August 30, 2008
Summary
Two novel Golgi-bypass pathways transport proteins and lipids from the endoplasmic reticulum to the plasma membrane. These pathways are BFA-insensitive and involve the intermediate compartment, impacting cellular secretion.
Area of Science:
- Cell Biology
- Molecular Biology
- Membrane Trafficking
Background:
- Proteins, lipids, and viruses synthesized in the endoplasmic reticulum (ER) traffic to the plasma membrane (PM) through poorly understood non-classical pathways.
- These pathways are characterized by brefeldin A (BFA) insensitivity, rapid kinetics, and involvement in lipid raft component trafficking.
Purpose of the Study:
- To elucidate the mechanisms and pathways involved in the non-classical transport of ER-synthesized molecules to the PM.
- To investigate the role of the intermediate compartment (IC) in Golgi-bypass transport.
Main Methods:
- Analysis of the intermediate compartment (IC) structure and dynamics in the presence of brefeldin A (BFA).
- Characterization of transport kinetics and BFA sensitivity of non-classical pathways.
Main Results:
- The intermediate compartment (IC) forms a stable, BFA-insensitive tubular network at the ER-Golgi boundary.
- Two distinct Golgi-bypass pathways to the PM originating from the IC were identified: a direct route from early IC elements and an indirect route via the endosomal system from late IC elements.
Conclusions:
- The IC serves as a critical hub for at least two bidirectional Golgi-bypass pathways to the PM.
- These pathways facilitate the efficient transport of specific cargo, including lipids and proteins, and influence the organization of secretory processes.
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