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Published on: July 30, 2014
ER cargo properties specify a requirement for COPII coat rigidity mediated by Sec13p
Alenka Copic1, Catherine F Latham, Max A Horlbeck
1Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
Science (New York, N.Y.)
|February 4, 2012
Summary
Sec13p protein is essential for forming transport vesicles from the endoplasmic reticulum. Its function in vesicle formation can be bypassed by mutations that alter membrane properties, suggesting a role in membrane curvature.
Area of Science:
- Cell Biology
- Molecular Biology
- Protein Dynamics
Background:
- Eukaryotic protein transport relies on COPII-coated vesicles budding from the ER.
- The Sec13-Sec31 complex is the outer layer of the COPII coat, hypothesized to induce membrane curvature.
- Understanding COPII coat function is crucial for deciphering intracellular trafficking pathways.
Purpose of the Study:
- To investigate the role of Sec13p in COPII vesicle formation.
- To explore how compromised COPII coats function within specific cellular contexts.
- To elucidate the relationship between coat structure and membrane deformation during vesicle budding.
Main Methods:
- Utilized yeast bypass-of-sec-thirteen (bst) mutants.
- Performed genetic analyses to assess protein function.
- Conducted biochemical assays to study vesicle formation.
Main Results:
- Sec13p is dispensable in bst mutants, allowing for functional studies of a weakened COPII coat.
- Sec13p is required for vesicle generation from membranes with asymmetric, curvature-inducing cargoes.
- The necessity of Sec13p diminishes when mutations increase membrane deformability.
Conclusions:
- Sec13p likely rigidifies the COPII cage, enhancing its membrane-bending capability.
- Membrane properties, such as deformability, influence the requirement for Sec13p in vesicle formation.
- This study provides insights into the mechanical regulation of COPII vesicle biogenesis.
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