Related Experiment Video
Updated: Jul 24, 2026
11:41
Evaluation of an Exclusive Spur Dike U-Turn Design with Radar-Collected Data and Simulation
Published on: February 1, 2020
ER export: public transportation by the COPII coach
1Institut de Pharmacologie Moléculaire et Cellulaire, CNRS, 660 route des Lucioles, 06560, Valbonne, France. antonny@ipmc.cnrs.fr
Current Opinion in Cell Biology
|July 17, 2001
Summary
The COPII coat forms transport vesicles from the ER. Its dynamic nature and cargo capture depend on export signals, membrane conditions, metabolism, and COPII subunit variations.
Area of Science:
- Cell biology
- Molecular biology
- Biochemistry
Background:
- The endoplasmic reticulum (ER) is a key organelle for protein synthesis and modification.
- ER-derived transport vesicles mediate the trafficking of proteins and lipids within the cell.
- The COPII (coat protein complex II) coat is essential for forming these transport vesicles at ER exit sites.
Purpose of the Study:
- To elucidate the dynamic nature of the COPII coat.
- To identify the key parameters governing efficient cargo capture into COPII vesicles.
- To understand the role of COPII subunit homologues in vesicle formation.
Main Methods:
- Biochemical assays to study COPII coat polymerization.
- In vitro reconstitution of vesicle budding.
- Analysis of cargo-receptor interactions.
- Genetic manipulation to study COPII subunit function.
Main Results:
- The COPII coat functions as a dynamic polymer.
- Cargo capture is influenced by specific export signals on cargo molecules.
- Membrane lipid composition and metabolic state significantly impact vesicle formation.
- A diverse set of COPII subunit homologues contributes to cargo specificity and vesicle biogenesis.
Conclusions:
- The COPII coat is a sophisticated molecular machine whose assembly and function are tightly regulated.
- Efficient ER-to-Golgi transport relies on a complex interplay of cargo signals, membrane properties, cellular metabolism, and COPII component diversity.
- Understanding these parameters is crucial for deciphering cellular trafficking pathways and associated diseases.
Related Concept Videos
02:12Short-distance Transport of Resources
Short-distance transport refers to transport that occurs over a distance of just 2-3 cells, crossing the plasma membrane in the process. Small uncharged molecules, such as oxygen, carbon dioxide, and water, can diffuse across the plasma membrane on their own. In contrast, ions and larger molecules require the assistance of transport proteins due to their charge or size. Transport across membranes also occurs within individual cells, playing a variety of essential roles for the plant as a whole.
01:31ABC Transporters: Exporter
ATP-binding cassette or ABC transporter is the largest superfamily of integral membrane proteins. The transporters have transmembrane-binding domains (TMDs) and nucleotide-binding domains (NBDs). The TMDs are specific to their substrates, whereas the NBDs are similar to engines that complete ATP hydrolysis to complete the substrate transport. They can be full transporters consisting of two TMDs and NBDs, half transporters with one TMD and NBD, while some encoded with a single TMD or NBD are...
01:27ABC Transporters: Importer
ATP-binding cassette or ABC transporters are a class of ATP-driven pumps that hydrolyze ATP to move solutes across the membrane. They can be grouped into importers and exporters. While exporters are present in all domains of life, importers exist only in bacteria and some plants.
In bacteria, based on the number of transmembrane helices and the chemical nature of their substrates, the ABC importers can be divided into three types:
In bacteria, based on the number of transmembrane helices and the chemical nature of their substrates, the ABC importers can be divided into three types:
01:21Carrier Transport
The generation of electrical current in semiconductors is fundamentally driven by two mechanisms: drift and diffusion. These processes are essential for the functionality and performance of semiconductor-based devices.
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
Drift Current:
The drift of charge carriers is started by an external electric field (E). Charged particles, such as electrons and holes, experience an acceleration between collisions with lattice atoms. For electrons, this results in a drift velocity (vd) given by:
01:29Electrical Transport
The electrical transport property of a material is defined by its resistance and conductivity. Resistance is the measure of a material's ability to resist the flow of electric current, while conductivity gauges its ability to allow the current to pass through, depending on the geometry of the measurement cell, such as electrode spacing and area. Conductivity is measured in Siemens (S). There are different types of conductance, including specific conductance, equivalent conductance, and molar...
01:31Transport Number
The transport number is the fraction of the total current carried by an ion in an electrolyte solution. It is defined as the ratio of the current carried by a specific ion to the total current flowing through the solution. The transport number, t, is central to understanding ionic mobility, which describes how fast an ion moves under the influence of an electric field. This link connects the physical behavior of ions in solution to the chemical processes that occur during electrochemical...