endoplasmic reticulum-Golgi intermediate compartment

Definition

Target type: cellularcomponent

A complex system of membrane-bounded compartments located between endoplasmic reticulum (ER) and the Golgi complex, with a distinctive membrane protein composition; involved in ER-to-Golgi and Golgi-to-ER transport. [GOC:pr, PMID:16723730]

The endoplasmic reticulum (ER)-Golgi intermediate compartment (ERGIC) is a dynamic and complex cellular structure that serves as a critical transit station between the ER and the Golgi apparatus. It is a network of interconnected, membrane-bound tubules and vesicles that extend from the ER outward towards the Golgi stack. The ERGIC plays a crucial role in protein sorting, modification, and transport, ensuring the proper delivery of newly synthesized proteins to their final destinations within the cell.

**Structure:**
* The ERGIC is characterized by its tubular-vesicular morphology, with a distinctive interconnected network of tubules and vesicles.
* The ERGIC is not a static structure but rather a dynamic compartment that constantly undergoes remodeling and reorganization.
* Its structure is influenced by factors like protein transport needs, cell type, and cellular stress.

**Function:**
* **Protein sorting:** The ERGIC acts as a sorting station for proteins synthesized in the ER. It helps to segregate proteins destined for the Golgi apparatus from those that remain in the ER.
* **Protein modification:** The ERGIC further modifies proteins by adding glycosylation modifications, which play crucial roles in protein folding, stability, and targeting.
* **Transport:** The ERGIC serves as a key hub for protein transport, facilitating the movement of proteins from the ER to the Golgi apparatus.
* **Quality control:** The ERGIC also plays a role in quality control, ensuring that only properly folded and modified proteins are transported to the Golgi.

**Molecular composition:**
* The ERGIC is enriched in specific proteins, including:
* **ERGIC53:** A transmembrane protein that serves as a marker for the ERGIC and plays a role in protein sorting.
* **Rab proteins:** GTPases involved in vesicle budding and transport.
* **SNARE proteins:** Proteins that mediate vesicle fusion and membrane trafficking.
* The ERGIC also contains various enzymes involved in glycosylation, protein folding, and other post-translational modifications.

**Relationship to other compartments:**
* The ERGIC is closely associated with the ER and the Golgi apparatus.
* It receives proteins from the ER and subsequently delivers them to the Golgi.
* The ERGIC is considered a transitional compartment between the ER and the Golgi, bridging the gap between these two critical organelles.

**Significance:**
* The ERGIC plays a vital role in cellular function, ensuring the proper trafficking and modification of proteins.
* Defects in ERGIC function can lead to various cellular dysfunctions and diseases.
* Studying the ERGIC provides insights into the complex processes of protein secretion, glycosylation, and cellular signaling.

**Conclusion:**
The ERGIC is an essential cellular compartment that acts as a central hub for protein sorting, modification, and transport. Its dynamic structure and molecular composition contribute to the efficient and regulated movement of proteins between the ER and the Golgi apparatus, ultimately ensuring the proper functioning of the cell.'
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Proteins (12)

Compounds (366)