trans-Golgi network transport vesicle

Definition

Target type: cellularcomponent

A vesicle that mediates transport between the trans-Golgi network and other parts of the cell. [GOC:mah]

Trans-Golgi network (TGN) transport vesicles are small, membrane-bound compartments that bud off from the TGN, a specialized region of the Golgi apparatus. These vesicles are essential for the efficient sorting and delivery of proteins and lipids to their final destinations within the cell. They are typically 50-100 nm in diameter and contain a diverse array of proteins, including cargo receptors, adaptors, and coat proteins.

The formation of TGN transport vesicles is a highly regulated process involving several key steps:

1. **Cargo Sorting:** Proteins destined for different cellular compartments, such as lysosomes, endosomes, and the plasma membrane, are sorted at the TGN. Cargo receptors bind to specific sorting signals within the proteins, ensuring that the correct cargo is packaged into the appropriate vesicle.

2. **Coat Recruitment:** Coat proteins assemble on the TGN membrane to shape and deform the membrane, forming a bud. Different coat proteins are associated with different types of transport vesicles. For example, clathrin-coated vesicles are involved in trafficking to lysosomes and endosomes, while COPI-coated vesicles transport proteins back to the ER.

3. **Vesicle Budding:** The coat proteins and other factors promote membrane curvature and eventually pinch off the vesicle from the TGN.

4. **Uncoating:** Once the vesicle has budded, the coat proteins are typically removed, allowing the vesicle to interact with its target membrane.

5. **Transport and Fusion:** The vesicle then travels through the cytoplasm to its target compartment, where it fuses with the membrane and releases its cargo.

**Key Features of TGN Transport Vesicles:**

* **Membrane Composition:** The vesicle membrane is enriched in specific lipids, such as cholesterol and sphingolipids, which contribute to the vesicle's stability and targeting.
* **Protein Composition:** TGN transport vesicles contain a diverse array of proteins, including:
* **Cargo receptors:** Bind specific cargo proteins and facilitate their sorting into the vesicles.
* **Adaptors:** Link cargo receptors to the coat proteins and help to stabilize the vesicle bud.
* **Coat proteins:** Shape the vesicle membrane and facilitate budding.
* **Rab GTPases:** Small GTPases that regulate vesicle trafficking and fusion.
* **SNARE proteins:** Membrane-bound proteins that mediate vesicle fusion with target membranes.

**TGN Transport Vesicles in Disease:**

Dysregulation of TGN transport vesicle formation and function can contribute to a wide range of human diseases, including:

* **Neurodegenerative disorders:** Defects in TGN transport can disrupt protein trafficking in neurons, leading to the accumulation of misfolded proteins and neuronal dysfunction.
* **Metabolic diseases:** Disruptions in lipid and protein trafficking from the TGN can affect cellular metabolism and contribute to metabolic disorders.
* **Cancer:** Altered TGN transport can promote cancer cell growth and metastasis.

The study of TGN transport vesicles is essential for understanding cellular function and for developing therapeutic strategies for a variety of human diseases.'
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Proteins (3)

Compounds (9)