clathrin-coated vesicle membrane

Definition

Target type: cellularcomponent

The lipid bilayer surrounding a clathrin-coated vesicle. [GOC:mah]

Clathrin-coated vesicles (CCVs) are small, spherical membrane-bound organelles that play a critical role in intracellular trafficking. Their membranes are characterized by a distinctive coat composed of the protein clathrin, which is assembled into a lattice-like structure. This coat provides structural support and helps in the selective packaging of cargo molecules for transport.

The clathrin-coated vesicle membrane is a complex structure that includes a variety of integral and peripheral membrane proteins.

**Integral membrane proteins** are embedded within the lipid bilayer and play diverse roles in vesicle formation, cargo selection, and membrane dynamics. Key examples include:

* **Adaptor proteins (APs):** These proteins bind to specific cargo molecules and mediate their recruitment to the clathrin coat. There are four main types of AP complexes (AP-1, AP-2, AP-3, and AP-4), each with distinct functions and cargo preferences.
* **Transmembrane cargo proteins:** These proteins are destined for transport to other cellular compartments and are directly or indirectly bound to APs. Examples include receptors, enzymes, and signaling molecules.
* **SNAREs:** These proteins are involved in the fusion of vesicles with target membranes. They interact with complementary SNAREs on the target membrane to facilitate membrane fusion.

**Peripheral membrane proteins** associate with the cytosolic surface of the membrane without being embedded in the lipid bilayer. They play crucial roles in regulating vesicle formation, cargo sorting, and coat assembly. Key examples include:

* **Clathrin:** The primary structural component of the coat, clathrin is a triskelion-shaped protein that assembles into a polyhedral cage around the vesicle.
* **Auxilin and Hsc70:** These proteins work together to disassemble the clathrin coat after vesicle formation, allowing the vesicle to deliver its cargo to the target membrane.
* **Dynamin:** This GTPase protein forms a ring around the neck of the budding vesicle and plays a crucial role in pinching off the vesicle from the donor membrane.

The lipid composition of the clathrin-coated vesicle membrane is also important for its function. Phosphoinositides, particularly phosphatidylinositol 4,5-bisphosphate (PIP2), are enriched in the membrane and play a role in recruiting and activating various signaling proteins, including APs and dynamin.

Overall, the clathrin-coated vesicle membrane is a highly specialized structure that enables efficient and selective transport of cargo molecules throughout the cell. It is a dynamic platform that undergoes constant assembly and disassembly, ensuring the proper delivery of essential molecules to their target destinations.'
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Proteins (3)

Compounds (5)