very-low-density lipoprotein particle receptor activity

Definition

Target type: molecularfunction

Combining with a very-low-density lipoprotein particle and delivering the very-low-density lipoprotein into the cell via endocytosis. [GOC:bf, ISBN:0198506732]

Very-low-density lipoprotein (VLDL) particle receptor activity involves the recognition and binding of VLDL particles, a type of lipoprotein responsible for transporting lipids, including triglycerides and cholesterol, from the liver to peripheral tissues. The receptor facilitates the uptake of VLDL particles into cells, primarily by endocytosis. This process is crucial for maintaining lipid homeostasis and preventing the accumulation of lipids in the bloodstream.

Here is a detailed breakdown of the molecular function:

**1. Recognition and Binding:**
- VLDL receptors possess specific binding sites that recognize and bind to VLDL particles.
- The interaction involves the recognition of specific apolipoproteins associated with VLDL, particularly apolipoprotein B-100 (apoB-100).
- This binding event is highly specific and dependent on the conformation and structure of apoB-100.

**2. Endocytosis:**
- Upon binding, the VLDL receptor undergoes a conformational change, triggering the formation of a coated pit.
- The coated pit invaginates, engulfing the VLDL particle and its associated receptor, forming an endocytic vesicle.
- The endocytic vesicle then detaches from the cell membrane and moves towards the cell's interior.

**3. Intracellular Trafficking and Degradation:**
- Within the cell, the endocytic vesicle fuses with lysosomes, acidic organelles containing hydrolytic enzymes.
- The lysosomal enzymes break down the VLDL particle, releasing its lipid components.
- The liberated lipids can be used by the cell for energy production, membrane synthesis, or other metabolic processes.

**4. Receptor Recycling:**
- The VLDL receptor is not degraded in the lysosome.
- It is recycled back to the cell surface, where it can bind to additional VLDL particles and repeat the endocytic cycle.

**5. Regulation:**
- VLDL receptor activity is subject to regulation by various factors, including dietary lipids, hormones (e.g., insulin), and intracellular signaling pathways.
- These regulatory mechanisms ensure that VLDL uptake is appropriately coordinated with the body's metabolic needs.'
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Proteins (1)

Compounds (1)