low-density lipoprotein particle receptor activity

Definition

Target type: molecularfunction

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

Low-density lipoprotein particle receptor activity is a crucial molecular function involved in the uptake and metabolism of low-density lipoproteins (LDLs), also known as "bad cholesterol," from the bloodstream. LDLs are composed of a core of cholesterol esters and triglycerides surrounded by a phospholipid monolayer containing apolipoprotein B-100 (apoB-100), a protein that acts as a ligand for LDL receptors. LDLs are essential for delivering cholesterol to various tissues throughout the body, but high levels of LDL in the blood can lead to the accumulation of cholesterol in the arteries, contributing to atherosclerosis and heart disease.

The process of LDL uptake is initiated when apoB-100 on the LDL particle binds to the LDL receptor, a transmembrane protein found on the surface of cells. This binding event triggers a cascade of events that ultimately leads to the internalization of the LDL particle and the release of cholesterol into the cell. Internalization involves the invagination of the cell membrane, forming a vesicle called an endosome. The endosome then fuses with a lysosome, an organelle containing enzymes that degrade the LDL particle, releasing cholesterol into the cell.

Low-density lipoprotein particle receptor activity is regulated by various factors, including the levels of cholesterol in the cell and the availability of LDL in the bloodstream. When intracellular cholesterol levels are high, the synthesis of LDL receptors is suppressed, reducing LDL uptake. Conversely, when cholesterol levels are low, LDL receptor synthesis is stimulated, increasing LDL uptake. This feedback mechanism helps to maintain cholesterol homeostasis in the body.

In summary, low-density lipoprotein particle receptor activity is a vital cellular function that plays a critical role in cholesterol metabolism and cardiovascular health. By mediating the uptake of LDLs, this activity ensures that cells have an adequate supply of cholesterol for membrane synthesis and other essential functions. Dysregulation of this activity can contribute to the development of atherosclerosis and other cardiovascular diseases.'
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Proteins (1)

Compounds (1)