cellular response to low-density lipoprotein particle stimulus

Definition

Target type: biologicalprocess

Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a low-density lipoprotein particle stimulus. [GOC:mah]

Cellular response to low-density lipoprotein particle stimulus is a complex process that involves a series of coordinated events, beginning with the binding of LDL particles to specific receptors on the cell surface. These receptors, primarily LDL receptor (LDLR), are responsible for mediating the uptake of LDL into the cell.

The binding of LDL to LDLR triggers a cascade of events that leads to the internalization of the LDL-receptor complex via endocytosis. This process involves the formation of clathrin-coated pits on the cell membrane, into which the LDL-receptor complex is incorporated. The coated pits then invaginate and pinch off to form intracellular vesicles called endosomes.

Within the endosomes, the LDL-receptor complex is sorted. The LDL is released from the receptor and transported to lysosomes, where it is broken down into its constituent parts: cholesterol, fatty acids, and amino acids. The cholesterol is then utilized by the cell for various functions, including membrane synthesis and hormone production.

Meanwhile, the LDLR is recycled back to the cell surface to participate in further rounds of LDL uptake. This recycling process ensures a constant supply of LDLR at the cell surface, allowing for the continuous uptake of LDL.

The regulation of LDL uptake is tightly controlled by several factors, including the concentration of cholesterol within the cell. When cholesterol levels are high, the synthesis of new LDLR is suppressed, and the existing LDLR is degraded at a faster rate, resulting in a decrease in LDL uptake. Conversely, when cholesterol levels are low, the synthesis of new LDLR is increased, and the degradation of existing LDLR is slowed down, leading to an increase in LDL uptake.

Dysregulation of LDL uptake can lead to various health problems. For example, mutations in the LDLR gene can result in familial hypercholesterolemia, a genetic disorder characterized by high levels of LDL in the blood. This condition can lead to premature atherosclerosis, a buildup of plaque in the arteries, which can increase the risk of heart attack and stroke.

In summary, cellular response to low-density lipoprotein particle stimulus involves a series of intricate steps that ensure the efficient uptake and processing of LDL, ultimately contributing to the maintenance of cellular cholesterol homeostasis.'
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Proteins (8)

Compounds (495)