Cholesterol metabolism Cholesterol disposal via hydroxylation is an important wa

Question

Cholesterol metabolism

Cholesterol disposal via hydroxylation is an important way to maintain cholesterol homeostasis. One protein that plays a critical role in this process is a cytochrome P-450 enzyme known as CYP27A1. This protein catalyzes the hydroxylation of cholesterol to form 27-hydroxycholesterol (an oxysterol). This oxysterol serves as a legend for the Liver X Receptor (LXR, a nuclear hormone receptor). LXR functions (in cooperation with the Retinoid X Receptor, RXR, by forming an LXR:RXR heterodimer) to increase the transcription of genes involved in maintaining cholesterol homeostasis. For each of the LXR targets listed below, describe the role of each in cholesterol metabolism (you may find it useful to talk about a particular tissue or cell-type

Explanation / Answer

a. ApoE- It acts as a signalling protein in blood and helps in transport of lipid and lipoproteins in blood. It is also responsible for cholesterol homeostasis regulation in brain.

b. LPL- LPL is important in cholesterol metabolism because it plays a role in transporting fats. It also functions in breaking down lipoproteins which are the fat-carrying molecules.

c. SR-B1- It is a cell-surface HDL receptor. It plays a crucial role in cholesterol metabolism by forming a productive lipoprotein/receptor complex which helps in mediating the uptake of HDL cholesterol.

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.