1. What is SREBP? What does it do?
2. Partners? (2)
3. Role of SREBP in cholesterol metabolism?
4. SREBP 1 vs. SREBP2? Do they work together or separately?
5. Role of insulin? Liver? Adipose tissue? Lipogenesis vs. lipolysis? (3)
1. Sterol REgulatory Binding Protein - tx regulator of lipid metabolism.
2. SCAP + INSIG
3. Low cholesterol --> SREBP signaling protein is cleaved goes to nucleus --> activates expression of LDL receptor, HMG CoA reductase, and FA biosynthetic genes.
4. SREBP1 - increases lipogenesis. SREBP2 - increases cholesterol synthesis. They work simultaneously.
5. Insulin activates SREBP1 promoting lipogenesis and secretion of lipids in VLDL form from liver.
- Adipose tissue: insulin binds to receptor -->
- increases SREBP1 --> increases lipogenesis.
Insulin also inhibits B-oxidation, increases glucose/lipid uptake, increases proteins involved in lipid uptake/esterification pathways.