The regulation of cholesterol synthesis is complex and occurs at multiple levels:
- Enzyme Regulation: The enzyme HMG-CoA reductase is the rate-limiting step and is tightly regulated by feedback inhibition, hormones, and phosphorylation. - Feedback Mechanisms: High levels of cholesterol inhibit the synthesis of HMG-CoA reductase and other enzymes involved in the pathway. - Gene Expression: Sterol regulatory element-binding proteins (SREBPs) regulate the expression of genes involved in cholesterol synthesis.
