Molecular Classification
Enzyme, Acyltransferase
Other Names
Sterol O-acyltransferase, SOAT, SOAT1, SOAT2, ACAT1, ACAT2
Disease Roles
AtherosclerosisAlzheimer's DiseaseCancer

Acyl-CoA Cholesterol Acyltransferase Overview

Acyl-CoA cholesterol acyltransferase (ACAT), also known as sterol O-acyltransferase (SOAT), is a membrane-bound enzyme that catalyzes the formation of cholesteryl esters from cholesterol and long-chain fatty acyl-CoA. This reaction is crucial for cellular cholesterol homeostasis, as it converts potentially toxic free cholesterol into a storage form—cholesteryl esters—which are sequestered in cytoplasmic lipid droplets or incorporated into lipoproteins. There are two main isoenzymes in mammals: ACAT1 (SOAT1), ubiquitously expressed and primarily involved in intracellular cholesterol homeostasis, and ACAT2 (SOAT2), mainly in the liver and intestine, playing a key role in lipoprotein assembly. ACAT activity is implicated in diseases like atherosclerosis, Alzheimer's, and cancer, making it a potential therapeutic target.

Mechanism of Action

Inhibition of cholesterol esterification

Biological Functions

Cholesterol esterification
Intracellular cholesterol homeostasis
Lipoprotein assembly
Steroid hormone synthesis
Cholesterol storage

Disease Associations

Atherosclerosis
Alzheimer's Disease
Cancer

Safety Considerations

  • Potential for off-target effects due to ubiquitous expression (ACAT1)
  • Complex role in lipid metabolism requires careful monitoring

Interacting Drugs

ACAT inhibitors (unspecified)

Associated Biomarkers

Biomarker
Cholesteryl ester levels
Oxysterol levels