ABCA1 Gene: Function, Mutations, and Associated Diseases

ABCA1 encodes a membrane-associated protein that belongs to the ATP-binding cassette (ABC) transporter superfamily. It functions as a cholesterol efflux pump, facilitating the transfer of cellular cholesterol and phospholipids to apolipoprotein A-I (apoA-I) to form high-density lipoprotein (HDL) particles. This gene is critical for reverse cholesterol transport and lipid homeostasis. Mutations in ABCA1 cause Tangier disease and familial hypoalphalipoproteinemia, characterized by severely reduced HDL levels and increased risk of cardiovascular disease.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• HDL metabolism

• Reverse cholesterol transport

• Lipid transport

• ABC transporters

ABCA1 is a 2261-amino acid transmembrane protein with two nucleotide-binding domains and two transmembrane domains. It mediates the active transport of cholesterol and phospholipids across the plasma membrane to lipid-poor apolipoproteins, primarily apoA-I, initiating HDL biogenesis. The protein is highly expressed in liver, intestine, and macrophages. Defects in ABCA1 lead to impaired HDL formation and lipid accumulation.