ABCG4 Gene - ATP Binding Cassette Subfamily G Member 4

ABCG4 is a member of the ATP-binding cassette (ABC) transporter superfamily, specifically subfamily G. It functions as a sterol transporter, playing a role in cholesterol and lipid homeostasis. The protein is a half-transporter that likely homodimerizes or heterodimerizes with other ABCG family members (e.g., ABCG1) to form a functional transporter. ABCG4 is expressed in various tissues, including the brain, liver, and macrophages, and is involved in the efflux of cholesterol and other sterols. It has been implicated in cellular lipid metabolism and may contribute to neurological processes.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• ABC transporters

• Cholesterol metabolism

• Lipid transport

ABCG4 is a 646-amino acid half-transporter with a nucleotide-binding domain (NBD) and a transmembrane domain (TMD). It localizes to the plasma membrane and intracellular vesicles. The protein functions as a sterol floppase, facilitating the efflux of cholesterol and other sterols to extracellular acceptors such as apolipoprotein A-I and high-density lipoprotein (HDL). ABCG4 is highly expressed in the brain, where it may regulate cholesterol homeostasis in neurons and glial cells. Its activity is ATP-dependent and requires dimerization, often with ABCG1.