ABCG5 and ABCG8 form an obligate heterodimer that mediates Mg(2+)- and ATP-dependent sterol transport across the cell membrane. Plays an essential role in the selective transport of the dietary cholesterol in and out of the enterocytes and in the selective sterol excretion by the liver into bile ( , ). Required for normal sterol homeostasis ( ). The heterodimer with ABCG5 has ATPase activity ( ).
Subcellular locations: Cell membrane, Apical cell membrane
Predominantly expressed in the liver (, ). Low expression levels in the small intestine and colon . Very low levels in other tissues, including brain, heart and spleen .