Catalyzes the translocation of specific phospholipids from the cytoplasmic to the extracellular/lumenal leaflet of membrane coupled to the hydrolysis of ATP (, ). Thereby, participates in phospholipid transfer to apolipoproteins to form nascent high density lipoproteins/HDLs . Transports preferentially phosphatidylcholine over phosphatidylserine . May play a similar role in the efflux of intracellular cholesterol to apolipoproteins and the formation of nascent high density lipoproteins/HDLs ( , ). Translocates phospholipids from the outer face of the plasma membrane and forces it through its gateway and annulus into an elongated hydrophobic tunnel in its extracellular domain .
Subcellular locations: Cell membrane, Endosome
Widely expressed, but most abundant in macrophages.