Probable lipid transporter involved in lipid countertransport between the endoplasmic reticulum and the plasma membrane. Its ability to bind phosphatidylserine, suggests that it specifically exchanges phosphatidylserine with phosphatidylinositol 4-phosphate (PI4P), delivering phosphatidylserine to the plasma membrane in exchange for PI4P  (Probable). Plays a role in negative regulation of lipid biosynthesis . Negatively regulates APOB secretion from hepatocytes (, ). Binds cholesterol and acidic phospholipids . Also binds 25-hydroxycholesterol . Binds phosphatidylserine .
Subcellular locations: Cytoplasm, Cytoskeleton
Associates with microtubules.