Lipid transporter involved in lipid countertransport between the Golgi complex and membranes of the endoplasmic reticulum: specifically exchanges sterol with phosphatidylinositol 4-phosphate (PI4P), delivering sterol to the Golgi in exchange for PI4P, which is degraded by the SAC1/SACM1L phosphatase in the endoplasmic reticulum . Binds cholesterol and a range of oxysterols including 25-hydroxycholesterol (, ). Cholesterol binding promotes the formation of a complex with PP2A and a tyrosine phosphatase which dephosphorylates ERK1/2, whereas 25-hydroxycholesterol causes its disassembly . Regulates cholesterol efflux by decreasing ABCA1 stability .
Subcellular locations: Cytoplasm, Cytosol, Cytoplasm, Perinuclear region, Golgi apparatus membrane, Endoplasmic reticulum membrane, Golgi apparatus, Trans-Golgi network
Predominantly cytosolic.
Widely expressed.