Catalyzes the transfer of phosphatidylinositol and phosphatidylcholine between membranes ( ). Also catalyzes the transfer of sphingomyelin (By similarity). Required for COPI-mediated retrograde transport from the Golgi to the endoplasmic reticulum; phosphatidylinositol and phosphatidylcholine transfer activity is essential for this function .
Subcellular locations: Golgi apparatus, Golgi apparatus membrane, Endoplasmic reticulum membrane
Widely expressed in various tissues including brain.