Catalyzes the transfer of phosphatidylinositol, phosphatidylcholine and sphingomyelin between membranes (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 (By similarity). a 1,2-diacyl-sn-glycero-3-phosphocholine(in) = a 1,2-diacyl-sn-glycero-3-phosphocholine(out) a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol)(in) = a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol)(out) an N-(acyl)-sphingosylphosphocholine(in) = an N-(acyl)-sphingosylphosphocholine(out) Constitutive phosphorylation of Ser-262 has no effect on phospholipid transfer activity but is required for Golgi targeting. Belongs to the PtdIns transfer protein family. PI transfer class I subfamily.