Regulates cellular transport and efflux of cholesterol (PubMed:26941018). Plays a role in phosphatidylinositol-4-phophate (PI4P) turnover at the neuronal membrane (By similarity). Binds via its PH domain PI4P, phosphatidylinositol-4,5-diphosphate, phosphatidylinositol-3,4,5-triphosphate, and phosphatidic acid (By similarity). Weakly binds 25-hydroxycholesterol (PubMed:17428193). Homodimer (By similarity). Interacts with OSBPL3 (By similarity). Co-localizes with OSBPL3 at contact sites between the plasma membrane and the endoplasmic reticulum. Expressed in brain and striated muscle (at protein level) (PubMed:14593528). Widely expressed (PubMed:11735225). Expressed in skeletal muscle (PubMed:14593528). Expressed in fetal brain and lung. By acetylated low-density lipoprotein. Belongs to the OSBP family.