Mediates the transfer of lipids between membranes at organelle contact sites (By similarity). Binds phospholipids (PubMed:34830155). Required for the formation or stabilization of ER-mitochondria contact sites which enable transfer of lipids between the ER and mitochondria (PubMed:30741634). Negatively regulates lipid droplet size and motility (PubMed:30741634). Required for efficient lysosomal protein degradation (PubMed:30709847).