Ceramide Transfer Protein (CERTL)

CERT mediates the ATP-dependent ER-to-Golgi transfer of ceramide in a non-vesicular manner. The biosynthesis of lipids involves steps that occur in different intracellular compartments. The movement of lipids within these compartments is important in lipid-mediated signalling. Human CERT is identical to a splice variant of human Goodpasture antigen-binding protein (GPBP26).CERT contains a phosphoinositide-binding pleckstrin-homology (PH) domain (which targets CERT to the Golgi by binding phosphatidylinositol-4-phosphate (PtdIns4P)), a middle region, and a putative lipid-transfer-catalysing domain called START. CERT and CERTL can specifically extract ceramide from phospholipid bilayers in a START-domain-dependent manner. CERT interacts with ER membranes and specifically extracts ceramide. CERT catalyses both the specific extraction of ceramide from donor vesicles and its transfer to acceptor vesicles. CERT can associate with the Golgi in a PtdIns4P dependent manner.