Binds LDL, the major cholesterol-carrying lipoprotein of plasma, and transports it into cells by endocytosis. In order to be internalized, the receptor-ligand complexes must first cluster into clathrin-coated pits. Interacts with ldlrap1. Rapidly endocytosed upon ligand binding. The NPXY motif mediates the interaction with ldlrap1. Belongs to the LDLR family.