low-density lipoprotein receptors specific receptors for low-density lipoproteins found in coated pits on the surface of mammalian cells. The coated pits are internalized forming coated vesicles from which the receptors are recycled back to the plasma membrane while particles of low-density lipoprotein are transferred to lysosomes where they are degraded, releasing free cholesterol, phospholipids, and amino acids. Genetic defects in are responsible for familial hypercholesterolemia .