Receptor-mediated endocytosis

The Receptor-mediated endocytosis is the selective uptake of macromolecules from the extracellular fiuid via clathrin-coated pits and vesicles. This procedure, that will takes  place  in most  animal  cells,  included  the macromolecule  binding  specifically  to  a  cell  surface  receptor  (that  is  an  integral  membrane  protein). Once it is bound to the receptor, the receptor–macromolecule difficult accumulates   in a clathrin-coated   pit and is then endocytosed   in a clathrin-coated vesicle.  Receptor-mediated endocytosis gives  a way of selectively  concentrating  particular  macromolecules  which are at low concentrations  in the extracellular  fiuid, thus raise  the efficiency of their uptake without having to take in huge quantities  of extracellular  fiuid. One of the excellences studied and understood receptor-mediated endocytic a process is the uptake of cholesterol through mammalian cells. Several viruses and other toxins gain entry to animal cells through receptor-mediated endocytosis. While the cells do not purposely have cell surface receptors which identify  the  viral  particle,  the  virus  has  include  to express  a protein  on its surface which mimics the right ligand recognized through the receptor, therefore allowing the virus to bind and be internalized.

                                 Figure: Receptor-mediated endocytosis involves clathrin-coated pits and vesicles.