Regulating Export of ER Cargo

摘要

Mammalian cells control the release of a variety of biologically active peptides and proteins into the circulation by regulating their secretion through the exocytic pathway. These secreted proteins serve as key chemical messengers, directing communication between cells. They are released with fast kinetics to 'activate signaling pathways, allowing the body to respond quickly and efficiently to physiological changes—a necessity if homeostasis is to be maintained. Large quantities of these chemical messengers are synthesized in advance by specialized secretory (endocrine and exocrine) cells and are stored in granules in the cytoplasm. They are released in response to signaling events initiated at the cell surface by the binding of a ligand to its receptor.