Regulated versus Constitutive Secretion – A Major Form of Intercellular Communication

The secretory pathway carries proteins to the cell surface membrane where they can be released. This process can be divided into two systems: the regulated secretory pathway, and the constitutive secretory pathway. For many proteins in the constitutive secretory pathway, this transport process occurs at a relatively constant rate that is determined by how quickly those proteins are synthesized. However, the regulated secretory pathway operates by creating a storage compartment within cells to store secretory cargo. Upon the appropriate stimulus, these storage compartments can fuse with the cell surface and allow a burst of contents to be rapidly secreted. Regulated secretion is used throughout multicellular organisms to accomplish a wide variety of tasks such as hormonal control and neuronal communication.