All Access Pass - 1 FREE Month!
Institutional email required, no credit card necessary.

Exocytosis

EXOCYTOSIS
1) Proteins synthesized in the endoplasmic reticulum and trafficked to the Golgi apparatus
2) From the Golgi, the proteins are sorted and can follow different paths:
3a) Constitutive secretory pathway
  • Also called default pathway as it does not require a signal for cargo to enter this pathway
  • Can transport soluble proteins or plasma membrane proteins
  • Transport vesicles fuse with the plasma membrane and release their contents (plasma membrane proteins become accessible to the extracellular space)
3b) Regulated secretory pathway
  • Found mainly in specialized cells that release molecules like hormones, neurotransmitters, etc.
  • Secretory vesicles are blocked from fusing with the plasma membrane without a proper signal
  • An extracellular ligand binds a cellular receptor which causes an intracellular signal that releases the block on the secretory vesicles
  • Secretory vesicles then fuse with the plasma membrane and release their cargo

Related Tutorials