The
secretory pathway is a series of steps a
cell uses to move
proteins out of the cell, a process known as
secretion. The path of a protein destined for secretion has its origins in the rough
endoplasmic reticulum, a membrane-bound
compartment in the cell. The protein then proceeds through the many compartments of the
Golgi apparatus and finally ends up in a
vesicle that transiently fuses at the cell
plasma membrane via permanent plasma membrane structures called
porosomes, depositing the proteins on the outside of the cell.