Назад Golgi apparatus in cytoplasm of neuron-
Golgi apparatus in cytoplasm of neuron. TEM image. 24,000X.

In the cytoplasm, Golgi apparatus is constituted by a number of such structures as fused stacks of flattened membrane cisterns (saccules). The stacks or dictyosomes #1, #2, #3 are found near the nucleus and centrosome (for more details, see further). The dictyosomes have poles. The cis-pole (arrivals) receives proteins from RER to modify them further. The trans-полюс (release) packs ready proteins into membrane containers and transfers them to different structures in three directions mostly.

The majority of proteins leaving the Golgi apparatus are glycoproteins, and their peptide parts are attached to small oligosaccharide chains. Glycosylation is one of the principal Golgi functions; it means the oligosaccharide synthesis and attachment. The process is realized gradually from the cis-pole to the trans-pole. The following substances are glycoproteins: integral membrane proteins, especially plasma membrane proteins; secretory proteins, e.g. pancreatic enzymes; proteins of lysosomal contents (enzymes) and lysosomal membranes. Thus, the trans-pole of Golgi gives rise to: 1) vesicles departing for the cell membrane (often they are clathrin-coated; 2) primary lysosomes, and 3) secretory granules.