Radioautographic and cytochemical studies on the synthesis and intracellular transport of glycoproteins

Abstract

SUBCOMPARTMENTALIZATION OF GOLGI APPARATUS. There is much evidence that the Golgi apparatus may consist of various subcompartments which differ from one another in morphology, biochemical content and function. These subcompartments do not always have the same properties in different cell types, however, and may change properties in one cell type at different times. Important glycosyltransferases are distributed throughout the Golgi stack in some cell types, indicating that subcompartmentalization is not essential for the process of glycosylation in this organelle. PRESENCE OF GLYCOPROTEINS OUTSIDE OF THE SECRETORY-ENDOCYTIC PATHWAY. Preliminary biochemical, cytochemical and radioautographic evidence indicates that glycoproteins may exist outside of the secretory-endocytic pathway. The presence of radioautographic reaction over the nucleoplasm of Schwann and satellite cells as early as 5 minutes after 3H-fucose administration suggest either that fucosylated glycoproteins must migrate very rapidly to this location or that fucosylation occurs within the nucleoplasm itself.