Final answer:
Tethers that work on the Golgi apparatus and endosomes include SNARE proteins, with V-SNAREs on vesicles binding to T-SNAREs on target membranes. Proteins within Golgi cisternae modify proteins for sorting and targeting to final destinations. Glycoproteins are exposed on the cell surface when vesicles fuse with the plasma membrane.
Step-by-step explanation:
The types of tethers that function on the Golgi apparatus and on endosomes are typically vesicle tethering proteins that include SNAREs (soluble NSF-attachment protein receptors) and SM proteins (Sec1/Munc18). On the trans face of the Golgi, vesicles are formed by cargo receptor proteins binding to specific cargo proteins with the assistance of coat proteins, including clathrin and COP proteins. These vesicles acquire V-SNARE proteins that must bind to their complementary T-SNARE proteins on target membranes to achieve membrane fusion.
Within the endomembrane system, vesicles, including those from the Golgi apparatus, are transported and modified. Various enzymes within the Golgi cisternae modify proteins by adding carbohydrate groups (glycosylation) or phosphate groups (phosphorylation), which are essential for sorting and targeting proteins to their final destinations, such as lysosomes. When vesicles budding from the trans Golgi network fuse with the plasma membrane, glycoproteins present on their surface are exposed to the exterior cell surface, contributing to the cell's functional capabilities.