【多选题】How do proteins destined for regulated secretion sorted and packaged in the Golgi network?
A.
Proteins destined for regulated secretion are sorted and packaged in the trans Golgi network. Proteins that travel by this pathway have special surface properties that cause them to aggregate with one another under the ionic conditions (acidic pH and high Ca2+) that prevail in the trans Golgi network.
B.
The aggregated proteins are packaged into secretory vesicles, which pinch off from the network and await a signal instructing them to fuse with the plasma membrane.
C.
Proteins secreted by the constitutive pathway, on the other hand, do not aggregate and are therefore carried automatically to the plasma membrane by the transport vesicles of the constitutive pathway.
D.
Selective aggregation has another function: it allows secretory proteins to be packaged into secretory vesicles at concentrations much higher than the concentration of the unaggregated protein in the Golgi lumen. This increase in concentration can reach 200-fold, enabling secretory cells to release large amounts of the protein promptly when triggered to do so.
【简答题】Mrs. Gump says:" Death is just a part of life. Something we're all destined to do." Is there anything in your life you are destined to do? What's it? Why?