Final answer:
Proteins travel from one organelle to another through vesicular transport, which involves transport vesicles fusing with target organelles. Complementary integral membrane proteins play a role in recognizing and sorting the proteins during transport.
Step-by-step explanation:
Proteins, whether luminal or transmembrane, travel from one organelle to the next through a process called vesicular transport. Transport vesicles bud off from the organelle containing the protein and fuse with the target organelle, delivering the protein to its destination. The proteins are recognized and sorted by complementary integral membrane proteins embedded in the vesicle and target organelle membranes.