Do you have a picture? It would really help answer your question
No I don’t have it
What is it
You may be referring to the cytoplasm here. That is the "filling" within the cell. But if you are looking for specific transport of proteins, the ER folds proteins and then transport vesicles move them to the Golgi.
This could be a mutualism rather than a commensal relationship because when<span> "cleaner fish" consume parasites and mucus from the skin of larger fish, they don't only receive food from the relationship, eliminating parasite and such from the large fish, but also they gain protection from predators, thus making the relationship a good example of mutualism, because both parts of the relationship gain something from the relationship itself. </span>