BFA compartment is composed of TGN/EE in plant cells. And it is composed of early endosome and endocytic vesicles in animal cell. Am I right? If this is true, it means BFA can inhibit downstream of endocytic and secretory pathway from TGN/EE to MVB. What is its targets (not only one)?
Effects of BFA depend strongly on the cell types and the composition of ARF GEFs (whether they are sensitive or resistant to the drug). Animal cells usually have BFA sensitive GEFs acorss the board and BFA cause fusion of Golgi with ER membranes to form a supercompartment. In tobacco leaf cells BFA also causes Golgi and ER to form a supercompartment. Arabidopsis thaliana roots have a GEF acting in the early ER-Golgi recycling pathway that is resistant to BFA, so in Arabidopsis roots you can see a different type of BFA body that involves Golgi and post Golgi organelles. The target is still an ARF GEF, but one that works on a later transport step than the early ER Golgi recycling route. It only partially affects the MVB, but yes some traffick to the MVB is disrupted during the drug treatment, and it is reversible when you wash the cells and incubate them without the drug.
BFA effects are also strongly dependent form cell position and type of vesicle traffic. In Arabidopsis roots traffic to plasma membrane were totally different in the zone of cell divsion and zone of cell elongation, including rapid root hairs growth. That's why BFA-body (after application of 1-2 µM of external BFA) is different even in the same cell types.